KIN 101 FINAL EXAM FLASHCARDS

human physiology chapter 14-20

what is the endocardium?

• inner

• layer of endothelial cells

what is myocardium?

• middle

• cardiac muscle

what is the epicardium?

• outer

• external membrane

what ist he pericardium and what does it have?

• membranous sac that encases and protects the heart

• fused with diaphragm

• within the sac is pericardial fluid that lubricates and allows heart/myocardium to operate in a friction free environment

what is an echocardiogram?

provides information on size, shape of the heart; pumping strength and location of any damage

compare the thickness of ventricular walls on the left and right side

• right ventricle is thin. is a low pressure pump

• left ventricle is thick. stronger and holds more blood, a high pressure pump to go everywhere

what is the mitral valve?

another name for the bicuspid valve on the left side of the heart

what happens to valves during ventricular contraction?

• oxygenated blood flows out of the aortic valve and deoxygenated blood flows out of pulmonary valve

• AV valves (right and left) remain closed to prevent blood flow backward to the atria

• ventricles and muscles are contracted and tense

what are semilunar valves?

they open and close in response to pressure diffeences

what happens to valves during ventricular relaxation?

• oxygenated blood flows into the mitral/bicuspid valve and deoxygenated blood flows into tricuspid valves

• semilunar valves prevent blood that what entered the arteries from flowing back into ventricles during ventricular relaxation

• ventricles and muscles, they are relaxed and filling with blood

what is coronary circulation

• movement of blood through veins and arteries that supply blood to the myocardium (heart muscle)

• left coronary artery supplies blood to left side of heart

• right coronary artery - supplies blood mainly to right side but assists left with some parts.

what does the systemic circulation include?

• arteries: carry oxygenated blood from the left ventricle to the tissues

• veins: carry deoxygenated blood back to the right atrium

what does the pulmonary circulation include?

• blood vessels that go from right ventricle to the lungs - pulmonary arteries

• blood vessels that go from lungs to left atrium - pulmonary veins

what is Ohm’s Law?

flow = change of pressure / resistance

what is the physiological equation for measuring pressure and blood flow

• Q = MAP/TPR

  • Q: cardiac output - heart function

  • MAP: mean arterial pressure - blood pressure

  • TPR: total peripheral resistance - blood vessels and diameter

what is cardiac output?

• beats/min (heart rate, bpm) x mL(blood)/beat (stroke volume) = mL/min

  • heart rate x stroke volume

• amount of blood leaving the ventricles every minute

• L and R ventricle are usually matched

what is MAP (mean arterial pressure)?

outward pressure exerted on walls of blood vessels

what is total peripheral resistance?

total resistance of all blood vessels that are most impacted by arterioles

what is resistance?

the radius of the blood vessels determines resistance and is physiologically regulated

what is vasodilation in term of resistance

• radius increase

• resistance decreases

• blood flow increases

• pressure increases

what is vasoconstriction in term of resistance

• radius decreases

• resistance increases

• blood flow decreases

• pressure increases

what is the flow and resistance relationship and what is the forumla?

• resistance opposes flow

• resistance increases, flow decreases and vice versa

  • flow = 1/R

what are the 3 things that resistance depends on?

• length of the tube (L)

• radius of the tube ( R)

• viscosity (n) of the fluid

  • R increases as L and n increases and r decreases

explain the MAP equation? (not blood flow one)

MAP = Q x R

• MAP: net driving pressure = p1 - P2

• Q: flow due to central factors

• R: resistance due to peripheral factors (diameter or r^4)

what are desmoses

• strong proteins that surrounds sarcomeres and bind neighbouring sarcomeres

• allows force to be transferred

gap junctions

• provide electrical connection

• electrical signals are transmitted via these protein pores

what is the action potential of a cardiac contractile cell?

1. sodium channels open

2. sodium channels close

3. calcium channels open and then fast potassium channels close

4. calcium channels close and then slow potassium channels open

5. resting potential starts.

explain the refractory periods and summation in cardiac muscle

• theres forced generation in heart muscle and thats proportional to number of active crossbridges

• dependent on how much calcium is bound to troponin

explain the refractory periods and summation in skeletal muscle

• forced generating in this muscle is proportional to number and frequency of stimulation

• tetanus and fused tetanus build tension

• summation determines level of tension

explain the excitation-contraction coupling in cardiac muscle

1. action potential enters from adjacent cell

2. voltage gated Ca2+ channels open and Ca2+ enters the cell.

3. Ca2+ induces Ca2+ release from S through RyR

4. local release causes Ca2+ spark

5. summed Ca2+ sparks create a Ca2+ signal.

6. Ca2+ binds to troponin to initiate contract then relaxation occurs when Ca2+ unbinds from troponin

7. calcium is put back into SR

8. calcium is exchanged with sodium and sodium gradient is maintained with SPPs

how is cardiac muscle contraction graded?

• the contraction force is generated proportionally to the number of active crossbridges

• how much calcium is bound to troponin

• sarcomere length affects force of contraction

what are the action potentials in cardiac autorhythmic cells?

• If channels open

• Some calcium channels open then If channels close, then more calcium channels open. calcium increases (depolarization)

• at the peak, calcium channels close and pottasium channels open

• potassium channels close. potassium decreases (repolarization)

• If channels open up again

what are If channels?

• leaky channels that are specalized channels found in pacemaker

• more active in SA nodes than AV nodes

what is stroke volume (SV) and it’s equation?

• amount of blood pumped by one ventricle during a single contraction

• units = ml/beat

• EDV (end diastolic volume) - ESV (end systolic volume)

compare and contrast end diastolic volume and end systolic volume

• EDV is the volume of blood in a ventricle just at the end of a diastole (hearts relaxation phase)

• max amount of blood in ventricle jutst before a contraction

• ESV is the volume of blood left in a ventricle at the end of a systole, hearts contraction phase

• amount of blood remaining after ventricle has ejected blood → aorta or pulmonary aretery

what are the two divisions of Q (cardiac output)

• heart rate (bpm)

• stroke volume (mL/beat)

  • EDV - ESV

what are two ways stroke volume can increase

1. increase end diastolic volume (more blood in the ventricle to be ejected. preload

2. increase ejection fraction (more blood in the ventricle IS ejected.) contractility

what is pulse rate?

time between pressure waves in an artery

what is systole, diastole and pulse pressure?

• highest pressure in the ventricles and arteries

• lowest pressure in the ventricles and arteries

• difference between systolic and diastolic pressures (S-D)

explain the process of atrial diastole

• P. Eletrical event. Atrial depolarization happens and the blood is being pushed to the ventricles from atria

  • atrial contdaction begins in the latter part of the P wave

• QRS: mechanical event. blood incoming to ventricle and contract happens (ventricular depolarization)

• T: atria is filling with blood and ventricle is squeezing blood out (ventricle repolarization)

what is heart rate?

time between two R waves and two P waves

what is the main function of the P wave, Q wave and R wave.

• depolarizes SA node then the atria

• SA node depolarizes and then the bundle of branches located in the septum

• purkinje fibers depolarize and ensuring coordination contract of the heart muscle

what does a normal electrocardiogram

• waves: deflections above/below the baseline

• segments: sections of baseline between waves

• intervals : combos of waves and segments

what is ejection fraction and the equation

• percentage of EDV ejected with a single contraction

• as this percentage goes up, you remove more blood from the heart chambers

• EF = stroke volume/end diastolic volume x100

what are the two segments of an ECG

• P-R: time between end of atrial depolarization and onsent of ventricle depolarization.

• S-T: end of ventricular depolarization and onsent of ventricular repolarization

what are the two intervals of an ECG

• PR: time between onset of atrial depolarization and ventrical depolarization

• QT: onsent of ventricular depolarzation and end of repolarization

compare the parasympathetic and sympathetic control on heart rate (heart rate and beats, neutrotransmiter, ion permability)

• decreases heart rate, receives Ach on muscarinic receptors and potassium increases. farther apart heart beats

• increases heart rate, norepinephrine receives b1-adrenergic receptors in SA nodes and increases sodium and calcium permeability. closer together heartbeats

what is the parasympathetic system control on the heart (neurotransmitter, ion permeability, polarization effect and heart rate effect)

• releases ACh to muscarinic receptors on autorhythmic cells

• potassium leaves the cell and calcium comes into the cell

• cell hyperpolarizes and lowers depolarization rate

• lowers heart rate

what is the sympathetic system control on the heart (neurotransmitter, ion permeability, polarization effect and heart rate effect)

• released norepinephrine to b1-receptors on autorhythmic cells

• sodium and calcium increase and go into the cell

• the rate of depolarization increases

• heart rate increases

what are the mechanical events of a cardiac cycle?

1. late diastole (all chambers are relaxed and ventricles fill passively)

2. atrial systole (atrial contraction forces a small amount of additional blood into ventricles)

3. isovolumic ventricular contraction - pushes AV valves closed but doesn’t create enough pressure to open semilunar valves

4. ventricular ejection - as ventricular pressure rises above pressure in arteries, semilunar valves open and blood is ejected

5. isovolumic ventricular relaxation - as ventricles relax, pressure drops. blood flows back into cusps of semilunar valves and snaps them closed.

explain the pressure-volume changes during cardiac cycle

• A-B: ventricle is filling

• B-C: isovolumic contraction. mitral valve closes and aortic valve opens

• C-D: ejection of blood into aorta (C volume - D volume = stroke volume)

• D-A: isovolumic relaxation

changes in pressure during the cardiac cycle

• A: aortic valve opens and blood leaves

• B: aortic valve closes and most blood has been ejected out of the heart

• C: bicuspid (mitral) valve closes - ventricles are full of blood

• D: mitral valve opens

what are the 3 factors that effect stroke volume?

1. preload - more stretch = more force

2. contractility

3. afterload

what are the neurotransmitter and sympathetic activity affects on contractility?

• norepinephrine can enhance contractility which is a positive inotropic agent.

• increased symapthetic activtity = stronger contractions and higher stroke volume. this is caused by increased epinephrine which can increase cardiac contraction

• decreased symapthetic activity = weaker contractions and lower sv

what is contractility?

hearts ability to contract more forcefully

what is frank-starling law of the heart?

• stroke volume is proportional to EDV

• fill more = empty more

what happens if afterload is increased?

• heart must work harder to maintain stroke volume

• ventricles increase force contraction, metabolic demands increase (more oxygen and atp)

what is afterload?

• a factor that effects stroke volume

• combined load of end diastolic volume and arterial resistance during ventricular contraction (ventricular force must be greater than resistance

• blood must be pushed through semilunar valves → circulation

what are the sympathetic effects on contractility?

• increased sympa activity means increased epinephrine release

• increased strength of contraction

• increases rate of contraction and relaxation but a lower contraction duration

how can you increase the blood volume in ventricles?

• increase venous return

  • amount of blood that returns to the heart from venous circulation

what are the 3 things venous return is affected by?

1. skeletal muscle pump

2. respiratory pump

3. venous constriction

how does a skeletal muscle pump affect venous return?

• contraction of skeletal muscle compresses veins and pushes blood toward the heart

• enhanced venous return

how does a respiratory pump affect venous return?

• decreased pressure on the inferior vena cava allows more blood to be drawn in from the abdoment

• enhanced venous return

how does venous constriction affect venous return?

• increased sympathetic activity causes the veins to constrict

• decreased volume in the veins

• more blood is squeezed out of the veins

what are the 3 components of poiseuille’s law?

• length (L) of the tube/blood vessel

• viscosity (η) or thickness of the blood/fluid

• resistance is inversely proportional to blood vessel radius

what are arteries

• act as a pressure reservoir

• has thick layers of vascular smooth muscles

• lots of elastic and fibrous connective tissue

what are arterioles?

• a site of variable resistance

  • controls resistance

• it is apart of the microcirculation

• less elastic and more muscular

  • lots of blood can flow through them

what are metarterioles

• branches of artierles

• partially has smooth muscle

• has precapillary sphincters that open and close to direct blood flow into capillaries or venous circulation

what happens as resistance decreases in blood vessels?

• total crocss-sectional area increases

• radius of individual vessels increase by a factor of 4

which blood vessel has the greatest cross-sectional area?

capillaries

how does the total cross sectional area increase?

• they increase as the blood vessels branch

• each vessel is small but the combined diameter (where the blood can flow) is greater

where is the velocity of the blood slowest?

where the cross sectional area is the greatest

what is our volume reservoir in the body?

• our veins - they can stretch so at rest they hold the majority of the blood volume at rest

• redistribution of the blood volumes can occur as cardiac output increases and tissues demand more o2 and nutrients (during events like exercise)

what are venules?

• they receive blood from capillaries

• has little connective tissue

• thin exchange of epithelium

• has a convergent pattern of flow

what are veins?

• take blood back to the heart

• has thin walls of vascular smooth muscle

• has 1 way valves to prevent backward flow

• closer to the body surface

• less elastic tissue

what are capillary beds?

• a site of nutrient and gas exchange (needs more during exercise)

• can control amount of blood that goes through capillaries which depends on how active the tissue is

what is angiogensis?

• development of new blood vessels

• necessary for normal development

• enhances heart and skeletal muscle blood flow

how do we measure blood pressure outside the body?

MAP = diastolic pressure + 1/3(pulse pressure)

what are the 4 factors that influence mean arterial pressure?

• blood volume

• cardiac output (how effective the heart pump is)

• resistance of the system to blood flow

• redistribution of blood between arterial and venous blood vessels

explain how blood volume is a factor of mean arterial pressure.

• determined by fluid intake and fluid loss. fluid loss could be passive or regulated at kidneys

• increased b.v leads to increased b.p and can either trigger vasodilation, lowering cardiac output, increased urine flow

  • all can lead to lowering blood pressure to normal

• high b.v = high b.p

explain how cardiac output is a factor of mean arterial pressure.

determined by heart rate and stroke volume

explain how resistance of the system to blood flow is a factor of mean arterial pressure.

• determined by the diameter of the arterioles

  • in vasoconstriction, theres more resistance, increased pressure and decreased flow

  • in vasodilation, lower MAP, lower pressure and increased flow

what is hyperemia?

• locally mediated increase in blood flow

  • active: matches blood flow to increased metabolism (has local control factors. paracrines can cause vasodilation)

  • reactive: follows a period of decreased blood flow

what is arteriolar resistance?

• resistance to blood flow in arterioles

• influenced by local and systemic control mechanisms

  • sympathetic system affects the diameter of the blood vessels. (norepi on alpha and ephi on beta)

what is myogenic autoregulation?

• adjusts blood flow

• contracts to resist stretching. is automatic

explain how relative distrubution of blood between arteiral and venous blood vessels is a factor of mean arterial pressure.

• is determined by diameter of veins

• willing to stretch to hold blood at rest

what is plasma composed of?

water (92%), proteins (7%), ions, gases, organic molecules, vitamins (1%)

what are the cellular elements of blood?

• red blood cells (RBC): erythrocytes

• platelets (cell fragments): from megakaryocyte

• white blood cells (WBC): leukocytes

what are the functions of plasma?

• transports materials around the body

• solvent for cellular elements

what is colloid osmotic pressure

• force keeping water within the plasma and preventing it from leaking out of blood vessels

• proteins in the plasma (ex: albumin) create this pressure

what are albumins?

• major contributor to plasma colloid osmotic pressure

• transport FFAs

what do white blood cells include? (LMNOP)

• lymphocytes

• monocytes

• neutrophils

• eosinophils

• basophils

what are eosinophils?

produce toxic compounds directed against invading pathogens

what is a neutrophils?

mobile phagocyte that ingests foregin substances and pathogens

what are monocytes?

• phagocytes

• engulf and digest invaders (bacteria, dead, damaged cells)

what are lymphocytes?

they produce specific immune responses directed against invaders

what are hematocrit?

• percentage of total blood volume thats occupied by packaged rbc’s

• ratio of rbcs to plasma

• in males: 40-54%

• females: 37-47%

whats the significance of the hemoglobin value?

• reflects oxygen-carrying capacity of rbc’s

• males: 14-17. females: 12-16

how long do red blood cells live and why?

• 120 days

• has no nuclues

if fully saturated, how many mL of o2 can 1g of hemoglobin transport?

1.34 mL of O2