Anatomy Exam 2 Flashcards
the volume of blood ejected from a ventricle with each ventricular contraction
stroke volume (SV)
the volume of blood ejected by a ventricle in 1 minute
cardiac output (CO)
What is the equation to find cardiac output?
CO = SV x HR
the potential capacity of the heart to function well beyond its basal level, in response to alterations in physiologic demands
cardiac reserve
changing the HR is the body’s principal mechanism of __________ control over CO
short-term
What factors affect heart rate?
autonomic nervous system, chemicals, other factors
what factors affect stroke volume?
preload, contractility, afterload
what is the key factor contributing to the regulation of heart rate?
the balance between the S-ANS and P-ANS
what parts in the body monitor factors that influence HR?
cardiovascular center, proprioceptors, baroreceptors, and chemoreceptors
sympathetic impulses increase the heart rate via the _____________________
cardiac accelerator nerve
where does the cardiac accelerator nerve extend from?
the sympathetic trunk to the SA (and AV) node
parasympathetic impulses decrease HR via the ___________
vagus nerve
where does the vagus nerve innervate
the SA (and AV) node
what is the neurotransmitter for postganglionic parasympathetic neurons?
acetylcholine
What are two examples of chemical regulation of HR?
hormones and cations
what are other factors that affect HR regulation?
age/gender, level of physical fitness, body temperature
the stretch of the heart before a contraction
preload
forcefulness of the squeeze
contractility
the force needed to open the aortic valve
afterload
the ability of a vessel to distend and increase volume with increasing transmural pressure
distensibility
_________ is the opposite of vascular tone
distensibility
venous distensibility is approximately ___ times larger than arterial distensibility
30
________ opposes vessel distensibility
vasoconstriction
vasoconstriction will increase ____________ to the heart
venous return
the volume of blood returned to the heart via the veins after each cardiac cycle
venous return
venous return determines the volume of blood present in the ventricle at the end of ________________
ventricular diastole
in normal conditions, venous return must ______ cardiac output
equal
what factors affect venous return
distensibility/vasoconstriction of the veins, total blood volume, filling time
What are the three primary pump mechanisms that maintain venous return
the cardiac pump, skeletal muscle pump, and respiratory pump
what is preload determined by
EDV
what does increasing preload result in
a stronger ventricular contraction
increasing venous return will increase _____, which will result in a stronger force of ____________ and an increased _________
EDV; ventricular contraction; SV
“The heart will pump what it receives”
Frank-Starling Law
what is contractility determined by
the tension generated by the individual ventricular fibers
The cardiac accelerator nerve not only innervates the nodes but it also innervates the ________________
contractile myocytes
stimulation of the cardiac accelerator nerve increases the strength of the _______ of the myocytes
contraction
chemicals that influence the contractility of the heart
inotropes
which inotropic agents increase ventricular contractility
positive
what are some examples of positive inotropic agents
Epi/NE; Ca; Dopamine; Digitalis
which inotropic agents decrease contractility
negative
what are some examples of negative inotropic agents
beta-blockers; Ca channel blockers; acidosis
what are key determinates of afterload
systemic vascular resistance and blood viscosity
the resistance to blood flow created by the blood vessels of the systemic circulatory system
systemic vascular resistance
systemic vascular resistance is largely influenced by what?
the S-ANS
what does SVR control
the degree of vasoconstriction of small blood vessels
the thickness of a fluid
viscosity
increasing blood viscosity increases _________
afterload
the Frank-Starling curves are based on the ______________________________
degree of contractility and afterload of the heart
the physiological process involving the growth of new blood vessels from pre-existing vessels
angiogenesis
what does angiogenesis help with?
growth and development, as well as wound healing
angiogenesis is a fundamental step in the transition of tumors from a _______ state to a _________ state
dormant; malignant
what are the five general types of blood vessels?
arteries, arterioles, capillaries, venules, and veins
at any given time, over _____ of the total blood volume in the body is found in the veins/venules
50%
the liver, spleen, and skin function as _______ _____________
blood reservoirs
arteries = ________
distribution
arterioles = ____________
resistance
capillaries = _____________
exchange
veins = _________
capacitance
a tissue’s ability to regain its original shape and size after being stretched, squeezed, or otherwise deformed
elasticity
the ability of a vessel to decrease lumen size by activation of vascular smooth muscle within the vessel wall
contractility
the ability of a hollow organ to distend and increase volume with increasing transmural pressure; or the tendency of a hollow organ to resist recoil when under a distending force
compliance
the compliance of a blood vessel describes its _____________
dispensability
compliance is proportional to _________
elasticity
the ability to hold large volumes of fluid
capacitance
the greater the amount of elastic tissue in a ______ _______, the greater the ________, and the smaller the _________
blood vessel; elasticity; compliance
the ability to hold large volumes of fluid
capacitance
____ are capacitance vessels
veins
compared to veins, arteries have more ___________ in their vessel walls
elastic tissue
arteries = ________ _______
elastic recoil
veins =
compliance & capacitance
what are the three layers of the wall of the blood vessel
tunica intima, tunica media, and tunic externa
capillaries only have a _____ _______
tunica intima
the layer of the blood vessel wall closest to the lumen
tunica intima
which layer of the blood vessel has direct contact with the blood
tunica intima
the tunica intima consists of both __________ and a _______ __________
epithelium; basement membrane
the specialized squamous epithelial layer of the tunica intima is called the __________
endothelium
damage to the endothelial lining and exposure of blood to the collage fibers beneath this layer is a primary cause of ______ ______ __________
blood clot formation
large arteries also have a thick, distinct layer of elastic fibers known as _________ ________ ___________
internal elastic lamina
which layer of the blood vessel wall is the thickest layer
tunica media
which wall consists primarily of smooth muscle supported by elastic CT fibers
the tunica media
the smooth muscle in the tunica media makes it possible for vessels to ________ and ________
vasoconstrict and vasodilate
a mild S-ANS stimulation, causing a slight vasoconstriction in most vasculature at rest
vascular tone
when sympathetic influence increases, ___________ ________
vasoconstriction increases
when sympathetic stimulation is withdrawn, ________ __________
vessels vasodilate
alpha receptors = _____________
vasoconstriction
beta receptors = _____________
vasodilation
the nerves that innervate the vascular smooth muscle are called ______ ________
nervi vasorum
nervi vasorum run within the walls of blood vessels and are generally all ________ _______
sympathetic fibers
the large arteries also have a thick, distinct ______ _______ __________
external elastic lamina
the layer of the blood vessel wall that consists primarily of collagen CT fibers and forms the outer protective layer
tunica externa
the tunica externa also contains ____ _________ that supply oxygen and nutrients to the vessel wall
vasa vasorum
arteries carry blood ____ from the heart to the tissues
away
arteries, functionally, posses both ________ and __________
elasticity and contractility
elasticity allows arteries to ___________________________
accept blood under great pressure
_________ _________ can limit bleeding from a wounded vessel
localized contractility
the arteries with the largest diameter
large/elastic arteries
which vessels can accommodate the high pressures generated during ventricular systole
large/elastic fibers
which vessels elastic recoil aids in propelling blood forward during ventricular diastole
large/elastic fibers
list six elastic arteries
- aorta
- pulmonary trunk, and R/L pulmonary artery
- brachiocephalic trunk
- R/L common carotid artery
- R/L subclavian artery
- R/L common iliac artery
medium-sized arteries that contain more smooth muscle than elastic fibers in their tunica media
medium/muscular arteries
which arteries are referred to as distributing arteries
medium/muscular arteries
very small, almost microscopic vessels
arterioles
very slight changes in smooth muscle tone can significantly change their _____ ____
lumen size
arterials are critical in slowing down ______ _____
blood flow
what are arterioles called
resistance vessels
factors that affect arteriolar lumen size
S-ANS and chemicals
Because lumen size is a determinate of vascular resistance, the S-ANS assumes a key regulatory function in _______ ________ and thus in regulating _____ ______
vascular resistance and blood flow
what chemicals cause vasodilation
nitric oxide, carbon dioxide, lactic acid, histamine
what are two powerful vasoconstrictors?
angiotensin II and vasopressin
microscopic vessels that connect arterioles to venules
capillaries
is pressure within the capillaries low or high
very low
the process of allowing exchange of nutrients and wastes between the blood and tissue cells through the interstitial fluid
capillary exchange
what is the primary function of capillaries?
capillary exchange
capillaries are often referred to as ?
exchange vessels
what are the three mechanisms that capillary exchange is accomplished?
- Diffusion (simple or facilitated)
- Vesicular Transport (aka transcytosis)
- Bulk Flow
in most regions, capillaries branch to form an extensive ________ ________ throughout the tissue
capillary network
The capillary network increases the total surface area across these exchange vessels, allowing a _______________________________
rapid exchange of large quantities of materials
the process of supplying blood to the target tissue
perfusion
the flow of blood through the capillaries
microcirculation
what is microcirculation regulated by?
arterioles and precapillary sphincters
the ability of tissue to locally and automatically adjust its own blood flow through its capillaries in order to match its metabolic demands
autoregulation
what are the three types of capillaries?
continuous, fenestrated, and sinusoidal(discontinuous)
what are capillaries composed of?
simple squamous epithelium and a basement membrane
which type of capillary is the least porous
continous
which type of capillary has extremely high permeability
sinusoidal
continuous blood capillaries have the ___________ intercellular clefts and sinusoidal blood capillaries have the _________ intercellular clefts
smallest; largest
the pressure in a capillary is at the highest at ?
the intercellular cleft at the arterial end
what two forces achieve capillary fluid dynamics
hydrostatic pressure and colloid osmotic pressure
the space between two adjacent endothelial cells
intercellular clefets
minute openings in the surface of the endothelial cells through which gases, liquids, or microscopic particles can pass
pores (aka circular fenestrae)
which two types of capillaries have a complete basement membrane
continuous and fenestrated
which capillary has a discontinuous basement membrane
sinusoidal
which type of capillary has no pores, and no gaps in the basement membrane?
continuous
true or false? the majority of our capillaries are continuous
true
continuous capillaries use _________ _________ for the movement of many substances across its single-celled layer
vesicular transport
a barrier separating the circulating blood from the CSF
Blood-Brain Barrier (BBB)
What is unique about the Blood-Brain Barrier?
It has no intracellular clefts, very few transport vesicles, and a thickened basement membrane
the capillary exchange of most substances is blocked, with the exception of four things?
- water
- glucose
- necessary amino acids
- some ions
fenestrated capillaries have pores in the endothelial cells that allow _____ _________ and limited amounts of ______ to diffuse through
small molecules; protein
examples of where fenestrated capillaries are located
small intestines, kidneys, choroid plexus, and several endocrine structures
the pores in sinusoidal capillaries are larger to allow _______ and various ________________ to pass through
RBCs; larger serum proteins
examples of where sinusoidal capillaries are located
liver, spleen, bone marrow
what is the relationship between sinusoidal capillaries and the liver?
it’s where many plasma proteins are synthesized
what is the relationship between sinusoidal capillaries and the spleen?
it’s where worn-out RBCs and platelets are taken out of circulation
what is the relationship between bone marrow and sinusoidal capillaries?
it’s where RBCs and platelets are put into the bloodstream
small vessels that are formed from the union of several capillaries
venules
where are venules located
at the end of a capillary network
venules merge to form ________
veins
veins have much less _______ and ________ as arteries
elastic tissue and smooth muscle
in comparison to arteries, veins have much thinner ______ and a _______ ________
walls; larger lumen
true or false? veins offer little resistance to blood flow
true
veins contain valves to prevent the ______ _____ __________
backflow of blood
weak valves can lead to what?
varicose veins
the pressure you feel when taking your pulse
pulse pressure
how is pulse pressure calculated?
taking the difference between systolic and diastolic BP
the arterial pulse pressure is greatly reduced across the arterioles, and is completely _______ by the time it reaches the capillaries
dampened
a direct connection between two tubular structures
anastomosis (or shunt)
naturally occurring arterial anastomoses connect the distal ends of the radial and ulnar arteries, providing collateral circulation to regions of the hands
deep and superficial volar (palmar) arches
the skin uses _________ ___________ _____ to reduce heat loss
physiologic arteriovenous shuts
A ______ _________ ________ might be used when treating a patient with colon cancer
surgical ileorectal anastomosis
diffusion is the most important mechanism for _______ _________
capillary exchange
diffusion of a molecule is directly related to the ______ _____ available for diffusion and the ______ ________ across the barrier
surface area; concentration gradient
which type of capillary exchange includes both endocytosis and exocytosis and involves the movement of macromolecules across capillary endothelium via the use of vesicles
vesicular transport (aka transcytosis)
the movement of a fluid and substances down a pressure gradient
bulk flow
____ _____ is bidirectional depending on the net filtration pressure derived from the 4 starling forces
bulk flow
what does bulk flow occur through
pores and intercellular clefts
is bulk flow passive or active transport
passive
when moving from the bloodstream into the interstitium, bulk flow is termed _________
filtration
when moving from the interstitium into the bloodstream, the process is termed _________
reabsorption
for bulk flow, changes in _______ _______ _______ and in the _____ ___ ______ ___ _________ _____ will alter exchange
pressure driving forces; size of pores or intercellular clefts
bulk flow is most important for ______ __________ between the vascular and interstitial space and is particularly important in the _________
fluid regulation; kidney
the pressures that work toward equilibrium and which influence the exiting and entering of fluid are collectively described by
Starling’s Law of the Capillaries
our blood plasma is a _____ _______ of largely fluid and proteins, where the proteins are the ______ _______.
colloidal mixture; colloid solutes
the most abundant and therefore significant protein colloid in our blood is ________
albumin
the movement of fluid across the walls of capillaries depends on the interplay of ________ and _________ ________
hydrostatic and osmotic pressures
the pressure exerted by a column of fluid
hydrostatic pressure
a PUSH fluid
hydrostatic pressure
the pressure of blood pushing against the walls of the capillaries
Blood Hydrostatic Pressure (BHP)
the pressure exerted by the interstitial fluid against the outside of the capillaries
Interstitial Fluid Hydrostatic Pressure (IFHP)
the pressure exerted by solutes within a fluid
osmotic pressure
the higher the albumin concentration, the greater the ________ __________
osmotic pressure
PULL pressure
Osmotic Pressure
the osmotic pressure created by the solutes within the blood
Blood Colloid Osmotic Pressure (BCOP)
the osmotic pressure created by colloids within the interstitial fluid/space that pulls fluid out of the capillaries and into the interstitial space
Interstitial Fluid Osmotic Pressure (IFOP)
the process by which fluid leaves the blood vessel
Filtration
The equation that determines if fluid will leave or enter in that particular segment of the vessel
Net Filtration Pressure (NFP)
What is the Net Filtration Pressure equation?
NFP = [BHP + IFOP] - [BCOP + IFHP]
true or false? the NFP must be calculated for the arterial end of the capillary and for the venous end of the capillary separately
true
positive number for NFP =
arterial end
negative number for NFP =
venous end
when the balance of filtration and reabsorption between interstitial fluid and plasma is disrupted, an abnormal increase in interstitial fluid occurs called
edema
factors for the cause of edema
- increased BHP in capillaries due to an increase in venous pressure
- decreased concentration of plasma proteins that lowers BCOP
- increased permeability of capillaries which allows greater amounts of plasma proteins to leave the blood and enter tissue fluid
- increased extracellular fluid volume as a result of fluid retention or a blockage of lymphatic vessels
what are the main divisions of the circulatory system
pulmonary circulation and systemic circulation
which circulation system describes the blood flow between the heart and lungs
pulmonary circulation
which circulation system describes the blood flow between the heart and the rest of the body
systemic circulation
what type of circulation describes the routes in the preborn baby?
fetal circulation
systemic circulation can be split into four different circulation systems
cerebral circulation, coronary circulation, hepatic circulation, and renal circulation
what is the pulmonary circulation responsible for
oxygenating the blood
where does the pulmonary circulation direct the blood from
from the right side of the heart, to the lungs, and back to the left side of the heart
largest artery in the body; diameter similar to a garden hose
aorta
gives rise to L/R coronary artery
aortic root
3 arteries arise from here: brachiocephalic, L. common carotid, L subclavian
aortic arch
the abdominal aorta ends in a _______________________________________
bifurcation at the vertebral level of L4
first branch off the aortic arch
brachiocephalic artery
large arteries in the neck
common carotid arteries
this artery enters through the foramina of the skull and is the source of blood for the anterior cerebral circulation
internal carotid artery
this artery supplies blood to the face
external carotid artery
pass beneath clavicles; supply the upper chest and arm
subclavian artery
blood supply for the posterior cerebral circulation
vertebral arteries
arteries located on the inside of the anterior chest wall
internal thoracic arteries
most major arteries of the abdomen come directly off the aorta
abdomen pelvis
a central venous catheter or central line refers to a large IV tube placed in a large vein typically placed in the ____, ____, _ _______
neck, chest, or groin
vein for neck =
internal jugular vein
vein for chest =
subclavian vein
vein for groin =
femoral vein
a peripherally inserted central catheter or PICC line is a central venous catheter that the insertion site is a vein in the ___ rather than a vein in the neck or chest
arm
veins in arm =
basilic vein or cephalic vein
the venous equivalent of the aorta in that they are large-diameter vessels that return blood from the systemic circulation to the heart
venae cavae
short vein that drains the upper half of the body
superior vena cava
drains the lower half of the body
inferior vena cava
brachiocephalic veins are formed by the union of the internal jugular vein and the subclavian vein
true
two main pairs of arteries that supply blood to the brain
internal carotid artery and vertebral artery
the liver is unusual in that it has a _______ _______ _________
double blood supply
what are the two supplies of blood to the liver
common hepatic artery and the hepatic portal vein
the common hepatic carries oxygenated blood
to the liver
the hepatoportal vein carries venous blood from
the GI tract to the liver for detox and processing nutrients
a system that carries blood between two capillary networks
portal system
what is the postnatal structure for the umbilical vein
ligamentum teres
what is the postnatal structure for the ductus venosus
ligamentum venosum
what is the fetal vessel for the foramen ovale
fossa ovalis
what is the fetal vessel for the ductus arteriosus
the ligamentum arteriousm
the flow of blood within the organs and tissues of the body
hemodynamics
what depends on the interplay of the factors that drive and resist blood flow
distribution of blood
when a fluid flows through a closed channel, the flow can be either _________ or _________
smooth or rough
smooth fluid flowing =
laminar flow
rough fluid flowing =
turbulent flow
the normal flow of blood throughout most of the circulatory system
laminar flow
which type of flow is characterized by concentric layers of blood moving in parallel down the length of a blood vessel
laminar flow
where is the highest velocity of a vessel found?
the center
where is the lowest velocity of a vessel found
along the vessel wall
what is the flow profile of laminar flow
parabolic
does laminar flow create noise or not
no
where does laminar flow occur
in long, straight blood vessels, under steady flow conditions
does turbulent flow create noise or not
yes
the turbulence created in the heart when blood hits up against a closed valve
lubb-dubb
an extra or unusual sound heard during the cardiac cycle
murmur
a vascular murmur. abnormal sounds generated by turbulent flow of blood in an artery due to either an area of partial obstruction or a localized high rate of blood flow through an unobstructed artery
bruit
a vascular murmur in the carotid arteries
carotid bruit
the maximum force of blood recorded in the artery during ventricular contraction
systolic blood pressure (SBP)
the lowest pressure in the artery recorded during ventricular relaxation
diastolic blood pressure (DBP)
the various sounds heard while measuring a BP with a sphygmomanometer
korotkoff sounds
what is the normal blood pressure of a resting young adult?
110/70
the marking on an arterial pressure graph associated with closing of the aortic valve
dicrotic notch
the calculated average pressure in the arteries
mean arterial pressure or MAP
On a graph, the MAP is located approximately _____ of the distance between the diastolic and systolic pressures, at a value closer to the DBP
1/3
What else is the MAP sometimes called?
driving pressure or perfusion pressure
if MAP drops below 60mmHg for an extended time, what happens
ischemia, which often leads to tissue hypoxia
what is the equation for MAP
MAP = DBP + 1/3 Pulse Pressure
what are the three factors that determine vascular resistance?
vessel diameter, total vessel length, blood viscosity
which factor is the most significant in determining vascular resistance
vessel diameter
the larger the lumen, the lower the resistance to ________ ______
forward flow
the vessel length increases the __________ __________
vascular resistance
the cardiovascular center of the brain receives input from higher brain regions and from sensory receptors such as _________, __________, and ______________
proprioceptors, baroreceptors, and chemoreceptors
_____________ monitor movements of joints and muscles
proprioceptors
_____________ are important pressure-sensitive mechanoreceptors, and respond to the pressure-induced stretching of the blood vessel in which they are found
baroreceptors
what are the two most important baroreceptors
carotid sinus and aortic arch baroreceptors
the ___________ is one of the body’s homeostatic mechanisms that helps maintain nearly constant BP levels
baroreflex
the baroreflex provides a rapid negative feedback loop in which an increased blood pressure reflexively causes ____________
a decreased heart rate
_____________ are sensitive to chemicals
chemoreceptors
______, ________, and ________ each stimulate the chemoreceptors to send impulses to the CV center, producing vasoconstriction and an increase in BP
hypoxia, hypercapnia, and acidosis
hormones affect BP and blood flow by altering ____, _____, and/or _______ ____________
CO, SVR, Blood Volume
what are three hormones that increase blood pressure?
RAA pathway, epinephrine/norepinephrine, antidiuretic hormone
what is a hormone that decreases blood pressure?
atrial natriuretic peptide
what does RAA stand for?
renin, angiotensin, aldosterone
this enzyme is secreted by JG cells of the kidney and catalyzes the reaction of Angiotensinogen -> Angiotensin I
Renin
this enzyme is an inactive plasma protein that must be converted by renin
Angiotensinogen
this enzyme has no physiological affect and must be converted to AT2 by ACE
Angiotensin i
this enzyme is located in the capillaries of the lungs and catalyzes the reaction of AT1 -> AT2
Angiotensin Converting Enzyme (ACE)
this enzyme causees systemic vasoconstriction, stimulates the release of aldosterone, and stimulates the release of ADH
Angiotensin II
this enzyme is released from the adrenal cortex and causes Na and H2O retention by the kidneys, thus increasing total blood volume
Aldosterone
this hormone is released from the posterior pituitary gland, it causes kidneys to retain water and causes vasoconstriction
antidiuretic hormone
this hormone is secreted by the heart and is a powerful vasodilator. it also increases the excretion of NA and H2O from the kidneys.
Atrial Natriuretic Peptide (ANP)
the heart releases ANP when BP is too ______
high
the kidneys release renin when BP is too ______
low
the advantage of intrinsic regulation is that it allows for individual organs to self-regulate based on their particular __________ ________ and _____
metabolic activity and need
the ability of a tissue to adjust its own blood flow to match its metabolic demand for oxygen, nutrients, and removal of wastes
autoregulation
the local buildup of certain chemicals acts as a metabolic control that causes terminal arterioles to dilate and relaxes the precapillary sphincters.
metabolic control
what do these metabolites include?
carbon dioxide, adenosine diphosphate, and acids
the purpose of this is to maintain appropriate blood flow
myogenic control
the ______ of the arterioles may also assist in autoregulation of blood flow
endothelium/nitric oxide
how is the brain, heart, and kidney’s ability to autoregulate
high
how is the skeletal muscle’s ability to autoregulate
moderate
how is the skin’s ability to autoregulate
low
