Circulation and defense
Download
1 / 90

Circulation and Defense - PowerPoint PPT Presentation


  • 338 Views
  • Uploaded on

Circulation and Defense. Circulatory System. Background. Closed system vs. open systems. Blood Vessels. Arteries Veins Capillaries. Blood Vessels. Arteries - away from heart -Thick elastic walls – why? - withstand pressure - Branch into arterioles

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Circulation and Defense' - sibley


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript


Background
Background

  • Closed system vs. open systems


Blood vessels
Blood Vessels

  • Arteries

  • Veins

  • Capillaries


Blood vessels1
Blood Vessels

Arteries - away from heart

-Thick elastic walls – why?

- withstand pressure

- Branch into arterioles

- smaller arteries


Specific arteries
Specific Arteries

  • Aorta

    - largest artery – 2.5cm in diameter

    - extends from left ventricle of heart

  • Carotid

    - from aorta to head

    - internal to brain, external to face

    - have chemoreceptors to detect pH


Specific arteries cont d
Specific Arteries cont’d

  • Coronary - branch off aorta & lead back to heart muscle

  • Brachial - extends from aorta to arms

  • Hepatic - from aorta to liver

  • Femoral - from aorta to legs

  • Renal - from aorta to kidneys


Veins
Veins

  • To heart

  • Thinner walls w/ some elastic

  • Valves to prevent backflow

  • Venules branch from capillaries to veins


Specific veins
Specific Veins

  • Inferior Vena Cava

    - from lower body to right atrium

    - all veins from lower body lead here

    - 3cm in diameter

  • Superior Vena Cava

    - from head to rt. atrium


Specific veins cont d
Specific veins cont’d

  • Jugular veins

    - from brain & face to superior vena cava


Capillaries
Capillaries

  • One cell thick

  • Site of gas exchange b/w cells & blood

  • Fluids from tissues re-enters blood due to hypertonicity (increased plasma protein concentration)

  • Edema – swelling of tissue – water retention


The heart
The Heart

2 pathways of circulation

- pulmonary circulation - b/w heart & lungs

blood becomes oxygenated at lungs

- systemic circulation

b/w heart & all body parts

blood drops off O2, picks up CO2

Path of blood through heart – see diagram


Features of the heart
Features of the Heart

Made of cardiac muscle (cross striated)

Heartbeat has 2 parts

1. Systole

- contracting of muscle

- ventricles push blood out

2. Diastole

- relaxed

- atria filling up


Heart action
Heart action

  • Both atria fill simultaneously

    - A-V valves closed

    - semilunars closed

  • A-V valves open as atria contract

  • Ventricles fill and A-V valves forced shut

  • Semilunars open as ventricles contract

  • Blood pushed into arteries

    semilunars forced to close

  • Lub-dupp sound is closing of valves


Regulation of heartbeat
Regulation of Heartbeat

  • Heart beats w/o control from CNS

  • Contractions coordinated by sinoatrial node(S-A node) AKA pacemaker

    - located in rt. atrium

    - made of cells that spontaneously initiate electrical impulses


Steps of heart beat
Steps of heart beat

- Pacemaker initiates impulse

- Electric current spreads across both atria causing them to contract

- A-V node in rt. Atrium hit by impulse

- A-V node stimulates ventricles to contract


Regulation of pacemaker
Regulation of Pacemaker

  • Medulla sends messages (hormones) to change heart rate

    - epinephrine aka adrenaline causes  heart rate

    - temperature causes  heart rate


Regulation of blood flow
Regulation of blood flow

  • Flow is not even to all parts

  • Smooth muscles in arterioles constrict & relax thus changing blood flow

  • Vasodilation - muscles relax & dilate thus  blood flow

  • Vasoconstriction – muscles contract & constrict the arteriole thus  blood flow

  • i.e. - after eating


Blood pressure
Blood Pressure

  • Greater the pressure the greater the flow

  • Negative feedback regulates pressure

  • Stretch receptors in aorta & carotids

  • If pressure  the heart rate should  & blood vessels should dilate

  • If pressure  the heart rate should  & vessels should constrict


Blood pressure cont d
Blood Pressure cont’d

  • Hypertension – high blood pressure

    - dilation doesn’t occur

    - medication helps dilate vessels


Functions of blood
Functions of Blood

  • Transport

    - O2

    - CO2 and other wastes

    - nutrients, hormones, electrolytes

  • Regulates pH

  • Regulates temperature


Components of blood
Components of Blood

  • 2 parts of whole blood

    1. Plasma – liquid 55%

    2. Cellular part – solid 45%

  • 4-6 L in ave. person


Plasma
Plasma

  • 90% water

  • 10%

    - substances moving from place to place

    ie, nutrients, hormones

    - electrolytes – dissolved ions

    osmotic balance & pH balance (7.4)


Plasma cont d
Plasma cont’d

  • Plasma proteins

    - enzymes

    - immunoglobulins – antibodies

    - fibrinogens – clotting

    - when these proteins are gone the plasma is called serum


Red blood cells
Red Blood Cells

  • Aka erythrocytes

  • Most numerous

  • Made in bone marrow

  • Carries O2 - hemoglobin binds w/iron

  • No nucleus when mature


White blood cells
White Blood Cells

  • 1 WBC for every 1,000 RBC

  • Larger than RBC’s

  • Defends against foreign particles

  • Made in bone marrow

  • Mature in spleen, thymus, tonsils, adenoids & lymph nodes


Wbc s cont d
WBC’s cont’d

  • Different types of WBC’s

    - macrophages – eating phagocytes

    - T lymphocytes

    - B lymphocytes


Platelets
Platelets

  • Chips of cells, no nucleus

  • Smaller than RBC’s

  • Blood clotting


The lymphatic system
The Lymphatic System

  • Some fluid (plasma) leaks out at capillaries & doesn’t return

  • Lymph system returns this fluid (now called lymph) to the circulatory system

  • Lymph nodes filter lymph and attack viruses & bacteria

  • System also functions in fat absorption

  • See diagram pg. 934



Two mechanisms
Two Mechanisms

  • Nonspecific

  • Specific


Nonspecific
Nonspecific

1st line

skin

mucous membranes

secretions like lysosyme


Nonspecific cont d
Nonspecific cont’d

- 2nd line

a. phagocytic WBC’s (eat & use digestive enzymes) - 3 kinds

1. Neutrophils

- attracted by chemicals (chemotaxis)

- amoeboid movements

- short life b/c self destruct


Phagocytic wbc s cont d
Phagocytic WBC’s cont’d

2. Monocytes which become macrophages

have long pseudopods & long life

3. Eosinophils – defend against lg. parasites like fluke


2 nd line cont d
2nd line cont’d

b. Natural Killer Cells

- destroy bodies own cells that are infected by virus or may cause tumors

- not phagocytic but cause lyseing


2 nd line cont d1
2nd line cont’d

c. Inflammatory response pg. 935

- wounded cells release histamine

- local vasodilation (capillaries dilate) causing more leaks

- signals phagocytic WBC’s

- more WBC’s to area (pus is dead phagocytes & fluids)

- local temperature 

- fever


2 nd line cont d2
2nd line cont’d

d. Antimicrobial proteins

* Interferon

- emitted from virus infected cell

- warns neighbors

- neighbors block entry by changing cell proteins

- prevents cell proliferation


2 nd line cont d3
2nd line cont’d

* Complement system

- 20 proteins interact in steps resulting in lysis of invader

- some work w/chemotaxins


Specific defense 3 rd line
Specific Defense – 3rd line

  • Also known as the immune system

  • Utilizes lymphocytes & antibodies

  • Four features of immune system

    1. Specificity

    2. Diversity

    3. Self/nonself recognition

    4. Memory


Specificity
Specificity

  • Recognizes & eliminates antigens

  • Antigens are any foreign invader that trigger an immune response

    - antibody generating


Diversity
Diversity

  • Responds to millions of types of invaders


Self nonself recognition
Self/Nonself Recognition

  • Is a problem for transplants

  • A breakdown here is an Autoimmune Disorder & results in attacking self cells


Memory
Memory

  • Remembers antigens previously encountered

  • Responds quicker & more effectively on 2nd or 3rd exposure


Acquired immunity
Acquired Immunity

Active Immunity

  • Body builds its own antibodies to fight invader

    2 types

    1. Natural as in chickenpox

    2. Stimulated by a vaccine


Acquired immunity1
Acquired Immunity

Passive

  • Antibodies given from one organism to another

    2types

    1. Take antibiotics

    2. From mother to child

  • Immunity persists only as long as the antibodies are present


How specific immunity arises
How specific immunity arises

Lymphocytes provide the specificity & diversity

1. originate from stem cells in marrow – mature elsewhere

ie. T-cells in thymus

B-cells in bone marrow


2. Travel through lymph vessels & concentrate in nodes & spleen

3. Antigen receptors on cell membrane



Immune responses 2 types
Immune Responses – 2 types memory (clonal selection)

1. Humoral Immunity

- works on free bacteria, viruses & toxins

- produces antibodies

- uses B-cells


Immune responses cont d
Immune responses cont’d memory (clonal selection)

2. Cell – Mediated Immunity

- works on bacteria, viruses inside of cells

- also on Protists, parasites, worms, transplants, cancer cells (nonself cells)

- uses direct action of lymphocytes

- uses T-cells

Diagram pg 942


Role of helper t cells
Role of Helper T Cells memory (clonal selection)


Antigen antibody
Antigen/Antibody memory (clonal selection)

Antigen – macromolecule that causes immune response

Antibody - Y-shaped quaternary protein

1. Called immunoglobulins

2. Antigen binding sites at tips – pg. 937

3. Types – IgM, IgA, IgG, IgB, IgE


Rh factor
Rh Factor memory (clonal selection)

  • Protein on RBC’s

  • Rh+ means you have this protein

  • Rh-means you don’t have it

  • Important during pregnancy – Why?


Disorders of immune system
Disorders of Immune System memory (clonal selection)

Autoimmune disease

- fails to recognize self

- lupus

- rheumatic fever


Disorders cont d
Disorders cont’d memory (clonal selection)

Allergies

- hypersensitivity of defense

- similar to defense against some parasitic worms

- hayfever – IgE recognizes pollen as invader


Disorders cont d1
Disorders cont’d memory (clonal selection)

Immunodeficiency

- Depressed humoral or cell-mediated response

- Causes

a. cancer – Hodgkin's

b. genetic – need bone marrow transplant

c. AIDS Acquired Immunodeficiency Syndrome


Disorders cont d2
Disorders cont’d memory (clonal selection)

- AIDS

a. infects cells with CD4 receptors

- T-cells (including helper T’s)

- some B-cells

- some macrophages


Aids cont d
AIDS cont’d memory (clonal selection)

b. Immune system responds ok at first then as more HIV’s accumulate imm. sys. can’t keep up

c. See graph pg 951

 HIV

T-cells

d. Eventually imm. sys. can’t fight off invaders


ad