circulatory system- heart and blood vessels quiz 1 Flashcards
3 functions of the circulatory system
- transports gases butrients molecules and waste
- regulates internal temp and transports hormones
- protects againsts viruses, toxic substances and blood loss from injury
what is the pulmonary pathway
blood moving between heart and lungs
what is the systemic system
blood moving from heart to the rest of the body
what is the heart
muscular organ, pumps blood through body to generate blood flow
what are blood vessels
veins, artiers, cappilars they act as a roadway for blood
what is blood
carries nutrients, oxygen, carbon dioxide, water and other materials throughout the body
describe heart structure
composed of cadiac muscle tissue
contractions are rymthic and involuntary
surrounded by a sac called the pericardium
tipped slightly to the left side of chest
what are the 4 chambers of the heart
two atria (top chambers and two ventricles (bottom chambers)
- right atrium and ventricle handle deoxygenated blood
- left atrium and ventricle handle oxygenated blood
*left and right artia/ventticle are sperated by a wall of tissue known as septum
what is the pericardium
fluid filled membrane that acts as shock absorber and prevents friction
what are valves
ensures blood flows only in one direction
what makes a heart sound
valves closing
what is the lub sound of a heart beat
ventricles contract the semilunar valves open and AV valve closes
what is the dub sound of a heart beat
as ventricles begin to relax (start filling up again), semilunar valves close, AV valve opens
what is the AV valve
Atrioventricular valve
opens to let blood flow from left ventricle to your aorta, closes to prevent blood flowing in the wrong direction, closed valve keeps blood from leaking from aorta back into your heart
what is the vena cavae
two large vessels that open into the right atrium
- superior: oxygen poor blood from upper body
- inferior: oxygen poor blood from lower body
what are arteries and structure
carry oxygen rich blood away from heart to the rest of the body
- thick elastic walls made of smooth muscles no valves, small lumen
what are arterioles
smaller then artiers, regulate blood flow into capillaries
what are veins and structure
carry oxygen poor blood from the body to the heart
- thinner non elastic vessels, vlaves, large lumen
what are venules
venules smaller then veins bigger then cappillaries, small vessels that collect blood from capilliaries and merge to form veins
what are capillaries and structure
very tiny vessles that join arteries to veins, location of gas, waste, hormone and nutrient exchange
- membranes, one cell thick
what are the 2 expections to the rules of artiers and viens
- pulmonary arteries carry deoxygenated blood from the right ventricles to the lungs
- pulmonary veins carry oxygenated blood from the lungs to the left atrium
path of depleated of oxygen blood through the body
- once it returns to the right atrium of the heart through the syoerior and inferior vena cave blood moves through the right atrium to the right ventricle where it is then pumped out of heart through pulmonary ateries to the lungs, here CO2 will be exchanged for O2
path of oxygenated blood through the body
- travel back to the heart where it enters the left atrium through pulmonary viens, blood flows into the left ventricle and is pumped out of the heart via the aorta where it then travels to other areas of the body
what is the coronary pathway
supplies heart muscles tissues with oxygen
- oxygen and nutrients are delivered to the heart through capillaries embeded directly in heart wall
- capillaries are supplied by 2 coronary arteries that branch off the aorta
- deoxygenated blood is carried away in coronary veins
what is atheroscierosis
cadriovascular diesase
- caused from being overwight, unhealthy, smoking, stress
- buildup of plaque on artery walls
- narrows artery and blood flow is decrease
what is arteriosclerosis
general term
thickening of artery walls, harder less elastic
what is blood flow path simple ( left ventricle to right atrium)
left ventricle
aorta
arteries
arteroies
capillaries
venules
veins
right atrium
what is blood pressure
blood passing through vessls exerts pressure against them
BP goes up and down with each cycle of the heart beat
measured in mmHg
varries from aorta to the viens as the diameter, composition and volume of vessels changes
- drops throughout circulatory system as number of vessels and resistance increase ( allowing for exchange of soulutes in capillaris)
what is systolic pressure
big squeeze/ contraction from heart ventricles pushes a volume of blood into vessles (pulmonary artery/ aorta)
(Max BP)
what is diastolic pressure
lowest bp
happens hwen ventricles relax before next contraction
almost drops to zero in relaxed in ventricles but never drops this low in vessels
what is heart rate
measured in bpm
lower heart rate at rest implies more efficient heart function and better cardiovascular fitness
what is stroke volume
amount of blood forced out of the heart, ml/ beat
depends on
- how easily it fills/ empties
- volume of blood returing to the heart, size, stechiness of ventricles
- strength of heart contractions/ artiers
what is cardiac output
HR multiplyed by stroke volume
what happens to BP and HR when you exercise
demands for oxygen are increased body responds by pumping more O2 rich blood to active tissues
increasing BPM
causes more blood to push agsint vessl walls increasing BP (systolic pressures)
what are sketal muscles
connected to bones help you move
volentarry
what is smooth muscle
one nucleas per cell
inside organs
involuntary
what is cardiac muscle
one nucleas
branched (many diff ways)
only in heart
many mitochondria
provides ATP sites of cell resp
involentary movemnts
strained
how does nervous stimulation affect heart rate
- sympathetic nervous system: increase in HR
- parasympathetic nervous system: decrease in HR
how does hormonal stimulation affect heart rate
from adrenal gland
increases heart rate
proccess of what controls heart neat
- sinoatrial (SA) node generates electrical stimulus resulting in..
2, contraction of atria which singals the… - artioventricular node (AV node) to transmit the message through the…
- Bundle of His to the apex of the heart
- Purkinjefibres which leads to…
- contraction of ventricles
what is a ECG and what does each point do
electrocadriodiagram can be used to reord electrical activity of the heart
P- contraction of atria
QRS- contraction of ventricles + artria
T- recovery of ventricles ( b/c recovery of ventricles occors at the same time as atrial recovery, recovery of atria cannot be detected
)
electrical control of the heart
contraction of heart is inihated by a bundle of tissues known as SA node in the right atrium called pacemaker cells
pacemakers triggers each heartbeat by firing electrical impulses
- impulse spreads leading to contraction of both atrias
- stimulation of av node
- once av node is stimulated conducts impulse to the bundle of his which spreads leading to the stimulation of ventricles leading to their contraction (QRS complex)
explain steps and what happens at each part of ECG
P- atrial exciation begins, atria contracts (SA node)
PQ- impulse delayed at AV nodes, ventricles fill with blood
QR- ventricular excitation in heart apex (bottom) and AV valves close (lub noise)
RS- ventricular exication complete (purkinije fibires)
T- ventricular relaxation semilunar valves close ( dub sounds)
prevents backflow of blood into ventricles
what happens if ventricles do not recover
heart rate increase
