Endocrine Flashcards
Nervous System vs. Endocrine System
Nervous:
- “Wired”
- Neurotransmitters travel a short distance
- Rapid response speed (milliseconds)
- Brief duration (milliseconds)
Endocrine:
- “Wireless”
- Hormones travel a long distance
- Slow response speed (mins-hrs)
- Longlasting effects (mins-days+)
Tropic Hormones
Target other endocrine glands and stimulate their growth and secretion.
Anabolic Hormones
Stimulate anabolism in target cells.
Steroid Hormones
- Molecules are manufactured by endocrine cells from cholesterol.
- Attach to soluble plasma proteins
- Receptors are found inside the cell instead of on the surface of the plasma protein.
- Mobile receptor model
Nonsteroid hormones
- Molecules are synthesized primarily from amino acids.
- Second messenger model
- Amplifies the effects of the hormone
- Operates more quickly than steroid - Fixed-membrane receptor
- Thyroid is an exception
Sex Hormones
Target reproductive tissues.
Second Messenger Model
1) Fixed receptor in the target cell’s plasma membrane
2) The message is then passed into the cell
3) Second messenger triggers the appropriate cell changes
Synergism
Combinations of hormones acting together to have a greater overall effect on a target cell.
Permissiveness
When a small amount of one hormone allows another to have its full effects on a target cell.
Antagonism
- When one hormone produces the opposite effects of another hormone.
- Fine-tunes the activities of target cells
Up-regulation
Increased number of hormone cells increases sensitivity of the target cell.
Down-regulation
Decreased number of hormone receptors decreases sensitivity of the target cell.
Hypothalamus
- Regulates pituitary gland
Pituitary Gland
- “Master gland”
- Hormones regulate all the other glands
Anterior Pituitary
- Growth Hormone (GH)
- Adrenocorticotropic Hormone (ACTH)
- Thyroid Stimulating Hormone (TSH)
- Follicle Stimulating Hormone (FSH)
- Luteinizing Hormone (LH)
- Prolactin (PRL)
Growth Hormone
- Indirectly promotes body growth by stimulating the liver + other tissues to make Insulin-like Growth Factor 1 (IGF-1).
- Promotes bone muscle and tissue growth.
- Stimulates fat metabolism.
- Acromegaly, gigantism, and pituitary dwarfism
Adenocorticotropic Hormone (ACTH)
Promotes and maintains normal growth and development of the adrenal cortex.
Hypersecretion of ACTH:
- Cushing syndrome/disease
Thyroid Stimulating Hormone (TSH)
Promotes and maintains growth and development of the thyroid gland.
Follicle Stimulating Hormone (FSH)
Females: Initiates development and maturity of follicles containing developing ovum.
Males: Stimulates development of seminiferous tubules and maintains sperm production.
Luteinizing Hormone (LH)
Females: Stimulates the formation and activity of the corpus luteum of the ovary (tissue left behind when the follicle ruptures to release the ovum).
Males: Stimulates the synthesis and secretion of testosterone.
Prolactin (PRL)
- Initiation of milk secretion
Hypersecretion:
- Prolactinoma
- common, benign pituitary tumor.
Hyposecretion:
- Milk production cannot be initiated or maintained.
Posterior Pituitary
- Antidiuretic Hormone (ADH)
- Oxytocin (OT)
Antidiuretic Hormone (ADH)
- Help body conserve water
- Cause water to be reabsorbed from tubules of the kidneys and returned to the blood.
- Stimulates contraction of the muscles in small artery walls to increase blood pressure.
- Hyposecretion of ADH: Diabetes insipidus
Oxytocin (OT)
- Aids in milk secretion
- Stimulates rhythmic contraction of smooth muscles in uterus during labor.
Pineal Gland
- Melatonin
Thyroid Gland
- Thyroid Hormone (TH)
- Calcitonin
Thyroid Hormone
- Regulation of metabolic rate of cells, processes of cell growth, and tissue differentiation.
- General target - can target any cell in the body
- Made up of 2 separate hormones; T3 (3 iodine atoms) and T4 (4 iodine atoms).
- Graves’ disease, Hashimoto thyroiditis, hyperthyroidism, hypothyroidism.
Calcitonin
- Tones down blood calcium levels
- Increases bone formation by osteoblasts
- Inhibits bone breakdown by osteoclasts
Parathyroid Gland
- Parathyroid Hormone
Adrenal Gland
- Aldosterone
- Cortisol
- Androgens
- Epinephrine
- Norepinephrine
Aldosterone
- Adjusts blood sodium levels; increases sodium reabsorption in the kidneys.
- Promotes water retention by the body
- Increases blood volume
- Decreases urine production
- Conn’s disease = hyperaldosteronism
Cortisol
- Accelerates breakdown of proteins into amino acids.
- Essential for maintaining normal BP
- Increased cortisol = decreased WBC = compromised immunity
- Increases as a response to stress
- Addison’s Disease (hypocortisol)
Androgens
- Small number of male hormones in both males and females
- Influence the appearance of pubic and axillary hairs in both genders
Epinephrine and Norepinephrine
- Epinephrine made in adrenal cortex; norepinephrine made in adrenal medulla.
- Nonsteroidal hormones
- Fight or flight
- Bind to sympathetic effectors to prolong and enhance the effects of sympathetic reaction.
Testes
- Testosterone
Ovaries
- Estrogen
- Progesterone
Thymus Gland
- Thymosin
- Thymopoietin
Gastric and Intestinal Mucosa
- Gastrin
- Secretin
- Cholecystokinin (CKK)
Heart (Gland)
- Atrial Natriuretic Peptide
OR - Atrial Natriuretic Hormone
Adipose Tissue
- Leptin
- Resistin
Kidneys (Gland)
- Erythropoietin
Pancreas Gland
- Insulin
- Glucagon
- Pancreatic Polypeptide
- Ghrelin
Insulin
- Promotes movement of glucose, fatty acids, and amino acids out of the blood and into tissue cells
- Lowers blood concentration of food molecules and promotes metabolism by tissue cells
- Diabetes Type 1, Type 2, Gestational
Glucagon
- Promotes movement of glucose from storage into the blood
- Stimulates conversion of glycogen to glucose in liver cells to increase blood glucose levels
Pancreatic Polypeptide
- Influences GI motility
- Feeling of hunger or fullness
Ghrelin
- Produced by cells in the stomach (gastric mucosa)
- Regulation and coordination of secretion motor activities involved in digestion
- Stimulates hunger; appetite boosting
Placenta
- human Chorionic Gonadotropin (hCG)
Acromegaly
Hypersecretion of GH after epiphyseal plates have closed.
Gigantism
Hypersecretion of GH before epiphyseal plates have closed.
Pituitary Dwarfism
Hyposecretion of GH during the growth years.
Cushing Disease
Hypersecretion of ACTH due to a pituitary tumor
OR High cortisol levels
- Upper body obesity
- Purple striae on abdomen, thighs, and breasts
- Round moon face
- Increased fat around the neck
- Relatively slender arms and legs
Hashimoto Thyroiditis
Autoimmune damage to thyroid resulting in hyposecretion of Thyroid Hormone (TH).
Graves’ Disease
- Hypersecretion of Thyroid Hormone (TH)
- Exothalamos (protruding eyes) and goiter
- Inherited/autoimmune
Hyperthyroidism
- Sluggishness/depression
- Feeling colder
- Forgetfulness
- Slow heart rate
- Weight gain
- Skin dryness
- Constipation
Hypothyroidism
- Nervousness
- Irritability
- Increased perspiration
- Heart racing
- Anxiety
- Hand tremor
- Difficulty sleeping
- Weight loss
- Hair loss
- Thinning skin
- Muscle weakness
Addison’s disease
- Hypocortisol
- Weight loss
- Muscle weakness
- Fatigue
- Low BP and sugar
- Darkening of skin
- Abdominal, joint, and muscle pain
- Irritability
- Depression
- Dehydration
