Endocrine System Flashcards
Define hormone and target, and state what differentiates hormones from other kinds of chemical regulators (i.e. autocrine and paracrine regulators)
Hormone: chemical substance produced at one location in the body, transported by the bloodstream, and exerting an effect at one or more locations other than it’s site of production
(i.e. made at one place but goes to another)
Target: the specific cells, tissues, and organs which respond to hormones because they contain specific receptors
autocrine- they act on the organs that produce them
paracrine - they act on the organs that produce them
Differentiate the four chemical categories of hormones in regard to the location of the receptors on the target cells and the effect of hormone/receptor interactions.
Part 1
- Steroid Hormones: sex hormones and those produced by cortex of adrenal gland
- Proteins or Polypeptides: majority of hormones
- Catecholamine hormones: norepinephrine and epinephrine
- Modified Amino Acids: T3 (triiodothyronine) and T4 (thyroxine)
Differentiate the four chemical categories of hormones in regard to the location of the receptors on the target cells and the effect of hormone/receptor interactions.
Part 2
Modified Amino Acids
Location of Receptors: Nucleus of Target Cells
Effect of Hormone/Receptor Interaction: direct activation of specific genes
Steroid Hormones
Location of Receptors: Cytoplasm of target Cells
Effect of Hormone/Receptor Interaction: Hormone/Receptor complexes are transferred to nuclei where they activate specific genes
Catecholamines, polypeptides, and proteins
Location of Receptors: On the cell membrane
Effect of Hormone/Receptor Interaction: Hormone/receptor complexes cause production of other compounds which activate enzymes that have already been produced
Divide the hormone producing structures of the body into two groups: the “true” endocrine organs and the structures belonging to other body systems that produce hormones.
TRUE ENDOCRINE ORGANS HAVE NO OTHER FUNCTIONS IN THE BODY
- Pineal gland (pineal body)
- Pituitary gland (hypophysis)
- Thyroid Gland
- Parathyroid Gland
- Adrenal (suprarenal) Gland
Structures belonging to other body systems:
- Hypothalamus (Nervous System)
- Pancreas (Dig System)
- Small Intestine (Dig System)
- Stomach (Dig System)
- Kidney (Urinary System)
- Thymus (Lymphatic System)
- Ovary (Reproductive System)
- Testis (Reproductive System)
- Heart (Cardiovascular System)
- Placenta
Name the location/parts of the pineal gland (body)
midline at posterior aspect of epithalamus
- contains lime concentrations - “brain sand”
Name the location/parts of the pituitary gland (hypophysis)
suspended from inferior aspect of the hypothalamus by infundibulum
- sits on sella turcica of sphenoid bone
- has an anterior (adenohypophysis) and a posterior lobe (neurohypophysis)
Name the location/parts of the thyroid gland.
below the larynx and superior end of trachea
- consists of left /right lobes
- consists of a connecting isthmus
Name the location/parts of the parathyroid glands.
posterior aspect of the left and right lobes of the thyroid gland
- 4 of them total: left/right superior and left/right inferior
Differentiate the hypothalamohypophysial tract from the hypothalamophyophysial portal system in regard to composition, specific location, destination, hormones transported, and purpose.
H. Tract
Composition: axons of neurosecretory cells
Location: within infundibulum
Destination: Posterior Lobe of pituitary gland
Transports: ADH and OXY
Purpose: remains in enigma
Differentiate the hypothalamohypophysial tract from the hypothalamophyophysial portal system in regard to composition, specific location, destination, hormones transported, and purpose.
H. portal system
Composition: venules
Location: around infundibulum
Destination: Anterior Lobe of pituitary gland
Transports: numerous hormones all of which target anterior lobe of pituitary gland
Purpose: deliver hormones to their target in concentrations sufficient to exert an effect
Name the location/parts of the adrenal (suprarenal) glands.
superior ends of kidneys
- two major layers: cortex and medulla
Layers of Adrenal Cortex:
- Zona Glomerulosa
- mineralocorticoid h. - Zona Fasciculata
- glucocorticoid h. - Zona Reticularis
- gonadocorticoid h.
Given the target and general effect (action) of a hormone, state the conditions that should cause an increase (and those that should cause a decrease) in the secretion/release of that hormone.
Increase of a hormone: stimulated when the effect of that hormone is needed in the body
Decrease of a hormone: when a hormone’s affect is adequate (or excessive), its secretion/release is inhibited
*negative feedback = general principle which regulates the secretion of all hormones
State the condition that should result from under or over secretion of a particular hormone.
Diabetes mellitus
Hyposecretion of insulin results in:
high blood sugar, glycosuria
State the condition that should result from under or over secretion of a particular hormone.
Hypoglycemia
Hypersecretion of insulin:
low blood sugar, fatigue
State the condition that should result from under or over secretion of a particular hormone.
Cushing’s syndrome
Tumor of adrenal cortex or hypersecretion of ACTH:
high levels of corticosteroids, “buffalo hump”, “moon face”
