pituitary gland

Question 1

what is the pituitary gland also known as ?

Answer 1

hypophysis

Question 2

what does this gland act as ?

Answer 2

the chemical co-ordinator of most of the endocrine glands

know as master gland

Question 3

where is the pituitary gland situated ?

Answer 3

attached to the hypothalamus at the base of the brain by a short stalk

in the small bone cavity in the floor of the cranium ( turkish saddle )

Question 4

how is the pituitary made up?

Answer 4

two glands

large anterior lobe

small posterior lobe

Question 5

how is the large posterior lobe made up ?

Answer 5

purely glandular

made up of secretory cells

Question 6

how is the small posterior lobe made up ?

Answer 6

it develops from the base of the brain

made mainly of neurons

Question 7

what are the hormones that the anterior lobe secretes ?

Answer 7

STH

TSH

ACTH

FSH

LH

ICSH

prolactin

Question 8

growth hormone / STH

Answer 8

somatrophic hormone

promotes skeletal/ muscular growth

( stimulates the synthesis of proteins )

Question 9

TSH/ thyroid stimulating hormone

Answer 9

TSH stimulates the thyroid gland to secrete thyroxin

Question 10

ACTH/ adrenocorticotrophic hormone

Answer 10

ACTH stimulates the adrenal cortex to secrete

cortisone + aldosterone

Question 11

FSH/ follicle stimulating hormone

Answer 11

in females - stimulates oogenesis in ovaries
(formation of eggs in the ova)

in males - stimulates spermatogenesis in testes
(sperm formation)

Question 12

LH/ lutenizing hormone

Answer 12

in females - stimulates ovulation

release of an egg from ovary

Question 13

ICSH/ interstitial cell stimulating hormone

Answer 13

chemically similar to LH

produced in males to stimulate testes to secrete testosterone

Question 14

prolactin

Answer 14

stimulates the production of milk

in the female mammary glands after the birth of the baby as long as baby continues to suckle

responsible for maternal instinct

Question 15

what are the growth disorders?

Answer 15

hypersecretion

hyposecretion

Question 16

what is hypersecretion of growth hormone ?

Answer 16

overdevelopment of skeleton (tall stature)

condition: gigantism

caused by tumor in the pituitary gland
extremely rare

Question 17

what is different about hypersecretion in adults ?

Answer 17

enlarged hands, jawbone + brows
(terminal skeletal structure)

condition: acromegaly

in adults, bones only thicken
as growth points in the long bones are no longer active

Question 18

what is hyposecretion of growth hormone ?

Answer 18

underdevelopment of the skeleton (short stature)

condition: pituitary dwarfism

causes by disease in the anterior lobe of pituitary

Question 19

what are the effects of hyposecretion?

Answer 19

height is reduced

body proportions are normal

not mentally retarded

sexually immature

Question 20

how can hyposecretion be treated ?

Answer 20

can be treated by injections of synthetic growth hormone (STH)

produced by genetically engineered bacteria

Question 21

what are the two types of dwarfism?

Answer 21

pituitary dwarfism-
lack of growth hormone
perfectly proportion
small, midge

defective gene-
a dwarf looks malformed
arms/legs are short vs torso/head normal size

Question 22

what happens in the posterior lobe ?

Answer 22

osmoreceptors in the hypothalamus detect an increase in osmolarity of blood

nerve impulses stimulate the posterior lobe to release ADH

Question 23

what is the role of ADH in the posterior lobe ?

Answer 23

help to conserve water if body is dehydrated

by causing more water to be reabsorbed back into the blood from the collecting ducts of the kidneys
(less water lost in urine)

Question 24

what are the occurring disorders related to the pituitary lobe ?

Answer 24

diabetes insipidus -
lack of ADH secretion

condition characterised by the loss of large quantities of dilute urine

5-10L per day