A+P Chapter 11: Cardiovascular System

system that allows continuous and controlled movement of blood

cardiovascular system

major function

transportation of oxygen, nutrients, hormones, and waste

beating heart of force behind

all movement such as heart, blood, and blood vessels

the cardiovascular system is very closely connected to

the respiratory system

hollow muscular organ which pumps blood through blood vessels

heart

size, weight, and location, of the heart

size → fist

weight → less than 1lb

shape → hollow cone

location of heart

• enclosed within middle cavity of ____

• flanked by the ____

• pointed end (apex) points towards the ____

• rests on the ____

thorax, lungs, left, diaphragm

double walled protective serous membrane enclosing the heart

pericardium

2 parts of the pericardium

fibrous pericardium and serous pericardium

outermost layer, protects the heart and anchors it to surrounding structures (diaphragm and sternum)

fibrous pericardium

two layer membrane, contains serous fluid for protection and to reduce friction

serous pericardium

2 parts of the serous pericardium

parietal pericardium and epicardium

lines interior of fibrous pericardium

parietal pericardium

hugs external surface of heart

epicardium

muscular layer of the heart, made of thick bundles of cardiac muscle

• contractile layer of heart

myocardium

thin endothelium that lines heart chambers

endocardium

heart contains ____ hollow chambers lined with ____

4, endocardium

two receiving chambers of the heart, located superiorly

atria

blood flows into each atria by ___ under ____ pressure

veins, low

two discharging chambers of the heart, located inferiorly

ventricles

divides the heart longitudinally and protects mixing of blood

septum

everything on the right side of the heart is what blood? and the left?

right is deoxygenated blood.

left is oxygenated blood

heart contains __ valves for blood to flow in one direction through heart

4

what is the purpose of valves

to prevent backflow of blood

located between the atrial and ventricular chambers on each side

atrioventricular valves (AV valves)

2 types of AV valves and what they are

Mitral valve → left AV valve, has 2 flaps

Tricuspid valve → right AV valve, has 3 flaps

tendons that anchor flaps of valves I ventricle walls

chordae tendineae

guards the base of the two large arteries leaving each ventricular chamber

semilunar valves (SL valves)

2 types of SL valves

pulmonary valves and aortic valves

at the base of the pulmonary artery on right side of heart

pulmonary valve

at the base of the aorta on left side of the heart

aortic valve

when are the AV and SL valves opened and closed

AV Valves

• open when heart is relaxed

• closed when ventricles contract

SL Valves

• open when ventricles contract

• closed when heart is relaxed

carries deoxygenated blood from the veins of the body into the right atrium

superior and inferior vena cava

superior vena cava drains…

inferior vena cava drains…

upper body

lower body

carries oxygenated blood from right ventricle to lungs for gas exchange

• branches off to left and right lung

pulmonary artery

carries oxygenated blood from the lungs to left atrium

• 2 sets, one from each lung

pulmonary veins

carries oxygenated blood from the left ventricle to body

aorta

blood travels from the heart to the lungs for gas exchange then back to heart

pulmonary circulation

blood travels from heart to body tissues then back to heart

systemic circulation

pathway of pulmonary circulation

1. blood enters right atria from superior or inferior vena cava

2. pressure causes tricupsid valve to open

3. blood empties into right ventricle

4. right ventricle contracts opening pulmonary valve

5. blood enters pulmonary artery

6. blood travels to lungs for gas exchange

pathway for systemic circulation

1. blood enters left atria from pulmonary veins

2. pressure causes mitral valve to open

3. blood empties into left ventricle

4. left ventricle contracts opening aortic valve

5. blood enters aorta

6. aorta branches off and blood travels to body

blood contained in the heart is not used by ____

myocardium

heart has its own ________

functional blood supply

branches off base of aorta into myocardium to encircle heart

• branches off into smaller arteries

coronary artery

drains myocardium

cardiac vein

empties cardiac veins into right atrium

• little holes on side of right atrium

coronary sinuses

cardiac muscle cells contract ____

regularly

muscle cells in different areas have ______

different rhythms

heart relies on

unifying control system

specialized tissue found only in the heart, sets rhythm of heart

• 4 parts

• causes heart muscle depolarization from atria to ventricles

• enforces contraction rate

intrinsic conduction system

what are the 4 parts of the intrinsic conduction system

1. sinoatrial node (SA)

2. Atrioventricular node (AV)

3. atrioventricular bundle (bundle of His) and bundle branches

4. purkinje fibers

small mass of cells located in right atrium, begins each heart beat and sets pace and rhythm for whole heart

• often called “the pacemaker”

• initial depolarization wave

sinoatrial node (SA)

located at junction of atria and ventricles, receives waste from SA node, causes atria to contract

atrioventricular node (AV)

located in septum of heart, receives wave from AV node

atrioventricular bundle (bundle of His) and bundle branches

located in walls of ventricles, causes ventricular contraction from the apex up

• contraction ejects blood into aorta and pulmonary artery

purkinje fibers

in healthy hearts ____ contract first followed by ____ contraction

atria, ventricular

heart is contracted and relaxed at ____ periods

different

events of one complete heart beat

cardiac cycle

the cardiac cycle is about ____ BPM and about ___ seconds per cycle

60-100, 0.8

2 parts of the cardiac cycle and what they are

systole →heart contraction

diastole →heart relaxation

how many periods to create one heart beat

3 periods

1. mid to late diastole

2. ventricular systole

3. early diastole

mid to late diastole

• heart is completely _____

• pressure is ___

• blood flowing ____ into and through ___ to _____

• SL valves ____

• AV valves ____

• at end, ____ contract emptying blood into _____

relaxed, low, passively, atria, ventricles, closed, opened, atria, ventricles

ventricular systole

• pressure ____ rapidly

• ___valves close preventing backflow

• pressure in ___ becomes higher than pressure in ___ leaving the heart

• __ valves are forced open

• blood rushes out of ___ and into ____

• ___are relaxed and __________

increases, AV, ventricles, arteries, SL, ventricles, arteries, atria, filling with blood

early diastole

• ____ begin to ____

• __valves close to prevent backflow

• pressure ____

• when pressure in ventricles drop below pressure in atria, __ valves are forced open

• ___begin to fill

ventricles, relax, SL, drops, AV, ventricles

the lub and dub of heart sounds are

lub → closing of AV valves

dub → closing of SL valves

amount of blood pumped out by each side of heart in 1 minute

• product of heart rate and stroke volume

cardiac output

volume of blood pumped out by a ventricle with each heart beat

• average is 70mL/beat

stroke volume

cardiac output equals _____ times ___

heart rate in bpm x stroke volume in mL per beat

abnormal or unusual heart sounds usually due to valve damage or deformity

• valves do not ________

• causes ___

• can be heard by _____ sound after normal heart sound

heart murmurs, close all the way, backflow, swish

occurs when heart muscle does not pump as well as it should

• progressive weakening of the heart

• circulation becomes ____

congestive heart failure, inadequate

right side of the heart fails and blood backs up in systemic circulation

• causes edema (swelling in body)

peripheral congestion

left side of the heart fails and the right side continues to pump blood into lungs

• blood unable to _______

• blood gets backed up in the ____

• ____ pressure in blood vessels

• causes _____ if not treated

pulmonary edema, return to heart, lungs, increases, suffocation