Circulation and defense
1 / 90

Circulation and Defense - PowerPoint PPT Presentation

  • 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

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


  • 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


  • 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


  • 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


  • 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


  • 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


1st line


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


  • Recognizes & eliminates antigens

  • Antigens are any foreign invader that trigger an immune response

    - antibody generating


  • 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


  • 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


  • Antibodies given from one organism to another


    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)


- 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)


- 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)


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



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