Cardiovascular System

Arteries (arterioles)

carries blood away from the heart

capillaries

the “inbetween” of veins and arteries

exchange of ustances between tissue and blood

wall consists of single layer of endothelium

veins

carries blood towards the heart

70% of blood is in venous side of circulation

have valves

3 layers of the arteries

endothelium (innermost), epicardium (outtermost), myocardium (thickest, middle)

aorta

largest artery, smaller arterioles branch from the trunk

vena cavae

largest vein

structure of the heart

2 atria, 2 ventricles, seperated by a septum

heart wall muscles

myocardium, myocardium, epicardium

atrioventricular valves

mitral/bicuspid and tricuspid valve

semilunar valves

aortic and pulmonary valve

pericardium

membrane sac that encloses the heart

produces pericardial fluid

fossa ovalis

hole in the right atria that closes after birth

foremane ovale

open hole In right atria

(in the womb fetus receives oxygen directly from mothers placenta, so until birth they don’t need to breathe on their own which is why there’s a hole)

chordae tendineae

inelastic cords in heart connecting valves and papillary tissue

prevents valves from flipping backwards holding them in place

papillary muscle

pillar like muscle that contract to prevent valves from flipping backwards, connecting chordae tendineae

lub dup meaning

lub- atrioventricular valves closing

dup- semilunar valves closing

normal heart rate BPM

60-80 bpm

systole and diastole

systole/highest - contraction of muscle

diastole/lowest - relaxation of heart muscle

nodal tissue

SA node - generates electrical impulses that initiate heartbeat (pacemaker)

AV node- delays electrical signal so atria contracts and empty blood (gatekeeper)

purkinje fibers

fiber that distribute electrical impulses to ventricular muscle so they can squeeze

control of heartbeat

medulla inputs to heart through ANS

parasympathetic - decrease in heartbeat

sympathetic -increase

hormones - epinephrine + norepinephrine increases (flight or fight)

electriocardiogram

records activity in heart (heart rate and rhythm)

p wave, t wave, and qrs complex

p wave, qrs complex, and t wave

p - atrial depolarization

qrs - ventricular depolarization, atria repolarize

t- ventricular repolarization

electricity backup

sa node - AV node - ventricles

trachycardia

pulse rest over 100 bpm

bradycardia

pulse at rest under 60 bpm

sinoatrial block

sa node signal doesn’t reach atria

atrioventricular block

signal gets delayed too much by AV node and too much goes to ventricles (p-r interval too long)

ventricular fibrillation

erratic quivering of ventricles (no pump)

coronary circulation

supplies heart muscle

lies on surface of heart and distributes blood

coronary veins enter into right atria

hepatic portal system

blood carries from hepatic portal vein to liver , blood gets cleaned and is carried out back to the inferior vena cava

varicose veins

really dark visible veins on skin

roots from weakened valves and backward pressure of blood

fibrinogen

maintains stable blood clotting and prevents excessive blood loss

immunoglobulins

identify and neutralize foreign bacteria/viruses

albumin

prevents fluid from leaking out of blood vessels into surrounding tissues

rbc characteristics

manufactured in red bone marrow

4-6.6 million per mL of blood

lack nucleus as they mature

hemoglobin

has red iron-containing pigment