BIOL G220: Ch. 22 Flashcards
Terms and concepts from Ch. 22: Heart
two basic types of blood vessels
arteries
veins
___ and _____ are where the heart propels ____ to and from most body tissues through
arteries; veins; blood
arteries carry blood ___ ___ the heart
away from
veins carry blood ___ ____ the heart
back to
great vessels
arteries and veins entering and leaving the heart
blood flow through the heart is ____ because of four valves within the heart
unidirectional
the heart is functionally two side-by-side ____ that work at the same rate and pump the same ___ of blood
pumps; volume
blood pressure is generated by..
the heart through alternate cycles of the heart wall’s contraction and relaxation
blood pressure
the force of the blood pushing against the inside walls of blood vessels
a minimum __ ___ is essential to circulate blood throughout the body
blood pressure
two circulations of cardiovascular system
pulmonary
systemic
pulmonary circulation
right side of the heart and pulmonary arteries and veins; conveys blood to the lungs and back to the left side of the heart
systemic circulation
left side of the heart and arteries and veins; conveys blood to most body tissues and back to the right side of the heart
position of the heart
slightly left of midline
deep to the sternum in a compartment of the thorax known as the mediastinum
during development, the heart rotates such that the right side or __ ___ is located more anteriorly
right border
the left side of ___ ___ is located more posteriorly
left border
base of the heart
posterosuperior surface of the heart in mainly the left atrium
superior border
formed by the great arterial vessels and the superior vena cava
apex
inferior conical end of the heart
inferior border
formed by right ventricle
pericardium
tough sac in which the heart is enclosoed
pericardium restricts ___ ____ so that..
heart movements; it moves only slightly within the thorax
two parts of pericardium
fibrous pericardium
serous pericardium
fibrous pericardium
tough outer sac
serous pericardium
composed of parietal and visceral layers; forms pericardial cavity
layers of heart wall (3)
- epicardium
- myocardium
- endocardium
epicardium
consists of the visceral layer (simple squamous epithelium) of the serous pericardium and areolar CT
myocardium
cardiac muscles; thickest of the three layers
endocardium
internal surface of the heart chambers and external surface of the heart valves (areolar CT and endothelium)
four hollow chambers of the heart is composed of two smaller ___ and to larger ____
atria; ventricles
auricle
muscular extensions formed from the anteroinferior orders of the atria
coronary sulcus
groove separated atria and ventricles
anterior interventricular sulcus and posterior interventricular sulcus are located between the..
right and left ventricles
ligamentum arteriosum
remnant ligament attaching aortic arch to pulmonary trunk
systemic arteries are ___, while veins are ___
red; blue
pulmonary arteries are ____, while veins are ____
blue; red
four chambers of the heart
- right atrium
- right ventricle
- left atrium
- left ventricle
four valves of the heart
- right atrioventricular
- pulmonary semilunar
- left atrioventricular
- aortic semilunar
muscular ridges in atria
pectinate muscles
muscular ridges in ventricles
trabeculae carnae
right av valve location
between right atrium and right ventricle
right av valve structure
three triangular-shaped cusps of dense CT covered by endothelium; chordae tendinae attached to free edges
right av valve function
prevents backflow of blood into right atrium when ventricles contract
pulmonary semilunar valve location
between right ventricles and pulmonary trunk
pulmonary semilunar valve structure
three semilunar cusps of dense connective tissue covered by endothelium; nochordae tendinae
pulmonary semilunar valve function
prevents backflow of blood into right ventricles when ventricle relaxes
left av valve location
between left atrium and left ventricle
left av valve structure
two triangular-shaped cusps of dense CT covered by endothelium; chordae tendinae attached to free edges edges
left av valve function
prevents backflow of blood into left atrium when ventricles contract
aortic semilunar valve location
between left ventricle and aorta
aortic semilunar valve structure
three semilunar cusps of dense CT covered by endothelium; no chordae tendinae
aortic semilunary valve function
prevents backflow of blood into left ventricle when ventricles relax
fibrous skeleton is located..
between the atria and ventricles
fibrous skeleton is formed from
dense regular CT
fibrous skeleton
provides structural support and acts as an electrical insulator between atria and ventricles
blood comes in through the __ ____ and out through the ___ ___
av valves; semilunar valves
right atrium
receives venous blood from heart, the muscles, and systemic circulation
(3) veins draining into the right atrium are…
- superior vena cava
- inferior vena cava
- coronary sinus
right atrioventricular valve (aka ___) separates..
right atrium from right ventricle
deoxygenated venous blood flow from the right ___ to the right ___ through the right ____ valve
atrium; ventricle; av
right atrioventricular valve is forced closed when the right ____ begins to contract, preventing blood backflow into the right ___
ventricle; atrium
right ventricle
receives deoxygenated venous blood from the right atrium
interventricular septum
form a thick wall between the right and left ventricles
trabecular carneae
large, irregular muscular ridges displayed in the inner wall of each ventricle
chordae tendineae prevent…
the cusps from flipping into the right atrium when the right ventricle contracts
conus arteriosus
smooth area at the superior end or roof of the ventricle
pulmonary semilunar valve
beyond the conus arteriosus, marking the end of the ventricle and the beginning of the pulmonary trunk
left atrium
oxygenated blood from the lungs travels through the pulmonary veins to the left atrium
left atrioventricular valve
aka____
separates left atrium and left ventricles; also referred to as the bicuspid or mitral valve
left atrioventricular valve is forced shut when..
left ventricle contracts
left ventricle
pumps blood to the entire body, except for the lungs, and there has to generate a great deal of course
aorticsemilunar valve
located at the superior end or roof of the left ventricle , marks the end of the left ventricle and the beginning of the aorta
left ventricular wall is typically ___ _____ than the right
3x thicker
___ and ____ coronary arteries travel within the ___ ___ and supply the heart wall muscle with oxygen and nutrients
right; left; coronary sulcus
the coronary arteries are the only branches given off by the __ ____ just superior to the aortic semilunar valve
ascending aorta
the right coronary artery branches into.. (2)
right marginal artery
posterior interventricular artery
right marginal artery
supplies the right border of the heart
posterior interventricular artery
supplies the posterior surface of the left and right ventricles
left coronary artery branches into.. (2)
anterior interventricular artery
circumflex artery
anterior interventricular artery
aka left anterior descending artery; supplies the anterior surface of both ventricles and most of the interventricular septum
circumflex artery
supplies the left atrium and ventricle
venous return of blood from the heart wall muscles occurs through three major coronary veins.. (3)
- great cardiac vein
- middle cardiac vein
- small cardiac veins
great cardiac vein
runs alongside the anterior interventricular artery
middle cardiac veins
runs alongside the posterior interventricular artery
small cardiac vein
travels close to the marginal artery
three major coronary veins all drain into the ____ ____ which drains into the __ __
coronary sinus; right atrium
cadiac muscle fibers contract as a __ ___ because they are all connected with low resistance cell-to-cell- junctions called ___ ____
single-unit; gap junctions
gap junctions comprise the ___ _____ shared by adjacent cardiac muscle fibers
intercalated discs
an electrical impulse and distributed ___ and ____ throughout the myocardium
immediately; spontaneously
autorhymicity
exhibited by the heart, capable of initiating its own heartbeat independent of external nerves
sinoatrial (SA) node aka the pacemaker
specialized cardiac muscles cells allowing the electrical impulse that initiates the heart beat
SA node location
posterior wall of the right atrium adjacent to the opening of the superior vena cava
impulses from the SA node travel via gap junctions to the left atrium and the ___ ____ located in the floor of the __ ___
atrioventricular (AV) node; right atrium
the impulse tehn leaves the __ ___ into the __ ____ (bundle of His), which extends into the ___ ___
AV node; atrioventricular (AV) bundle; interventricular septum
once within the septum, the __ __ divides into __ and __ bundles
AV bundle; left; right
the ___ and ___ bundles pass the impulse to conduction cells called ___ ___ that begin at the ___ of the heart
left; right; Purkinje fibers; apex
the purkinje fibers spread the impulse superiorly from the ___ to all of the ventricular ______
apex; myocardium
5 steps of conducting system of the heart
- muscle impulse is generated at the SA node. it spreads throughout the atria and to the AV node by the internodal pathway.
- av node cells delay the muscle impulse as it passes to the av bundle.
- the av bundle conducts the muscle impulse into the interventricular septum
- within the interventricular septum, the left and right bundles split from the av bundles
- the muscle impulse is delivered to Purkinje fibers in each ventricle and distributed throughout the ventricular myocardium.
top-down at ___
bottom-up at ___
atrium; ventricles
the heart is innervated by both the __ and ___ of the autonomic NS
sympathetic; parasympathetic
cardiac plexus
anatomical components of both nervous system divisions
autonomic innervation does not initiate a heartbeat, but it can ___ or ___ the rate of the heartbeat
increase; decrease
sympathetic innervation of the heart
cardioacceleratory center sends nerve signals along sympathetic nerves, which results in an increase in both heart rate and force of contraction
parasympathetic innervation of the heart
cardioinhibitory center sends nerve signals along the vagus nerves (CN X), which results in a decrease in the heart rate
sympathetic innervation starts with neurons…
T1-T5
preganglionic axons enter the ____ trunk and synapse on gangionic neurons
sympathetic
postganglionic axons project from all three ___ ganglia and travel to the heart via ___ ___
cervical; cardiac nerves
parasympathetic innervations starts with..
neurons in the medulla oblongata via the left and right vagus nerves (CN X)
cardiac cycle
time from the start of one heartbeat to the initiation of the next
systole
contraction of a chamber
diastole
relaxation of a chamber
during ventricular systole, ventricular contractions pushes blood against the open __ valves, causing them to close.
AV
during ventricular systole, contracting papillary muscles and the chordae tendinae prevent ____ valve flaps from everting into the atria
AV
during ventricular systole, ventricles contract, forcing ___ valves to open and blood to enter the pulmonary trunk and ascending aorta
semilunar
during ventricular diastole, ventricles relax and fill with blood both passible and then by atrial contraction as ____ valves remain open
AV
during ventricular diastole – during ventricular relaxation, some blood in the ascending aorta nad pulmonary trunk flows back towards the ventricles, filling the ____ valve cusps and forcing them to close
semilunar
5 phases of the cardiac cycle
- atrial systole
- early ventricular systole
- late ventricular systole
- early ventricular diastole
- late ventricular diastole
chamber actions, ventricular pressure, valves: atrial systole
chambers: atria contract, ventricles relax
ventricular pressure: < atrial pressure, < arterial trunk pressure
valves: AV valve open, semilunar valves closed
chamber actions, ventricular pressure, valves: early ventricular systole
chambers: atria relax, ventricles contract
ventricular pressure: > atrial pressure, < arterial trunk pressure
valves: AV valves closed, semilunar valves closed
chamber actions, ventricular pressure, valves: late ventricular systole
chambers: atria relax, ventricles contract
ventricular pressure: > atrial pressure, > arterial trunk pressure
valves: AV valves closed, semilunar valves open
chamber actions, ventricular pressure, valves: early ventricular diastole
chambers: atria relax, ventricles relax
ventricular pressure: > atrial pressure, < arterial trunk pressure
valves: AV valves closed, semilunar valves closed
chamber actions, ventricular pressure, valves: late ventricular diastole
chambers: atria relax, ventricles relax
ventricular pressure: < atrial pressure, < arterial trunk pressure
valves: AV valves open, semilunar valves closed
blood flow through the heart starting at systemic veins
systemic veins --> superior and inferior venae cavae --> right atrium --> right av valve --> right ventricle --> pulmonary semilunar valve --> pulmonary trunk and arteries --> gas exchange in the lungs --> pulmonary veins --> left atrium --> left av valve --> left ventricle --> aoric semilunar valve --> aorta --> systemic arteries --> gas and nutrient exchange in peripheral tissue --> systemic veins