CIRCULATION

CIRCULATION

Cardiovascular & lymphatic systems

Functions

Transport

Defense / immunity

Homeostasis

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Types of Circulatory Systems

Open circulatory system

Contains vascular elements

Mixing of blood & body fluids in open cavities (sinuses)

E.g., arthropods

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Types of Circulatory Systems

Closed circulatory system

Contains continuous vascular elements

Blood & body fluids kept separate

E.g., vertebrates

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Quick Quiz: True or false: A fish has a

closed circulatory system.

A) True

B) False

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Major Components of Vertebrate

Cardiovascular Systems

Heart

Pump

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Major Components of Vertebrate

Cardiovascular Systems

Heart

Vessels

Arteries

Carry blood away from the

heart

Veins

Carry blood toward the heart

Capillaries

Connections between arteries &

veins

Site of gas & nutrient exchange

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Major Components of Vertebrate

Cardiovascular Systems

Heart

Vessels

Blood

Transport “fluid”

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Chambers

Atria

Ventricles

Valves

Atrioventricular

Semilunar

Vessels

Vena cava

Pulmonary artery

Pulmonary veins

Aorta

The Mammalian Heart

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Pathway of Blood Flow

Body

R-atrium

R-ventricle

Lungs

L-atrium

L-ventricle

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lub

dub

Quick Quiz: Where does blood go

when it leaves the left ventricle?

A) Left atrium

B) Body

C) Right ventricle

D) Lungs

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Circulatory Pathways

Pulmonary circuit

Heart lungs heart

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Circulatory Pathways

Systemic circuit

Heart body heart

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Circulatory Pathways

Coronary circulation

Heart heart

Right & left coronary arteries from base of aorta

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Cardiac Output

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Quick Quiz: True or false: the

pulmonary arteries carry oxygen-rich

blood.

A) True

B) False

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Comparison of Vertebrate Systems

Mammals, birds, crocodiles

4 chambered heart

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Comparison of Vertebrate Systems

Reptiles & amphibians

3 chambered heart

Common ventricle

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Comparison of Vertebrate Systems

Fish

2 chambered heart

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Quick Quiz: Which of these chambers

does a frog NOT have?

A) Left atrium

B) Left ventricle

C) Right atrium

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Cardiac Conduction System

Autorhythmic

Structures

Sinoatrial (SA) node

“Pacemaker”

70 bpm

Atrioventricular (AV) node

Bundle branches

Purkinje fibers

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Cardiac Conduction System

Gap junctions

Communication junctions between cardiac cells

abutting ends of two

cardiac muscle cells

gap junction

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Electrocardiogram (ECG)

P wave

Atrial contraction (depolarization)

QRS wave

Ventricular contraction

T wave

Ventricular repolarization

Jimmie the bulldog 23

Arrhythmias

Irregular heart rates

Bradycardia

Tachycardia

Fibrillation

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Quick Quiz: Where is the heart’s

primary “pacemaker” found?

A) Atrioventricular node

B) Sinoatrial node

C) Purkinje fibers

D) Aorta

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Blood Vessels

Arteries

Thick walls

High pressure

Elastic fibers

Veins

Thin walls

Low pressure

Valves

Capillaries

Ultra thin

Single cell layer 26

Veins

Directional flow controlled by valves

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Blood Vessels

Path of blood flow in systemic circulation:

Heart

Aorta

Arteries

Arterioles

Capillaries

Venules

Veins

Vena cava

Heart

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Capillary Flow

“Outward flow” at the arteriole end of the

capillary bed

“Inward flow” at the venule end of the capillary

bed

Blood Vessels

Blood flow regulated by controlling vessel

diameter

Vasoconstriction

Constrict lumen

Decreases flow / increases pressure

Vasodilation

Dilate lumen

Increases flow / decreases pressure

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Blood Pressure

Blood pressure = pressure applied to walls of

blood vessels by the blood

Systolic pressure

Arterial pressure during ventricular contraction

Diastolic pressure

Arterial pressure during ventricular relaxation

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Systemic Blood Pressure

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Quick Quiz: Blood pressure in a vein is

_________ in an artery of the same

size.

A) Higher than

B) Lower than

C) The same as

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Atherosclerosis

Plaque formation

Cholesterol & fat deposits in wall of arteries

Coronary Bypass Surgery

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Blood

Volume & Composition

5 L (adult)

Blood Cell Generation

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Blood Typing

Heritable genetic traits

Markers (antigens) expressed on surface of rbc’s

A type antigens

B type antigens

O = no antigens present

Immune response will be initiated if foreign

antigens are recognized

Important for blood transfusions

Incompatible blood types will be attacked

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Agglutination Reaction

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Rh Factor

+ / - for Rh antigen

Anti-Rh antibodies may be produced in response

to transfusion or pregnancy

Consequences

Reaction to subsequent transfusions

Erythroblastosis fetalis

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Erythroblastosis Fetalis

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Quick Quiz: Blood type results from

markers on/in...

A) Plasma

B) Red blood cells

C) White blood cells

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