Ch 41: Animal Hormones Flashcards
Hormones
A chemical signal that enters the blood and activates targeted cells far from the site of release
Secreted by endocrine cells
Released by neurohormones
Peptide/Protein hormones
Water-soluable (hydrophilic)
Easily transportable in blood
Receptors are on the cell’s surface
Ex. insulin
Steroid hormones
Cholesterol
Lipid soluble
Needs carrier proteins in the blood
Intracellular receptors
Amine hormones
Mostly synthesized from the amino acid tyrosine
Can be water-soluble or lipid-soluble
Ex. Epinephrine and Thyroxine
Fight or flight response
Response to fear or danger Heartbeat gets faster and stronger Blood vessels in the digestive tract constrict throughout the body Liver releases glucose Fat releases fattty acids Epinephrine mediates the response
Secretary organs
Endocrine glands that can secrete multiple hormones
Antidiuretic hormone (ADH)
Increases water retention by the kidneys
Oxytocin
Promotes bonding
Stimulates contractions and milk flow
Posterior Pituitary
Extension of the hypothalamus
Doesn’t have cells that secrete hormones
Anterior Pituitary
Only secretes neurohormones when the hypothalamus says
Thyroid gland
Found around the neck
Produces and stores thyroxine and calcitonin
Thyroxine
Regulates metabolism
Important for development and growth
Calcitonin
Maintains calcium levels
Stimulates the incorporation of calcium into bone
TRH
Thyrotropin releasing hormone
Released by the hypothalamus
Stimulates the anterior pituitary
TSH
Thyrotropin (thyroid stimulating hormone)
Released by the anterior pituitary
Stimulates the thyroid
Goiter
An enlarged thyroid gland
Caused by both hyperthyroidism and hypothyroidism
Hyperthyroidism
Caused by an excess of thyroxine
Antibody-binding activated TSH receptors on the thyroid and increases thyroxine
Thyroid is continually stimulated
Hypothyroidism
Thyroxine deficiency
Reduced metabolic rate
Main cause - iodine deficiency
Thyroid enlarges to compensate low thyroxine
Adrenal gland
Cortex + medulla
Cortisol
Mediates metabolic response to stress
Secreted by the cortex
Aldosterone
Salt water balance
Secreted by the adrenal cortex
Epinephrine
Adrenaline
Secreted by the medulla
Norepinephrine
Noradrendaline
Fight or flight response
Secreted by the medulla
Beta cells
Produce insulin
Alpha cells
Produce glucagon
Glucagon
Stimulates liver to convert glycogen to glucose
Delta cells
Produce somatostatin
Somatostatin
Inhibits the release of insulin and glucagon
Diabetes Mellitus
Too much glucose in blood and urine
Increase urine output and dehydration
Can cause numerous health complications
Type I Diabetes
Lack of insulin caused by beta cell dysfunction
An autoimmune disease - the body attacks beta cells
Type II Diabetes
Insulin responsiveness deficiency
Androgens
Male hormones
Estrogens and progesterone
Female hormones
Synthesized from testosterone by aromatase
GnRH
Gonadotropin releasing hormone
Stimulates the anterior pituitary during testosterone regulation
Luteinizing hormone
Secreted by the anterior pituitary
Stimulates the ovary
Involved in testosterone overuse in women
FSH
Follicle stimulating hormone
Secreted by the anterior pituitary
Stimulates the ovary
Involved in testosterone overuse in women
Adrenal medulla
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Adrenal cortex
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