[ENDO] PITUITARY GLAND (EXTRA).pdf

~600 mg

What is the approximate weight of an adult pituitary gland?

400-900 mg

What is the range of adult pituitary gland weight?

~13 mm

What is the approximate longest transverse diameter of the pituitary gland?

6-9 mm

What is the vertical height range of the pituitary gland?

9 mm

What is the anteroposterior dimension of the pituitary gland?

4th-5th week

At what gestational age does Rathke's pouch form?

Anterior pituitary

What is the origin of Rathke's pouch?

15-25%

What percentage of cells in the anterior pituitary are lactotrophs?

1

To which G-protein-coupled receptor family do dopamine receptors belong?

2

How many types of dopamine receptors are located on lactotroph cells?

4-20 ng/mL

What is the normal prolactin concentration range in non-pregnant, non-lactating women?

Lower

How do prolactin concentrations in men compare to those in non-pregnant, non-lactating women?

100-200 ng/mL

What is the range of prolactin concentrations during late pregnancy and lactation?

7 days

How long postpartum does it take for prolactin secretion to decrease without continuous nipple stimulation?

191

How many amino acids are in a growth hormone molecule?

22,005 Da

What is the molecular weight of growth hormone?

35-45%

What percentage of functional pituitary cells are somatotrophs?

2

How many pre-dimerized GH receptor (GHR) components does GH complex with?

20 hours

What is the half-life of IGF-1 in the blood?

20 minutes

What is the half-life of GH in the blood?

1%

What percentage change in osmolality is plasma vasopressin sensitive to?

10-15%

What percentage change is required in blood volume or pressure for a significant response in plasma vasopressin?

280-295 mOsm/kg H2O

What is the normal range of plasma osmolality maintained by osmoreceptors?

Target Cell

What type of cell responds to hormones?

Releases hormone, binds own receptor

What is the secretion/function of an autocrine cell?

Autocrine Cell

What type of cell releases hormone and binds to its own receptor?

Releases hormone, affects nearby cells

What is the secretion/function of a paracrine cell?

Paracrine Cell

What type of cell releases hormone and affects nearby cells?

Releases hormones into bloodstream

What is the secretion/function of an endocrine cell?

Endocrine Cell

What type of cell releases hormones into the bloodstream?

Secretes neuroendocrine hormones into blood; Communicate via synapses

What is the secretion/function of a neuron in the context of the endocrine system?

Neuron

What type of cell secretes neuroendocrine hormones into the blood?

Synthesizes steroid hormones (stimulated by hormones)

What is the secretion/function of a steroidogenic cell?

Steroidogenic Cell

What type of cell synthesizes steroid hormones when stimulated by other hormones?

Expresses prolactin; Inhibited by dopamine

What is the secretion/function of a lactotroph cell?

Lactotroph Cell

What type of anterior pituitary cell expresses prolactin and is inhibited by dopamine?

Expresses FSH and LH; Influenced by GnRH

What is the secretion/function of a gonadotroph cell?

Gonadotroph Cell

What type of anterior pituitary cell expresses FSH and LH and is influenced by GnRH?

Expresses growth hormone (GH); Stimulated by GHRH

What is the secretion/function of a somatotroph cell?

Somatotroph Cell

What type of anterior pituitary cell expresses growth hormone (GH) and is stimulated by GHRH?

Expresses thyroid stimulating hormone (TSH); Stimulated by TRH

What is the secretion/function of a thyrotroph cell?

Thyrotroph Cell

What type of anterior pituitary cell expresses thyroid stimulating hormone (TSH) and is stimulated by TRH?

Expresses ACTH; Stimulated by CRH

What is the secretion/function of a corticotroph cell?

Corticotroph Cell

What type of anterior pituitary cell expresses ACTH and is stimulated by CRH?

Produces dopamine (inhibits prolactin)

What is the secretion/function of a tuberoinfundibular cell?

Tuberoinfundibular Cell

What type of hypothalamic neuron produces dopamine that inhibits prolactin?

Secretes releasing/inhibiting hormones into tissue (e.g., median eminence)

What is the secretion/function of a neurohumoral cell?

Neurohumoral Cell

What type of hypothalamic cell secretes releasing or inhibiting hormones into the median eminence?

Secretes posterior pituitary hormones (ADH, Oxytocin)

What is the secretion/function of a magnocellular neuron?

Magnocellular Neuron

What type of hypothalamic neuron secretes ADH and oxytocin?

Possesses V2 receptors for ADH (water reabsorption)

What is the function of an epithelial principal cell in the renal tubules?

Epithelial Principal Cell

What type of cell in the renal collecting tubules possesses V2 receptors for ADH?

Contracts for milk ejection (stimulated by oxytocin)

What is the function of a myoepithelial cell in the breast?

Myoepithelial Cell

What type of cell in the breast contracts for milk ejection in response to oxytocin?

Protein deposition, reproduction (stimulated by IGF-1)

What is the function of a chondrocyte?

Chondrocyte

What type of cell is stimulated by IGF-1 for protein deposition and reproduction in cartilage?

Protein deposition, reproduction, new bone formation (stimulated by IGF-1)

What is the function of an osteocyte?

Osteocyte

What type of cell is stimulated by IGF-1 for protein deposition, reproduction, and new bone formation in bone?

Prolactin

Which hormone is produced by the anterior pituitary and targets the breast and reproductive system?

Milk production, Inhibits reproduction

What are the key functions/effects of prolactin?

Inhibited by Dopamine, Stimulated by suckling, Estrogen, GHRH, Oxytocin

How is prolactin regulated?

Growth Hormone (GH)

Which hormone is produced by the anterior pituitary and targets most tissues, the liver, and bone?

Growth, Protein synthesis, Fat use, Glucose sparing

What are the key functions/effects of growth hormone (GH)?

Stimulated by GHRH, Inhibited by Somatostatin, IGF-1, Glucose, Fatty Acids

How is growth hormone (GH) regulated?

FSH (Follicle-Stimulating Hormone)

Which hormone is produced by the anterior pituitary and targets the ovaries and testes?

Follicle growth, Estrogen production

What are the key functions/effects of FSH in females?

Sperm production

What are the key functions/effects of FSH in males?

Stimulated by GnRH, Inhibited by Estrogen, Progesterone

How is FSH regulated?

LH (Luteinizing Hormone)

Which hormone is produced by the anterior pituitary and targets the ovaries and testes?

Ovulation, Progesterone production

What are the key functions/effects of LH in females?

Testosterone production

What are the key functions/effects of LH in males?

Stimulated by GnRH, Positive feedback by Estrogen (surge), Inhibited by Estrogen, Progesterone

How is LH regulated?

TSH (Thyroid Stimulating Hormone)

Which hormone is produced by the anterior pituitary and targets the thyroid gland?

Thyroid hormone production (Thyroxine, Triiodothyronine)

What is the key function/effect of TSH?

Stimulated by TRH, Inhibited by Thyroid Hormones

How is TSH regulated?

ACTH (Adrenocorticotropic Hormone)

Which hormone is produced by the anterior pituitary and targets the adrenal glands?

Cortisol, Adrenal androgen release

What are the key functions/effects of ACTH?

Stimulated by CRH

How is ACTH regulated?

Oxytocin

Which hormone originates in the hypothalamus but is released by the posterior pituitary and targets the breast and uterus?

Milk ejection, Uterine contraction

What are the key functions/effects of oxytocin?

Stimulated by Nipple stimulation

How is oxytocin regulated?

ADH (Antidiuretic Hormone)

Which hormone originates in the hypothalamus but is released by the posterior pituitary and targets the kidneys and blood vessels?

Water reabsorption, Blood pressure increase

What are the key functions/effects of ADH?

Stimulated by High osmolality, Low blood pressure/volume, Inhibited by Low osmolality, High blood pressure/volume

How is ADH regulated?

TRH (Thyrotropin-Releasing Hormone)

Which hormone is produced by the hypothalamus and targets the anterior pituitary?

Stimulates TSH release

What is the key function/effect of TRH?

Inhibited by Thyroid Hormones

How is TRH regulated?

GnRH (Gonadotropin-Releasing Hormone)

Which hormone is produced by the hypothalamus and targets the anterior pituitary?

Stimulates FSH and LH release

What is the key function/effect of GnRH?

Inhibited by Estrogen, Progesterone, Prolactin

How is GnRH regulated?

GHRH (Growth Hormone-Releasing Hormone)

Which hormone is produced by the hypothalamus and targets the anterior pituitary?

Stimulates GH release

What is the key function/effect of GHRH?

Stimulated by Exercise, Sleep, Fasting, Inhibited by Somatostatin

How is GHRH regulated?

Somatostatin

Which hormone is produced by the hypothalamus and targets the anterior pituitary?

Inhibits GH release

What is the key function/effect of somatostatin?

Stimulated by Glucose, Amino acids

How is somatostatin regulated?

Estrogen

Which lipid-derived hormone is produced by the ovaries, adrenal cortex, testes, and placenta?

Uterus, Breast, Brain, Pituitary, Hypothalamus

What are the main targets of estrogen?

Female characteristics, Menstrual cycle, Feedback on FSH/LH/GnRH, Breast development

What are the key functions/effects of estrogen?

Stimulated by FSH, LH, Inhibits FSH/LH at certain levels, Stimulates LH surge

How is estrogen regulated?