heart

heart anatomy q

what is the main function of the cardiovascular system

to deliver and remove molecules to meet the bodys demands

what system regulat the CV system

nervous and endocrine

what are the three main components of the cardiovascular system

heart, blood vessels. blood

what is the primary function of the heart

pumpms blood through the body

what regulator role does the heart have

sensory and endocrine functions for blood pressure and blood volume

what is the main function of blood vessels

act as tubular conduit system for blood

how do blood vessles help regulat the body

they act as sensory and effector organs for blood pressure regulation and blood distribution

what is teh primary function of blood

carriers materials to and from cells

what important communication role does blood have

transports hrmones between organs and systems

if the endorcine system releases hormones that increase blood volume, which component of the CV system directly carries out this change

blood and blood vessels (adjust distributiona nd pressure)

why are blood vessles considered both sensory and effector organs

they can detect changes like pressure and respond by constricging or dilating

if the heart has endocrine functions why is it important beyond just pumping

it helps reuglar blood pressure and volume by releasing hormones

what do the atria do

recieve blood

what do the ventricles do

pump blood out of the heart

what is the pericardium

a protective sac that surrounds the heart

what are the two man parts of the pericardium

fibrous and serous

what is the function of the fibrous pericardium

provides protecion and prevents overexpansions of the heart

what is the function of serous pericardium

reduces friction as the heart beats

what is the heart wall made of

cardium (layer of cardiac tissue, mainly myocardium)

what is the function of myocardium

contracts to pump blood

which has tichker myocardium atria or ventricels

ventricles

why are the ventricles thicker

they pump blood out of the heart at higher pressure

which ventricle has the thickers left or right

leftw

why is the left ventricle thicker

it pumps blood to the entier body (systemic circulation) requiring higher pressure

what is the function of atrioventricular valves

allows blood flow from atria to ventricles and prevent backflow

when do AV valves open

when ventricles are relaxedw

what causes AV valves to open

blood entering the atria pushes valve cusps into the ventriceslw

when do AV valves close

when ventircles contract

what causes AV valvves to close

blood pressure pushes agains the cusps

what is the function of papillary muscles

contract to tighten chordae tendineae

what do chordae tendineae do

prevent AV valve cusps from flipping into the atria

what is the function of smielunar valves

allow blood to leave the ventricles and prevent backflow

when do semi vales open

when ventircels contract

what causes semi valves to open

blood pressure from ventircles pushing against the cuspswh

when do semi valves close

when ventricles relaxe

what causes them to clsoe

blood in the arteries pushes back against the cusps

Front: If the chordae tendineae were damaged, what would happen?

Back: AV valves could prolapse (flip into atria), causing backflow of blood

Front: Why don’t semilunar valves need chordae tendineae?

Back: Their structure and arterial pressure prevent backflow without needing support

Front: If the left ventricle became weaker, which circulation would be most affected?

Front: If the left ventricle became weaker, which circulation would be most affected?

Front: During ventricular contraction, which valves are open and which are closed?

Back: Semilunar valves open; AV valves closed

in what direction does blood flow in arteries vs veines

arteries carry blod away from the heart, veins carry blood toward the hear

what connect artiers and veins

capilliaries

what are arterioles

small branches of arteries leading to capillaries

what are venules

small vessels that collect blood from capilaires into veins

are artiers typically oxygenated or deoxygenated

oxygenated except pulmonary arters

how do artery walls compare to viens

arteries are thicker

what are capilaires made of

basement membrnaes (very thin for exchange)

what are artiers and veins made of

connective tissues, smooth muscle , and endothelium

what percentage of blood is plasma

55

what % is rbc

45

what % is wbc and platlets

1

what is the shape of erthyocytes RBC

biocanve disc

why are RBc bioncanve

increases surface area and flexibilty

what is the main function of RBC

transport oxygen and some carbond dioxide

what is the path of blood flow through the heart and body

Left atrium → left ventricle → body → capillaries (O₂ out, CO₂ in) → right atrium → right ventricle → lungs → back to left atrium

what happens at the capillaries in the systemic ciruclation

oxygen leaves and carbon enters

what do the lungs do in ciruclation

add oxygen to blood and remove carbon

what are the venae cavae

two large veins that return blood the to right atrium

what is series blood flow

blood flow through organs one after another

what is parallel blood flow

blood is distributed to multiple organs at the same time

why is parallel blood flow important

ensures all organs recive equal oxygen and nutrients

what advantage does parallel flow give the body

allows independent regulation of blood flow to different organs

what is regional control of blood flow

adjusting blood flow to specific organs based on need

why must cardiac muscle contract in a synchronized manner

to effectively pump blood throguh the body

what coordinates heart contractions

the conduction system in the myocardium

what is autorthmiticty

the hears ability to generate its own electrical activty

is the carida muscle myogenic or neurogenic

myogenic (self initiated)

is skeletal muscle myogenic or neurogenic

neurogenic (requires nerve input0

what are pacemaker cells

specialized cells that spontaneously generate action potentiasl

where are pacemaker cells primairly located

SA and AV node

which node sets the pace of the heart

SA node

what is the function fo conduction fibers

transmit action potentials through the ehart

what is unique about conduction fibers

they are large damtere cardiac cells that conduct signals quickly

if capilaries were thicker how would gas exchange be affected

it would decrease because diffusion distance increases

why can the body send more blood to muscles during exericse

paralles flow allows redistribution of blood

if the sa node stops working what happens

another pacemaker like AV node takes over but at a slower rate

why is the heart bale to beat without the nervous sytem input

becuase it is myogenic and has autorhythmic pacemaker cells

if arteirs lose elasticity how would blood presusre be affected

blood presure would increase

what is the normal conduction pathway of the heart

Back: SA node → atrial muscle → AV node → AV bundle → right and left bundle branches → Purkinje fibers → ventricular muscle

what happens to the AP at the AV node

conduction slows to allow the atria to contract before the ventricels

where does the AP start

SA NODE

how does the AP potential travel to the apex of the heart (THE BODY)

rapidly through the conduction system ( AV bundle → bundle branches → Purkinje fibers

how does ventricular contraction occur after the AP reaches the apex

AP spreads upwards throughly ventricular muscle, causing coordinated contraction

what happens after the action passes through the heart

the heart reutrns to resting state untile the next AP

what is an ecg

non invasice recoridng of the hearts electrical activty

why can electrical acitvty be recorded on the body surface

body fluids conduct the electircal current generated by nervous nad muscle tissue

what does each ECG lead represent

a differntly electrical view of the heart showign direction and magnitude of current

which direction does current flow in a standard ECG lead

Back: Positive electrode → left atrium/ventricle; negative electrode → right atrium/ventricle (direction depends on lead)

what does the p wave reprensent

atrial depolarization

what does p wave represent

atrial depolarization

what does QRS complex represent

ventricular depolarization

what does the t wave represent

ventricular repolarization

what does an ecg loook like

what is lead 1 positve nad negative

• + left arm

  • - right arm

what is lead 2 pos and neg

• pos left leg

  • neg right arm

what is led 3 pos and neg

• pos left leg

  • neg left arm

how do the p wave, qrs, t wave direction relate to lead polarity

waves point toward the positive electrod, away from positive= downward deflection

what ECG wave corresponds to ventricular depolarization

QRS

what wave relates to ventricular repolariation

T wave