cardiovascular system Flashcards
what are the four chambers of the mammalian heart?
left and right atrium
left and right ventricle
what are the atria and ventricles separated by?
AV valves
what are the two sides of the heart separated by?
septum
what is the septum that separates the ventricles?
interventricular septum
what form of network are the cardiac muscles arranged?
syncytium
describe how syncytium works
makes all fibers contract together at the same time
how are the atria and ventricles able to contract in a coordinated fashion to pump blood?
syncytium
true or false: the heart does not have an intrinsic contracting ability without a stimulus
false: The heart does have intrinsic contracting ability in the absence of a stimulus.
where does the impulse of contraction originate from?
sinoatrial node
contractions of the heart are transmitted to the AV node where it’s propagated to the rest of the heart through what specialized fibers?
purkinje fibers
what do purkinje fibers form?
bundle of his
how can the heart rate be increased or decreased?
autonomic nerves
what is the functional blood supply?
most of the blood that the heart pumps and goes to the rest of the body
nutrient supply to the heart is through a small fraction of the blood that is distributed through the ______________________
coronary blood vessels
specialized muscles in ventricles that are attached to the AV valve
papillary muscles
thick cords that attach the papillary muscles to the valves
chordae tendinae
inside of the heart covered by thin membrane
endocardium
what membrane is the heart muscles itself lined by?
myocardium
what thin membrane lines the outside of the heart?
epicardium
which ventricular wall is thicker? right or left?
left
what runs around the heart separating the atria from the ventricles?
coronary groove
why is the left ventricle larger than the right?
the left has to be strong enough to pump blood through the aorta to the rest of the body which causes the left ventricle to extend to both the right and left side of the heart
what two grooves separate the right and left ventricle?
paraconal and subsinosal grooves
the paraconal groove is found beside the _____________ which is a cone-shaped prominence on the right ventricle from which the pulmonary trunk arises
conus arteriosus
The subsinosal groove is found below the ____________ that is located in the right atrium.
coronary sinus
what is the coronary sinus?
“pool” that collects venous blood from the heart muscle
what is the fibrous sac that covers the heart?
pericardial sac
what fluid does the pericardial sac contain?
pericardial fluid
what are the three layers of the arteries?
tunica intima
tunica media
tunica adventitia
describe tunica intima
- thinnest layer
- endothelial cells surrounded by connective tissue
describe tunica media
- thickest layer
- consists of elastic fibers, connective tissue, vascular smooth muscles
describe tunica adventitia
- made of connective tissue
- contains nerves that regulate the vessels
what is the purpose of arteries?
- carry blood from the heart to various organs
- relax and contract in rhythm with heart and maintain blood pressure
what is the purpose of veins?
- carry blood to heart
- dilate to accommodate the increase in blood volume
what is the purpose of capillaries?
- act as bridge between arteries and veins
- thin walls that allow for nutrients including oxygen to pass from blood to tissues as well as substances from tissues back into circulation
oxygenated blood is pumped through arteries BUT what is the one exception?
pulmonary veins carry oxygenated blood
Blood pressure continues to drop from larger arteries to smaller arteries, arterioles and is the least when it reaches the __________
capillary bed
Venous blood from the parts of the body that are caudal to the heart drain into the _________________
caudal vena cava
Venous blood from the parts of the body that are caudal to the heart drain into the _________________
caudal vena cava
Venous blood from parts of the body that are cranial to the heart drain into the __________________
cranial vena cava
list the layers of the pericardium from superficial to deep
fibrous
serous (parietal)
(pericardial fluid)
serous (visceral)
heart muscle
true or false: the lungs are not functional in the womb
true
during development, blood that flows from the right ventricle to the pulmonary trunk gets shunted to the aorta through a connecting blood vessel called the ______________
ductus arteriosus
if the ductus arteriosus continues to remain open after birth instead of being sealed and fibrosed, what may result?
patent ductus arteriosus- improper oxygenation of blood
how is the blood from the right atrium shunted to the left atrium?
foramen ovale
if the foramen ovale remains partially open after birth, what is it called and what happens?
patent foramen ovale
- does not cause much harm
what is interventricular septal defect?
opening in the interventricular septum in fetus causing death of the newborn
purpose of common carotid arteries
supply blood to head
subclavian arteries
supply blood to head, neck, thoracic wall and forelimbs
intercostal arteries
in thorax
arteries to digestive organs
unpaired-celiac, cranial and caudal mesenteric
renal arteries
kidneys
how many chambers of the heart do all domestic species have?
4
what is the fibrous connective tissue that separates the atria from the ventricles that has islands of fibrocartilage that can be ossified to form bony structures and which species is this found in?
ossa cordis
bovine
in equines, the right coronary artery supplies __% of the myocardium and the left coronary artery __%
70
30
in domestic species besides the horse, both the right and left coronary arteries supply __% of the myocardium
50
in larger species, how do the brachiocephalic trunk, subclavian arteries and carotid arteries compare to domestic species like pigs and dogs?
from the brachiocephalic trunk, the subclavian arteries and carotid arteries are paired in species like horses and ox
what are lymphatic vessels lined with?
endothelial cells
smooth muscles
connective tissue (adventitia)
how does lymph flow in vessels?
by gravitational force and hydrostatic pressure from surrounding tissues
what do afferent lymph vessels do?
bring lymph into lymph nodes
which lymph vessels enter the lymph nodes and form a plexus and open into the lymph sinuses of the cortex of the lymph nodes?
afferent
what do efferent lymph vessels do?
carry filtered lymph from lymph nodes
which lymph vessels start from the lymph nodes and drain into other lymph nodes in the path of drainage or into veins?
efferent
how do lymph movement move across the lymphatic vessels?
contraction and relaxation of smooth muscles in the lymph vessels and is aided in their efforts by valves
what is the main function of lymph vessels?
primarily transport lymph from the tissues to the circulation.
what is lymph?
pale fluid that contains proteins, a few white blood cells and molecules that are too large to diffuse from tissues into the venous capillaries
where do small lymph vessels arise blindly from?
interstitial space
larger lymph vessels ultimately drain into what?
thoracic duct which empties into the vena cava
what do lymph nodes do?
help monitor local infections, inflammation etc. very much like a check point.
This is part of the body’s surveillance system.
true or false: arteries have valves
false
true or false: veins and lymphatics have very low pressure and contain valves to facilitate uni-directional flow of fluid
true
