Physiology Test 4 Flashcards
(28 cards)
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)
Pericardium
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
Arteries
High oxygen
Exception is pulmonary vein
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
Lining
- cells of the inner lining of blood vessels is the same as the lining of the heart
- called endothelial cells
Terminology
- 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
Arteriole
Highly muscular
Little to no elastin
Regulate blood flow to capillary bed
- sphincter
Capillaries
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
