Human Anatomy and Physiology II
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Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

  • Human Anatomy and Physiology II

  • KAAP310-14S

    • Lectures: Tue Thu 9:30-10:45 Kirkbride 004

    • Labs (HSC 228)

    • 30: Mon 10:10-12:05KellySebzda

    • 31: Thu 2:30-4:25Kelly Sebzda

    • 32: Mon 2:30-4:25Tyler Kmiec

    • 33: Mon 4:40-6:35 Bryce Muth

    • Run: Tue 2:15From CSB entrance

  • Course Web Sitewww.udel.edu/sakai

  • William [email protected] 148

  • Kelly [email protected] 201

  • Tyler [email protected] 201

  • Bryce [email protected] 201

  • Department of Kinesiology and Applied Physiology


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Human Anatomy and Physiology II

    KAAP310-14S

    Grading – see syllabus.

    75% Classroom

    70%: Ten tests (worst is dropped so nine count)

    5%: Clicker

    25% Laboratory

    Department of Kinesiology and Applied Physiology


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Human Anatomy and Physiology II

    KAAP310-14S

    UD Capture: Recording of what is projected on screen and classroom audio. http://udcapture.udel.edu/2013f/kaap310-010/

    Clickers: Register your clicker on Sakai.

    Clicker questions: 1 point for answering, 1 more point if correct.

    Clicker grade: Full credit if you get 75% or more of the points available. Reduced proportionally if not.

    If a student is observed using more than one clicker, both clicker numbers will be noted and grades reduced for both students.

    • No adjustments for forgotten or broken clickers, low batteries, etc.

    Department of Kinesiology and Applied Physiology


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Human Anatomy and Physiology II

    KAAP310-14S

    • Tips

    • This class is not the same as KAAP 309.

    • Do not rely on memorization.

    • Understanding physiology requires knowing more than the what or where. You need to understand the why and the how.


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Human Anatomy and Physiology II

    KAAP310-14S

    • Tips

    • Everyone will work hard.

    • Read the book, come to class, ask questions.

    • Use the recorded lectures to review and not as a substitute for coming to class.

    • Use the online resources.


    Exam questions

    Exam Questions

    Knowledge

    Comprehension

    Application


    Knowledge question

    Knowledge Question

    ________ are chemical messengers that are released in one tissue and transported in the bloodstream to alter the activities of specific cells in other tissues.

    Hormones

    Neuropeptides

    Neurotransmitters

    Humoral antibodies

    none of the above


    Comprehension question

    Comprehension Question

    An activated G protein can trigger

    the opening of calcium ion channels in the membrane.

    the release of calcium ions from intracellular stores.

    a fall in cAMP levels.

    a rise in cAMP levels.

    all of the above


    Application question

    Application Question

    Destruction of the supraoptic nucleus of the hypothalamus would have which result?

    loss of emotional response

    loss of GH secretion

    loss of ADH secretion

    loss of loss of regulatory factor secretion

    loss of melatonin secretion


    Endocrine system overview

    Endocrine System: Overview

    • Controls and integrates

      • Reproduction

      • Growth and development

      • Maintenance of electrolyte, water, and nutrient balance of blood

      • Regulation of cellular metabolism and energy balance

      • Mobilization of body defenses

    • Acts with the nervous system to coordinate and integrate the activity of body cells

    • Influences metabolic activities by means of hormones transported in the blood

    • Responses occur more slowly but tend to last longer than those of the nervous system

    • Endocrinology

      • Study of hormones and endocrine organs


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Other tissues and organs that produce hormones: adipose cells, thymus, cells in walls of the small intestine, stomach, kidneys, heart

    Pineal gland

    Hypothalamus

    Pituitary gland

    Thyroid gland

    Parathyroid glands

    (on dorsal aspect

    of thyroid gland)

    Thymus

    Adrenal glands

    Pancreas

    Ovary (female)

    Testis (male)

    Figure 16.1


    Chemical messengers

    Chemical Messengers

    • Hormones: long-distance chemical signals that travel in the blood or lymph

    • Autocrines: chemicals that exert effects on the same cells that secrete them

    • Paracrines: locally acting chemicals that affect cells other than those that secrete them

    • Autocrines and paracrines are local chemical messengers and will not be considered part of the endocrine system


    Mechanisms of hormone action

    Mechanisms of Hormone Action

    • Hormone action on target cells may be to

      • Alter plasma membrane permeability of membrane potential by opening or closing ion channels

      • Stimulate synthesis of proteins or regulatory molecules

      • Activate or deactivate enzyme systems

      • Induce secretory activity

      • Stimulate mitosis


    Chemistry of hormones

    Chemistry of Hormones

    • Two main classes

      1.Amino acid-based hormones

      • Amino acid derivatives, peptides, and proteins

        2.Steroids

      • Synthesized from cholesterol

      • Gonadal and adrenocortical hormones


    1 water soluble hormones all amino acid based hormones except thyroid hormone

    1. Water-soluble hormones (all amino acid–based hormones except thyroid hormone)

    • Two mechanisms, depending on their chemical nature

      • Water-soluble hormones (all amino acid–based hormones except thyroid hormone)

        • Cannot enter the target cells

        • Act on plasma membrane receptors

        • Coupled by G proteins to intracellular second messengers that mediate the target cell’s response

    Extracellular fluid

    Hormone (1st messenger)binds receptor.

    G protein (GS)

    Receptor

    • Cannot enter the target cells. Act on plasma membrane receptors. Coupled by G proteins to intracellular second messengers that mediate the target cell’s response

    Cytoplasm


    2 lipid soluble hormones steroid thyroid hormones

    2. Lipid-soluble hormones (steroid/thyroid hormones)

    Steroidhormone

    Plasmamembrane

    Extracellular fluid

    The steroid hormonediffuses through the plasmamembrane and binds anintracellular receptor that directly activates genes.

    Cytoplasm

    Receptorprotein

    Receptor-hormonecomplex

    Nucleus


    Plasma membrane receptors and second messenger systems camp

    Plasma Membrane Receptors and Second-Messenger Systems - cAMP

    Extracellular fluid

    1

    Hormone (1st messenger)binds receptor.

    Adenylate cyclase

    G protein (GS)

    5

    cAMP acti-vates proteinkinases.

    Receptor

    Activeproteinkinase

    GDP

    Inactiveprotein kinase

    2

    3

    4

    Receptoractivates Gprotein (GS).

    G proteinactivatesadenylatecyclase.

    Adenylatecyclaseconverts ATPto cAMP (2ndmessenger).

    Hormones thatact via cAMPmechanisms:

    Triggers responses oftarget cell (activatesenzymes, stimulatescellular secretion,opens ion channel,etc.)

    GlucagonPTHTSHCalcitonin

    EpinephrineACTHFSHLH

    Cytoplasm

    Figure 16.2


    Plasma membrane receptors and second messenger systems

    Plasma Membrane Receptors and Second-Messenger Systems

    • cAMP signaling mechanism

      • Activated kinases phosphorylate various proteins, activating some and inactivating others

      • cAMP is rapidly degraded by the enzyme phosphodiesterase

      • Intracellular enzymatic cascades have a huge amplification effect


    Plasma membrane receptors and second messenger systems1

    Plasma Membrane Receptors and Second-Messenger Systems

    • PIP2-calcium signaling mechanism

    PIP2 – phosphatidyl inositol bisphosphate

    • DAG activates protein kinases; IP3 triggers release of Ca2+

    • Ca2+ alters enzymes or channels or binds to the regulatory protein calmodulin

    http://www.ruf.rice.edu/~rur/issue1_files/barron.html


    Other signaling mechanisms

    Other Signaling Mechanisms

    • Cyclic guanosine monophosphate (cGMP) is second messenger for some hormones

    • Some work without second messengers

      • E.g., insulin receptor is tyrosine kinase enzyme that autophosphorylates upon insulin binding  docking for relay proteins that trigger cell responses


    Intracellular receptors and direct gene activation

    Intracellular Receptors and Direct Gene Activation

    Steroidhormone

    Plasmamembrane

    Extracellular fluid

    1

    The steroid hormonediffuses through the plasmamembrane and binds anintracellular receptor.

    Cytoplasm

    Receptorprotein

    Receptor-hormonecomplex

    2

    The receptor-hormone complex entersthe nucleus.

    Hormoneresponseelements

    Nucleus

    3

    The receptor- hormonecomplex binds a hormoneresponse element (aspecific DNA sequence).

    DNA

    4

    Binding initiatestranscription of thegene to mRNA.

    mRNA

    5

    The mRNA directsprotein synthesis.

    New protein

    Figure 16.3, step 5


    Intracellular receptors and direct gene activation1

    Intracellular Receptors and Direct Gene Activation

    Steroidhormone

    Plasmamembrane

    Extracellular fluid

    1

    The steroid hormonediffuses through the plasmamembrane and binds anintracellular receptor.

    • Steroid hormones and thyroid hormone

      • Diffuse into their target cells and bind with intracellular receptors

      • Receptor-hormone complex enters the nucleus

      • Receptor-hormone complex binds to a specific region of DNA

      • This prompts DNA transcription to produce mRNA

      • The mRNA directs protein synthesis

    Cytoplasm

    Receptorprotein

    Receptor-hormonecomplex

    2

    The receptor-hormone complex entersthe nucleus.

    Hormoneresponseelements

    Nucleus

    3

    The receptor- hormonecomplex binds a hormoneresponse element (aspecific DNA sequence).

    DNA

    4

    Binding initiatestranscription of thegene to mRNA.

    mRNA

    5

    The mRNA directsprotein synthesis.

    New protein

    • Promote metabolic activities, or promote synthesis of structural proteins or proteins for export from cell

    Figure 16.3


    Target cell specificity

    Target Cell Specificity

    • Target cells must have specific receptors to which the hormone binds

      • ACTH receptors are only found on certain cells of the adrenal cortex

      • Thyroxin receptors are found on nearly all cells of the body


    Target cell activation

    Target Cell Activation

    • Hormones influence the number of their receptors

      • Up-regulation—target cells form more receptors in response to the hormone

      • Down-regulation—target cells lose receptors in response to the hormone

    • Target cell activation depends on three factors

      • Blood levels of the hormone

      • Relative number of receptors on or in the target cell

      • Affinity of binding between receptor and hormone


    Hormones in the blood

    Hormones in the Blood

    • Hormones are removed from the blood by

      • Degrading enzymes

      • Kidneys

      • Liver

        Half-life—the time required for a hormone’s blood level to decrease by half

    • Hormones circulate in the blood either free or bound

      • Steroids and thyroid hormone are attached to plasma proteins

      • All others circulate without carriers

    • The concentration of a circulating hormone reflects:

      • Rate of release

      • Speed of inactivation and removal from the body


    Interaction of hormones at target cells

    Interaction of Hormones at Target Cells

    • Multiple hormones may interact in several ways

    • Permissiveness: one hormone cannot exert its effects without another hormone being present

    • Synergism: more than one hormone produces the same effects on a target cell

    • Antagonism: one or more hormones opposes the action of another hormone

    • Permissiveness: one hormone cannot exert its effects without another hormone being present

    • Synergism: more than one hormone produces the same effects on a target cell

    • Antagonism: one or more hormones opposes the action of another hormone


    Control of hormone release

    Control of Hormone Release

    • Blood levels of hormones

      • Are controlled by negative feedback systems

      • Vary only within a narrow desirable range

    • Hormones are synthesized and released in response to

    • Humoral stimuli

    • Neural stimuli

    • Hormonal stimuli


    Humoral stimuli

    Humoral Stimuli

    • Changing blood levels of ions and nutrients directly stimulates secretion of hormones

    • Examples:


    Humoral stimuli1

    Humoral Stimuli

    (a) Humoral Stimulus

    Capillary blood contains

    low concentration of Ca2+,

    which stimulates…

    1

    • Declining blood Ca2+ concentration stimulates the parathyroid glands to secrete PTH (parathyroid hormone)

    • PTH causes Ca2+ concentrations to rise and the stimulus is removed

    Capillary (low

    Ca2+ in blood)

    Thyroid gland

    (posterior view)

    Parathyroid

    glands

    Parathyroidglands

    PTH

    …secretion of

    parathyroid hormone (PTH)

    by parathyroid glands*

    2

    Figure 16.4a


    Neural stimuli

    Neural Stimuli

    (b) Neural Stimulus

    Preganglionic sympathetic

    fibers stimulate adrenal

    medulla cells…

    1

    • Nerve fibers stimulate hormone release

      • Sympathetic nervous system fibers stimulate the adrenal medulla to secrete catecholamines

    CNS (spinal cord)

    Preganglionic

    sympathetic

    fibers

    Medulla of

    adrenal

    gland

    Capillary

    …to secrete catechola-

    mines (epinephrine and

    norepinephrine)

    2

    Figure 16.4b


    Hormonal stimuli

    Hormonal Stimuli

    (c) Hormonal Stimulus

    The hypothalamus secretes

    hormones that…

    1

    • Hormones stimulate other endocrine organs to release their hormones

      • Hypothalamic hormones stimulate the release of most anterior pituitary hormones

      • Anterior pituitary hormones stimulate targets to secrete still more hormones

      • Hypothalamic-pituitary-target endocrine organ feedback loop: hormones from the final target organs inhibit the release of the anterior pituitary hormones

    Hypothalamus

    …stimulate

    the anterior

    pituitary gland

    to secrete

    hormones

    that…

    2

    Pituitary

    gland

    Thyroid

    gland

    Adrenal

    cortex

    Gonad

    (Testis)

    …stimulate other endocrine

    glands to secrete hormones

    3

    Figure 16.4c


    Nervous system modulation

    Nervous System Modulation

    • The nervous system modifies the stimulation of endocrine glands and their negative feedback mechanisms

      • Example: under severe stress, the hypothalamus and the sympathetic nervous system are activated

        • As a result, body glucose levels rise


    Interaction with a membrane bound receptor will transduce the hormonal message via

    Interaction with a membrane-bound receptor will transduce the hormonal message via __________.

    • depolarization

    • direct gene activation

    • a second messenger

    • endocytosis


    Receptors for steroid hormones are commonly located

    Receptors for steroid hormones are commonly located _________.

    • inside the target cell

    • on the plasma membrane of the target cell

    • in the blood plasma

    • in the extracellular fluid


    The pituitary gland and hypothalamus

    The Pituitary Gland and Hypothalamus

    • The pituitary gland (hypophysis) has two major lobes

      • Posterior pituitary (lobe):

        • Pituicytes (glial-like supporting cells) and nerve fibers

      • Anterior pituitary (lobe) (adenohypophysis)

        • Glandular tissue


    Case study

    Case Study

    History of Present Illness:

    Lucia Sanchez is a 24 year-old woman who presented to her physician with a chief complaint of urinary frequency (polyuria) and excessive thirst (polydipsia). Her polyuria began abruptly two weeks prior to her doctor's appointment. Prior to that time, Lucia voided approximately five times per day. She estimated that she was now voiding twenty times per day. Two days prior to her visit to the doctor's office she was advised to collect her urine in order to check its volume in a 24 hour period; her total urine volume measured 12 liters.Lucia also noticed an intense craving for ice water that began at about the same time as her polyuria. If she did not have access to water, she would become extremely thirsty and dizzy. She denied any change in her appetite. She also denied the use of any medications.


    Pituitary hypothalamic relationships

    Pituitary-Hypothalamic Relationships

    • Posterior lobe

      • A downgrowth of hypothalamic neural tissue

      • Neural connection to the hypothalamus (hypothalamic-hypophyseal tract)

      • Nuclei of the hypothalamus synthesize the neurohormones oxytocin and antidiuretic hormone (ADH)

      • Neurohormones are transported to the posterior pituitary


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Paraventricular nucleus

    Hypothalamus

    1

    Hypothalamic neurons synthesize oxytocin or antidiuretic hormone (ADH).

    Posterior lobe

    of pituitary

    Optic

    chiasma

    Supraoptic

    nucleus

    Infundibulum

    (connecting stalk)

    2

    Oxytocin and ADH are transported down the axons of the hypothalamic- hypophyseal tract to the posterior pituitary.

    Inferior

    hypophyseal

    artery

    Hypothalamic-

    hypophyseal

    tract

    Axon terminals

    3

    Oxytocin and ADH are stored in axon terminals in the posterior pituitary.

    Posterior lobe

    of pituitary

    4

    When hypothalamic neurons fire, action potentials arriving at the axon terminals cause oxytocin or ADH to be released into the blood.

    Oxytocin

    ADH


    Pituitary hypothalamic relationships1

    Pituitary-Hypothalamic Relationships

    • Anterior Lobe:

      • Originates as an out-pocketing of the oral mucosa

      • Hypophyseal portal system

        • Primary capillary plexus

        • Hypophyseal portal veins

        • Secondary capillary plexus

    • Carries releasing and inhibiting hormones to the anterior pituitary to regulate hormone secretion


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Hypothalamus

    Hypothalamic

    neurons synthesize

    GHRH, GHIH, TRH,

    CRH, GnRH, PIH.

    Anterior lobe

    of pituitary

    Superior

    hypophyseal

    artery

    1

    When appropriately stimulated, hypothalamic neurons secrete releasing or inhibiting hormones into the primary capillary plexus.

    2

    Hypothalamic hormones travel through portal veins to the anterior pituitary where

    they stimulate or inhibit

    release of hormones made in the anterior pituitary.

    Hypophyseal

    portal system

    • Primary capillary

    plexus

    A portal system is two capillary plexuses (beds) connected by veins.

    3

    In response to releasing hormones, the anterior pituitary secretes hormones into the secondary capillary plexus. This in turn empties into the general circulation.

    • Hypophyseal

    portal veins

    • Secondary

    capillary plexus

    GH, TSH, ACTH,

    FSH, LH, PRL

    Anterior lobe

    of pituitary


    Anterior pituitary hormones

    Anterior Pituitary Hormones

    • Growth hormone (GH)

    • Thyroid-stimulating hormone (TSH) or thyrotropin

    • Adrenocorticotropic hormone (ACTH)

    • Follicle-stimulating hormone (FSH)

    • Luteinizing hormone (LH)

    • Prolactin (PRL)

    • All are proteins

    • All except GH activate cyclic AMP second-messenger systems at their targets

    • TSH, ACTH, FSH, and LH are all tropic hormones (regulate the secretory action of other endocrine glands)


    Growth hormone gh or somatotropin

    Growth Hormone (GH or Somatotropin)

    Hypothalamus

    secretes growth

    hormone—releasing

    hormone (GHRH), and

    somatostatin (GHIH)

    Inhibits GHRH release

    Stimulates GHIH

    release

    Feedback

    Anterior

    pituitary

    Inhibits GH synthesis

    and release

    • Stimulates most cells, but targets bone and skeletal muscle

    • Promotes protein synthesis and encourages use of fats for fuel

    • Most effects are mediated indirectly by insulin-like growth factors (IGFs)

    Growth hormone

    Direct actions

    (metabolic,

    anti-insulin)

    Indirect actions

    (growth-

    promoting)

    Liver and

    other tissues

    Produce

    Insulin-like growth

    factors (IGFs)

    Effects

    Effects

    Carbohydrate

    metabolism

    Extraskeletal

    Skeletal

    Fat

    Increases, stimulates

    Reduces, inhibits

    Increased protein

    synthesis, and

    cell growth and

    proliferation

    Increased cartilage

    formation and

    skeletal growth

    Increased

    fat breakdown

    and release

    Increased blood

    glucose and other

    anti-insulin effects

    Initial stimulus

    Physiological response

    Result

    Figure 16.6


    Growth hormone gh or somatotropin1

    Growth Hormone (GH or Somatotropin)

    Hypothalamus

    secretes growth

    hormone—releasing

    hormone (GHRH), and

    somatostatin (GHIH)

    Inhibits GHRH release

    Stimulates GHIH

    release

    Feedback

    Anterior

    pituitary

    Inhibits GH synthesis

    and release

    • GH release is regulated by

    • Growth hormone–releasing hormone (GHRH)

    • Growth hormone–inhibiting hormone (GHIH) (somatostatin)

    Growth hormone

    Direct actions

    (metabolic,

    anti-insulin)

    Indirect actions

    (growth-

    promoting)

    Liver and

    other tissues

    Produce

    Insulin-like growth

    factors (IGFs)

    Effects

    Effects

    Carbohydrate

    metabolism

    Extraskeletal

    Skeletal

    Fat

    Increases, stimulates

    Reduces, inhibits

    Increased protein

    synthesis, and

    cell growth and

    proliferation

    Increased cartilage

    formation and

    skeletal growth

    Increased

    fat breakdown

    and release

    Increased blood

    glucose and other

    anti-insulin effects

    Initial stimulus

    Physiological response

    Result

    Figure 16.6


    Homeostatic imbalances of growth hormone

    Homeostatic Imbalances of Growth Hormone

    • Hypersecretion

      • In children results in gigantism

      • In adults results in acromegaly

    • Hyposecretion

      • In children results in pituitary dwarfism


    Thyroid stimulating hormone thyrotropin

    Thyroid-Stimulating Hormone (Thyrotropin)

    Hypothalamus

    TRH

    Regulation:

    • Stimulated by thyrotropin-releasing hormone (TRH)

    • Inhibited by rising blood levels of thyroid hormones that act on the pituitary and hypothalamus

    Anterior pituitary

    TSH

    Thyroid gland

    Thyroid

    hormones

    Stimulates

    Target cells

    Inhibits

    Figure 16.7


    Thyroid stimulating hormone thyrotropin1

    Thyroid-Stimulating Hormone (Thyrotropin)

    Hypothalamus

    TRH

    • Produced by thyrotrophs of the anterior pituitary

    • Stimulates the normal development and secretory activity of the thyroid

    Anterior pituitary

    TSH

    Thyroid gland

    Thyroid

    hormones

    Stimulates

    Target cells

    Inhibits

    Figure 16.7


    Adrenocorticotropic hormone corticotropin

    Adrenocorticotropic Hormone (Corticotropin)

    • Secreted by corticotrophs of the anterior pituitary

    • Stimulates the adrenal cortex to release corticosteroids

    • Regulation of ACTH release

      • Triggered by hypothalamic corticotropin-releasing hormone (CRH) in a daily rhythm

      • Internal and external factors such as fever, hypoglycemia, and stressors can alter the release of CRH


    Gonadotropins

    Gonadotropins

    • Follicle-stimulating hormone (FSH) and luteinizing hormone (LH)

    • Secreted by gonadotrophs of the anterior pituitary

    • FSH stimulates gamete (egg or sperm) production

    • LH promotes production of gonadal hormones

    • Absent from the blood in prepubertal boys and girls

    • Regulation of gonadotropin release

      • Triggered by the gonadotropin-releasing hormone (GnRH) during and after puberty

      • Suppressed by gonadal hormones (feedback)


    Prolactin prl

    Prolactin (PRL)

    • Secreted by lactotrophs of the anterior pituitary

    • Stimulates milk production

    • Regulation of PRL release

      • Primarily controlled by prolactin-inhibiting hormone (PIH) (dopamine)

    • Blood levels rise toward the end of pregnancy

    • Suckling stimulates PRH release and promotes continued milk production


    The posterior pituitary

    The Posterior Pituitary

    • Contains axons of hypothalamic neurons

    • Stores antidiuretic hormone (ADH) and oxytocin

    • ADH and oxytocin are released in response to nerve impulses

    • Both use PIP-calcium second-messenger mechanism at their targets


    Oxytocin

    Oxytocin

    • Stimulates uterine contractions during childbirth

    • Also triggers milk ejection (“letdown” reflex) in women producing milk

    • Acts as a neurotransmitter in brain


    Antidiuretic hormone adh

    Antidiuretic Hormone (ADH)

    • Hypothalamic osmoreceptors respond to changes in the solute concentration of the blood

    • If solute concentration is high

      • Osmoreceptors depolarize and transmit impulses to hypothalamic neurons

      • ADH is synthesized and released, inhibiting urine formation


    Antidiuretic hormone adh1

    Antidiuretic Hormone (ADH)

    • ADH works at the kidney to control water loss

    • If solute concentration is high (sensed by osmoreceptors in the hypothalamus)

      • A large amount of ADH is released, inhibiting water loss

    • If solute concentration is low

      • ADH is not released, allowing water loss

    • Alcohol inhibits ADH release and causes copious urine output


    Homeostatic imbalances of adh

    Homeostatic Imbalances of ADH

    • ADH deficiency—diabetes insipidus; huge output of urine and intense thirst

    • ADH hypersecretion (after neurosurgery, trauma, or secreted by cancer cells)—syndrome of inappropriate ADH secretion (SIADH)


    Case study1

    Case Study

    History of Present Illness:

    Lucia Sanchez is a 24 year-old woman who presented to her physician with a chief complaint of urinary frequency (polyuria) and excessive thirst (polydipsia). Her polyuria began abruptly two weeks prior to her doctor's appointment. Prior to that time, Lucia voided approximately five times per day. She estimated that she was now voiding twenty times per day. Two days prior to her visit to the doctor's office she was advised to collect her urine in order to check its volume in a 24 hour period; her total urine volume measured 12 liters.Lucia also noticed an intense craving for ice water that began at about the same time as her polyuria. If she did not have access to water, she would become extremely thirsty and dizzy. She denied any change in her appetite. She also denied the use of any medications.


    Case study2

    Case Study


    Case study3

    Case Study

    Lucia was hospitalized and underwent an oral dehydration test. She was denied any fluid intake, and doctors carefully analyzed her vital signs and urine output during this process. Because she had been advised to drink a lot of water before coming to the hospital, her initial supine and upright blood pressure were normal. The analysis showed that Lucia was urinating at a rate of approximately 500 cc's per hour; her urine specific gravity remained at 1.001 even though she became dehydrated to the point where she became orthostatic (her blood pressure dropped when she changed from the supine to the upright position).


    Case study4

    Case Study

    Diagnosis: Central diabetes insipidus

    Lucia was given ADH which resulted in a marked decline in her urine output from 500 cc/hour to 70 cc/hour. Nurses administered IV fluids to correct her dehydration. Lucia was discharged and instructed to take desmopressin acetate, an oral form of ADH. This will mimic her physiologic levels of ADH, and help her kidneys retain water.


    Adh the musical

    ADH The Musical


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    An overview of the relationships between hypothalamic and pituitary

    hormones, and some effects of pituitary hormones on target tissues

    Hypothalamus

    Indirect Control through Release

    of Regulatory Hormones

    Direct Release

    of Hormones

    Sensory

    stimulation

    Osmoreceptor

    stimulation

    Growth

    hormone-

    releasing

    hormone

    (GH-RH)

    Growth

    hormone-

    inhibiting

    hormone

    (GH-IH)

    Thyrotropin-

    releasing

    hormone

    (TRH)

    Prolactin-

    releasing

    factor

    (PRF)

    Corticotropin-

    releasing

    hormone

    (CRH)

    Prolactin-

    inhibiting

    hormone

    (PIH)

    Gonadotropin-

    releasing

    hormone

    (GnRH)

    Regulatory hormones are released into

    the hypophyseal portal system for delivery

    to the anterior lobe of the

    pituitary gland.

    Adrenal cortex

    Anterior lobe of

    pituitary gland

    Posterior lobe

    of pituitary gland

    ADH

    ACTH

    Adrenal

    glands

    GH

    Kidneys

    TSH

    OXT

    Liver

    MSH

    PRL

    Thyroid

    gland

    Males: Smooth

    muscle in ductus

    deferens and

    prostate gland

    LH

    FSH

    Somatomedins

    Females: Uterine

    smooth muscle and

    mammary glands

    Glucocorticoids

    (steroid

    hormones)

    Melanocytes (uncertain

    significance in healthy

    adults)

    Ovaries

    of female

    Bone, muscle,

    other tissues

    Testes

    of male

    Mammary

    glands

    Thyroid

    hormones

    Inhibin

    Testosterone

    Estrogen

    Progesterone

    Inhibin


    Thyroid gland

    Thyroid Gland

    • Consists of two lateral lobes connected by a median mass called the isthmus

    • Composed of follicles that produce the glycoprotein thyroglobulin

    • Colloid (thyroglobulin + iodine) fills the lumen of the follicles and is the precursor of thyroid hormone

    • Parafollicular cells produce the hormone calcitonin


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Figure 16.8


    Thyroid hormone th

    Thyroid Hormone (TH)

    • Major metabolic hormone

    • Increases metabolic rate and heat production (calorigenic effect)

    • Plays a role in

      • Regulation of tissue growth

      • Development of skeletal and nervous systems

      • Reproductive capabilities

    • Actually two related compounds

      • T4 (thyroxine); has 2 tyrosine molecules + 4 bound iodine atoms

      • T3 (triiodothyronine); has 2 tyrosines + 3 bound iodine atoms

        Affects virtually every cell in body


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Thyroid follicle cells

    Colloid

    1

    Thyroglobulin is synthesized anddischarged into the follicle lumen.

    Tyrosines (part of thyroglobulinmolecule)

    Capillary

    4

    Iodine is attached to tyrosinein colloid, forming DIT and MIT.

    Golgiapparatus

    RoughER

    Thyro-globulincolloid

    Iodine

    DIT (T2)

    MIT (T1)

    3

    Iodideis oxidizedto iodine.

    2

    Iodide (I–) is trapped(actively transported in).

    Iodide (I–)

    T4

    5

    Iodinated tyrosines arelinked together to form T3and T4.

    T3

    Lysosome

    T4

    6

    Thyroglobulin colloid isendocytosed and combinedwith a lysosome.

    T3

    7

    Lysosomal enzymes cleaveT4 and T3 from thyroglobulincolloid and hormones diffuseinto bloodstream.

    Colloid inlumen offollicle

    T4

    T3

    To peripheral tissues

    Figure 16.9, step 7


    Transport and regulation of th

    Transport and Regulation of TH

    • T4 and T3 are transported by thyroxine-binding globulins (TBGs)

    • Both bind to target receptors, but T3 is ten times more active than T4

    • Peripheral tissues convert T4 to T3


    Regulation of th

    Regulation of TH

    • Negative feedback regulation of TH release

      • Rising TH levels provide negative feedback inhibition on release of TSH

      • Hypothalamic thyrotropin-releasing hormone (TRH) can overcome the negative feedback during pregnancy or exposure to cold

    Hypothalamus

    TRH

    Anterior pituitary

    TSH

    Thyroid gland

    Thyroid

    hormones

    Stimulates

    Target cells

    Inhibits

    Figure 16.7


    Homeostatic imbalances of th

    Homeostatic Imbalances of TH

    • Hyposecretion in adults—myxedema; endemic goiter if due to lack of iodine

    • Hyposecretion in infants—cretinism

    • Hypersecretion—Graves’ disease

      • Autoimmune disease

      • Exophthalmos

    Figure 16.10


    Calcitonin

    Calcitonin

    • Produced by parafollicular (C) cells

    • No known physiological role in humans

    • Antagonist to parathyroid hormone (PTH)

    • At higher than normal levels

    • Inhibits osteoclast activity and release of Ca2+ from bone matrix

    • Stimulates Ca2+ uptake and incorporation into bone matrix

    • Regulated by a humoral negative feedback mechanism (Ca2+ concentration in the blood)

    • No important role in humans; removal of thyroid (and its C cells) does not affect Ca2+ homeostasis


    Dr jahn s endocrine song

    Dr. Jahn’s Endocrine Song


    Parathyroid glands

    Parathyroid Glands

    • Four to eight tiny glands embedded in the posterior aspect of the thyroid

    • Contain oxyphil cells (function unknown) and chief cells that secrete parathyroid hormone (PTH) or parathormone

    • PTH—most important hormone in Ca2+ homeostasis


    Parathyroid glands1

    Parathyroid Glands

    Usually four (up to eight) tiny glands embedded in the posterior aspect of the thyroid

    Pharynx

    (posterior

    aspect)

    Chief

    cells

    (secrete

    parathyroid

    hormone)

    Thyroid

    gland

    Parathyroid

    glands

    Oxyphil

    cells

    Esophagus

    Trachea

    Capillary

    (a)

    (b)

    Figure 16.11


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Hypocalcemia

    (low blood Ca2+)

    PTH is most important hormone for calcium homeostasis

    PTH release from

    parathyroid gland

    Increases blood calcium levels 3 ways

    Activation of

    vitamin D by kidney

    Ca2+ reabsorption

    in kidney tubule

    Osteoclast activity

    in bone causes Ca2+

    and PO43- release

    into blood

    Ca2+ absorption

    from food in small

    intestine

    Ca2+ in blood

    Initial stimulus

    Physiological response

    Result


    Homeostatic imbalances of pth

    Homeostatic Imbalances of PTH

    • Hyperparathyroidism due to tumor

      • Bones soften and deform

      • Elevated Ca2+ depresses the nervous system and contributes to formation of kidney stones

    • Hypoparathyroidism following gland trauma or removal

      • Results in tetany, respiratory paralysis, and death if untreated


    Adrenal suprarenal glands

    Adrenal (Suprarenal) Glands

    Capsule

    • Paired, pyramid-shaped organs atop the kidneys

    • Structurally and functionally, they are two glands in one

      • Adrenal medulla—nervous tissue; part of the sympathetic nervous system

      • Adrenal cortex—three layers of glandular tissue that synthesize and secrete corticosteroids

    Zona

    glomerulosa

    Zona

    fasciculata

    Adrenal gland

    Cortex

    • Medulla

    • Cortex

    Zona

    reticularis

    Kidney

    Adrenal

    medulla

    Medulla

    (a) Drawing of the histology of the

    adrenal cortex and a portion of

    the adrenal medulla


    Adrenal cortex

    Adrenal Cortex

    Capsule

    Zona

    glomerulosa

    mineralocorticoids

    Zona

    fasciculata

    Adrenal gland

    glucocorticoids

    Cortex

    • Medulla

    • Cortex

    Zona

    reticularis

    Kidney

    sex hormones,

    or glucocorticoids

    Adrenal

    medulla

    Medulla

    (a) Drawing of the histology of the

    adrenal cortex and a portion of

    the adrenal medulla

    Figure 16.13a


    Mineralocorticoids

    Mineralocorticoids

    • Regulate electrolytes (primarily Na+ and K+) in ECF

      • Importance of Na+: affects ECF volume, blood volume, blood pressure, levels of other ions

      • Importance of K+: sets RMP of cells

    • Aldosterone is the most potent mineralocorticoid

      • Stimulates Na+ reabsorption and water retention by the kidneys; elimination of K+


    Mechanisms of aldosterone secretion

    Mechanisms of Aldosterone Secretion

    • Renin-angiotensin mechanism: decreased blood pressure stimulates kidneys to release renin, triggers formation of angiotensin II, a potent stimulator of aldosterone release

    • Plasma concentration of K+: Increased K+ directly influences the zona glomerulosa cells to release aldosterone

    • ACTH: causes small increases of aldosterone during stress

    • Atrial natriuretic peptide (ANP): inhibits renin and aldosterone secretion, to decrease blood pressure


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    • Aldosteronism—hypersecretion due to adrenal tumors

      • Hypertension and edema due to excessive Na+

      • Excretion of K+ leading to abnormal function of neurons and muscle

    Primary regulators

    Other factors

    Blood volume

    and/or blood

    pressure

    K+in blood

    Stress

    Blood pressure

    and/or blood

    volume

    Hypo-

    thalamus

    Heart

    Kidney

    CRH

    Direct

    stimulating

    effect

    Anterior

    pituitary

    Renin

    Initiates

    cascade

    that

    produces

    Atrial natriuretic

    peptide (ANP)

    ACTH

    Angiotensin II

    Inhibitory

    effect

    Zona glomerulosa

    of adrenal cortex

    Enhanced

    secretion

    of aldosterone

    Targets

    kidney tubules

    Absorption of Na+ and

    water; increased K+ excretion

    The RAAS Song

    Blood volume

    and/or blood pressure

    Figure 16.14


    Glucocorticoids cortisol

    Glucocorticoids (Cortisol)

    • Cortisol(hydrocortisone) is the only significant glucocorticoid in humans

      • Released in response to ACTH, patterns of eating and activity, and stress

      • Prime metabolic effect is gluconeogenesis—formation of glucose from fats and proteins

      • Promotes rises in blood glucose, fatty acids, and amino acids – saves glucose for brain

    • Keep blood sugar levels relatively constant

    • Maintain blood pressure by increasing the action of vasoconstrictors


    Homeostatic imbalances of glucocorticoids

    Homeostatic Imbalances of Glucocorticoids

    • Hypersecretion—Cushing’s syndrome

      • Depresses cartilage and bone formation

      • Inhibits inflammation

      • Depresses the immune system

      • Promotes changes in cardiovascular, neural, and gastrointestinal function

    • Hyposecretion—Addison’s disease

      • Also involves deficits in mineralocorticoids

        • Decrease in glucose and Na+ levels

        • Weight loss, severe dehydration, and hypotension


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Figure 16.15


    Gonadocorticoids sex hormones

    Gonadocorticoids (Sex Hormones)

    • Most are androgens (male sex hormones) that are converted to testosterone in tissue cells or estrogens in females

    • May contribute to

      • The onset of puberty

      • The appearance of secondary sex characteristics

      • Sex drive

      • Estrogens in postmenopausal women


    Adrenal medulla

    Adrenal Medulla

    • Chromaffin cells secrete epinephrine (80%) and norepinephrine (20%)

    • These hormones cause

      • Blood vessels to constrict

      • Increased HR

      • Blood glucose levels to rise

      • Blood to be diverted to the brain, heart, and skeletal muscle

    • Epinephrine stimulates metabolic activities, bronchial dilation, and blood flow to skeletal muscles and the heart

    • Norepinephrine influences peripheral vasoconstriction and blood pressure


    Adrenal medulla1

    Adrenal Medulla

    • Hypersecretion

      • Hyperglycemia, increased metabolic rate, rapid heartbeat and palpitations, hypertension, intense nervousness, sweating

    • Hyposecretion

      • Not problematic

      • Adrenal catecholamines not essential to life


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Short-term stress

    More prolonged stress

    Stress

    Nerve impulses

    Hypothalamus

    CRH (corticotropin-

    releasing hormone)

    Spinal cord

    Corticotroph cells

    of anterior pituitary

    Preganglionic

    sympathetic

    fibers

    To target in blood

    Adrenal cortex

    (secretes steroid

    hormones)

    Adrenal medulla

    (secretes amino acid-

    based hormones)

    ACTH

    Catecholamines

    (epinephrine and

    norepinephrine)

    Mineralocorticoids

    Glucocorticoids

    Short-term stress response

    Long-term stress response

    1. Increased heart rate

    2. Increased blood pressure

    3. Liver converts glycogen to glucose and releases

    glucose to blood

    4. Dilation of bronchioles

    5. Changes in blood flow patterns leading to decreased

    digestive system activity and reduced urine output

    6. Increased metabolic rate

    1. Retention of sodium

    and water by kidneys

    2. Increased blood volume

    and blood pressure

    1. Proteins and fats converted

    to glucose or broken down

    for energy

    2. Increased blood glucose

    3. Suppression of immune

    system

    Figure 16.16


    Is the adrenal hormone responsible for maintaining appropriate blood sodium levels

    __________ is the adrenal hormone responsible for maintaining appropriate blood sodium levels.

    • Cortisol

    • DHEA

    • Aldosterone

    • Epinephrine


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    During times of stress, elevated levels of _______ often occur, which explains why we get a cold during final exam time.

    • cortisol

    • aldosterone

    • ACTH

    • androgens


    Pineal gland

    Pineal Gland

    • Small gland hanging from the roof of the third ventricle

    • Pinealocytes secrete melatonin, derived from serotonin

    • Melatonin may affect

      • Timing of sexual maturation and puberty

      • Day/night cycles

      • Physiological processes that show rhythmic variations (body temperature, sleep, appetite)


    Pancreas

    Pancreas

    • Triangular gland behind the stomach

    • Has both exocrine and endocrine cells

      • Acinar cells (exocrine) produce an enzyme-rich juice for digestion

      • Pancreatic islets (islets of Langerhans) contain endocrine cells

        • Alpha () cells produce glucagon (a hyperglycemic hormone)

        • Beta () cells produce insulin (a hypoglycemic hormone)


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Pancreatic islet

    •  (Glucagon-

    producing)

    cells

    •  (Insulin-

    producing)

    cells

    Pancreatic acinar

    cells (exocrine)


    Glucagon and insulin

    Glucagon and Insulin

    • Effects of Glucagon

    • Major target is the liver, where it promotes

      • Glycogenolysis—breakdown of glycogen to glucose

      • Gluconeogenesis—synthesis of glucose from lactic acid and noncarbohydrates

      • Release of glucose to the blood

    • Effects of insulin

      • Lowers blood glucose levels

      • Enhances membrane transport of glucose into fat and muscle cells

      • Inhibits glycogenolysis and gluconeogenesis

      • Participates in neuronal development and learning and memory


    Insulin action on cells

    Insulin Action on Cells

    • Activates a tyrosine kinase enzyme receptor

    • Cascade leads to increased glucose uptake and enzymatic activities that

      • Catalyze the oxidation of glucose for ATP production

      • Polymerize glucose to form glycogen

      • Convert glucose to fat (particularly in adipose tissue)


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Stimulates glucose uptake by cells

    Tissue cells

    Insulin

    Stimulates

    glycogen

    formation

    Pancreas

    Glycogen

    Glucose

    Blood

    glucose

    falls to

    normal

    range.

    Liver

    Stimulus

    Blood

    glucose level

    Stimulus

    Blood

    glucose level

    Blood

    glucose

    rises to

    normal

    range.

    Pancreas

    Liver

    Glycogen

    Glucose

    Stimulates

    glycogen

    breakdown

    Glucagon

    Figure 16.18


    Factors that influence insulin release

    Factors That Influence Insulin Release

    • Elevated blood glucose levels – primary stimulus

    • Rising blood levels of amino acids and fatty acids

    • Release of acetylcholine by parasympathetic nerve fibers

    • Hormones glucagon, epinephrine, growth hormone, thyroxine, glucocorticoids

    • Somatostatin; sympathetic nervous system


    Homeostatic imbalances of insulin

    Homeostatic Imbalances of Insulin

    • Diabetes mellitus (DM)

      • Due to hyposecretion or hypoactivity of insulin

      • Three cardinal signs of DM

        • Polyuria—huge urine output

        • Polydipsia—excessive thirst

        • Polyphagia—excessive hunger and food consumption

      • Fats used for cellular fuel  lipidemia; if severe  ketones (ketone bodies) from fatty acid metabolism  ketonuria and ketoacidosis

      • Untreated ketoacidosis  hyperpnea; disrupted heart activity and O2 transport; depression of nervous system  coma and death possible

    • Hyperinsulinism:

      • Excessive insulin secretion; results in hypoglycemia, disorientation, unconsciousness


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    Table 16.4


    Human anatomy and physiology ii kaap310 14s lectures tue thu 9 30 10 45 kirkbride 004

    When the pancreas releases insulin in direct response to blood glucose, this is an example of ________ stimulation.

    • humoral

    • neural

    • hormonal

    • negative feedback


    Ovaries and placenta

    Ovaries and Placenta

    • Gonads produce steroid sex hormones

    • Ovaries produce estrogens and progesterone

    • Estrogen responsible for:

      • Maturation of female reproductive organs

      • Appearance of female secondary sexual characteristics

      • With progesterone causes breast development and cyclic changes in the uterine mucosa

    • The placenta secretes estrogens, progesterone, and human chorionic gonadotropin (hCG)


    Testes

    Testes

    • Testes produce testosterone that

      • Initiates maturation of male reproductive organs

      • Causes appearance of male secondary sexual characteristics and sex drive

      • Is necessary for normal sperm production

      • Maintains reproductive organs in their functional state


    Other hormone producing structures

    Other Hormone-Producing Structures

    • Heart

      • Atrial natriuretic peptide (ANP) reduces blood pressure, blood volume, and blood Na+ concentration

    • Gastrointestinal tract enteroendocrine cells

      • Gastrin stimulates release of HCl

      • Secretin stimulates liver and pancreas

      • Cholecystokinin stimulates pancreas, gallbladder, and hepatopancreatic sphincter


    Other hormone producing structures1

    Other Hormone-Producing Structures

    • Kidneys

      • Erythropoietin signals production of red blood cells

      • Renin (an enzyme) initiates the renin-angiotensin mechanism

    • Skin

      • Cholecalciferol, the precursor

        of vitamin D

    • Adipose tissue

      • Leptin is involved in appetite control, and stimulates increased energy expenditure

      • Adiponectin – enhances sensitivity to insulin


    Other hormone producing structures2

    Other Hormone-Producing Structures

    • Skeleton (osteoblasts)

      • Osteocalcin prods pancreatic beta cells to divide and secrete more insulin, improving glucose handling and reducing body fat

    • Thymus

      • Thymulin, thymopoietins, and thymosins are involved in normal the development of the T lymphocytes in the immune response


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