The pituitary gland

Question 1

What does the pituitary gland control?

Answer 1

• Adrenal function
• Thyroid function
• Gonadal function
• Water balance
• Metabolism
• Growth
• Partituation
• Lactation

Question 2

Explain the hypothalamo-hypophyseal portal system

Answer 2

• Network of tiny vessels which transfer trophic hormones from the hypothalamus to the anterior pituitary
• Small numbers of neurosectomy neurons sufficient control
• Hormones released from neurosecretory neurons at the median eminence
• Very small amounts of hormones required
• Short distance: very rapid and dynamic

Question 3

What does trophic hormones mean?

Answer 3

They govern the release of other hormones

Question 4

What does hypophysiotropic mean?

Answer 4

Produced by endocrine cells in the hypothalamus

Question 5

What does troph mean?

Answer 5

Relating to growth

Question 6

List the hormone families and major individual hormones secreted by the adenohypophysis (anterior pituitary lobe)

Answer 6

• Thyroid stimulating hormone (TSH) aka thyrotropin
• Adrenocorticotropic hormone (ACTH) aka corticotropin
• Gonadotropins
- Follicle stimulating hormone (FSH)
- Growth hormone (GH)
• Prolactin (directly stimulates milk production from the breast during lactation)

Question 7

List the neurohormones produced by the hypothalamus including those secreted by the neurohypophysis (posterior pituitary lobe)

Answer 7

• There are at least 5 hypothalamic “releasing hormones”
- Thyrotropin releasing hormone (TRH)
- Corticotropin releasing hormone (CHR)
- Growth hormone releasing hormone (GHRH)
- Gonadotrophin releasing hormone (GnRH)
- Prolactin releasing hormone (PRH)
• There are also inhibiting hormones from the hypothalamus
- Growth hormone inhibiting hormone (GHIH)
- Dopamine aka prolactin inhibiting hormone
• The posterior pituitary
- Vasopressin (aka anti-diuretic hormone ADH)
- Oxytocin