Hormones Flashcards
Exocrine glands
- nonhormonal substances (sweat, saliva)
- have ducts to carry secretion to membrane surfaces
Endocrine glands
- produce hormones
- lack ducts
Exocrine examples
sweat, saliva, pancrease
Endocrine examples
pituitary, pancreas
Steroid
- testosterone
- estrogen
- aldosterone
- cortisol
Nonsteroid
- insulin
- glucagon
- ADH
Negative feedback
process that returns conditions to a set value (homeostasis) and turns off the response once values return to normal
Example of negative feedback
- insulin (body produces insulin when blood sugar elevates)
- glucagon (body produces glucagon when blood sugar lowers)
Positive feedback
Process by which changes causes increasing similar changes (less common)
Example of positive feedback
oxytocin and uterine contractions (uterine contractions increase in
frequency and intensity and oxytocin
levels increase until parturition or child
birth)
ACTH
- adrenocorticotropin hormone
- stimulates the adrenal cortex
FSH
- follicle stimulating hormone
- stimulates the follicles in the ovaries
- stimulates production of sperm cells
in the testes
LH
luteinizing hormone
PRL
- prolactin
- sustains milk production after birth
TSH
- thyroid stimulating hormone
- stimulates the thyroid
ADH
- antidiuretic hormone (vasopressin)
- increases water reabsorption in the
kidneys - can cause blood pressure to rise
- diabetes insipidus (pituitary diabetes)
->ADH deficiency, polyuria
OT
- oxytocin
- causes uterine contractions leading to
birth - positive feedback mechanism
T4
- thyroxine
- regulates metabolism
T3`
- triiodothyronine
- regulates metabolism
PTH
- parathyroid hormone
- released with hypocalcemia
- triggers osteoclasts
- stimulates kidney tubules to reabsorb
Ca++ (calcium) and secrete PO4-3
(phosphate) - activates vitamin D
What is in the pituitary gland (anterior lobe)?
PRL, TSH, ACTH, FSH, LH, growth hormone
What is in the pituitary gland (posterior lobe)?
OT, ADH
What is in the thyroid gland?
T3, T4, calcitonin
Growth hormone
promotes growth of long
bones and increases cell uptake of amino acids mainly
Pituitary dwarfism
too little as a child
Pituitary giantism
too much as a child
Acromegaly
too much as an adult
Calcitonin
- released with hypercalcemia
- stimulates osteoblasts
Goiters
enlarged thyroid gland
Endemic goiters
due to iodine deficiency
Toxic goiters
due to a disease state in the person or chemical exposure such as sick building syndrome
Cretinism
- low T3 and T4 at birth
- detected with heal stick shortly
after birth - given hormones to supplement this
Hyperthyroidism
- elevated thyroid activity
- higher T3 and T4 levels which cause
metabolism to work faster - body temp. elevates; eyes bulge out
Hypothyroidism
- low thyroid activity
- body temp. lowers, weight gain, brittle
hair/nails, dry skin
Hyperparathyroidism
calcium levels go up
Hypoparathyroidism
calcium levels lower
Osteoma
tumor in bone
What is in the adrenal cortex?
aldosterone, cortisol, androgens
Aldosterone
regulates sodium and potassium by stimulating the reabsorption of Na+ and the secretion of K+ in the kidney tubules
Androgens
male sex hormones, supplements the gonads, can be converted to estrogen
Cortisol
- released with high stress, reduces
inflammation and immune system,
stimulates gluconeogenesis (makes glucose from non carbs)
What are the 2 adrenal gland disorders?
crushing’s syndrome, addison’s disease
Crushing’s syndrome
- overactive adrenal glands
- extreme weight gain
- sodium retention
Addison’s disease
- underactive adrenal glands
- sleek body
- can look tanned or dark pigmentation
What is in the adrenal medulla?
- epinephrine (adrenaline),
- norepinephrine (noradrenaline)
- enhances fight or flight
What is in the pancreas
islets of langerhans, acinar cells
Islets of langerhans
- endocrine part of pancreas
- alpha cells secrete glucagon
- beta cells secrete insulin
Acinar cells
- exocrine part of pancreas
- release digestive enzymes through a
duct that runs into small intestine
Hyperglycemic
- high blood pressure
- beta cells release
Hypoglycemic
- low blood sugar
- alpha cells release
Glycogen
chain of glucose
Type 1 diabetes
- juvenile diabetes
- rare (5-10%)
- dependent on insulin
- autoimmune disease where body
attacks beta cells in the pancreas, so
insulin is not produced - can cause infections
Type 2 diabetes
- adult onset
- more common (90-95%)
- initially not dependent on insulin
- insulin resistant, where cells ignore
insulin, especially in adipose tissue
Problems with uncontrolled diabetes
- damage to blood vessels and nerves is
common - diabetic retinopathy leading to
blindness - kidney damage leading to kidney
dialysis - increased risk of heart disease
- loss of nerve sensation and poor
circulation - poor healing wounds
- increased risk of gas gangrene (1/4 of
all diabetics have amputation)
Gestational diabetes
- type 2 diabetes
- get during pregnancy
- usually leads to high birth weight
What is in the pineal gland?
melatonin
Melatonin
involved in circadian rhythms (24 hour cycle)
What’s in the thymus (heart) gland?
thymosin
Thymosin
- stimulates T cells or T lymphocyte
maturation - large in young mammals, degenerates
after puberty
What are in ovaries?
estrogen, progesterone
Estrogen
- responsible for secondary sex
characteristics at puberty in females - breast development, wider
hips/thighs, axillary and groin hair
Progesterone
- comes from the corpus luteum, the
remaining follicle cells that remain
in the ovary after ovulation - helps maintain pregnancy
What is in testes?
testosterone
Testosterone
- responsible for secondary sex
characteristics at puberty in males - broader shoulders, increase muscle
tissue, deepening voice; facial, axillary,
and groin hair
Physical stress
- not enough sleep
- too much caffeine
- too much alcohol
- pain
- smoking
Psychological stress
- death of loved one
- divorce
- losing a job
- exams
- getting in arguments
- pandemics
What happens to body during stress?
- increased heart rate which can
increase blood pressure - increased blood sugar which can
increase risk for type 2 diabetes - decreased immune function (decrease
in T cells and interferon) - sympathetic nervous system is active,
so increased problems with digestive
system - short term memory normally
decreases to some degree
Hormones that increase from stress?
- insulin
- epinephrine
- norepinephrine
- cortisol
