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Physiology Exam III
ACC Human Physiology Christensen Cardiovascular System
164
Health Care
10/23/2009

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Cards

Term
Name the 2 kinds of cardiac muscle cells
Definition
Conduction Cells 1% and Contraction Cells 99%
Term
What are the 5 parts of the conduction system?
Definition

1. Sinoatrial node

2. Atrioventricular node

3. Atrioventricular Bundle of His

4. Bundle branches

5. Conduction myofibers (purkinje)

Term
Which part of the conduction system leads to atrial depolarization and contraction?
Definition
Spread of depolarization from SA node to AV node
Term
Which part of hte conduction system leads most of ventricular depolarization and contraction?
Definition
Purkinje fibers
Term

Depolarization in the "pacemaker potential" consists of 2 phases; slow depolarization and fast depolarization.

 

What causes the slow depolarizatoin?

Definition
There is a special channel that responds to hyperpolarization; this channel is permeable to both Na+ and K+, but since the gradient is greater for Na+ entry, Na+ floods in and depolarization occurs
Term
What causes the fast depolarization?
Definition
When depolarization reaches treshold (-40 mV), voltage-gated Ca channels open and calcium floods in
Term

Repolarization of a contractile cardiac muscle cell consists of 3 phases: rapid initial repolarization slow (plateau) repolarization, and rapid final repolarization

 

What causes the rapid initial repolarization?

Definition
Initial rapid reversal in polarity (K+ out)
Term
What causes the slow (plateau) repolarization?
Definition
Slow Calcium in offsets Potassium moving out
Term
What causes the rapid final repolarization?
Definition
Rapid Potassium out (many voltage gated K+ channels open)
Term

True or False

Cardiac muscle cell contraction is similar to skeletal muscle cell contraction in that both involvte excitation/contraction coupling, cross bridge cycling between actin and myosin and the sliding filament mechanism?

Definition
TRUE
Term
Why is wave summation and tetany not possible in cardiac muscle like it is in skeletal muscle?
Definition
Because long refractory period occurs in conjuction with prolonged plateau phase; ensures alternate periods of contraction and relaxation which are essential for pumping blood
Term
What is the cardiac cycle?
Definition
Events that take place during one heart beat
Term

True or fasle

 

At no time during the cardiac cycle should all 4 chambers be in systole

Definition
true
Term

True or False

 

At no time during the cardiac cycle should all 4 chambers be in diastole?

Definition
False
Term
Explain isovolumetric ventricular contraction
Definition
Ventricular volume does not chanbe because semilunar and AV vavles are closed (no blood can go out); ventricular pressure has to exceed arterial pressure before semilunar valve opens and ventricular volume decreases due to ejection
Term
Explain isovolumetric ventricular relaxation
Definition
Ventricular volume does not change because the semilunar and AV valves are closed (no blood can come in); atrial pressure from fillasing has to exceed ventricular pressure before AV valve opens and ventricular volume increases due to filling
Term
Explain why the dicrotic notch occurs
Definition
There is an increase in arterial pressure when the semilunar valve closes
Term
What makes S1 the first heart sound?
Definition
AV vavles closing
Term
What makes S2 the second heart sound?
Definition
Semilunar valves closing
Term
Define cardiac output
Definition
the amount of blood ejected from the left ventricle in one minute
Term
Define stroke volume
Definition
the amount of blood ejected from the left ventricle in one beat
Term
What is the formula for determing CO?
Definition
CO = SV X HR
Term
What is the formula for determing SV?
Definition
SV = EDV - ESV
Term
Name 3 major ways stroke volume can be regulated?
Definition

1. EDV (preload)

2. afterload

3 contractility

Term
What is preload?
Definition
EDV (volume in ventricle at end of diastole
Term
What does the Frank Starling Mechanism state?
Definition
Incfreased EDV increases stretch which increases contraction strength which inreases SV
Term
Is the Frank-Starling mechanism an intrinsic or extrinsic control mechanism?
Definition
Intrinsic (it occurs even if the heart is removed from the body
Term
Name 4 ways to increase venous return and therefore increase EDV?
Definition

1. skeletal muscle pump and vein valves

2. respiratory activity

3. vasoconstriction by ANS

4. blood volume (controlled by hormones such as ADH, aldosterone, angiotensin II)

Term
What is the effect of excercise on SV? (consider venous return, EDV, and contraction strength)
Definition
skeletal muscle contraction squeezes on veins forcing blood toward heart and inreasing venous return. Frank - Starling mechanism: inreased EDV increases stretch which increases contraction strenght (contractility ) increases Stroke volume which decreases HR (heart does not have to work so hard)
Term
Describe the effect of respiratory activity on venous return?
Definition
diaphragm contraction forces diaphragm down which  increaes pressure in abdominal cavity and decreases pressure in thoracic cavity; blood flows from high to low pressure towards the heart.
Term
Increased peripheral resistance increases or decreases blood pressure?
Definition
increases
Term
Describe Afterload
Definition
Arterial pressure determines SV; blood can only be ejected from ventricle when ventricular pressure exceeds arterial pressure; ifarterial pressure is high, then SV will be decreased. So, arterial pressure presents an impedance to the ejection of blood from the ventricle (called an afterload)
Term
How does increased peripheral resistance effect Stroke Volume?
Definition
IPR increases BP wich increases afterload which decreases SV
Term
Explain the mechanism of how NE increase contractility?
Definition
NE activates a G protein mechanism that opens Calcium channels (more calcium in the sarcoplasmic reticulum enhances interaction between myosin and actin)
Term
What is the effect of slower HR on EDV and why does this occur?
Definition
Slower HR increases filling time for ventricle which increases EDV (preload) and increases stretch which increaes contractility and increases Stroke Volume
Term
Name 2 hormones that have an effect on HR. What are the effects and what glands secrete these hormones?
Definition

Epinephrine - produced by adrenal MEDULLA; increases HR like NE

 

Thyroid hormone - produced by thyroid gland; inreaess NE/E effects

Term
Name the 3 routes by which substances pass between the blood and interstitial fluid?
Definition

1. through clefts between endothelial cells

2. through fenestration (pores) in endothelial cells

3. through plasma membrane and cytoplasm of endothelial cells

Term
Definition
Term
List the 3 mechanisms by which substances pass between the blood and interstitial fluid? which is the most important?
Definition

1. Passive diffusion - MOST IMPORTANT; substances move from high concentration to low concentratoin

2. transcytosis - endothelial cells pick up droplets of fluid from one side of the plasma membrane (pinocytosis) and transport them via vesicles across the cell and discharge the fluid on the ot her side of exocytosis

3. filtration/reabsorption - capillaries filter plasma at the arteriole end of the capillary bed and reabsorb it at the venule end of the capillary bed.

Term
Definition
Term
Capillaries filter plasma at what end of the bed?
Definition
arteriole
Term
capillaries reabsorb plasma at what end of the capillary bed?
Definition
venule
Term
What is the "pushing out" force?
Definition
Filtration
Term
What is the "pulling in " force?
Definition
Reabsorption
Term
Specifically, filtration pressure is what kind of pressure and where does it come from?
Definition
filtration is HYDROSTATIC pressure and comes from the left ventricle
Term

What is the avg hydrostatic pressure at the arterial side of the capillary?

What is the avg at the venous side?

Definition

35 mgHg at arterial

20 mgHg at venous

Term
Reabsorption is what kind of pressure?
Definition
Osmotic
Term
Where does reabsorption / osmotic pressure come from?
Definition
Proteins taht are too large to be filtered stay in the capillaries; this high solute concentration in the capillaries draws the water back in at the venous end of the capillary bed.
Term
What "osmotically active" protein is found in plasma but not in interstitial fluid?
Definition
Albumin
Term
What is the function of albumin in the plasma?
Definition
Albumin is osmotically active; it is responsibel for the osmotic pressure that reabsorbs water at teh venule end of the capillary bed.
Term

What is the avg osmotic pressure at the arterial end?

What is the avg osmotic pressure at the venous end?

Definition
24 mm Hg for both
Term
Osmolarity of blood describes the WHAT  concentration?
Definition
solute
Term
As water is reabsorbed, solute follows. What is this phenomenon called?
Definition
solven drag
Term
Even through filtration pressure is higher than the reabsorption pressure, a lot more fluid doesn't leave the capillaries than reenters them. Why?
Definition
There is much more surface area at teh venule end of the capillary bed
Term
What results in more surface area at the venous end of the capillary bed than the arterial end?
Definition

1. more capillary branches at the venule end of the bed than at the arteriole end.

2. Capillaries are larger in diameter at the venule end of the bed than at the arteriole end.

Term
What is the effect on blood pressure if blood osmalarity is too high?
Definition
Increases blood pressure since too much ISF is reabsorbed - inreases blood volume, which increases blood pressure.
Term
What is the effect on blood pressure if blood osmalarity is too low?
Definition
Decreases blood pressure sine there is insufficient ISF reabsorbed which decreaes blood volume and thus decreases blood pressure
Term
Why is hemoglobin packaged in rbc instead of being free in the plasma?
Definition
Hemoglobin would inrease blood osmolarity if it was not packaged inside a rbc; this would inreasse blood pressure.
Term
consider true and shunt capillaries in capillar beds. Which one is referred to as the "straight shot" capillary?
Definition
Shunt capillaries
Term
If ANS cannot control capillary diamter (radius) then how does the body control blood flow through a cap. bed?
Definition
constrictoin/ dlation of precapillary sphincters regualted blood flow through capillary beds.
Term
Constriction of precapillary sphincters closes woff which type of cap. bed?
Definition
True cap. beds
Term
Describe a situation when true cap. beds might be bypassed?
Definition

1. digestive system capillaries during stress when sympathetic divsion overrides the parasympathetic divsion.

2. When the hypothalamus is inducing a fever, blood flow to the skin in restricted so that heat is not given off to the environment.

Term
Define blood pressure
Definition
Blood pressure is the force blood exerts agaisnt the blood vessel wall
Term
What are Korotkoff sounds?
Definition
sound of blood agaisnt arterial wall when vessel is partially occluded by BP cuff?
Term
Why is a BP cuff used to take BP?
Definition
to occlude an artery; initially cuff completely closes off vessel. but then pressure is released so that vessels open up (Korotkoff sounds are heart - begining sounds indicate systolic pressure) as one continues to release pressure in cuff and cuff pressure drops below diastolic pressure, sounds are no longer heart
Term
What happens to Korotkoff sounds when the cuff pressure drops below diastolic pressure?
Definition
they disappear
Term
What is the formula for determining pulse pressure?
Definition

PP = SP - DP

difference between systolic pressure and diastolic pressure

Term
Define Map
Definition
Mean Arterial Pressure - it is themean pressure you would obtain if you took measurements at several interavals trhoguhout a cardiac cyclike (like every 0.1 sec)
Term
What is the formula for MAP?
Definition
MAP - DP + 1/3 PP
Term
What would be an avg value for MAP in blood vessels at heart level?
Definition
90 mmHg
Term
Why does MAP have such a funky formula (geometric mean) why cant we just find the arithmetic mean?
Definition
At lower heart rates, MAP is not the avg between SP and DP - the curve is  spread out; the area under the curve is much greater for SP than DP; simply averaging the two would giv you a MAP that is too high
Term
At high heart rates what happens to MAP?
Definition
at high heart rates MAP is more closely approximated by the arithmetic mean of systolic and diastolic pressure because of the change in shape of the arterail pressure graph - in thsi case the graph becomes more NARROW
Term
What phase makes arteries expand and absorb some of the force of the ejected blood?
Definition
systole
Term
At what fase do arteriaes recoil exerting pressure on the blood?
Definition
Diastole
Term
What is the #1 way blood flow is controlled?
Definition
Blood vessel diameter (radius
Term
What does vasocontriction do to blood flow?
Definition
decreases blood flow
Term
What is the layer in the blood vessel controlled by ANS?
Definition
Tunica media
Term
What is peripheral resistance?
Definition
The opposition to blood flow resulting from friction developed as blood flows through a blood vessel. The smaller the blood vessel the higher the peripheral resistance
Term
Which vessels are the major resistance vessels?
Definition
arteries
Term
What does inreased peripheralresistance do to blood flow?
Definition
decreases blood flow
Term
What does inreased peripheral resistance do to stroke volume?
Definition
decreases stroke volume
Term
Name 3 factors regulating blood flow?
Definition

1. Vessel diameter (radius)

2. Blood viscosity

3. Blood vessel length

Term
Veins have a higher complicance than arteries. What does thi smean?
Definition
less muscualr walls than arteries; blood causes more distenstion (expansion) in veins than in arteries
Term
How much of the blood is foundin the veins?
Definition
About 2/3
Term
6 factors that effect venous return?
Definition

1. skeletal muscle pump

2. venous valves

3 respiratory activity

4. cardiac suction

5. vasoconstriction

6. blood volume - influenced by thirst center in hypothalamus, urine volume (hrmones ADH and aldosterone) and distribution of water between plasma and interstital fluid

Term
Explain how the skeletal muscle pump increases venous return.
Definition
skeletal muscle squeezes on veins during contraction, and due to vein valves. Blood is forced toward the heart (increases EDV or preload)
Term
How does cardiac suction increase venous return?
Definition
When the heart is in diastole pressure falls just below that in the veins so that blood moves toward the heart
Term
Name 2 hormones that decrease urine volume, increasing blood volume, Include the glands that produce them.
Definition

1. Aldosterone - produced by the adrenal cortex.

2. ADH produced by the hypothalamus and stored in the posterior pituitary.

Term
What is reactive hyperemia?
Definition
Increased metabolism increases oxygen need and increases buildup of waste therefore hypoxia and decrease in pH and vasodilation of blood vessels to inrease blood flow.
Term
Is reactive hyperemia an example of instrinsic or extrinsic regulation?
Definition
intrinsic
Term
Explain the action of intrinsic myogenic control of blood vessel diamter in organs such as the brain?
Definition
Occurs in some organs, such as the brain; a decrease in arterial pressure causes cerebral vessels to dilate so that adequate rates of blood flow can be maintanied despite the decreased pressure.
Term

Baroreceptor, Chemoreflex, Medullary Ischemic reflex?

Similar to golgi tendon organ?

Definition
Baroreflex
Term

Baroreceptor, Chemoreflex, Medullary Ischemic reflex?

Receptor in artery that monitors blood chemistry?

Definition
Chemoreflex
Term

Baroreceptor, Chemoreflex, Medullary Ischemic reflex?

Initiated by hypothalamus?

Definition
Medullary Ischemic Reflex
Term

Baroreceptor, Chemoreflex, Medullary Ischemic reflex?

Stretch receptor in artery?

Definition
Baroreflex
Term

Baroreceptor, Chemoreflex, Medullary Ischemic reflex?

Response to a drop in brain perfusion?

Definition
Medullary ischemic reflex
Term
What hormone is produced by juxtaglomerular apparatus in the kidney?
Definition
Angiotensin II
Term
What hormone is produced by heart; alosterone antagonist; increases sodium secretion in kidneys
Definition
Atrial Natrieretic peptide
Term
What hormone is another name is vasopressin?
Definition
ADH
Term
What hormone isproduced by the adrenal medulla?
Definition
epinephrine
Term
What hormone is produced by the adrenal cortex under the influence of the anterior pituitary gland?
Definition
alosterone
Term
What hormone is causes the kidneys to reabsorb salt ; water follow thus decreasing urine volune and increasing blood volume and increasing blood pressure?
Definition
Aldosterone
Term
What hormone isproduced by the hypothalamus; targets kidneys (increases reabsorption of water) turns off sweat glands to retain water, and results in vasoconstriction; all to increase blood volume and blood pressure?
Definition
ADH
Term
What hormone produceses by basophils; results in vasodilation as part of inflammatory resposne?
Definition
Histamine
Term
What hormone isconverted from renin; vasocontstriction, activates thirst center in hypothalamus increasse aldosterone production?
Definition
Angiotensin II
Term
Name the 2 primary determinants of MAP?
Definition

1. Cardiac Output

2. Total peripheral resistance.

 

MAP = CO X total peripheral resistance.

Term
What is Plasma
Definition
Liquid, cell free portion of the blood
Term
Serum
Definition
plasma that is depleted of its clotting factors
Term
What are 2 advantages to rbc's lacking a nucleus?
Definition

1. It gives them their shape (biconcave disc) which allows them to flex as they pass through capillaries and allows more surface area for gas exchange.

2. It allows them to carry more hemoglobin

Term
What is a disadvantage to rbc's lacking a nucleus?
Definition
They have no genetic material (DNA) to direct protein synthesis - they cannot make new proteins so they only last around 120 days
Term
What is an advantage to rbc's lacking mitochondria?
Definition
They do not use any oxygen they are carrying for their aerobic respiration (ATP production); mitochondria are the site for the electro transport system (where lots of ATP are produced)
Term
Describe the hemoglobin molecule
Definition
The hemoglobin molecule consists of 4 identical proteins called globins and four nonprotein pigments called hemes (each contains an iron atom)
Term
How many oxygen molecules can a hemoglobin molecule carry at once?
Definition
4; each iron binds to an oxygen molecule
Term
The kidneys have hormonal control over hematopoiesis through the production of what hormone?
Definition
Erythropoietin
Term
Specifically, what is the target of this hormone?
Definition
Bone marrow; it increases hematopoiesis
Term
What may account for a higher hematocrit in males?
Definition
Testosterone
Term
Why do rbcs die?
Definition
They have no DNA to direct protein synthesis, so nothing can be repaired in the cell; for example their plasma membranes get damaged due to friction against the walls of the small diameter capillaries
Term
How long do rbcs live?
Definition
approximately 120 days
Term
Where is the rbc graveyard?
Definition
spleen msotly and back up is the liver
Term
What is recycled after rbc destruction?
Definition
The iron in the hemoglobin
Term
What is leftover and how does the body rid itself of this compound?
Definition
Heme is degraded into a greenish yellow pigment (biliverdin) and then converted to bilirubin by the liver; bilirubin is a component of bile produced by the liver. Bile is used in the small intestine for the emulsification of fats, absorption of fat soluble vitamins etc. So it leaves the body in the feces.
Term
How can a baby get hemolytic disease of the newborn?
Definition
If the mother is Rh negative and the father is Rh positive there is a chance th ebaby will be Rh positive; Once sensitized from a previous pregnancy, the mother's Ab will cross the placenta and harm the baby
Term

How is hemolytic disease of the newborn prevented?

Rhogam (anti Rh antibodies) is administered to Rh negative mothers who have Rh positive partners, to block this reaction

Definition
Term
What are 2 important consequences of Transfusion reactions?
Definition

1. The donor's red blood cells are attacked by the recipients antibodies causing clumping or agglutination of rbcs. This leads to clogging of small blood vessels through the body.

2. Red blood cells are lysed releasing their hemoglobin in the blood stream (hemolysis). Circulating hemoglobin passes into kidney tubules and can block the tubules, causing renal shutdown. If complete renal failure occurs, the person may die

Term
What kind of anemia decreases hemoglobin concnetration due to a B12 deficiency?
Definition
pernicious anemia
Term
What kind of anemia results from insufficient numbers of rbcs due to blood loss?
Definition
Hemorrhagic anemia
Term
What kind of anemia is insufficient numbers of rbc's due to bone marrow cancer?
Definition
aplastic anemia
Term
What kind of anemia is a genetic disease which causes change in structure of hemoglobin molecule; causes a change in shape of rbc's?
Definition
Sickle cell anemia
Term
What kind of blood condition causes an excess of rbcs which increases blood viscosity?
Definition
polycythemia
Term
Explain the structure of a platelet?
Definition
Large cells called megakaryocytes shed fragments of their cytoplasm and each fragment becomes enclosed by a piece of the cell's membrane
Term
What do you call the mechanism of blood clotting?
Definition
hemostasis
Term
What is the normal platelet count?
Definition

300,000 mm cubed

Term
What organs remove old platelets from circulation?
Definition
Macrophages (wbc's) in the spleen and liver remove platelets after 4 - 10 days.
Term
List and explain the 4 major phases involved in hemostasis?
Definition

1. Vascular spasms - immediate response to blood vessel injury is vasoconstriction; fxn: reduce blood loss through hemorraging.

2. Platelet plug formation - plateles swell and form spiky processes; they also become " sticky" and adhere to the exposed area and to each other; the release of different chemiacls attracts great numbers of platelets to the area; platelet plugs are loosely knit.

3. Coagulation - blood becomes gel like; a plasma protein called prothrombin is converted into the enzyme thrombin; the enzyme thrombin catalyzes the joining of plasma fibrinogen molecules into a fibrin mesh, which traps blood cells and seals the hole.

4. Clot removal - clot is later dissolved.

Term
Describe the coagulation phase of hemostasis
Definition
Prothrombin is converted into the Enzyme thrombin. Thrombin catalyzes the joining of fibrinogen molecules into a mesh, which traps cells and seals the hole
Term
Which anticoagulant is found in spoiled sweet clover, and interferes with vitamin K function?
Definition
Coumadin
Term
which anticoagulant is produced by bacteria?
Definition
streptokinase
Term
Which anticoagulant is derived from wbc's found in beef lungs and hog intestines; activates antithrombin?
Definition
Heparin
Term
which anticoagulant is produced by leeches; blocks thrombin by binding to it?
Definition
hirudin
Term
Which anticoagulant prevents platelets from sticking together by inhibiting prostaglandin production?
Definition
aspirin
Term
How would you reverse the warfarin effect?
Definition
megadoses of Vit. K to overwhelm the drug
Term
Why is hemoglobin protein packaged in a rbc instead of being free in the plasma?
Definition
Free hemoglobin in the plasma would increase the osmolarity of the blood, increasing osmotic pressure (reabsorption pressure); this would cause high blood pressure and would also interfere with hydrostatic (filtration pressure)
Term

True or False

If a patient has A+ blood she is able to receive one transfusion of B+ blood without a transfusion reaction occurring?

Definition
False; she has preformed anti-B (antibody against B)
Term

True or False

If a patient has A- blood she is able to receive one transfusion of A+ blood without a transfusion reaction occurring?

Definition
True, one has to be sensitized to the Rh factor (no preformed Ab)
Term
What is autoregulation?
Definition
Blood flow to organs can be adjusted to meet metabolic needs
Term
continuous capillaries
Definition
Most common; abundant in skin and muscles; called continuous, but have small gaps or clefts between the endothelial cells (large enough to allow limited passage of fluids and small solutes)
Term
Fenestrated capillaries
Definition
found in small intestine, endocrine glands, kidneyds; endothelial cells have large fenestrations (pores) more permeable than continuous capillaries
Term
Sinusoid (leaky capillaries)
Definition
Found in liver, bone marrow, lymphoid tissues, some endocrine glands; these capillaries have large clefts and fenestrations; allow alrge molecules (proteins) and even blood cells to pass out of hte vessel; blood moves sluggishly thorugh sinusoids allowing blood to be processed and modified.
Term
What are the 3 routes that substances pass between blood and interstital fluid?
Definition

1. through intercellular clefts between endothelial cells

2. through fenestrations (pores)

3. through the endothelial cell plasma membrane and cytoplasm

Term
myogenic control - reactive hyperemia
Definition
Occurs in some organs, such as the brain; a decrease in arterial pressure causes cerebral vessels to dilate so that adequate reates of blood flow can be maintained despite the decreased pressure
Term
Tell me about Aldosterone
Definition
Produced by the adrenal cortex; causes kidney tubules cells to reabsorb Na+; sine water follows Na+, water is also reabsorbed and returned to the blood which increases blood volume and increases blood pressure; urine volume is subsequently decreased
Term
Atrial natriuretic peptide
Definition
Produced by atria; aldosterone antagonist; increases sodium secretion by kidneys so that salt is passed in the urine and water is not reabsorbed; increases urine volume and decreases blood volume, decreasing blood pressure
Term
Tell me about Histamine?
Definition
Produced by basophils and other whit blood cells; results in vasodilation (part of inflammatory response)
Term
Tell me about ADH / Vasopressin
Definition
Produced by the hypothalamus; stored and released by the posterior pituitary; increases blood pressure; 3 targets include (1) kidneys (causes them to reabsorb water and return it to the blood) 2. Sweat glands (turns them off) and 3. smooth muscle of tunica media which creates vasoconstriction.
Term
Tell me about Angiotensin II (AG-II)
Definition
Renin released from Juxtaglomerular cells of kidney acts on Angiotensinogen which turns into angiotensin I which turns into Angiotensin II; a potent vasoconstrictor, activates thirst center in hypothalamus and increases aldosterone production by adrenal cortex.
Term
What is the resistance equatio?
Definition

eight X viscosity X length

____________________

pie times radius to the fourth power

Term
What does flow equal?
Definition
change in pressure
Term
Blood flow to indiviaul tissues is regulated by selecteive vasoconstriction and vasodilation of which vessels?
Definition
Arterioles
Term
What is hyperemia? How does active hyperemia differ from reactive hyperemia?
Definition
Hyperemia is a localized region of increased blood flow. In active hyperemia, the increased blood flow is in response to an increase in metabolism. Reacive hypermia is an increase in flow that follows a period of decreased blood flow.
Term
Definition
Term
What is the PR segment?
Definition
AV nodal delay
Term
ST segment?
Definition
Time during which ventricles are contracting and emptying
Term
TP interval
Definition
Time during which ventricles are relaxing and filling
Term
Definition