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Flashcards in Physiology Test 4 Deck (28):

First physiological function in any developing mammal embryo

Cardiac system


Used to move nutrients and waste throughout the body

Cardiac system


Parts of the Cardiac System

Vessels (arteries, vein, and capillaries)
Fluid (blood plasma)
Pump (heart)
Lymphatic System


Outer connective tissue layer covering the heart
Heart is moved into pericardial sac during development
Fluid filled for lubrication of heart during beating
Fluid increases during periods of injury or infection (can constrict heart motion)



Layers of the Heart

Epicardium - outside
Myocardium - muscle
Endocardium - lining on inside of the heart


Chambers of the Heart

Right atrium
Right ventricle
Left atrium
Left ventricle


Atrioventricular Valves (AV)

Separates atria from ventricle
One-way blood flow
Right AV = tricuspid
Left AV = bicuspid or mitral


Semilunar Valves

Separate heart (ventricle) from vessels
Both are tricuspid
Right pulmonary semilunar valve
Left aortic semilunar valve



High oxygen
Exception is pulmonary vein



Low oxygen
Exception is pulmonary artery


Blood Flow Through the Heart

Right atrium
Right ventricle
Left atrium
Left ventricle


Right Atrium

Receives blood from venous system (return from body)
Cranial and caudal vena cava
Passive return
Low in O2, high in CO2
Pumps blood through tricuspid valve into right ventricle


Right Ventricle

Still low in O2, high in CO2
Pumps blood through right pulmonary semilunar valve into pulmonary artery to lungs


Left Atrium

Blood returns from lungs via pulmonary veins
High in O2, low CO2
Pumped through mitral (bicuspid) valve into left ventricle


Left Ventricle

High O2, low CO2
Blood pumped through the aortic semilunar valve into systemic blood supply
- Systemic = whole body
- Via the aorta


Continuous network
Complete system called circulatory system
- cells of the inner lining of blood vessels is the same as the lining of the heart
- called endothelial cells
- in general, all blood flow away from heart takes place in arteries (with exception of the pulmonary artery)
- all blow flow to the heart takes place in veins

Blood Vessels


Blood leaves Left Ventricle, large arteries

Large amount of elastic fibers
- help move blood by rebound effect


Small arteries

Some of the elastic fibers replaced by smooth muscle
Smooth muscle contractions constrict artery causing decreased blood flow



Highly muscular
Little to no elastin
Regulate blood flow to capillary bed
- sphincter



Single layer of endothelial cells
Laid out in groups (called capillary beds)
Site of gas, nutrient, and waste exchange between body and circulatory system
- through slits (clefts) between cells


Venule and Veins

Return vessels for moving blood back to the heart
Contain valve at irregular intervals to prevent backflow
Lowest pressure of any region of circulatory system
- however, constriction of major veins can be used to raise blood pressure
First vein structure are the venues
- little muscle
True veins
- more muscle
- largest veins are the vena cava which return blood directly to the heart


The Pulmonary System

Run by right ventricle
For blood circulation through the lungs
Capillary beds paired to smallest branches of lungs (alveoli)
- exchange of CO2 for O2


The Systemic Circulatory System

Run by left ventricle
Supplies oxygenated blood and nutrients to body
First branches supply the heart
Portal Vessels
- re-branching of vein to form capillary beds
- cleans blood (liver and kidneys)
- Delivers hormones directly to target organs (hypothalamus and Anterior pituitary)


Lympathic System

Only one that are not connected directly to the heart (open-ended)
Lymph capillaries
- found in interstitial space
Larger lymph vessels parallel veins of cardiac system
Afferent lymph vessels empty into lymph glands


Afferent lymph vessels empty into lymph glands

Site of germinal cells that form lymphocytes
Mobile lymphocytes
- generally enter blood stream to function
- antibody production
- sensitized lymphocytes
Fixed macrophages


Fixed Macrophages (White Blood Cells)

Engulfs materials into lymph as it passes through lymph node
Enlarged lymph node due to trapped material, inflammation or proliferation of macrophages
Important that lymph nodes are checked during meat processing for signs of disease
Cancer cells can also be trapped by lymphatic system, serve as a conduit for cell to spread throughout the body
- empties fluids from lymph nodes into blood vessels by means of large efferent vessels


Lymph fluid

Similar to interstitial fluid
Possible less protein
Capillaries specialized fro protein absorption


Larges lymphoid organ
- (oid) acting like
- circulating fluid is blood
- two filtering regions (red and white)
Effects on blood
- site of destruction of erythrocytes (red blood cells)
-aged and abnormal
- storage site for iron
- reservoir for blood
- especial erythrocytes