Lab 01 - Endocrine Anatomy and Histology.docx - Nur 0003...

Nur 0003
Lab 01 - Endocrine Anatomy and Histology
Goals
1. To Identify the location of the major endocrine glands in the body.
2. To understand the histology of the major endocrine glands.
3. To learn the major hormones secreted by the major endocrine glands.
I. The Endocrine System
A. Location of major endocrine glands
1. Head
 Hypothalamus(junction between the endocrine and nervous systems)
 Pituitary (a.k.a. hypophysis)
 Pineal body
2. Neck
 Thyroid
 Parathyroid – posterior of thyroid gland
3. Thorax
 Thymus(especially enlarged in fetuses and infants)
 Heart
4 Abdomen
 Pancreas
 Adrenals
 Gonads - ovaries and testes
 Stomach and intestinal linings
B. Hormones and their Targets
1. Hormone
 Chemical Signal
 Released in small amounts by specialized epithelial cells
 Travels through blood to target tissues.
2. Targets
 Target tissues have receptors that will bind with the appropriate hormone.
 Receptors can be membrane bound (protein) or intracellular (steroid)
 Some target tissues will down regulate over time, meaning they become less
sensitive to the amounts of hormone present.
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II. Pituitary Gland
A. Anatomy of the Pituitary gland
 Located in the sella turcica (Turkish saddle) of the sphenoid bone.
 Connected to the hypothalamus by a stalk called the infundibulum.
 Adenohypophysis (anterior pituitary) - cuboidal epithelial tissue.
 The anterior pituitary is connected the hypothalamus via a portal system (a
special system of blood vessels in which two capillary beds are connected
together directly) known as the hypothalamohypophyseal portal system .
 Releasing hormones from the hypothalamus trigger the anterior Pituitary to
secrete its hormones, or in some special cases inhibit the anterior pituitary from
releasing hormones(the inhibiting hormones)
 Examples of releasing and inhibiting hormones include: GHRH, GnRH, TRH,
CRH, and PIH and GHIH.
 Neurohypophysis (posterior pituitary) - nervous tissue.
 The posterior pituitary does not secrete* any hormones because it is primarily
nervous tissue. Axons from the hypothalamus pass down the
hypothalamohypophyseal tract to terminate here and release their chemical
products as needed.
B. Hormones secreted by the anterior pituitary gland
1. Growth Hormone (GH) a.k.a. somatotropin
Structure- protein
Target – Many tissues, but mainly muscle and connective tissue.
Response - a.a uptake for protein & glycogen synthesis, growth in tissues,
stimulates muscle and bone growth.
Clinical - pituitary dwarfism and pituitary giants (gigantism), and acromegaly
2. Prolactin (PRL)
Structure – protein
Target - mammary glands (primarily)
Response - stimulates mammary glands to produce milk soon after birth
Tropic hormones - hormones whose targets are other endocrine glands.