circulatory system(test) Flashcards
Heart
- size of fist
- located in mediastinum
- tilted to the left
- 4 chambers
- makes a lub dub sound
- sack around called pericardium
pericardium
sack around the heart
double layer membrane around the heart to reduce friction
4 chambers of heart
atrium
- top, right and left
- smaller and weaker than ventricles
- where blood comes into the heart
ventricles
- bottom, right and left
- left is stronger than the right, stronger muscle
- right sends blood to the lungs, left does everything else
4 vessels connecting to the heart
arteries: take blood away from the heart, connect to ventricles
- aorta: comes out of left ventricle, biggest artery, goes everywhere
- pulmonary: comes out of right ventricle, goes to lung, not rich in oxygen
veins: take blood away from the heart, connect to atrium
- vena cava: dumps into right atrium, blood from body to right atrium, everywhere but lungs
- pulmonary: blood rich in oxygen, come from lungs to left atrium
4 heart valves
1 way valves, prevent blood from going the wrong direction
AV valves: atrium-ventricle
- bicuspid(mitral), left valve
- tricuspid, right side
semilunar valves: @ beginning of arteries
- aortic, beginning or aorta arteries
- pulmonary, beginning of pulmonary arteries
how does the heart get oxygen
from coronary arteries, capillaries, veins
capillaries feed.
when artrum contracts…
blood goes to ventricle
the amount of blood in atrium when atrium contracts only makes up 20% of blood in ventricle, the ventricle is mostly filled by veins
contracting units
atrium and ventricles
conducting system
SA node, AV node, AV bundle, purkinje fibers
SA node
top right of heart, pacemaker
squeezing blood from atrium to ventricles
AV node
between atrium and ventricles
gets signal from SA node and sends message on, if SA isn’t working, AV will work on its own
arteries
- high pressure
- thickest walls
- blood away from the heart
- blood pressure measured here
veins
- low pressure
- one way valves
- blood to heart
- most of body’s blood (70%)
- movement is caused by skeletal muscle
- blue things see in skin
capillaries
- thinnest walls
- permeable
- only one blood cell at a time passing through
numbers relating to blood pressure
top number: systolic, high
bottom number: diastolic, low
blood pressure
up…
- increased blood volume
- increased heart rate (exercise)
down…
- decreased blood volume
cardiac output
stroke volume
volume of blood pumped per minute
hypotension
low blood pressure
hypertension
high blood pressure
arteries and arterioles
typically contain 25% of blood in circulation
pressure varies between 40-100 mm of mercury
- need pressure to move blood
most organs receive blood from more than one artery
- alternate ways in case one gets blocked
arteries are built to withstand the greatest pressure of the system, strong walls, thick layer of connective tissue, more muscular than veins
veins and venules
70% of blood is in veins and venules
little smooth muscle
low pressure
- pressure isn’t moving the blood, have to keep moving to keep blood moving, skeletal muscles
many of medium veins, especially in limbs, have one way valves
veins generally have a greater diameter than arteries but thinner walls. not as elastic, but stretch a little.
capillaries
actual site of exchange(oxygen, CO2, food and waste)
walls are a single cell thick, things move in and out
arranged in capillary beds
extremely abundant in most tissues of the body
only about 5% of blood is in capillaries, most are shut
lymphatic system
also known as immune system
lymph vessels, lymph nodes - WBC, lymph fluid
lymph fluid
when plasma is outside the blood
lymph vessels
like veins but open ended
lymph nodes
WBC used to filter
fluid flows through
functions of the cardiovascular system
transportation
- food and oxygen from digestive system to the cells
- waste and CO2 from cells to urinary and respiratory systems
- transport hormones throughout the body
homeostasis
- maintain acid based balance
- regulate temperature
- maintain fluid and electrolyte balance
protection
- clotting and inflammation, limit spread of disease
- immune system- WBC
top of the heart is called the…
base
bottom of the heart is called the…
apex
wall of heart
epicardium: outside layer of membrane
myocardium: layer that is actual cardiac muscle, thick, cells interlace and excite each other
endocardium: delicate membrane on the inside
anyerysm
weak section in artery walls
could bulge, break, and cause internal bleeding
corinary circulation
blood coming off aorta to feed outside of heart is going through the coronary artery when the ventricle is resting. every other place gets blood when ventricle squeezes
circle of willis
seven arteries linked together so if there is blockage can reroute easier (going to the brain)
hepatic portal system
instead of taking blood directly to vena cava, blood goes to the liver to be inspected
defense system
why does the heart need a constant supply of oxygen and nutrients?
the heart never rests, so it can never build up a storage of glycogen
EKG, PQRST wave, what are each part?
P: SA node sending out a message (atrium)
QRS: electrical current through the ventricles
AV node, AV bundles, purkinje fibers
T: repolarization of the ventricles
braclycardia
heart rate lower than 60
tachycardia
heart rate greater than 100
flutter
short bursts of 200-300 bpm
fibrillation
heart beat is out of rhythm
normal blood pressure
120/80
building up of plaque
- cholesterol build up in arterial wall
- immune system releases macrophages to eat cholesterol
- macrophages become foam cells full of cholesterol
- foam cells accumulate and become plaque
-smooth muscles form a cop over to try and smooth it out - foam cells try to break out, weaken the cap
- the cap cracks, and a chunk breaks off
- the chunk gets into bloodstream and forms a clot that blocks blood flow, killing you
cardiovascular training
benefits
- blood volume
- stroke volume
- lung volume
- heart size
- CO2 extraction
- lower heart rate
- lower blood pressure
high blood pressure
140/90
varicose veins
can take them out because most of blood flow is deep and there is other ways of transportation
