Physiology

Question 1

Endocrine

Answer 1

ANP - Atrial Natriuretic Peptide. Response to increased atrial pressure
BNP - B-type Natriuretic Peptide. Response to overstretched ventricles

Question 2

Cardiac phases

Answer 2

Phase 0: Na influx into cardiac myocetes causes rapid depolarization - upstroke
Phase 1: Inactivation of fast Na with K efflux with a notch of initial repolarization
Phase 2: Ca influx through L-type ca channels the plateau phase
Phase 3: Inactivation of Ca channels with K efflux - rest of repolarization
Phase 4: Removal of excess Na and Ca with restoration of membrane potential

Question 3

Digoxin

Answer 3

Increasing the influx of calcium> increases the force of contraction

Question 4

Frank-Starling law

Answer 4

Cardiac output is proportional to the venous return
Contraction is proportional to the length of myocardial fiber
Greater blood influx equals greater stretching

Question 5

Cardiac Cycle

Answer 5

1st heart sound is closing of tricuspid and mitral valves
2nd heart sound - closure of pulmonary and aortic valves
3rd congestive heart sounds
4th hypertrophic ventricles

systole - between 1 and 2 contraction
diastole - between 2 and 1 relaxation

Question 6

PQRS

Answer 6

P - atrial depolarization
PR interval - from P wave to start of Q
QRS complex - ventricular depolarization
QT interval - beginning of the Q wave to the end of the T wave
ST segment - end of S wave to start of T
T wave - ventricular depolarization

Question 7

Heart rate control - sympathetic

Answer 7

T1-5, middle and inferior cervical ganglia

Increase heart rate - chronotropism - increase rate of phase 4
Increase conduction speed - dromotropism - decrease the PR interval
Increase force of contraction - iontropism - increase Ca influx in phase 2

Question 8

Heart rate control - para-sympathetic

Answer 8

Vagus nerve via its cardiac branches

Decreases heart rate - negative chronotropism
Decreases conduction velocity - negative dromotropism
Decreases force contraction - negative iontropism

Question 9

Baroreceptor mechanism

Answer 9

Carotid sinus (CN IX) and aortic arch (CN X) relay information to the brain stem

Drop in BP causes heart rate to increase

Question 10

Poiseullie’s law

Answer 10

Peripheral resistance is proportional to viscosity of blood and to the length of vessel
Inversely related proportinal to the radius of vessel (prime effector)

Question 11

La Place law

Answer 11

Pressure is related to the tension, size and shape of the vessel

Question 12

Pituitary Gland General

Answer 12

Master control gland under the influence it is under the control of the hypothalamus
Pars Intermedia - Melanin Stimulating Hormone

Question 13

Anterior Pituitary Lobe

Answer 13

Adenohypophysis
Secretes:
ACTH - Adrenocroticotrpin Hormone. Synthesis of cortisol in the adrenal cortex. excess in Cushings syndome
FSH - Follicle Stimulating Hormone. Ovaries produce estrogen. Sertoli cells for spermatogenesis
LH - Luteinizing hormone. Ovulation and the production of progesterone in ovary. Interstitial cells of Leydig in the testis produce testosterone
GH - bone and tissue growth via somatomedins A-C. excess seen in gigantism, decreased seen is pituitary dwarfism
TSH - Stimulates thyroid to produce thyroxin. Increased hyperthyroid, decreased hypothyroid
Prolactin - breast development and milk production. does not cause milk ejection

Question 14

Posterior Pituitary Lobe

Answer 14

Neurohypophysis
Hormones are stored in posterior lobe
Oxytocin - paraventricular nucleus in hypothalamus. Contraction of uterine muscle and myoepithelial cells.
ADH - supraoptic nucleus. Collecting ducts in the kidney. Released by water deprivation. Prevents water from being excreted

Question 15

Adrenal Cortex layers

Answer 15

Zona glomerulosa - Aldosterone
Zona Fasciculata - Cortisol
Zona Reticularis - Androstenedione

Question 16

Aldosterone

Answer 16

na reabsorption from distal convoluted tubule
water retention and an increase in blood pressure
Under the influence of renin from the kidney

Excess - Conn’s syndrome: high Na, hypertension and low K

Question 17

Cortisol

Answer 17

Glucocorticoid
Regulates metabolism of: fat, carbs, proteins
Maintains blood pressure via alpha 1 receptors
Decreases bone formation
Suppresses inflammation

Question 18

Androstenione

Answer 18

from Zona Reticularis

Gives estrogen, progesterone and testosterone

Question 19

Insulin

Answer 19

Found in the Islets of langerhans. Secreted by beta type.
Moves glucose from the blood to inside the cell
Synthesis of fat, glycogen and protein and cell uptake of K

Question 20

Glucagon

Answer 20

Secreted by alpha cells of pancreas
Causes the liver to convert glycogen to glucose - promotes glycogenolysis
Released when blood glucose levels are low

Question 21

Somatostatin

Answer 21

Secreted by delta cells of pancreas. or D cells in stomach and hypothalamus
inhibits: growth hormone, renin, insulin, GH, gastrin, glucagon

Question 22

Pepsinogen

Answer 22

from chief cells of stomach and in the presence of HCl becomes Pepsin

Question 23

HCl and intrnsic factor are secreted from___

Answer 23

Parietal cells

IF is required for absorption of B12

Question 24

Secretin

Answer 24

released by S cells in presence of chyme in the small intestine
Stimulates pancreatic acinar cells to release bicarbonate and water

Question 25

Bicarbonate

Answer 25

From pancreatic acinar cells in pancreas and brunner's glands in duodenum neutarlizes gastric acid. acts as buffer. protects duodenal wall. makes pH alkaline With secretin, decreases gastric motility

Question 26

Cholecystokinin

Answer 26

CCK From I cells in duodenum Contraction of gallbladder and relaxation fo sphincter of Oddi. Bile excretion Pancreas releases enzymes

Question 27

Exocrine cells of pancreas

Answer 27

trypsinogen chymotrypisn pancreatic amylase - digestion of starch to produce maltose lipase - fat into fatty acids and glycerol

Question 28

Endocrine cells of pancreas

Answer 28

glucagon - a Insulin - b Somatostatin - d

Question 29

Glucagon-like peptide 1

Answer 29

resembles glucagon. Secreted by the K cells in duodenum and jejunum Inhibits gastric emptying

Question 30

Ghrelin

Answer 30

P cells in the stomach | Increased before meals and decreased after aeting

Question 31

Motilin

Answer 31

Secreted by cells in duodenum Controls the cyclical movement of teh gut Increased in the fasting state

Question 32

Blood clotting pathway

Answer 32

``` vascular Factor XII activated by damaged tissue XII activates XI XI activates IX IX activates VIII and then X ``` tissue VII is activated by tissue damage activates X X converts prothrombin to thrombin. Converts fibrinogen to fibrin Forms the clot

Question 33

Immunoglobulin

Answer 33

IgG - most abundant, promotes phagocytosis, and cell lysis. passive immunity IgA - Saliva, tears and breast milk IgM - secreted early on, promotes agglutination, phagocytosis and cell lysis (opsonization) IgD - surface antibody on B lymphocytes IgE - important in parasitic infections and some allergic responses

Question 34

Cell mediated immunity

Answer 34

Relies on activated T lymphocytes Combats viral and fungal infections. Exposure to foreign antigen. cytotoxic T lymphocytes - lyse cells carrying antigens helper T lymphocytes - activated by macrophage - processed antigens. lymphokines are released: interleukin 2-6 and interferon Suppresor T lymphocytes - inhibit lymphocytic function

Question 35

Kidney endocrine

Answer 35

Erythropoietin: Produced by Interstitial cells in response to hypoxia, acts on myeloid tissue in bone marrow and increases production of red blood cells. Renin: Produced in the juxtaglomerular appartus in response to a drop in BP

Question 36

Renin-Angiotensin-Aldosterone

Answer 36

Drop in renal blood flow results in a decrease NaCl delivery to macula densa (located near afferent and efferent arterioles of glomerulus. sensitive to salt concentration Juxtaglomerular appartus is made up of a segment of distal convulted tubule. Renin is released from juxtaglomeular cells in the walls of afferent arteriole. causes angiotensin to be secreted by the liver and converted to angiotensin II in the lung by an enzyme