Biol 2401 Endocrine, Digestive, and Nutrition Notes

Endocrine System



1.Pineal gland

 Small gland hanging from the small ventricle
 Secretory product is melatonin

2.endocrine Vs. Nervous

Nervous System Endocrine System
Responds rapidly Responds slowly
Short duration responses Long term duration
Acts via potentials and neurotransmitters Acts via hormones released into the blood
Acts at specific locations determined by axon Acts at diffuse locations- targets can be anywhere
pathways blood reaches
Neurotransmitters act over very short distances Hormones act over long distances


3.hypothalamic hormones and relationships with anterior and posterior pituitary

 Hypothalamus hormones: 6
o Gonadotropin- releasing hormone
o Thyrotropin -releasing hormone
o Corticotropin- releasing hormone
o Prolactin-inhibiting hormone
o Growth- releasing hormone
o Somatostatin
 Anterior Pituitary hormones: 7
o Follicle-stimulating hormone
o Luteinizing hormone
o Thyroid- stimulating hormone
o Prolactin
o Growth hormone
o Melanin-stimulating hormone
o Adrenocorticotropic hormone
 Posterior Pituitary hormone
o ADH
o Oxytocin
 Hypothalamus relationship with Anterior Pituitary Gland:
o 1. Gonadotropin
 Follicle- stimulating
 Luteinizing
o 2. Thyrotropin
 Prolactin
 Thyroid-stimulating

, o 3. Corticotropin
 Adrenocorticotropic
o 4. Somatostatin
 Thyroid-stimulating



4.hypophyseal portal system

~ a portal system is two capillary beds connected by veins

~ consists: primary/secondary capillary plexus and hypophyseal portal veins

 Branches of the internal carotid arteries deliver blood to the pituitary.
 The tract runs through the infundibulum
 Arises from neurons in the para ventricular and supraoptic nuclei
 Cells synthesize on of two neurohormones and transport them along the axons of the posterior
pituitary
 When the hypothalamic neurons fire, they release the stored hormones into the capillary bed



 After touching the posterior lobe , the anterior lobe goes into neurohypophysis loses connection
with the oral mucosa
 The primary capillary plexus in the infundibulum communicates inferiorly via small hypophyseal
portal veins with a secondary capillary plexus



Anterior Pituitary:

 1. When, stimulated neurons secrete releasing or in habiting hormones into the primary capillary
plexus
 2. Hypothalamic hormones travel through the portal veins to the anterior pituitary where they
stimulate or inhibit release of hormones made in the anterior pituitary gland
 3. Response to releasing hormones the anterior pituitary hormones into the secondary capillary
plexus




5.negative feedback regulations



6.antagonistic regulation
7.stalk of pituitary gland

8.nervous aspect of posterior pituitary lobe