Hypothalamic pituitary axis and growth hormone Flashcards
What is the hypothalamic pituitary axis?
a functional unit that links the endocrine and nervous system (hypothalamus and pituitary)
What is the sella turcica?
A socket of bone below the hypothalamus where the pituitary gland sits
What is the Infundibulum?
The pituitary stalk that physically connects the hypothalamus with the posterior pituitary
List a few processes that is regulated by the hypothalamic pituitary axis
- Body growth
- Reproduction
- Adrenal gland function
- Milk secretion
- Lactation
- Water homeostasis
What are the two parts of the pituitary gland and where to they originate from?
1) Anterior (adenohypophysis) = evagination of oral ectoderm (Rathke’s pouch)
2) Posterior (neurohypophysis) = neuroectoderm
Describe the function of the posterior pituitary gland
Stores and releases oxytocin and ADH (synthesised in supraoptic and paraventricular nuclei of the hypothalamus)
Describe the function of the anterior pituitary gland
Produces and secretes 6 hormones that is stimulated (or inhibited) by tropic hormones from the hypothalamus
Describe how the tropic hormones from the hypothalamus stimulate/inhibit the target endocrine cells of the anterior pituitary
- transported down to the median eminence
- released to the hypophyseal portal system (blood supply)
Oxytocin (effect and where its produced/secreted)
- Milk let down and uterus contraction in birth
- Produced in the hypothalamus; secreted from posterior pituitary
ADH/Vasopressin (effect and where its produced/secreted)
- Regulates body water volume
- Produced in the hypothalamus; secreted from posterior pituitary
TRH (effect and where its produced/secreted)
- Tropic
- Thyroid releasing hormone
- Produced and released from hypothalamus
PIH/Dopamine (effect and where its produced/secreted)
- Tropic
- Prolactin release-inhibiting hormone
- Produced and released from the hypothalamus
CRH (effect and where its produced/secreted)
- Tropic
- Corticotropin releasing hormone
- Produced and released from hypothalamus
GnRH (effect and where its produced/secreted)
- Tropic
- Gonadotropin releasing hormone
- Produced and released from hypothalamus
GHRH (effect and where its produced/secreted)
- Tropic
- Growth hormone releasing hormone
- Produced and released from hypothalamus