Endocrine 2

Question 1

Describe the Adrenal Glands

Answer 1

found superior to each kidney in the retroperitoneal space, composed of adrenal cortex - produces steroid hormones that affect homeostasis, adrenal medulla - norepinephrine, epinephrine dopamine - these cause ‘fight or flight’ response to physical or emotional stress

Question 2

Describe the roles of norepinephrine and epinephrine

Answer 2

increases heart rate - increases cardiac output and b.p.
increase blood flow - to heart, liver, skeletal muscles and adipose tissue
dilate airways - and increase blood glucose levels

Question 3

Describe the Thymus Gland

Answer 3

found behind the sternum, secretes thymosin - important in immunity

Question 4

Describe the Pineal Gland

Answer 4

found in the brain, thought to contribute to setting the body’s biological clock - retina perceives less light stimulating the pineal gland to secrete melatonin - which promotes sleepiness

Question 5

Describe the gonads - the ovaries

Answer 5

produce oestrogen and progesterone and are responsible for secondary sex characteristics - enlargement of breasts and widening of hips at puberty, ovaries produce inhibin - reduces secretion of FSH, during pregnancy = relaxin secreted - helps maintain suitable uterine environment

Question 6

Describe the gonads - the testes

Answer 6

they secrete testosterone - enables the descent of the testes before birth, they regulate sperm production, stimulates secondary sex characteristics - such as beard growth and deepening of the voice

Question 7

Dysfunction of the Endocrine System can be widespread and can be caused by …

Answer 7

Hyposecretion or Hypersecretion of hormone

Faulty/inaequate numbers of hormone receptors

Question 8

DISORDER - POSTERIOR PITUITARY GLAND
diabetes insipidus (DI)

Answer 8

defects in ADH receptors/inability to secrete ADH
CAUSES - traumatic damage to posterior pituitary/hypothalamus, non-functional receptors, kidney damage
EFFECTS - excretion of large volumes of urine with resulting dehydration and thirst, death may occur in sufferer of DI if without water for a day or so

Question 9

DISORDER - PANCREATIC ISLET DISORDERS diabetes mellitus

Answer 9

Type 1 diabetes = insulin level low because person’s immune system destroys the pancreatic beta cells,
Type 2 diabetes = non-insulin dependent diabetes mellitus (NIDDM) more common, 90% of all cases
CAUSES - insulin is unavailable to aid transport of glucose into body cells = blood glucose level is high and glucose ‘spills’ into urine (glycosuria)
EFFECTS - excessive urine production due to an inability of the kidneys to reabsorb water, excessive thirst and excessive eating

Question 10

DISORDER - THYROID GLAND congenital hypothyroidism

Answer 10

hypo secretion of thyroid hormones (present at birth) can cause severe mental retardation and stunted bone growth
hypothyroidism during the adult years produces myxedema sluggishness/weight gain
CONDITION - Hyperthyroidism is Grave’s Disease
REASON - thyroid gland continually over production of thyroid hormones
EFFECTS - an enlarged thyroid and oedema behind the eyes, - called exophthalmos which causes the eyes to protrude

Question 11

DISORDER - PARATHYROID GLAND hypoparathyroidism

Answer 11

too little parathyroid hormone = deficiency of Ca2
CAUSE - accidental damage to parathyroid glands or to their blood supply during thyroidectomy surgery
EFFECTS - abdominal cramps, brittle nails, dry hair and skin

Question 12

DISORDER - PARATHYROID GLAND hyperparathyroidism

Answer 12

overproduction of parathyroid hormone = blood levels of Ca2 raised
CAUSE - tumour of one of the parathyroid glands
EFFECTS - soft and easily fractured bones, formation of kidney stones, personality changes and lethargy

Question 13

DISORDER - ADRENAL GLAND cushing’s syndrome

Answer 13

hyper secretion of cortisol by the adrenal cortex
CAUSES - adrenal gland tumour or a tumour elsewhere that secrets ACTH - stimulates excessive secretion of cortisol
EFFECTS - redistribution of body fat, resulting in a rounded, flushed ‘moon face’

Question 14

DISORDER - ADRENAL GLAND addison’s disease

Answer 14

hypo secretion of glucocorticoids and aldosterone
CAUSES - problems with adrenal gland which affects secretion of glucocorticoids and aldosterone
EFFECTS - abdominal pain/weakness can progress to very low blood pressure and coma

Question 15

DISORDER - PITUITARY GLAND giantism

Answer 15

hyper secretion of HGH during childhood causes an abnormal increase in the length of long bones

Question 16

DISORDER - PITUITARY GLAND pituitary dwarfism

Answer 16

hypo secretion of HGH in childhood slows bone growth and the epiphyseal plates close before normal height is reached

Question 17

DISORDER - PITUITARY GLAND acromegaly

Answer 17

hyper secretion of HGH adulthood - epiphyseal plates are already closed, the bones of the hands, feet, cheeks and jaws thicken and the nose enlarges.