Ch 19 Cardiovascular System: Heart

cardiac muscle cell

Found in the heart wall (myocardium). -Short & striated cells -sarcolemma, t-tubules, SR, myofibrils, myofilaments (arranged in sarcomeres) -lacks stem cellsso they can't replace themselves if damaged

Perfusion

The supply of oxygen to and removal of wastes from the cells and tissues of the body as a result of the flow of blood through the capillaries maintained by cardiovascular system

Pericardium

Tough, fibrous sac that surrounds and protects the heart

functional end arteries

What the left and right coronary arteries are considered because, although these coronary arteries have anastomoses, if one of the arteries becomes blocked these anastomoses are too tiny to shunt sufficient blood from one artery to the other.

functional syncytium

a chamber; functions as a single unit

heart murmur

abnormal heart sound that is the first indication of heart valve problems

pericardial effusion

accumulation of fluid in the pericardial cavity from leaky capillaries can limit hearts movement / ability to pump blood

end artery

an artery that is the only supply of oxygenated blood to a portion of tissue

aorta

arterial trunk on left side of heart that receives the oxygenated blood from the left ventricle to transported to systemic cells

pulmonary trunk

arterial trunk on right side of heart that receives deoxygenated blood from right ventricle to be transported to the lungs (where the blood becomes oxygenated)

The ______ of the heart receives blood and the ______ pump blood to the lungs and body tissues.

atria // ventricles

The fibrous skeleton of the heart is located between the ______.

atria and ventricles

The atria are separated from the ventricles externally by a relatively deep _______ sulcus that extends around the circumference of the heart.

atrioventricular (coronary)

coronary arteries

blood vessels that branch from the aorta and carry oxygen-rich blood to the heart muscle

arterial anastomosis

body tissues served by two or more arteries however if one becomes blocked, it is too small to shunt blood from one artery to the other

left coronary artery

branches into the circumflex artery and anterior interventricular artery to supply blood to the left ventricle, left atrium, and interventricular septum

right coronary artery

branches to the right marginal artery and posterior interventricular artery to supply the right ventricle and right atrium

Arteries

carry blood away from heart

veins

carry blood to the heart

The thin strands attached to atrioventricular valves are called ______.

chordae tendineae

coronary circulation

circulation of blood through the coronary blood vessels to deliver oxygen and nutrients to the heart muscle tissue

fibrous pericardium

composed of dense irregular connective tissue that encloses the heart (does not attach to it) attached superiorly to the base of the arterial trunks (pulmonary trunk / aorta) and inferiorly to the diaphragm anchors heart, and prevents heart chambers from overfilling with blood

visceral layer of serous pericardium

composed of simple squamous and underlying delicate layer of areolar connective tissue, adheres directly to heart forming the visceral pericardium **aka the epicardium**

parietal layer of serous pericardium

composed of simple squamous and underlying delicate layer of areolar connective tissue, adheres to inner surface of fibrous pericardium

papillary muscles

cone-shaped muscular projections of the right ventricular wall that are responsible for pulling the atrioventricular valves closed by means of the chordae tendineae

The ______ delivers oxygen-rich blood to the thick heart wall while the ______ carries the deoxygenated blood away from the heart wall.

coronary arteries // coronary veins

infarction

death of tissue due to lack of blood supply

In the pulmonary circuit, ______ blood is transported from the right side of the heart to the ______.

deoxygenated;lungs

pericardial sac

encloses the heart; consists of the fibrous pericardium and parietal pericardium

cardiomegaly

enlarged heart; associated with high BP or coronary heart disease

coronary sinus

enlarged vessel on the posterior aspect of the coronary sulcus that returns deoxygenated blood to the right atrium

The outermost heart layer of the heart wall is the ______ and is also known as the ______ layer of the serous pericardium.

epicardium // visceral

endothelium

epithelial layer that lines blood vessels and heart

As we age, ______ is deposited in the epicardium, and so this layer becomes ______.

fat // stronger (thicker)

Lubb sound

first sound generated from the closing of the atrioventricular valves

myocardial infarction

heart attack; sudden and complete occlusion of a coronary artery causing a region of the myocardium to be deprived of oxygen

heart

hollow, four-chambered double pump -there are two sides (L & R) -great vessels attached -two sets of valves attached

The right and left atria are separated by the ______.

interatrial septum

coronary arterial blood flow

intermittent; the vessels are open when the heart is relaxed and compressed when the heart is contracts

The right and left ventricles are separated by the ______.

interventricular septum

Oxygenated blood is transported from the lungs to the ______ side of the heart.

left

The systemic circulation is the movement of blood from the ______ side of the heart to the systemic cells of the body and back to the ______ side of the heart.

left // right

aortic semilunar valve

located between the left ventricle and the ascending aorta tricuspid

right AV valve

located between the right atrium and right ventricle tricuspid

pulmonary semilunar valve

located between the right ventricle and the pulmonary trunk tricuspid

Myocardium

middle later composed of MOSTLY cardiac muscle tissue thickest layer contraction of muscle in this layer generates the force necessary to pump blood

pulmonary veins

on left side of heart; return oxygenated blood from lungs to left atrium

As blood is pumped by the ventricles into the arterial trunks, it pushes against the cusps, forcing the semilunar valves to ______.

open

semilunar valves

open from force of blood when the ventricle contracts and blood enters the arterial trunks close when ventricles relax and pressure of ventricle becomes less than pressure of arterial trunk; blood moves back toward the ventricle and is caught in the three cusps of the valve -closure prevents backflow of blood into the ventricle

The systemic circulation includes the movement of ______ blood through the left side of the heart.

oxygenated

The posterior atrial wall is smooth, but the auricle and anterior wall exhibit obvious muscular ridges, called ______.

pectinate muscles

3 layers of the heart

pericardium, myocardium, endocardium

small cardiac vein

positioned alongside the right marginal artery

pericardial cavity

potential space between the parietal and visceral pericardium that contains serous fluid

Desmosomes

protein filaments that anchor into a protein plaque located on the sarcolemma act as mechanical junctions to prevent cardiac muscle cells from pulling apart

gap junctions

protein pores between adjacent sarcolemma provide pathway for flow of ions between cardiac cells allow an action potential to move along sarcolemma to stimulate simultaneous activation of cardiac cells within a chamber to cause synchronous contraction of that chamber

fibrous skeleton functions

provides structural support anchors heart valves provides framework for attachment of cardiac muscle tissue acts as an electric insulator to prevent atria and ventricles from contracting at the same time

right ventricle

pumps deoxygenated blood to the lungs via the pulmonary artery

left ventricle

pumps oxygenated blood to the body out of the aorta

right side of heart

receives deoxygenated blood from the body and pumps it to the lungs

right atrium

receives deoxygenated blood from the body through the vena cava and pumps it into the right ventricle which then sends it to the lungs to be oxygenated

left side of heart

receives oxygenated blood from the lungs and pumps it to the body

left atrium

receives oxygenated blood from the lungs via the pulmonary veins

The pulmonary circulation includes the movement of blood from the ______ side of the heart to the lungs and then to the ______ side of the heart.

right // left

The opening for the coronary sinus is located in the wall of the ______.

right atrium

two sides of the heart

right side & left side; allows for separation of circulating deoxygenated and oxygenated blood each side has a receiving chamber (atrium) and a pumping chamber (ventricle)

overall pattern of blood flow

right side of the heart --> lungs --> left side of the heart --> systemic cells of the body --> back to the right side

Dubb sound

second sound generated from the closing of the semilunar valves

pericardial fluid

secreted into pericardial cavity to to lubricate serous membranes to minimize friction with every heartbeat normal amount is approx. 10-50 mL

capillaries

sites of exchange, either between the blood and alveoli of lungs or between blood and systemic cells

intercalated discs

structure unique to cardiac muscle cells found at cell-to-cell junctions they link the cells together mechanically and electrically

The ______ empty into the right atrium.

superior and inferior vena cavae

anterior interventricular artery

supplies blood to the interventricular septum and anterior walls of the left ventricles

Cirumflex Artery

supplies lateral wall of left ventricle

right marginal artery

supplies the lateral wall of the right ventricle

posterior interventricular artery

supplies the posterior surface of the left and right ventricles

Which side of the heart is more visible from a posterior view?

the left side

Which side of the heart is more visible from an anterior view?

the right side

ventricle

thick-walled, larger chamber that pumps blood to the aorta and pulmonary arteries

chordae tendineae

thin bands of fibrous tissue that attach to the valves in the heart and prevent them from closing (keep them taut) aka the heart strings!

atria

thin-walled, smaller chamber that receives blood from the vena cavae or pulmonary veins

general function of cardiovascular system

to circulate blood throughout the body to meet the changing needs of body cells it provides mechanism for transport of nutrients, waste products, respiratory gases and cells

serous pericardium

two layers: parietal layer and visceral layer

venae cavae

vein that returns deoxygenated blood from the systemic cells of body to right atrium

how do the semilunar valves prevent backflow?

when blood enters the pockets of the valves, it causes the cusps to fill and expand and meet at the artery center

great cardiac vein

within anterior interventricular sulcus positioned alongside anterior interventricular artery

heart position within thoracic cavity

within mediastinum between the lungs superior = base inferior = apex

middle cardiac vein

within posterior interventricular sulcus alongside posterior interventricular artery

coronary veins

Blood vessels that transport deoxygenated blood away from the heart toward the right atrium.

left AV valve

(mitral) located between the left atrium and left ventricle bicuspid

pulmonary circulation

**movement of blood to and from the lungs** deoxygenated blood is transported from right side of heart through blood vessels to the lungs where gas exchange occurs (O2 moves into blood from alveoli, CO2 out of blood into alveoli) the now oxygenated blood is then transported through blood vessels to left side of the heart

systemic circulation

**movement of blood to and from the systemic cells** oxygenated blood is transported from the left side of the heart through blood vessels to the systemic cells where gas exchange occurs (O2 out of blood into cells, CO2 into blood out of cells) the now deoxygenated blood is then transported through blood vessels to the right side of the heart

AV valves

-between atria and ventricles -function to prevent backflow of blood from the ventricles to the atria -open due to pressure from blood!! -when open, cusps of valves extend into the ventricles allowing blood to move from atrium to ventricle -when ventricles contract, blood is forced superiorly as the pressure rises, causing the AV valves to close -chordae tendinae & papillary muscles prevent valve from inverting when it is closed

Endocardium

Smooth lining inside heart chambers that forms the external surface of the valves composed of simple squamous and underlying areolar

fibrous skeleton

Supports the heart internally and is composed of dense irregular connective tissue