Pituitary Gland

Question 1

What is the pituitary gland?

Answer 1

“Master” endocrine glands because it secretes several hormones that control other endocrine glands

Question 2

Where is the pituitary gland?

Answer 2

Small region of the brain below the thalamus

Lies in the hypophyseal fossa of the sella turcica of the sphenoid bone

Question 3

What does the pituitary gland link?

Answer 3

The nervous and endocrine system

Question 4

How many cells does the hypothalamus synthesise?

Answer 4

At least 9 different hormones

Question 5

How many cells does the pituitary gland synthesise?

Answer 5

Seven

Question 6

What is the shape and size of the pituitary?

Answer 6

Pea shaped structure

1-1.5cm

Question 7

What does the pituitary gland attach to?

Answer 7

The hypothalamus by a stalk (infundibulum)

Question 8

What are the two portions of the pituitary gland?

Answer 8

Anterior pituitary gland

Posterior pituitary gland

Question 9

What are the two parts of the anterior pituitary gland in an adult?

Answer 9

Pars distalis (larger portion)
Pars tuberalis (forms sheath around infundibulum)

Question 10

What is the posterior pituitary composed of?

Answer 10

Neural tissue

Question 11

What does the posterior pituitary consist of?

Answer 11

Pars nervosa

Infundibulum

Question 12

What’s the third part of the pituitary gland?

Answer 12

Pars Intermedia (only in fetal development)

Question 13

What are the six major anterior pituitary hormones?

Answer 13

GH (Somatotropin)
TSH (Thyroid stimulating hormone)
ACTH (Adrenocorticotropic hormone)
FSH (Follicle stimulating hormone)
LH (Luteinising hormone)
Prolactin

Question 14

What is GH (Somatotropin) involved in?

Answer 14

Insulin-like growth factor (IGF-1) & metabolic effects

Question 15

What is TSH (Thyroid stimulating hormone) involved in?

Answer 15

Secretion of thyroid hormones

Question 16

What is ACTH (Adrenocorticotropic hormone) involved in?

Answer 16

Cortisol from adrenal cortex

Question 17

What is FSH (Follicle stimulating hormone) involved in?

Answer 17

Inhibin from Sertoli cells, Corpus luteum

Oestrogen from granulosa cells of follicle

Question 18

What is LH (Luteinising hormone) involved in?

Answer 18

Testosterone from Leydig cells

Progesterone from Corpus luteum

Question 19

What is prolactin involved in?

Answer 19

Breast development & milk production

Question 20

What are the six hypothalamic releasing factors?

Answer 20

GnRH (Gonadotropin Releasing Hormone)
GHRH (Growth hormone releasing hormone)
SST (Somatostatin)
TRH (Thryotropin, TSH-releasing hormone)
CRH (corticotropin releasing hormone)
Dopamine (amine not a peptide hormone)

Question 21

What is GnRH (Gonadotropin Releasing Hormone) for?

Answer 21

Stimulates release of LH and FSH (production of gametes)

Question 22

What is GHRH (Growth hormone releasing hormone) for?

Answer 22

Stimulates release of growth hormone, GH

Question 23

What is SST (Somatostatin) for?

Answer 23

Inhibits release of growth hormone, GH

Question 24

What is TRH (Thryotropin, TSH-releasing hormone) for?

Answer 24

Increase release of thyroid stimulating hormone, TSH

Question 25

What is CRH (corticotropin releasing hormone) for?

Answer 25

Increases release of corticotropin (ACTH) may stimulate prolactin release

Question 26

What is Dopamine (amine not a peptide hormone) for?

Answer 26

Decreases prolactin release

Question 27

What is the anterior pituitary hormone feedback long and short control loops?

Answer 27

``` Stress and Non-stress neural inputs Hypothalamus Corticotropin releasing hormone (CRH) Anterior Pituitary Adrenocorticotropic hormone (ACTH) Adrenal cortex Cortisol (end product feedbacks) ```

Question 28

What can the two additional hypothalamic hormones of the posterior pituitary hormones?

Answer 28

ADH (Anti-Diuretic Hormone) | Oxytocin

Question 29

What is ADH released as a posterior pituitary hormone?

Answer 29

Also known as Vasopressin (two functions) Causes production of hypertonic urine (dilute) Causes increase in systemic mean arterial blood pressure

Question 30

What is Oxytocin released as a posterior pituitary hormone?

Answer 30

Released as part of the suckling reflex Causes contraction of smooth muscle cells (myo-epithelial cells and smooth muscle in breast duct cells to enhance milk flow- let down reflex)

Question 31

What is Oxytocin also involved with?

Answer 31

Other sex hormones Oestrogen- causes breast duct development in puberty Progesterone and prolactin cause breast alveoli development Prolactin stimulates breast milk production by alveolar cells

Question 32

What are the two phases of the LH and FSH in female reproductive system?

Answer 32

Follicular phase | Luteal phase

Question 33

What is the follicular phase for LH and FSH in female reproduction?

Answer 33

LH FSH Thecal cells -> Androgens -> Granulosa cells Inhibin Oestrogen Inhibits FSH only Inhibits ant pit FSH & LH

Question 34

What is the luteal phase in female reproduction?

Answer 34

Granulosa cells develop LH receptors and combine with thecal cells to produce progesterone which continues to inhibit LH production

Question 35

What is the LH and FSH in the male reproductive system?

Answer 35

FSH -> Sertoli cells -> Sperm production LH -> Leydig cells -> Testosterone