Pituitary Gland Overview

Questions and Answers

Where is the pituitary gland located?

At the base of the brain in the Sella turcica within the sphenoid bone.

What type of connection does the posterior pituitary have with the hypothalamus?

No connection

Neural (correct)

Hormonal

Vascular

Which of the following hormones is released from the anterior pituitary?

Antidiuretic hormone (ADH)

Oxytocin

Somatomedin

Luteinizing hormone (LH) (correct)

What type of cells in the anterior pituitary secrete growth hormone?

Somatotropes Signup and view all the answers

The secretion of antidiuretic hormone (ADH) is controlled by the anterior pituitary.

False Signup and view all the answers

The main hormone responsible for the promotion of growth is __________.

Growth hormone (GH) Signup and view all the answers

Which hypothalamic hormone stimulates the release of thyroid-stimulating hormone (TSH)?

Thyrotropin releasing hormone (TRH) Signup and view all the answers

What effect does growth hormone (GH) have on proteins?

Increases the rate of protein synthesis and deposition. Signup and view all the answers

Match the following anterior pituitary hormones with their functions.

TSH = Stimulates the thyroid gland ACTH = Stimulates adrenal glands FSH = Regulates reproductive processes LH = Triggers ovulation or testosterone production Signup and view all the answers

Study Notes

Overview of the Pituitary Gland

Located at the base of the brain within the Sella turcica of the sphenoid bone.
Connected to the hypothalamus via the pituitary stalk.
Known as "The Master Gland" due to its regulation of other endocrine glands.
Secretion is controlled by the hypothalamus.

Lobes of the Pituitary Gland

Posterior Pituitary (Neurohypophysis)
- Neural connection with the hypothalamus.
- Embryological origin from the third ventricle of the brain.
Anterior Pituitary (Adenohypophysis)
- Vascular connection with the hypothalamus.
- Derived from the oral cavity's invagination (Rathke’s pouch).

Hormones Secreted by the Pituitary Gland

Posterior Pituitary Hormones
- Oxytocin: involved in childbirth and lactation.
- ADH (Antidiuretic Hormone): regulates water balance in the body.
- Neurophysin: a prohormone released alongside oxytocin or ADH.
Anterior Pituitary Hormones
- Basophils
  - TSH (Thyroid-stimulating hormone)
  - ACTH (Adrenocorticotropic hormone)
  - FSH (Follicle-stimulating hormone)
  - LH (Luteinizing hormone)
- Acidophils
  - GH (Growth hormone): promotes growth.
  - PRL (Prolactin): stimulates milk production.

Cell Types in the Anterior Pituitary

Somatotropes: Secrete growth hormone; constitute about 50% of anterior pituitary cells.
Corticotropes: Produce adrenocorticotropin (ACTH).
Thyrotropes: Secrete thyroid-stimulating hormone (TSH).
Lactotropes: Produce prolactin (PRL).
Gonadotropes: Synthesize gonadotropic hormones (LH and FSH).

Hypothalamus Functions

Integrates endocrine and nervous system activities.
Secretes releasing and inhibitory hormones that regulate anterior pituitary secretion.
Sends nerve signals to control posterior pituitary hormone release.
Utilizes hypothalamic-hypophysial portal vessels for hormone transport to anterior pituitary.

Hypothalamic Hormones and Their Effects

TRH (Thyrotropin Releasing Hormone): Stimulates TSH release.
CRH (Corticotropin Releasing Hormone): Induces ACTH release.
GnRH (Gonadotropin Releasing Hormone): Promotes LH and FSH release.
GHRH (Growth Hormone Releasing Hormone): Stimulates GH release.
GHIH (Growth Hormone Inhibitory Hormone, Somatostatin): Inhibits GH release.
Dopamine (Prolactin-inhibiting hormone): Inhibits prolactin release.

Actions of Growth Hormone (GH)

Promotes growth by increasing cell size and number.
Enhances protein synthesis and maintains positive nitrogen balance.
Increases mobilization of fatty acids; affects carbohydrate metabolism, leading to insulin resistance.
Stimulates cartilage proliferation at growth plates, facilitating linear growth.
Encourages secretion of insulin-like growth factor-1 (IGF-1) from the liver, which mediates GH effects.

Somatomedins

GH influences growth indirectly through somatomedins, primarily IGF-1.
IGF-1 secretion is independent of GH before birth but is stimulated by GH afterward.

Description

Explore the essential functions and anatomical features of the pituitary gland, often referred to as 'The Master Gland' due to its crucial role in hormone regulation. This quiz covers aspects such as its location, lobes, and connection to the hypothalamus.