cardiovascular system structures exam 4 Flashcards
what is the heart
an autorythmic pump, composed of three tissue layers and mostly cardiac muscle
what is the structure of the heart
encased in a pericardial sac
has four chambers
separated by valves and a septum
what are the four chambers of the heart
right and left ventricles
right and left atria
draw diagram of the heart and label everything
and explain the different functions of the parts of the heart
on paper
what are the different inputs to the heart
vena cava: receives O2 depleted blood from body at the right atrium
pulmonary veins: receive oxygenated blood from lungs at the left atrium
hormones and autonomic nerves
what happens when ventricles contract strongly
1) send blood to the lungs from right ventricle via pulmonary artery
2) send blood to the whole body from the left ventricle via the aorta
3) send blood to the heart muscle via the coronary arteries and veins on surface of heart
what are heart valves
since the heart receives oxygen depleted blood sending it to the lungs for gas exchange and then sending oxygenated blood to the body, there are valves that prevent the mixing of the two types of blood between chambers
keeps blood flowing in the right direction
what do nodes and nodal tissue in the heart do
heart beat is dependent on nodal tissue
sinus nodes entrain the rest of the heart to beat in synchrony
what happens when beat is interrupted
when conduction system of the impulses causing the beat is interrupted by heart attack, infection, aging; other areas beat independently causing heart arrhythmia
what is the difference in the kind of blood that veins and arteries carry
veins carry low O2 blood
arteries carry high O2 blood
(except for pulmonary vein and artery)
explain nodal tissues and electrophysiology
in nodal tissues the muscles contract by a series of changes to their membranes permeabilities to electrolytes
the signal arising in the SA node is conducted via special muscle tissues
what are special muscle tissues
the bundle of fibers to the apex of the heart and to the ventricular epicardium
how is heart output evaluated
by the pulse rate and by its stroke volume: essentially the volume of blood that the left ventricle actually pumps into the aorta
where does demand on the heart come from
a variety of inputs:
exercise
changes in altitude
state of then psyche (fear, depression, etc)
what are the physiological mechanisms of the cardiovascular system
barocepters, adrenal glands, autonomic nervous sytem
what are some effects of heart disease
arrhythmias, coronary artery disease and angina, valvular disease, narcotic tissue= dead heart tissue
what is the purpose of arteries
transport blood away from heart, almost always oxygenated
exception compromises pulmonary arteries that bring oxygen-depleted blood from right ventricle to the lungs
what is the artery structure
endothelium
smooth muscle and elastic fiber
connective tissue
what does the thick muscle of arteries allow for
the vessel to constrict, raising blood pressure
the vessel to relax, lowering blood pressure
this allows the CV system to respond to O2 and other needs
what is the structure of capillaries and their functions
layer of endothelium only; can be opened or closed depending on body needs
capillaries are responsible for gas exchange and providing tissues with nutrients, hormones, etc
what is the purpose of veins and their structure
three layered but with less muscle issue, have valves that work in conjunction with skeletal muscular contraction
veins return blood to heart but they are not under pressure from the heart like arteries are
what does respiration help with
helps venous return
incompetent venous values are the cause of varicose veins
what is the process of pulmonary circulation
1) right ventricle pumps blood via the pulmonary artery to the lungs
2) lung alveoli are air sacs surrounded by single cell endothelial-lined capillaries
3) blood from heart is oxygen depleted
4) simple diffusion down concentration gradients (oxygen into capillaries and CO2 into alveoli)
what does the left atrium do
return oxygenated blood from the lungs to the heart
what is systematic circulation
1) blood is pumped by the left ventricle into the aorta; this pumping must be strong enough to overcome peripheral resistance (the whole body)
2) gas exchange occurs in capillary beds
what does the hepatic portal vein collect
capillaries in the digestive system which have picked up food (glucose, amino acids, lipids)
what does the liver collect
glucose, storing it as glycogen, and also detoxifies some materials
blood leaving the liver enters the hepatic vein which drains to the inferior vena cava
how does movement of materials work
1) arteriole end of capillary beds, blood pressure is higher than blood osmotic pressure: thus water and its dissolved materials leave the capillaries
2) as moved down a capillary , the BP drops so that gases and nutrients move down their concentration gradients
what are some blood vessel diseases
hypertension, atherosclerosis and infarction, stroke, heart attack, and aneurysm
what is aneurysm (draw on paper and explain)
on paper
what is another name for a heart attack and what is a heart attack
a coronary
artery fills with plaque and oxygen and nutrients cannot get through
