Physiology of the Pituitary Gland

Flashcards about pituitary gland physiology.

What are the two main parts of the pituitary gland?

Anterior and posterior pituitary

What structure connects the hypothalamus to the pituitary gland?

Infundibulum

What is the older name of the pituitary gland?

Hypophysis

What type of tissue makes up the anterior pituitary?

Epithelial tissue

What are the five types of cells in the anterior pituitary?

Somatotrophs, Thyrotrophs, Gonadotrophs, Lactotrophs, Corticotrophs

What hormone do somatotrophs secrete?

Growth hormone (GH)

What hormone do thyrotrophs secrete?

Thyroid-stimulating hormone (TSH)

What hormones do gonadotrophs secrete?

FSH and LH

What hormone do lactotrophs secrete?

Prolactin (PRL)

What hormone do corticotrophs secrete?

ACTH and LPH

What is another name for growth hormone-releasing hormone (GHRH)?

Somatocrinin

What does GHRH stimulate the secretion of?

Growth hormone

What does TRH stimulate the secretion of?

Thyroid-stimulating hormone

What does CRH stimulate the secretion of?

Adrenocorticotropic hormone

What does PRH stimulate the secretion of?

Prolactin

What does GnRH stimulate the secretion of?

FSH and LH

What is another name for growth hormone-inhibiting hormone (GHIH)?

Somatostatin

What does GHIH suppress the secretion of?

Growth hormone

What is another name for prolactin-inhibiting hormone (PIH)?

Dopamine

What does PIH suppress the secretion of?

Prolactin

Which anterior pituitary cell type is most abundant?

Somatotrophs

What percentage of the anterior pituitary cell population do somatotrophs comprise?

50%

What is the first hormone typically to be lost in pituitary dysfunction?

Growth hormone (GH)

What is a symptom of excess growth hormone?

Hyperglycemia

What is the diabetogenic effect?

Causes diabetes mellitus (lack of insulin activity).

What type of tissue makes up the posterior pituitary?

Neural tissue

What are the two parts of the posterior pituitary?

Pars nervosa and infundibulum

What two hormones are produced by the posterior pituitary?

Vasopressin and oxytocin

What are the principal actions of oxytocin?

Stimulates contraction of smooth muscle cells of the uterus during childbirth and stimulates milk ejection.

What are the principal actions of ADH?

Conserves body water, decreases water loss through perspiration, and raises blood pressure by constricting arterioles.

What part of the hypothalamus contains the paraventricular nucleus?

Supraoptic region

Where are the mammillary bodies located?

Mammillary region of the hypothalamus

Where is the arcuate nucleus located?

Tuberal region of the hypothalamus

What is the function of the mammillary bodies?

Relay stations for reflexes related to the sense of smell

Which hypothalamic nuclei form the hypothalamohypophyseal tract?

Paraventricular and supraoptic nuclei

What activities does the preoptic region participate in?

Regulating certain autonomic activities

Name two important functions of the hypothalamus.

Control of the ANS and production of hormones

Where does the pituitary gland lie?

Hypophyseal fossa of the sella turcica of the sphenoid bone

What is another name for the anterior pituitary?

Adenohypophysis

What is another name for the posterior pituitary?

Neurohypophysis

What is the larger portion of the anterior pituitary?

Pars distalis

What forms a sheath around the infundibulum?

Pars tuberalis

Name one of the hypothalamic releasing hormones.

Growth hormone-releasing hormone (GHRH)

Name one of the hypothalamic inhibiting hormones.

Growth hormone-inhibiting hormone (GHIH)

What does FSH promote in females?

Ovarian follicle development and estrogen secretion

What does LH promote in females?

Follicle maturation and progesterone release

What part of the brain is the major link between the nervous and endocrine systems?

Hypothalamus

What is released in response to uterine distension and stimulation of nipples?

Oxytocin (OT)

The hypothalamus is located inferior to what?

Thalamus

Which part of the pituitary atrophies during human fetal development?

Pars intermedia