chapter 11 cardiovascular system Flashcards
what is the average BPM for a healthy adult?
75 BPM
arteries =
vessels that carry blood away from the heart
veins =
vessels that carry blood back to the heart
great vessels =
arteries and veins entering and exiting the heart
the heart has 2 side by side pumps in it. where does each one direct blood?
right side = directs blood to the lungs to oxygenate the blood
left side = directs blood to body tissues to transport:
1) respiratory gases
2) nutrients
3) hormones
4) waste
blood pressure =
the force of the blood pushing against the inside walls of the blood vessels
how does the heart generate BP?
by alternating cycles of contraction and relaxation
pulmonary circulation =
pumps deoxygenated blood from the right ventricle of the heart, to the lungs, and then returns oxygenated blood to the left atrium
systemic circulation =
pumps oxygenated blood from the left ventricle and transports respiratory gases, nutrients, hormones, and waste to and from tissues of the body. then deoxygenated blood is returned to the right atrium
pericardium =
tough sac that encloses the heart
pericardium function =
to restrict movement of the heart in the thorax
what 2 parts is the pericardium composed of?
1) fibrous pericardium
2) serous pericardium
what is the fibrous pericardium?
tough outter sac
what is the serous pericardium?
serous membrane composed of visceral and parietal layers
where is the pericardial cavity?
thin space between the two layers of serous pericardium that contains serous fluid
what are the 3 layers of the heart wall from superficial to deep?
1) epicardium
2) myocardium
3) endocardium
epicardium =
visceral layer of serous pericardium
myocardium =
cardiac muscle (thickest of the 3 layers)
endocardium =
internal surface of the heart chambers
which chambers in the heart are the smaller chambers?
the 2 atria
what does the anterior part of each atrium form?
an auricle
what is the flow of blood through the heart?
right atrium___right ventricle___lungs___left atrium___left ventricle___body tissues___right atrium
what sides of the heart are responsible for what circulatory systems?
right side = pulmonary
left side = systemic
coronary sulcus =
the groove separating the atria and ventricles
where is the anterior interventricular sulcus located?
where is the posterior interventricular sulcus located?
anterior interventricular sulcus = between ventricles on the anterior side of the heart
posterior interventricular sulcus = between ventricles on the posterior side of the heart
what are the 4 chambers of the heart?
right atrium
right ventricle
left atrium
left ventricle
what are the two atrioventricular valves and their locations?
tricuspid valve (between the right atrium and right ventricle)
bicuspid/mitral valve (between the left atrium and the left ventricle)
what are the 2 semilunar valves and their locations?
pulmonary semilunar valve (between right ventricle and the pulmonary trunk)
aortic semilunar valve (between left ventricle and aorta)
closure of which valves cause the first heart sound “lubb”?
the atrioventricular valves
closure of what valves causes the second heart sound “dupp”?
the semilunar valves
how many flaps does the pulmonary semilunar valve have?
3
what is the physical difference between the right and left ventricular walls?
the left ventricular wall is about 3 times thicker than the right
how are oxygen and nutrients dilivered to the heart muscle?
coronary arteries
how do cardiac muscle fibers contract as a single unit?
the intercalated disks between muscle cells contain gap junctions which allow electrical impulses to be distributed immediately and spontaneously throughout the myocardium
sinoatrial node (S/A Node) =
the hearts pacemaker
electrical impulses of the heart begin here
where is the sinoatrial node (S/A Node) located?
on the posterior wall of the right atrium
electrical impulse travels from the sinoatrial node to where?
from the SA node to the atrioventricular node and to the left atrium via gap junctions
where is the atrioventricular node located?
the floor of the right atrium
cardiac cycle =
time from the start of one heartbeat to the start of the next
(includes both contraction and relaxation)
systole=
contraction of a heart chamber
diastole =
relaxation of a heart chamber
systolic / diastolic millimeters of murcury =
blood pressure screening
BP of a healthy adult?
120/80 mm H/G or below
CO =
cardiac output
cardiac output =
the amount of blood pumped by each side of the heart in 1 minute
SV =
stroke volume
stroke volume =
volume of blood pumped by each side of the heart in one contraction
how much blood is pumped out of the left ventricle with each heartbeat?
about 70ML
what 3 factors modify heartrate?
1) neural controls (ANS)
2) hormones and ions
3) physical factors
which branches of the nervous system affect the heart and how is it affected by each branch?
1) sympathetic nervous system speeds heart rate
2) parasympathetic nervous system slows heart rate
how do ions affect HR?
excess or lack of calcium, sodium, or potassium ions can modify HR
of arteries and veins, which have thicker walls?
arteries have thicker walls
what are the 3 layers of the walls of veins and arteries? (superficial to deep)
1) tunica externa
2) tunica media
3) tunica intima
blood flow through the different types of arteries and veins =
elastic arteries___muscular arteries___arterioles___capillaries___venules___small to medium sized veins___large veins
which types of blood vessels have valves?
veins
what are the 3 different types of arteries?
(largest to smallest)
1) elastic arteries
2) muscluar arteries
3) arterioles
which arteries contain elastic fibers?
elastic arteries and muscular arteries
what do elastic fibers allow arteries to do?
allows them to stretch when the heart pumps blood through them
what are the 2 layers of elastic fiber in muscular arteries?
2 concentric rings:
1) internal elastic lamina
2) external elastic lamina
where is the internal elastic lamina?
(muscular arteries)
between tunica intima and tunica media
where is the external elastic lamina?
(muscular arteries)
between the tunica media and tunica externa
most names arteries are which type of arteries?
muscular arteries
how many layers of smooth muscle cells are in the tunica media of arterioles?
less than 6 layers of smooth muscle cells
what causes vasoconstriction of tunica muscle fibers of arterioles?
what does the vasoconstriction cause?
sympathetic innervation
vasoconstriction elevates blood pressure upstream and reduces flow to downstream capillaries
what is the diameter of capillaries?
theyre slightly larger than erythrocytes
(smallest blood vessels)
most capillary walls consist of only what?
only tunica intima(single layer of endothelial cells) and a basement membrane
what is the function of blood capillaries?
allow metabolic exchange between blood and tissue
what feeds capillary beds?
metarterioles
what is a precapillary sphincter and where are they located?
smooth muscle around a capillary that controls blood flow
theyre located at the origin of each true capillary
what are the 3 different types of blood capillaries?
1) continuous
2) fenestrated
3) sinusoids
capillaries where endothelial cells form a complete lining aided by tight junctions =
continuous capillaries
capillaries where endothelial cells contain pores that allow fluid exchange between blood and interstitial fluid =
fenestrated capillaries
capillaries that have large gaps between endothelial cells and a discontinuous/absent basement membrane which allows transport of large molecules and cells from blood =
sinusoids
how much of the bodies blood is held in veins at rest?
about 60%
venules merge to form what?
veins
smaller and medium sized veins travel with what other vessels?
muscular arteries
large veins travel with what other vessels?
elastic arteries
what is the skeletal muscle pump?
muscles bulge as they contract and push on veins, helping move more blood to the heart
why do veins have valves?
to prevent pooling and allow flow in only one direction
what are the 2 venous pumps that assist in getting blood back to the heart?
1) skeletal muscle pump
2) respiratory pump
atherosclerosis stage 1 =
1) excess LDL enter arterial wall and become oxidized
2) WBCs eat LDL molecules and form foam cells
atherosclerosis stage 2 =
1) fibrous cap forms over lipid core
2) becomes calcified and hardens arteries
atherosclerosis stage 3 =
plaque ruptures and blood clott forms
