Endo (pt 1/7) Basic Overview of Anatomy & Hormones Flashcards
-Uses electrical impulses to send messages
-Quick onset
-Localized effect
-Organs: Brain, spinal cord, and nerves
Nervous System
-Uses hormones as messengers
-Slow onset
-Broad Effect
-Organs: glands
Endocrine System
What are the 6 glands that make up the Endocrine System?
Pituitary, Thyroid, Parathyroid, Adrenals, Pancreas, and Sex Glands (ovaries & testes)
Do Endocrine glands have ducts?
No; ductless glands of internal secretion
Where do Endocrine glands release their secretions?
Directly into the blood.
What are the 3 broad functions of the Endocrine System?
1) Metabolic functions in the body
2) Transfer of substances through cell membranes
3) Hormones concerned with cellular metabolism
What are the 3 different subcategories of Hormones?
1) Peptides (protein hormones)
2) Amines (Amino-Acid Derivatives)
3) Steroids
-Hormones synthesized in endocrine cells
-Are processed by the cell
-Stored in secretory granules within the endocrine gland
Peptides (Protein Hormones)
What are examples of Peptides (Protein Hormones)?
Insulin
Growth Hormone
Vasopressin
Angiotensin
Prolactin
Erythropoietin
Calcitonin
Somatostatin
ACTH
Oxytocin
Glucagon
Parathyroid Hormone
Derived from the Amino Acid Tyrosine.
Amines (amino acid derivatives)
Thyroid Hormones
Catecholamine Hormones
Amines (amino acid derivatives)
An Amine; synthesized from the naturally occurring amino acid, Tryptophan
Serotonin
Hormones derived from cholesterol, that require specific pathways and enzymes.
-Not stored in vesicles
-Synthesized and released on demand
Steroids
What are examples of Steroid Hormones?
Glucocorticoids
Mineralocorticoids
Androgens
Estrogens & Progestins
What are the 3 different types of Hormonal Signaling?
Endocrine, Paracrine, and Autocrine
The transmission of a hormonal signal through the bloodstream to a distant target cell.
Endocrine Signaling
The Pituitary Gland uses what kind of signaling?
Endocrine
A hormone signal acting on a neighboring cell of a different type.
Paracrine Signaling
A secreted hormone acts on the producer cell itself, or on neighboring, identical cells
Autocrine Signaling
What kinds of signals can excite or inhibit the Hypothalamus?
Pain, depressing or exciting thought, olfactory sensations, electrolytes, water, and other hormones.
Which part of the Pituitary is an outgrowth of the Hypothalamus?
Posterior Pituitary
What kind of tissue is found in the Posterior Pituitary?
Glial Type cells
The ____ Pituitary is continuous with the Hypothalamus via the __________.
Posterior; Hypophyseal Stalk
Communication between the hypothalamus and the posterior pituitary is via?
Nervous signals
Embryologically, how did the Anterior Pituitary originate?
From an invagination of the pharyngeal epithelium. Its cells are epithelial
How does the Hypothalamus communicate with the Anterior Pituitary?
Via hormones released from the Hypothalamus, that travel to the Anterior Pituitary via hypothalamo-hypophyseal portal vessels.
What is the major source of blood flow to the Anterior Pituitary?
Hypothalamo-Hypophyseal Portal Vessels
-Venous plexus
-Little to no arterial supply
Adenohypophysis is?
Anterior Pituitary
Neurohypophysis is?
Posterior Pituitary
Where is the Pituitary Gland located?
In the midbrain, sitting in the hypophyseal fossa in the sella turcica of the Sphenoid bone.
Fixed space = NO GROWTH POTENTIAL for tumors without compression of tissues
What are the 3 parts of the Anterior Pituitary?
1) Pars distalis
2) Pars tuberalis
3) Pars intermedia
Which is the largest part of the Anterior Pituitary, consisting of cords of epithelial cells specialized to secrete 6 hormones?
Pars distalis
What are the 6 hormones secreted by the Pars Distalis of the Anterior Pituitary?
Growth
Thyroid Stimulating
Adrenocorticotropic
Follicular Stimulating
Leutinizing
Prolactin
What is the part of the Anterior Pituitary that surrounds the anterior aspect of the infundibular stalk?
Pars tuberalis
What is the part of the Anterior Pituitary that is a thin layer of epithelial cells located between the pars distalis and the neurohypophysis?
Pars intermedia
What are the 2 parts of the Posterior Pituitary?
1) Infundibular Stalk
2) Pars nervosa (the posterior pituitary itself)
An actual connection that allows for nervous signaling to occur.
Posterior Infundibular Stalk
What are the two hormones released from the Posterior Pituitary?
ADH and Oxytocin
Causes decreased excretion of water by the kidneys, and contraction of almost any smooth muscle in the body, although the amount needed for smooth muscle constriction is much more than that needed for antidiuresis.
-Acts on kidney tubules
ADH (Antidiuretic hormone or Vasopressin)
Causes contraction of the smooth muscle of the uterus during delivery, and in the breast to cause let down of milk.
Oxytocin
What are the target organs of Oxytocin?
Mammary glands and smooth muscle of the uterus
Which of the 6 hormones released by the Anterior Pituitary does NOT target a specific gland?
Growth Hormone (Somatotropin) affects almost all tissues of the body
What are the target organs of FSH and LH?
Gonads & testes
What is the target organ of Prolactin?
Mammary glands
What is the target organ of ACTH?
Adrenal Cortex
What is the target organ of TSH?
Thyroid Gland
Which hormones stimulate the production of hormones by a peripheral endocrine gland, the liver, bone, or other tissues?
GH
TSH
ACTH
LH
FSH
Which hormones act directly on target tissues?
Prolactin
ADH
Oxytocin
