Endocrine

Question 1

Why does the endocrine system take a while to work

Answer 1

• Don’t need rapid response
• Long term response
• Longer than nervous system because it’s transmitted via blood

Question 2

What are neurotransmitters

Answer 2

chemical messengers that work via the neurons for a short-term response

Question 3

Are neurotransmitters pre or post synaptic

Answer 3

The neurotransmitter is released in a regulated fashion from the presynaptic neuron into the synaptic cleft. The neurotransmitter binds to a post synaptic receptor and produces a response in the postsynaptic neuron

Question 4

How does a post-synaptic cell receive a signal

Answer 4

They have receptors that are designed to receive that specific signal so it doesn’t bind to random cells in the body

Question 5

What are hormones and what type of model do the cells have

Answer 5

chemical messengers secreted by endocrine glands or tissue that circulate in the blood. most are bound to proteins

they carry instructions from one part of the body to another

lock & key model for interaction with receptors

Question 6

what is a gland

Answer 6

a collection of epithelial cells that produce secretions
- endo and exo crine

Question 7

what is the diff between endocrine & exocrine glands

Answer 7

the difference is the location in which secretions are released

exocrine secretions are released into ducts e.g. tears, saliva, digestive enzymes in the pancreas

endocrine secretions are released into the blood and transported via the blood to target cells e.g. insulin & glucagon in pancreas, and 9 different hormones of the pituitary gland

Question 8

what is the process of a hormone circulating in the blood and binding to it’s receptor

Answer 8

1. hormone is secreted by endocrine glands or tissue & circulate in the blood
2. hormones carry instructions from one part of the body to another
3. hormone reacts with specific receptors on or inside the target cell
4. a cell response is activated & alters metabolic activities of many tissues & organs simultaneously

Question 9

how long can bound and unbound hormones remain in the circulation

Answer 9

unbound < 1hr, bound = days

Question 10

what are the structures of hormones [EXAM Q DONT NEED TO KNOW STRUCTURE]

Answer 10

1. lipid soluble = steroid, T3, T4
2. water soluble = lipid insoluble = amino acid derivatives, peptides, protein hormones

Question 11

what do hormones activate

Answer 11

a cellular response

Question 12

where are the receptors of lipid-soluble hormones

Answer 12

pass through lipid rich plasma membrane to bind with receptor in nucleus or cytoplasm

Question 13

how do water soluble hormones bind

Answer 13

second messenger system to get information to nucleus
they can only interact with the surface of the target cell
activates G protein –> amplifier enzyme –> adencylate cylcase –>

Question 14

how are endocrine glands controlled

Answer 14

• feedback mechanism (-ve & +ve)
• simple control: changes in comp of extracellular fluid e.g. blood glucose = insulin / glucagon
• complex control: several hormones e.g. stress = crh, acth, cortisol. ovarian cycle = GnRH, FSH, LH, estrogen, progesterone

Question 15

what is simple endocrine control

Answer 15

vital parameter –> sensor –> control centre –> effector –> response

blood gluc –> pancreatic beta cells –> pancreatic beta-cells again –> insulin –> cells in liver etc. take & store glucose = normal levels of blood sugar –> pancreatic cells will stop producing insulin

Question 16

what is complex endocrine control

Answer 16

vital parameter –> sensor –> control centre –> MULTIPLE EFFECTORS –> response

stress –> hypothalamus –> hypothalamus –> CRH –> ACTH in pituitary –> cortisol (adrenal) –> cortisol targets body cells

Question 17

describe feedback control of endocrine secretion at hypothalamus

Answer 17

diagram

Question 18

don’t need to know names of hypothalamus anatomy but what their functions are

Question 19

what is the exception to the hypothalamus releasing hormones that act on the anterior or posterior pituitary

Answer 19

directly stimulates release of 2 hormones (epi & norepi) from adrenal glands

Question 20

what are the ways the hypothalamus controls hormones

Answer 20

1. synthesises & secretes 7 regulatory hormones
2. synthesises ADH (antidiuretic) & OXT (oxytocin)
3. directly stimulates release of epinephrine & norepinephrine

Question 21

what 7 regulatory hormones does the hypothalamus synthesize & secrete & what is their purpose

Answer 21

GHRH = growth hormone releasing hormone
GHIH = growth hormone inhibiting hormone
PRF = prolactin releasing factor
PIF = prolactin inhibiting factor
TRH = thyrotropin releasing hormone
GnRH = gonadotropin releasing hormone
CRH = corticotropin releasing hormone

Question 22

the hypothalamus stimulates the adenohypophysis to secrete which 6 hormones

Answer 22

GH: stimulates liver, cartilage, bone, muscle etc. to synthesise and secrete insulin like growth factors

PRL: prolactin for milk secretion by mammary glands

TSH: thyroid stimulating hormone

FSH: follicle stimulating hormone for secretion of estrogen from ovaries in women & sperm from testes in men

LH: lutenizing hormone for estrogen & progesterone during ovulation & testosterone from testes

ACTH: adrenocorticotropic hormone for secretion of glucocorticoids (mainly cortisol) by adrenal cortex

MSH: melanocyte stimulating hormone, exact purpose unknown but causes skin darkening

Question 23

learn general details of the hormones

Question 24

what is the purpose of oxytocin apart from emotions

Answer 24

contractions during labour

Question 25

what are the effects of a pituitary tumour on GH

Answer 25

tumor has more cells so more growth hormone is being secreted at excessive levels: 1. pituitary gigantism 2. acromegaly: excess growth hormones after growth plates have closed

Question 26

where is the thyroid gland and what is made of

Answer 26

made of follicles that secrete thyroid hormones

Question 27

what are the thyroid gland hormones & their difference

Answer 27

calcitonin: secreted by parafollicular/C cells for homeostasis of calcium T3: pre-cursor T4: active form difference: iodine group (extra in T4)

Question 28

what is the purpose of thyroid hormones

Answer 28

- increase metabolic rate - increase protein synthesis via O2 consumption and ATP production - inc carb & lipid metabolism

Question 29

how is the thyroid hormone controlled [EXAM Q ON INPUTS, OUTPUTS, CONTROLLERS]

Answer 29

negative feedback loop 1. TRH via hypothalamus regulatory hormone 2. TSH via anterior pituitary hormone 3. T3 & T4 4. effector cells

Question 30

what is hypothyroidism [EXAM Q] name causes & clincial features

Answer 30

causes = autoimmune e.g. hashimoto's or iodine deficiency clinical features = incr TSH, decr metabolic rate, muscle weakness, CNS dysfunction, goitre

Question 31

what is hyperthyroidism & it's causes & distinguishing clinical features [EXAM Q]

Answer 31

excess T3 & T4 causes = Grave's autoimmune disease (most common), metastatic thyroid tumour, no -ve feedback clinical features = incr metabolic rate, excessive sweating, weight loss, nervousness, hyperactivity, incr systolic pressure, decr diastolic pressure, incr peripheral vasodilation

Question 32

CT of normal vs enlarged thyroid gland

Question 33

what is the purpose of the parathyroid glands & what are it's pathologies

Answer 33

malfunction = parathyroid adenoma

Question 34

what are calcium homeostasis abnormalities

Answer 34

hypoparathyroidism hyperparathyroidism

Question 35

how are pancreatic hormones controlled

Answer 35

when blood glucose levels increase, beta cells secrete insulin to transport it across plasma membranes when blood glucose levels decrease, alpha cells release glucagon to stimulate glucose release from glycogen stores in the liver

Question 36

why do you need to fast before a blood test

Question 37

how is excess glucose stored

Answer 37

as glycogen in the liver

Question 38

what are the abnormal functions of pancreas

Answer 38

diabetes: 1. type 1: - insulin dependent, autoimmune disorder - inadequate insulin production 2. type 2: - reduced insulin sensitivity, or insulin resistant -caused by obesity, age, family history

Question 39

what are clincial signs of type I diabetes

Answer 39

hyperglycemic excessive hunger (polyphagia) incr glusone in urine dehydration (polydipsia) decr blood volume & pressure coma & death

Question 40

what are clinical signs of type II diabetes

Answer 40

(same as type 1) hyperglycemic excessive hunger (polyphagia) incr glusone in urine dehydration (polydipsia) decr blood volume & pressure coma & death

Question 41

what are the adrenal glands & another term for them

Answer 41

suprarenal

Question 42

what are the parts of the adrenal glands & their functions

Question 43

what are the disorders of adrenal function

Answer 43

medulla: - formed from neuroendocrine cells, so associated with nervous system - pheochromocytoma = neuroendocrine tumour that can be fatal if untreated - addison's disease cortex: - cushing's syndrome - cushing's disease - high levels of cortisol in general = toxic to cells, disturbance of cells and homeostasis

Question 44

what is leptin

Answer 44

peptide hormone that produces adipocytes signals size of fat stores regulates energy expenditure by inhibiting hunger

Question 45

what are clinical signs of leptin deficiency

Answer 45

- abnormal eating behaviours - delayed puberty

Question 46

what is another name for the pituitary gland

Answer 46

hypophysis

Question 47

what bone does they hypophysis lie with in

Answer 47

sella turcica

Question 48

how are anterior pituitary hormones transported

Answer 48

via systemic blood supply to target cells

Question 49

what is addison's disease, it's causes & symptoms

Answer 49

insufficient amounts of adrenal cortex hormones, particularly cortisol caused by stress symptoms are fatigue, muscle weakness, weight loss, vomiting, diarrhoea

Question 50

what is cushing's disease, it's causes

Answer 50

tumour in pituitary gland that stimulates excessive ACTH release = excess glucocorticoids from adrenal gland = mainly cortisol

Question 51

what is cushing's syndrome, it's causes

Answer 51

exposure to excessive levels of cortisol via excess steroid medication or excess production of an endogenous hormone

Question 52

what are symptoms of cushings

Answer 52

rapid weight gain, sweating, hirsutism, insomnia, reduced libido, infertility

Question 53

what is hypoparathyroidism, causes & symptoms

Answer 53

decr parathyroid hormone = decreased Ca in blood = hypocalcemia causes are intestinal malabsorption of Ca kidney disease causing decreased Ca absorption decr mobilisation of Ca from bone symptoms are neurological e.g. neuromuscular excitability

Question 54

what is hyperparathyroidism, causes & symptoms

Answer 54

overactivity of the parathyroid gland = over secretion of PTH = high sustained Ca = hypercalcemic causes are PT tumours, or response to low Ca and it's causes

Question 55

what is cretinism

Answer 55

congenital hypothyroidism that's left untreated and results in severe physical & mental stunting