Endocrine System

Question 1

What is homestasis

Answer 1

Counteract changes in internal environment dynamic equilibrium

Question 2

Examples of homeostasis

Answer 2

Cell - regulation ca2+ conc
Tissue - balance between cell proliferation and cell death
Organ - kidney regulates water and ion conc in blood
Organisms - constant body temp

Question 3

Hormone classifation

Answer 3

Peptide/polypeptide -largest group shirt chains of amino acids
Amines - synthesised from aromatic amino acids
Glycoproteins - large protein molecule - LH FSH TSH
Steroids - derived from cholesterol cortisol aldosterone and testosterone

Question 4

Major endocrine glands

Answer 4

Hypothalamus
Pituitary gland
Parathyroid
Thymus
Pancreas
Pancrea
Adrenal gland
Ovary and testes

Question 5

Hormone definition

Answer 5

Chemical signal produce by endocrine gland or tissue that travel ink bloodstream to cause an effect on other tissues

Question 6

Anterior pituitary gland hormones

Answer 6

Growth hormone prolactin
Trod simulating hormone
Corticotrophin
FSH
LH

Question 7

Growth hormone

Answer 7

Simulates growth and division of mst body cells
Secretion highest in childhooand adolescence
Release stimulated by GHRH and suppressed by GHRIH

Question 8

Prolactin

Answer 8

Prepares breast for lactation

Question 9

Thyroid stimulating hormone

Answer 9

Stimulated release by TRH from hypothalamus
Stimulates growth and activity of thyroid gland

Question 10

Corticotrophin

Answer 10

Corticotrophin releasing Norma one from hypothalamus promotes synthesis and release of ACTH by anterior pituitary gland
Stimulate growth and activity of adrenal cortex

Question 11

FSH and LH

Answer 11

On troll secretion of oestrogen and progesterone in menstrual cycle

Question 12

Posterior pituitary gland hormones

Answer 12

Oxytocin
Antidiuretic hormone

Question 13

Oxytocin

Answer 13

Releasing increasing amounts of oytocin into the blood responding to increases stimulation of sensory stretch receptors in cervix

Question 14

Antidiuretic ADH

Answer 14

Reduces urine output
Acts on DCT and collecting ducts of kidney increasing permeability to water
More reabsorption so less urine produced.

Question 15

Corticosteroids

Answer 15

Exert actions by regulating gene transcription
Readily diffuse across plasma membrane
Bind to glucorticord receptors
Receptors bond to dna sequence

Question 16

Aldosterone

Answer 16

Regulates gene transcription
Plays central role in regulation for plasma na+ k+ and arterial blood pressure e
In distal convoluted tubule and collecting docs here it promote expression of na+/k+ pump promoting reabsorption of na + and excretion of k+ thereby influencing water retention blood volume and therefore blood pressure

Question 17

RAAS

Answer 17

Cells in Afferent arterioles release renin in response to sympathetic smlation and low blood volume.
Renin converts angiotensinogen to angiotensinogen 1
Angiotensinogen converting enzyme converts angiotensinogen 1 into 2- a vasoconstrictor = high blood pressure
Angiotensin 2 raised blood potassium levels also stimulate adrenal gland secrete aldosterone which stimulates na and h2o re absorption in kidney increases blood volume and pressure.

1. VASOCONSTRICTION
2. INCREASES EXPRESSSION OF NA K PUMP EABSORPTION OF NA AND WATER INTO BLOOD
3. TRANSLOCATION OF AQUAPORIN CHANNELS ACIDS REABSORPTION OF WATER BACK NTO BLOOD

Question 18

Cortisol

Answer 18

Regulates gene transcription
Crease protein breakdown in muscle
Increase lipolysis in fat
Resistance in stress
Anti inflammatory effects
Depression of immune response

Question 19

Androgens

Answer 19

Inner layer f adrenal cortex eceretesandrogens
In males deydroepiandostereme is converted into testosterone in testes
In females adrenal androgens promote libido and converted to oestrogen

Question 20

Thryoid gland

Answer 20

Lies against and around front larynx and trachea
2 lobes joined by ishmus
Parathyroid and thyroid are distinct glands

Question 21

Thyroid hormone

Answer 21

Simulate metabolic rate by increases number and size of mitochondria

Question 22

Glucocorticoid actions on metabolism

Answer 22

Maintain energy balance and responding to stree
cortisol released in bloodstream and binds to receptors
In liver - stimulates gluconeogenesis and helps increase glucose levels
In muscles - reduces uptake of amino acids in muscle cells and increase release in muscle tissue which diverts amino acids to liver where they can be used gluconeogenesis
In fat theybreakdown into fatty acids and glycerol the fatty acids can be used as energy source

Question 23

Lipid soluble hormones bind to intracllular receptor

Answer 23

Easily pass through membrane
Once infused the cell they bind to intracellular receptors which are located in the cytoplasm or nucleus
This hormone receptor complex then act as as transcription receptor influencing gene expression and protein synthesis

Question 24

Water soluble hormones bind to cells surface receptors

Answer 24

Bind to surface receptors
Triggers series of intracellular responses
Often involves secondary messages like cAMP
Leads to various cellular responses

Question 25

Mechanisms of communication via hormones

Answer 25

Aautocrine
Paracrine
Endocrine
Neurone