Cardio vascular system

cardiac cycle

2 systolic and 1 diastolic phases, rhythmic contraction and relaxation

systolic phase

contraction

atrial: occurs first, blood → ventricles

ventricular systole: occurs second, blood → release blood to arteries

diastolic

relaxation, refilling the chambers with blood

blood pressure measurement with sphygmomanometers

1. pressurized cuff is placed on left arm, stethoscope bell placed under near brachial artery

2. cuff is inflated, temporarily disrupting brachial blood flow

3. slowly release pressure from the cuff, first sound is systolic, last sound is diastolic

occulision

limiting or blocking blood flow

baroreceptors

cells that monitor blood pressure in arteries, signaling through cranial nerves to medulla

decrease in BP

activate sympathetic branch, vasoconstriction, RAAS = raise BP

increase in BP

activate parasympathetic, lower BP

laminar blood flow

smooth and uninterrupted flow of blood, no sound

turbulent flow

interrupted, obstructed flow, produces sound

continuity equation

flow rate (Q) is constant, as surface area (A) inc. so does blood velocity (V)

Q1=Q2 or A1xV1=A2xV2

PQRST Wave

displays cardiac cycle electrically, depolarization and repolarization of the heart, rhythm, ♡ rate

P

atrial contraction/systole and depolarization

QRS complex

Q= atrioventricular node, delays atrial and ventricular systole

R= cells recieve rhythm, spread electrical activity

S= ventricular contraction/systole, depolarization

T

repolarization to “resting voltage”, ventricles refill

artery

Thick walls to promote forward flow, small lumen

vein

thin walls, large lumen, valves to prevent back flow

capillaries

single layer of cells as wall, small tinyyy lumen, allow for the exchange of materials (blood ←→ tissue)

flow of blood through blood vessels

arteries → arterioles → capillaries → veneules → veins

bulk flow

capillaries thin single-celled wall allows for rapid, passive movement of ions

filtration

occurs at arteriole end because of forward pressure”squeezing”

BP > osmotic pressure/outside fluid

reabsorption

occurs at veneule end, more relaxed vessels

BP < osmotic pressure

net filtration pressure NFP

Arteriole end- (capillary hydrostatic pressure (Pc) - intersitial fluid hydrostatic pressure (Pif))

Venule end- (osmotic force due to plasma protein concentration (πp) - Osmotic force due to intersistial fluid protein concentration (πif))

NFP = (Pc-Pif) - (πp-πif)

blood composition

plasma (water, proteins, and metabolites) and formed elements (RBCs)

maintain homeostasis

1. blood osmolarity: level of how many solutes and water are in the blood

2. Blood pH ~ 7.4

3. Body temp

clotting factors

activate prothrombin → thrombin in coagulation cascade, thrombin catalyze fibrinogen → fibrin (not water soluble, glue), add platelets

antigens

on the surface to identify as being native

Type A: antigen A, antibody B

Type B: antigen B, antibody A

Type AB: antigen A,B, antibody N/A

Type O: antigen N/A, antibody A,B

agglutinins

antibodies target the antigen not expressed on that individuals blood cells

Rh Factor

protein expressed or not expressed on the outer surface of RBC’s, Rh- only generate antibodies if exposed to Rh+ blood

blood thinners

drugs that reduce the risk of blood clots by lowering clotting protein levels

sickle cell trait

point mutation that changes shape of hemoglobin and RBC and cant carry O2 as well