THE ENDOCRINE SYSTEM
I. GROSS ANATOMY:
Learn to recognize and identify the following structures on plastic models,
torsos and
preserved specimen available in the lab.
A. Pituitary gland in sella turcica
B. Pineal gland (hormone=melatonin)
C. Thyroid gland
D. Parathyroid glands (hormone=parathyroid hormone a.k.a. PTH)
E. Pancreas
F. Adrenal glands
G. Ovaries and Testes
II. HISTOLOGY: Learn to recognize and identify the following
structures in microscopic view, and give a function or product where
applicable.
A.
Pituitary gland: (hypophysis)
Pituitary
Pituitary
1. Anterior lobe (adenohypophysis): cells appear dense,
cytoplasm staining darkly
a. Follicle-stimulating hormone (FSH)
b. Luteinizing hormone (LH)
c. Adrenocorticotropic hormone (ACTH)
d. Thyroid-Stimulating Hormone (TSH)
e. Growth Hormone (GH)
f. Prolactin (PRL)
g. Melanocyte-Stimulating Hormone (MSH)
h. Gonadotropin-releasing hormone (GnRH)
2. Posterior lobe (neurohypophysis): cells are few, overall
appearance is fibrous, lightly
stained
a. Oxytocin
b. Antidiuretic hormone (ADH)
B. Thyroid gland: follicles containing
thyroglobulin (a.k.a. colloid)
Thyroid
Thyroid
1. Hormone produced by the follicles when it combines thyroglobulin +
iodine atoms= T4 (thyroxine) and T3 (triiodothyronine)
2. Hormone produced by the parafollicular cells=Calcitonin (a.k.a.
thyrocalcitonin)
C. Pancreas:
Pancreas
1. Acini--darkly stained pyramid-shaped cells arranged 5-8 cells with
tip of pyramid pointing
toward central duct, base of pyramid to outside; this is the
exocrine portion of the
pancreas producing digestive enzymes.
2. Islets of Langerhans--isolated clusters of cells; cytoplasm doesn't
stain well, nuclei stand out; this is the
endocrine portion of the pancreas. Hormones produced by
the islets include:
a. Insulin
b. Glucagon
D. Adrenal
gland: Look at the slide first without the microscope by holding it up
to the light or
by placing the slide on a white sheet of paper. Notice a difference in
color shading between
the outer rim and an inner strip of tissue. The outer rim is the
adrenal cortex. The inner strip is the
adrenal medulla. Place the slide on the scanning lens and
re-examine for the cortex and medulla.
Adrenal
Adrenal
1. Cortex
a. Mineralocorticoids (example: aldosterone)
b. Glucocorticoids (example: cortisol)
c. Gonadocorticoids (example: sex hormones)
2. Medulla
a. Epinephrine
b. Norepinephrine
E. Ovary:
Ovary
Ovary
Ovary
Ovary
1. Primordial follicles containing
the primary oocytes at or near outer surface of the ovary
2. Primary follicles containing primary oocytes surrounded by cuboidal
granulosa cells
3. Secondary follicles containing secondary oocyte and
first sign of antrum
4. Graafian (or vesicular) follicle possessing a well-defined antrum and
the secondary oocyte
5. Ovum (secondary oocyte) surrounded by zona pellucida and corona radiata
6. Hormones produced by the thecal and granulosa cells of the ovarian follicle include:
a. Estrogen
b. Progesterone
c. Inhibin
d. Relaxin
F. Testes:
Testes
Testes
1. Seminiferous tubules
(cross-section)
2. Germinal epithelium with spermatogonia at periphery of seminiferous
tubules
3. Interstitial cells
4. Spermatids near or in lumen
possessing a head, midpiece, and tail
5. Hormones produced by the interstitial cells
a. Testosterone
b. Inhibin
FOR THE LAB PRACTICAL, BE ABLE TO RECOGNIZE ANY OF THE ABOVE ENDOCRINE GLANDS AND STRUCTURES ASSOCIATED WITH THEM, EITHER IN GROSS PRESENTATION OR MICROSCOPIC PRESENTATION. BE ABLE TO NAME A PRODUCT OF A PARTICULAR PART OF A GLAND OR A FUNCTION OF A PARTICULAR STRUCTURE IN THE GLAND.