Test 2-cardio/lymph Flashcards
What are the 4 functions of the heart?
generate BP, routing blood, ensuring one way flow, regulating blood supply
how does the cardiovascular system ensure one way flow
valves
how does the cardiovascular system regulate blood supply
changes in contraction rate and force match blood delivery to changing metabolic needs
CO2/O2 exchange happens in __________.
capillaries
What area is the heart located in?
Mediastinum
What are the two main parts of the pericardium?
fibrous pericardium and serous pericardium
what does the fibrous pericardium do?
prevents over distention and acts as an anchor
what does the serous pericardium do?
made of the parietal pericardium which lines the fibrous outer layer and visceral pericardium (epicardium which covers the heart surface.
what are the three layers of heart tissue
epicardium, myocardium, endocardium
what is the myocardium
composed of caridac muscle cells and responsibility for heart contraction
pectinate muslces
muscular ridges in auricles and right atrial walls
trabeculae carnae
muscular ridges and columns on the inside walls of ventricles
where does the right coronary artery supply blood
posterior aspect of heart
where does the right marginal artery supply blood
lateral wall of right ventricle
where does the posterior interventricular artery supply blood
posterior and inferior aspects of heart
where does the left marginal artery supply blood to
lateral wall of left ventricle
where does the circumflex artery supply blood?
extends to posterior aspect of heart
what does the great cardiac and small cardiac vein do
drain right margin of the heart
Where do veins of the heart empty before going to the right atrium
coronary sinus
What three places does the right atrium receive blood from?
superior/inferior vena cava, coronary sinus
where does the left atrium receive blood from
four pulmonary veins
what is the interatrial septum
wall between the atria
What is the fossa ovalis
a depression in the interatrial septum which is a remnant of the fetal opening between the atria
what are tendon structures connected to the atrioventricular valves
chordae tendinae
what causes the atrioventricular valves to open and close
papillary muscles
can the atrioventricular valves be open at the same time as the semilunar valves?
no
What is the precursor structure to the fossa ovalis
foramen ovale
what are the characteristics of cardiac muslce
elongated, branching cells containing 1-2 centrally located nuclei. contains actin and myosin myofilaments.
what are intercalated disks
specialized cell-cell contacts. cell membranes interdigitate, desmosomes hold cells together, and gap junctions allow action potentials to propagate
What is the first step of conduction through the heart
SA nodes initiate action potential and travels through the atria
what is the second step in conduction through the heart
action potentials reach the AV node at the bottom of the right atrium and pass through the av bundle
what is the third step in conduction through the heart
the AV bundle divides into right and left branches and action potential moves down the interventricular septum
what is the fourth step in the conduction through the heart
action potential is carried by purkinje fibers from the bundle branches to the ventricular walls and papillary muslces
what is an ectopic pacemaker or ectopic focus
excitable group of cells that cause a premature heart beat outside of normally functioning SA node of heart
What creates the plateau phase of the action potential
Ca+2 channels stay open which lengthens the depolarization effects
in skeletal muscle the action potential is conducted along the length of a single fiber. How is cardiac muscle different?
action potential conducted from cell to cell
Why is cardiac action potential propagation slower than skeletal?
gap junctions and small diameter of fibers
what is absolute refractory period
cardiac muscle cell completely insensitive to further stimulation for a short period
what is relative refractory period
cell exhibits reduced sensitivity to additional stimulation
what is long refractory period
prevents tetanic contractions
What happens during the P wave
atrial depolarization and onset of atrial contraction
what happens during the QRS complex
ventricular depolarization and atrial repolarization. ventricular contraction
what happens during the T wave
repolarizaiton of ventricles preceds ventricular relaxation
diastole is _______
systole is ________
contraction
relaxation
What is the first heart sound and what happens
lubb. AV valves close
What is the second heart sound and what happens
dupp. semilunar valves close
if there is a third heart sound what does that indicate
turbulent flood flow into ventricles and detected near end of first third of diastole
what is mean arterial pressure (MAP)? how is it calculated
average blood pressure in the aorta. cardiac output x peripheral resistance.
What is cardiac output and how is it calculated?
amount of blood pumped by heart per minute. stroke volume x heart rate
what is venous return
amount of blood returning to heart from peripheral circulation
What is end-diastolic/systolic reserve volume
amount of blood left in ventricle at end of filling/end point ejection
What is cardiac reserve
difference between CO at rest and maximum CO
What is peripheral resistance
total resistance against which blood must be pumped
intrinsic regulation
results from normal functional characteristics (not neural or hormonal regulation)
what is preload
amount of stretch of the ventricular walls. the greater the preload the greater the force of contraction
what is afterload
pressure the contracting ventricles must produce to overcome the pressure in the aorta and move blood into the aorta
extrinsic regulation
neural and hormonal control of the heart
parasympathetic stimulation
supplied by vagus nerve, decreases heart rate, acetylcholine is secreted and hyperpolarizes the heart.
sympathetic stimulation
supplied by cardiac nerves which innervate the SA and AV nodes, coronary vessels, and atrial and ventricular myocardium. Increases heart rate and force of contraction. Epi and Norepi released
What happens when the heart beat increases
increases cardiac output causes a lower end-systolic volume. heart empties to a greater extent
How does epinephrine and norepinephrine control the heart
quick response increases heart rate and pumps blood out faster
What does excess extracellular potassium do
increases the heart rate and stroke volume (tachycardia) initially and then leads to a slower heart rate (bradycardia/heart block)
what does a deficiency in extracellular potassium do
decreases heart rate and no change in force
what does excess extracellular calcium do
lowers action potential frequency and therefore heart rate
what does a extracellular calcium deficiency do
increases heart rate. death usually due to tetany of skeletal muslce before heart
where are barorecptors located. where do they send information?
internal carotids. medulla oblongata
where are oxygen chemoreceptors located
aorta, internal carotids
where are receptors for H+, CO2, located
medulla oblongata
how is temperature related to heart rate
directly proportional
what will the cardioregulatory center to to the parasympathetic and sympathetic systems if blood pressure increases? decreases?
- parasympathetic up, sympathetic down
2. parasympathetic down, sympathetic down
what will the cardioregulatory center to to the parasympathetic and sympathetic systems if blood pH increases? decreases?
- parasympathetic up, sympathetic down
2. parasympathetic down, sympathetic down
What are the effects of aging on the heart
more significant response to excercise, hypertrophy of left ventricle, decrease in maximum heart rate, increased tendency for abnormal heart function, atrophy of cells contraction= arrhythmia, coronary artery disease, congestive heart disease
What are the functions of the circulatory system
carry blood, exchange nutrients, waste products, and gasses, transport molecules, regulate blood pressure, directs blood flow.
what is the flow of blood from elastic arteries to large veins
elastic arteries, muscular arteries, arterioles, capillaries, venules, small veins, medium/large veins.
What are the three main layers of vessels
tunica intima, tunica media, and tunica adventitia
What are some characteristics of the tunica intima
it is the innermost layer which is surrounded by a basal membrane,connective tissue layer, and internal elastic membrane
What are some characteristics of the tunica media
smooth muscle cells arranged circularly around the blood vessel
what happens to the bp and flow during vasoconstriction? vasodilation?
- up, down
2. down, up
What are some characteristics of the tunica adventitia
connective tissue that varies from dense regular towards the center of the vessel to loose farther from the vessel
What are elastic or conducting arteries
large diameter and higher pressure when fluctuating between systolic and diastolic. more elastic tissue than muscle. Thick tunica intima and thin tunica adventitia
What are muscular arteries
more smooth muscle allows vessel to regulate blood supply by constricting or dilating
what are arterioles
smallest arteries where the three tunics can still be differentiated. transport blood from small arteries to capillaries
capillaries
consists of endothelial cells (simple squamous), basal membrane, and loose CT. scattered pericapillary cells
what are pericapillary cells
cell between the endothelial cell and basal membrane which includes fibroblasts, macrophages, or undifferentiated smooth muscle cells
how do lipid soluble and small water soluble molecules move through the PM
diffusion
how do large water soluble molecules get out of cappilaries
move through fenestrae or between endothelial cells
what are the 5 types of cappilaries
continuous, fenestrated, sinusoidal, venous sinuses
continuous cappilary
no gaps b/w endothelial cells, no fenestrae, less permeable to molecules. muscle, nervous tissue
fenestrated capillaries
endothelial cells have numerous fenestrae, pores, highly permeable. intestinal villi, ciliary process of eye, choroid plexus, glomeruli of kidney
sinusoidal capillaries
large diameter with large fenestrae, less basement membrane permeable to large molecules like hormones
venous sinuses
most permeable to molecules like RBC is spleen
metarterioles
connect arteriole with cappilary system
thoroughfare channel
main channel which connects arteriole and venule
venules
drain capillary network. have endothelial cells with little amount of smooth muscle
small veins
have smooth muscle which forms a continuous layer
large veins
tunica intima is thin, adventitia is predominant layer.
what are valves made of in veins, where are they most concentrated
made of folds in intima. more in lower extremeties
what is the order of flow from elastic arteries to medium and large veisn
elastic arteries, musclular arteries, arterioles, metarterioles, thoroughfare channels, precapillary sphincters, arterial caps, venous caps, venules, small veins, medium/large veins
vasa vasorum
blood vessels that supply the walls of arteries and veins
portal veins
connects two capillary network without a pumping mechanism in between.
arterivenous anastemoses
arterioles to small veins with no capillaries. found in sole of foot, palm of hand, terminal phalanges, nail bed
what types of vessels are most innervated
small arteries and arterioles
arterisclerosis
degenerative change making arteries less elastic
atherosclerosis
deposition of plaque on walls between endothelium and vessel wall
what three arteries exit the aortic arch
brachiocephalic, left common carotid, left subclavian
which arteries does the shoulder, chest, and back receive blood from
subclavian and axillary
what artery does the palm receive blood from
superficial and deep palmar arches
what artery does the thumb and fingers receive blood from
digital arches
what organs do the celiac trunk supply blood to
stomach, duodenum, liver
what organs do the splenic artery supply
stomach and spleen
what organs do the superior messenteric artery supply
pancreas, small intestine, and colon
what organs do the inferior messenteric artery supply
colon and rectum
what are the major veins which return blood to the right atrium
superior/inferior vena cava, coronary sinus
types of veins
superficial, deep, sinuses
What are the two portal systems in the body
hypothalamohypophyseal portal and hepatic portal
What does the hepatic portal system connect? Is it poor/rich in nutrients/toxins?
connects intestinal capillaries to liver. nutrient rich and toxin rich. liver will biotransform toxic substances into non toxic substances and/or can transport to the liver
What is the past of blood in the hepatic portal vein
capillaries in GI tract, hepatic portal vein, liver sinusoids (caps), hepatic veins
what is blood pressure
measure of force exerted by blood against the wall
what are korotkoff sounds and how are they used to measure blood pressure?
sounds produced by blood flowing through vessels while releasing pressure in a cuff. The first sound of crisp tapping is the cystolic and when the sound goes away that is the diastolic
laminar flow
streamlined flow in which interior of blood vessel is smooth and equal diameter. The outer layer moves slower than the inner layer
turbulent flow
interrupted flow in which fluid is passing a constriction, sharp turn or rough surface
how is rate of flow expressed?
volume/time (L/min)
How is flow effected if P1 increases, resistence decreases? flow=(P1-P2)/R
- flow up
2. flow up
How is viscosity, length, and diameter related to resistance =(128vl)/(piD^4)
v- proportional
l- proportional
D- inversely proportional
how does the cardiovascular increase flow during a work out
increase diameter
What blood component influences viscosity the most?
RBC count (hematocrit)
critical closing pressure
pressure at which a blood vessel collapses and blood flow stops
laplace’s law
F=diameter x pressure
vascular compliance
blood vessel gets bigger as pressure increases to accommodate.
does the venous system or arterial system have greater compliance
venous to act as blood reservoir
does cross sectional area increase or decrease as diameter decreases?
increase
does flow increase or decrease with a decrease in diameter
decrease
does pressure increase or decrease as diameter decreases
decrease
what affects capillary exchange
BP, capillary permeability, and osmosis
What two factors affect net filtration pressure (force responsible for moving fluids across capillary walls)
hydrostatic pressure and osmotic pressure
hydrostatic pressure
physical pressure of blood flowing through vessels or fluid in interstitial spaces
osmotic pressure
movement of solutes from an area of high concentration to low
what are the 4 fluid pressures
blood colloid osmotic pressure, blood hydrostatic pressure, interstitial colloid osmotic pressure, tissue hydrostatic pressure
what is net filtration pressure
net hydrostatic pressure-net osmotic pressure
What happens when capillaries become more permeable?
proteins can leak into interstitial fluid increasing ICOP. fluids move from capillaries into the interstitial fluid causing edema
what leads to edema
inflammatory chemicals increase permeability, hypertonic conditions of plasma proteins reduces BCOP , blockage of veins , blockage or removal of lymph vessels
venous tone
continual state of partial contraction
how does gravity affect blood pressure
in a standing position, hydrostatic pressure increases BP below heart and decreases above heart
what are the three types of control in terms of blood flow in tissues
local control, nervous system, and hormonal control
local control of blood flow in tissues
blood flow should be proportional to metabolic needs (capillary sphincter)
nervous system control of blood flow in tissues
responsible for routing blood flow and maintaining pressure
hormonal control of blood flow in tissues
sympathetic action potentials stimulate epinephrine ann norepinephrine
vasomotion
periodic contraction and relaxation of precapillary sphincters
what is the long term local control of blood flowo
capillaries become more dense in a region that regularly has increased metabolic rate
what happens in the adrenal medullary mechanism response to increase sympathetic stimulation?
adrenal medulla releases epi and norepi which mimics sympathetic stimulation of heart and blood vessels.
what different effects does epinephrine have
epi acts on alpha receptors causing vasoconstriction and beta receptors cause vasodilation
CNS ischemic response
elevation of BP in response to lack of blood flow to the medulla oblongata
long term regulation of blood pressure
renin-angiotensin-aldosterone mechanism, vasopresin, atrial natriuretic mechanism, fluid shift mechanism, stress-relaxation response
what is the renin angiotensin aldosterone mechanism
kidneys detect decreased BP, secrete renin, which converts angiotensis to angiotensin I, ACE converts angiotensin I to angiotensin II, angiotensin II is a vasoconstrictor and stimulates adrenal cortex to secrete aldosterone which causes reuptake of water and increases BP
how does ADH increase BP
increases reabsorbtion of water in the kidneys
atrial natriuretic hormone
released from cardiac muscle cells when BP increases, simulating an increase in urinary production causing a decrease in blood volume and pressure
fluid shift
movement of fluid from interstitial spaces into capillaries in response to low BP
stress relaxation response
adjustment of blood vessel smooth muscle response to changes in volume
effects of aging on the circulatory system
degenerative changes, increased resistance to flow
What are the three functions of the lymphatic system
fluid balance, fat absorption, defense
how does the lymphatic system control fluids
excess interstitial fluids enter lymphatic capillaries and become lymph
what is chyle
a fluid from the digestive tract that contains absorbed fat.
how does the lymphatic system aid in defense
the lymphatic system filters foreign substances from lymph in the lymph nodes
lymphedema
swelling that generally occurs in arms or legs caused by removal or damage to the lymph nodes which prevents lymph fluid from draining well
what is lymph made of
water + solutes
where do the solutes in lymph come from?
blood plasma and cells
What do lymphatic vessels do
carry lymph away from heart
are lymphatic capillaries more or less permeable than blood capillaries
more
what are lymph nodes
areas distributed along vessels that filter lymph
what are lymphatic ducts
ducts which drain tissue and move lymph into major veins
where does the right lymphatic duct drain lymph from
right side of head, right upper limb, right thorax
where does the thoracic duct drain lymph from
left side of head, left upper limb, left thorax and both legs
what fibers act as a filter net
fine collagen reticular fibers produced by reticular cells
what are three examples of encapsulated lymphatic tissue
lymph nodes, spleen, thymus
what are two examples of nonencapsulated lymphatic tissue
peyer’s patches, and tonsils
what is diffuse lymphatic tissue?
dispersed lymphocytes and macrophages. blends with other tissues
what are characteristics of lymphatic nodules
denser aggregations and numerous loose connective tissue
what is the purpose of tonisls
provide protection against foreign substances in the nasopharynx and oral cavity
what are the three types of tonsils
palatine, pharyngeal, lingual
what do lymph nodes do
remove substances by phagocytosis or stimulate lymphocytes to proliferate in germinal centers
what are the functions of the spleen
destroy defective RBC, detects and responds to foreign substances, limited reservoir for blood
what happens during slow flow in the spleen
there is no direct capillary connection between arteries and veins so blood percolates through splenic cords
what are splenic cords
reticular cells which produce reticular ribers
where does the thymus have the most amount of lymphocytes
cortex
what happens in the thymus
site of maturation for T cells which attack foreign substances
