Endocrine System

Question 1

how do hormones travel from the hypothalamus to the anterior pituitary gland?

Answer 1

through the portal vessels

Question 2

how does the hypothalamus stimulate the posterior pituitary gland to release hormones?

Answer 2

through nerve impulses

Question 3

what hormones are released from the hypothalamus?

Answer 3

corticotrophin releasing hormone, gonadotrophin releasing hormone, thyrotrophin releasing hormone, growth hormone releasing hormone, somatostatin, prolactin releasing hormone, dopamine

Question 4

What hormones are released from the anterior pituitary gland?

Answer 4

adrenocorticotrophin hormone, growth hormone, FSH, LH, prolactin

Question 5

What hormones are released from the posterior pituitary gland?

Answer 5

Oxytocin, ADH

Question 6

What is goitre?

Answer 6

an iodine deficiency resulting in over stimulation of thyroid gland, get a swelling at neck

Question 7

What is the role of the thyroid hormone?

Answer 7

To form the basal metabolic rate, increase the metabolic rate and up-regulate adrenoreceptors

Question 8

What is the role of insulin?

Answer 8

to lower blood glucose levels, by increasing the uptake of glucose in muscle and adipocytes. Also increases glycogen and lipid formation and protein synthesis

Question 9

What stimulates insulin release and what inhibits it?

Answer 9

stimulates - high blood glucose levels, vagus nerve

inhibits - somatostatin, sympathetic NS and adrenaline

Question 10

What is the role of glucagon?

Answer 10

To increase blood glucose level, by causing glycogenolysis and gluconeogenesis

Question 11

What stimulates glucagon release and what inhibits it?

Answer 11

stimulates - low blood glucose levels, autonomic NS

inhibits - insulin, somatostatin

Question 12

What is diabetes mellitus?

Answer 12

Insulin deficient, cells unable to uptake glucose to lower blood glucose levels

Question 13

What does the medulla of the adrenal glands produce?

Answer 13

adrenaline

Question 14

what layers of the cortex of the adrenal glands produce what?

Answer 14

glomerulosa - mineralocorticoid, aldosterone
fasiculata - glucocorticoid, cortisol
reticularis - androgens

Question 15

Describe mechanical filtration in lymph nodes

Answer 15

high flow in vessels, gets into subscapular space and slows down, allows any particles in the fluid to settle on the cortex or the medullary cords

Question 16

Describe biological filtration in lymph nodes

Answer 16

the cortex contains t cells which can phagocytose the particles and remove infection. the medulla contains b cells for an antibody response

Question 17

what are the components involved in the immediate response to haemorrhage

Answer 17

vascular response, platelet response, coagulation, acts to prevents blood loss

Question 18

explain the vascular response in stopping blood loss

Answer 18

adrenaline released upon blood loss or trauma, causes vasoconstriction to increase blood pressure and stop blood flow through the artery to reduce loss.

Question 19

describe platelet response in stopping blood loss

Answer 19

platelets come into contact with collagen in blood vessel wall due to trauma, causes platelet aggregation. under positive feedback, release of thromboxane causes further aggregation, forms platelet plug to stop blood loss

Question 20

describe the common pathway in coagulation cascade

Answer 20

factor X activated in presence of Ca, phosphate and factor V. Factor Xa then converts prothrombin to thrombin, this activates fibrinogen to soluble to fibrin, also activates factor XIII. factor XIIIa then converts soluble fibrin to insoluble fibrin

Question 21

what is the difference between the extrinsic and the intrinsic pathway for coagulation

Answer 21

extrinsic - by tissue damage, initiates coagulation

intrinsic - by vascular damage, maintains the coagulation

Question 22

describe fibrinolysis

Answer 22

plasminogen converted to plasmin which converts fibrin to soluble fibrin fragments, when coagulation no longer required

Question 23

what is the aim of the short term physiological response to haemorrhage and how does the body achieve this?

Answer 23

restore blood pressure, by stimulating sympathetic NS, increases vasoconstriction, HR and stroke volume. also increases release of aldosterone and ADH for more fluid resoprtion

Question 24

what is the aim of the medium term physiological response to haemorrhage and how is this achieved?

Answer 24

restore blood fluid, increasing vasoconstriction causes the hydrostatic pressure to decrease, meaning less fluid is pushed out through the capillaries, and more fluid is reabsorbed. also aldosterone and ADH increased with more renin release

Question 25

what is the aim of the long term physiological response to haemorrhage and how is this achieved?

Answer 25

to restore blood constituents, erythropoietin released by kidney to stimulate RBC production, takes a few months

Question 26

what are the stages in response to stress?

Answer 26

alarm - fight or flight, resistance - adaptation, exhaustion

Question 27

describe the alarm stage in response to stress

Answer 27

sympathetic nervous system, increasing heart rate and stroke volume and vasoconstriction, stimulates glucagon for glucose release and adrenal medulla for adrenaline. adrenaline hormone increases the duration of this response and stimulates glucocorticoid production in adrenal cortex, cortisol. this is when stress is ongoing, increases gluconeogenesis and protein break down, immunosuppressant and anti-inflammatory

Question 28

why is it important to know if patients are on steroid therapy

Answer 28

this medication suppresses the immune system, therefore they might not be respond as well to treatment

Question 29

how can stress be used an analgesic

Answer 29

it releases endorphins which suppress nociception and pain pathway

Question 30

describe the resistance stage in stress response

Answer 30

patient's alarm response is sufficient to over come the stressor, either adapt to the stressor and become resistant or stressor removed.

Question 31

describe the exhaustion stage in stress response

Answer 31

unable to remove stressor, stress response is maintained, cortisol levels are high for a long period of time, ill due to immunosupressant and adrenal failure

Question 32

why is it important to control the levels of Ca in the body

Answer 32

for membrane potential, cardiac action potential and second messenger system - muscle contraction

Question 33

how does the parathyroid hormone control plasma Ca

Answer 33

it is released when plasma Ca levels are low, causes activation of vitamin K for Ca absorption in the gut, increased Ca reabsorption in the kidney and stimulates enzyme colleginerase for osteoclast activity - more bone resorption to release Ca into the plasma

Question 34

how does calcitonin control plasma Ca

Answer 34

released for prafollicular cells in response to high Ca levels, stimulates bone formation by osteoblasts, and more secretion of Ca in kidneys

Question 35

how does vitamin D control plasma Ca

Answer 35

kidney converts it to calcitroil which increases absorption of calcium in diet

Question 36

what diseases are caused by deficiency of vitamin D

Answer 36

weak bones and deformed formation in children - rickets or in adults just weak - osteomalacia

Question 37

why can fixed appliances not be given before the age of 12

Answer 37

because the skull is still growing until the age of 12 so fixed appliances may alter the shape or structure of the forming skull and facial bones

Question 38

what hormones are essential for normal growth

Answer 38

thyroid hormone, growth hormone and sex hormones

Question 39

describe how thyroid hormone effects growth

Answer 39

growth in foetus and infant, required for protein synthesis in brain and neurone development, indirect growth, stimulated by growth hormone

Question 40

what is the result of lack of thyroid hormone

Answer 40

severe mental impairments in infancy

Question 41

describe the actions of growth hormone

Answer 41

anti-insulin, increases blood glucose levels and prevents glucose uptake in cells, stimulates IGF for proliferation of cartilage at epiphyseal plates, glucose release from liver,

Question 42

what is the result of excess growth hormone in adults

Answer 42

acromegaly, cannot get longitudinal growth so increase in bulk, thicker bone in mandible and skull

Question 43

what is the role of sex hormones in growth

Answer 43

cause the pubertal growth spurt, increases proliferation of cartilage but also causes closure of growth plates, stimulated by growth hormone and IGF 1

Question 44

what hormone stunts growth

Answer 44

cortisol