Endocrine system

Question 1

Major endocrine glands (8)

Answer 1

Pineal
Pituitary
Thyroid
Thymus
Adrenal
Pancreas
Ovary 
Testes

Question 2

Functions of the endocrine system (4)

Answer 2

1. Regulates metabolism
2. Regulates fluid and electrolytes
3. Counteracts the effects of stress
4. Regulates growth

Question 3

Gland secretion patterns

Answer 3

Endocrine - released into bloodstream
Autocrine - acts on same cell that releases it
Paracrine - released into surrounding tissue

Question 4

Amines

Answer 4

Catacholamines and thyroid hormones

Question 5

Proteins and peptides

Answer 5

Insulin, calcitonin, oxytocin, GH

Question 6

Steroid

Answer 6

Mineralocorticoids, glucocorticoids and gonadocorticoids

Lipid-based so can diffuse into cells

Question 7

Hormones are secreted in response to…

Answer 7

Level of some constituent of the blood
Other hormones
Stimulation of nerves

Question 8

Patterns of interaction

Answer 8

Antagonistic - stop an effect
Permissive - allow things to happen
Synergistic - more than the sum of their parts

Question 9

Hypothalamus

Answer 9

Interface between neuronal and hormonal activity
Secretes regulatory hormones which control hormone release from pituitary gland
Neural control over endocrine cells of adrenal gland

Question 10

Posterior pituitary

Answer 10

Secretes ADH and oxytocin

Question 11

Anterior pituitary

Answer 11

Secretes releasing and inhibitory hormones

e.g. TSH, GH, FSH, LH, growth hormone, prolactin

Question 12

3 levels of the adrenal cortex

Answer 12

Zona glomerulosa produces mineralocorticoids (kidney and fluid)
Zona fasciculata produces glucocorticoids (stress)
Zona reticularis produces gonadocorticoids

Question 13

Adrenal medulla

Answer 13

Adrenaline and noradrenaline are released after firing of splancnic nerve from hypothalamus

Question 14

Adrenal disease (3)

Answer 14

Cushings - excessive ACTH
Hypoadrenocorticism/Addison’s disease
Pheochromecytoma - tumour of chromaffin cells

Question 15

Hormone releasing cells in the pancreas

Answer 15

Alpha cells secrete glucagon
Beta cells produce insulin
Gamma cells produce pancreatic peptide
Delta cells produce somatostatin

Question 16

When blood glucose increases…

Answer 16

1. Insulin is secreted
2. Binds to receptor outside cell
3. Receptor and insulin are endocytosed
4. Glucose transport proteins are inserted into the cell membrane
5. Glucose is internalised and blood glucose drops

Question 17

When blood glucose decreases…

Answer 17

1. Glucagon is secreted
2. Stimulates breakdown of glycogen in liver and skeletal muscle
3. Glycogen becomes glucose

Question 18

Type I diabetes

Answer 18

Pancreas doesn’t secrete insulin well

Question 19

Type II diabetes

Answer 19

Problems with insulin receptors

Question 20

Two forms of thyroid hormone

Answer 20

T3 - tri-odo thyroxine

T4 - thyroxine

Question 21

Physiological effects of thyroid hormone (6)

Answer 21

Bind to mitochondria to increase ATP production
Activate genes that stimulate energy use
Increase metabolic rate
Lipolysis
Protein synthesis
Enhance effects of some neurotransmitters

Question 22

Regulation of thyroid hormones (negative feedback loop)

Answer 22

1. Hypothalamus releases TRH
2. Pituitary releases TSH
3. Thyroid gland produces T3 and T4
4. Blood levels of T3 and T4 are normal
5. T3 and T4 bind to proteins
6. As levels drop, binding proteins release T3 and T4
7. As levels increase again, hypothalamus inhibits pituitary

Question 23

Treatment for hypothyroidism

Answer 23

HRT - l-thyroxine

Adverse effects - abnormal heart rhythms, osteoporosis