ANAT 1: Hypothalamus/Pituitary

Question 1

Components of the Diencephalon (“Interbrain”)?

Answer 1

Epithalamus (Includes Pineal Gland)
Thalamus
Hypothalamus (Posterior Pituitary)

Question 2

Location of Pineal Gland?

Answer 2

Located in Epithalamus of Diencephalon (Posterior Roof of Third Ventricle)

Question 3

Role of Pineal Gland?

Answer 3

Secretes Melatonin
“Circadian rhythm”
Modulation of wake/sleep patterns via neuronal signals from retina

Question 4

Role of the Hypothalamus?

Answer 4

Responsible for integration of neuro-humoral responses by linking nervous and endocrine systems

Question 5

What is the Master Gland of the endocrine system?

Answer 5

Pituitary

Question 6

How is Hypothalamic/Pituitary System Organized?

Answer 6

Hypothalamus (Coordinating center):
produces releasing factors that activate the Anterior Pituitary to secrete hormones (FSH/GH/Prolactin/ACTH/TSH)

Neuronal signaling activates the Posterior Pituitary (Oxytocin/ADH)

Question 7

Region of the hypothalamus that releases ADH and Oxytocin?

Answer 7

Supraoptic Nucleus/Paraventricular areas of hypothalamus/Posterior Pituitary

Question 8

Posterior Pituitary vs. Anterior Pituitary?

Answer 8

Anterior (Adenohypophysis) - HIGHLY VASCULAR classic gland structure linked to the hypothalamus by blood vessels (FSH/GH/Prolactin/ACTH/TSH)

Posterior (Neuorhypophysis) - an extension of nerve cells from the hypothalamus (Oxytocin/ADH)

Question 8

Region of the hypothalamus that produces inhibitory/releasing hormones that act on the anterior pituitary?

Answer 8

Tuberal Area

Question 9

Another name for the pituitary gland?

Answer 9

Hypophysis

Question 10

Pituitary Gland Formation?

Answer 10

Posterior Pituitary: Neural in origin, derived from down growth of diencephalon

Anterior Pituitary: Ectodermal in origin, derives from Rathke’s pouch as an outgrowth of primitive oral cavity

Question 11

What connects the pituitary to the hypothalamus?

Answer 11

Stalk (Infundublulum)

Question 12

Anterior Lobe of PItuitary Gland (3 Parts):

Pars Distalis:

• ______ (Stimulates thyroid follicular cells to release T4 (80%) and T3)
• ______ (Cortisol release from cortex of adrenal)
• ______ (controls menstrual cycle and stimulates the growth of eggs in the ovaries. Controls sperm production)
• ______ (Ovarian production of estradiol => Ovulation, Testicular testosterone production)
• _______ (production of breast milk)
• _______ (Growth via local IGF-1 production+ protein, carbohydrate, lipid metabolism)

Pars Intermedia: _______ - Melanocytes

Pars Tuberallis: _________________

Answer 12

Anterior Lobe of PItuitary Gland (3 Parts):

Pars Distalis:

• TSH (Stimulates thyroid follicular cells to release T4 (80%) and T3)
• ACTH (Cortisol release from cortex of adrenal)
• FSH (controls menstrual cycle and stimulates the growth of eggs in the ovaries. Controls sperm production)
• LH (Ovarian production of estradiol => Ovulation, Testicular testosterone production)
• PROLACTIN (production of breast milk)
• GH (Growth via local IGF-1 production+ protein, carbohydrate, lipid metabolism)

Pars Intermedia: MASH - Melanocytes

Pars Tuberallis: Wraps around infundublium

Question 13

Secretions of the Neurohypophysis and their effects?

Answer 13

Pars Nervosa (Supraoptic/Paraventricular nuclei) of Posterior Pituitary:

• ADH (control blood pressure by acting on the kidneys and the blood vessels)
• Oxytocin (uterine contractions in labor and contractions of breast tissue to aid in lactation after childbirth)

Question 14

System of blood vessels linking hypothalamus and ANTERIOR Pituitary?

Answer 14

Hypophyseal

Question 15

Describe the Hypophyseal Portal System? Primary vs. Secondary?

Answer 15

Primary Capillary Plexus: Fenestrated capillaries allow entry of regulatory factors from the Hypothalamus (Parvocellular neurons) into circulation

Secondary Plexus: Portal veins from hypophyseal artery travel here, serves endocrine releasing cells of anterior lobe

Question 16

Cell Types of the Anterior Pituitary? (5)

Answer 16

Somatotorphs (GH)
Lactotrophs (Prolactin)
Thyrotropin (TSH)
Gonadotrophs (FSH and LH)
Croticotrophs (ACTH)

Question 17

Suckling reflex
1. Baby suckles
2. Sensory nerve activation
2. Activation of ___________ neurons
4. Action potential to __________ pituitary
5. Release of ___________ into blood
6. Expells milk

Answer 17

Oxytocin Suckling reflex
1. Baby suckles
2. Sensory nerve activation
2. Activation of Manocellualr neurons
4. Action potential to posterior pituitary
5. Release of oxytocin into blood
6. Expells milk

Question 18

Example of Negative Endocrine Feedback Loop?

Answer 18

Thyroid Hormones