Concept 2: The Cardiovascular System

list the overall function of the cardiovascular system

to transport 02 + nutrients TO cells transport waste AWAY from cells all while maintaining blood pressure

summarize how the cardio system uses the heart, blood vessels, and blood to accomplish this function

-heart: pumps that moves blood thru blood vessels

-blood vessels: form a closed system of delivery routes that begins and ends @ the heart

-blood: connective tissue that transports oxygen + nutrients to cells

explain 3 factors that can cause resistance to blood flow through the vessels

-viscocity: the thicker the blood, the more resistant it is to flow

-vessel diameter: allows for easier, faster flow with larger-in-diameter blood vessels

-vessel length: allows for more blood to pumped through at once and reach more of the body thru one pathway

describe the location of the heart in your body, using appropriate anatomical terminology

within mediastinum of thoracic cavity

superior to the abdomen

inferior to the throat

posterior to the sternum

anterior to the vertebral column

protected by ribs

lungs on either side

explain the purpose of the pericardial cavity

allows the heart to contract in a friction-less movement

explain the importance of valves in the heart

valves in each chamber keep the heart flowing in one direction

-atrioventricular valve (AV): prevents backflow into atria when vents contract

-semilunar valve (SV): prevents backflow into vents

summarize the pathway that oxygen-poor blood will take in order to become oxygen-rich blood that can then be distributed to the tissues in our body

body tissues --> superior/inferior vena cava/coronary sinus --> right atrium --> tricuspid --> right vent --> pulmonary valve --> pulmonary trunk --> pulmonary arteries --> LUNGS

differentiate between the distinct roles and structures utilized in pulmonary, systemic, and coronary circulation

pulmonary: takes blood to lungs to be re-oxygenated

systemic: takes re-oxygenated blood back to rest of body

coronary: provides blood with nutrients needed to transport back to cells

describe what makes cardiac muscle tissue unique from other muscle tissues

-striated

-contracts using sliding filament model

-short + branched + interconnected

-have large mitocondria to keep cardiac cells energized

summarize how the intrinsic cardiac conduction system works

pacemaker cells allow the heart to generate its own electrical impulses to keep it beating regularly. by triggering their own APs, we call this the intrinsic cardiac conduction system. this is found in the SA node + AV node

describe the mechanism that causes us to hear a heartbeat through a stethoscope

we hear the sounds associated with the heart valves closing during the cardiac cycle, which are the "lub + dub" of the heart thru the stethoscope

lub: made when AV valves close when vents contract to build up pressure to pump blood out

dub: made when SL valves close

summarize how the heart uses both electrical and mechanical events to circulate blood throughout the body through the cardiac cycle

-electrical events (APs) stimulate mechanical events (pressure changes)

1) mid-to-late diastole

-low pressure in heart --> blood flows passively thru atria + open AV valves in vents

-depolarization --> atria to contract, compressing blood + high pressure

-once pressure in atria is higher than in vents, AV valves forced open --> propels blood into vents --> max vol. in vents

-atria then relax + pressure drops (atrial diastole)

2) contraction (systole)

-vents contract --> increased pressure, closing AV valves

-SL valves forced open

3) ventricular ejection: blood rushes out of vents into aorta + pulm. trunk

4) relaxation (early diastole): vents relax, pressure down, SL valves close

list some of the extrinsic controls that contribute to regulation of the cardiac cycle

-changes in autonomic immune system

-hormones

-age

-ion levels

-gender

-cardio fitness/health

-body temp.

blood flow

volume of blood flowing through vessel, organ, or entire circulatory system in given period (mL/min)

blood pressure

BP ; force per unit area exerted on a vessel wall by the blood inside (mmHg)

resistance

opposition to flow ; measure of amount of friction blood encounters as it passes thru blood vessels

blood vessels

tubelike structures that carry blood throughout the body ; begin + end @ heart ; arteries, veins, and capillaries are three major types

arteries

take blood away from the heart

arterioles

mini-arteries that branch out of arteries into capillaries

capillaries

transfer blood b/t veins & arteries

capillary beds

interweaving groups of capillaries

veins

carry blood to heart

venules

smallest vein components that pull blood from capillaries

pericardium

protects the heart + anchors it to surrounding structures

myocardium

responsible for the contractions of the heart that give us a heartbeat + allow the heart to function as a pump

contractile cardiac muscle cells

responsible for heart's pumping

pacemaker cells

noncontractile cells that spontaneously depolarize without neural input

heartbeat

pulsation of the heart

systole

when heart contracts

diastole

when heart relaxes

pulse

beat/rhythm of the heart as felt through the walls of the arteries

electrocardiogram

record of the electrical activity of the heart

CPR

cardiopulmonary resuscitation; artificial means of providing circulation and breathing during cardiac and respiratory arrest

AED

automated external defibrillator used to restart one's heart that is out of rhythm

tourniquet

device used to control bleeding that constricts all blood flow to and from an extremity