Unit 4b - Final Review Flashcards
Homeostasis
The body maintains a constant balance to adjust to a fluctuating environment
negative feedback
Mechanisms that make adjustments to bring the body back within the acceptable range.
positive feedback
amplifies/reinforces change
hormones
chemical regulators produced by cells in one part of the body that affect cells in another part of the body
non-target hormones
affect many cells (e.g. growth hormone, insulin, epinephrine, etc.)
target tissues
have specific receptor sites to which hormones bind.
steroid hormones
Made from cholesterol (lipid); fat-soluble; not soluble in water
protein hormones
contains amino acid chains; water soluble
tropic hormones
stimulate a specific target gland to secrete another hormone
antagonistic hormones
a pair of hormones that have opposite effects on one another
antagonistic hormones examples:
insulin (lower blood glucose) and glucagon (raises blood glucose).
calcitonin and PTH.
pheromones
chemicals that affect organisms of the same species
secretory cells
specialized cells that perform the secretory function
neurosecretory cells
Release hormones into body fluids or storage organs; hormones are released at a later time
exocrine glands
produces sweat, mucus, or digestive enzymes. Products are sent to locations via ducts
endocrine glands
ductless glands
Produce hormones which are released into body fluids
anterior =
front
posterior =
back
anterior pit gland is mostly…
glandular tissue
posterior pit gland is mostly…
neural tissue
the pituitary gland is
the master gland which controls other endocrine glands
anterior pit. gland
produces its own hormones. release is regulated by the hypothalamus
posterior pit. gland
stores and releases hormones produced by the hypothalamus
ADH and Oxytocin
2 types of cells in the pancreas
Producing digestive enzymes (exocrine)
Produces hormones (endocrine)
insulin
brings blood sugar down → converts glucose into glycogen for storage
glucagon
brings blood sugar up. converts glycogen into glucose.
diabetes mellitus
inadequate production of insulin by the islets of langherhans (beta cells)
diabetes mellitus side effect
high blood sugar which has to be expelled in large amounts of urine. Little sugar is able to be stored = low energy. fats and proteins are used instead for energy.
type 1 diabetes (junevile)
early degeneration of beta cells in the islets of Langerhans (must be treated by insulin injections)
type 2 diabetes (adult)
decreased insulin production by insulin cells
gestational diabetes
temporary, occurs during 2-4% of pregnancies. Increases risk of Type 2 in mother and child.
Islet cell transplant:
islet cells are extracted from the pancreas of the donor and infused into the recipient’s liver.
adrenal medulla =
short term stress responses.
epinephrine and epinephrine
adrenal glands
hats on top of kidneys
adrenal cortex (outer)
long term stress responses.
mineralcorticoids –> aldosterone
glucocorticoids –> cortisol
Higher levels of thyroid hormones secreted
= sugars and nutrients oxidized faster
Warmer individuals, tend not to gain weight
Lower levels of thyroid hormones
= sugars oxidized slower
Excess blood sugar is converted into liver and muscle glycogen
Excess sugar -> fat
Colder, dryer skin.
iodine
needed for thyroid hormones. lack of iodine results in a goiter = an enlarged thyroid gland.
Hyperthyroidism:
excess secretion, high body temperature, sweating, high blood pressure
Hypothyroidism:
low secretion, lethargy in adults, cretinism (dwarfism) in infants.
Calcium levels are regulated by…
calcitonin and parathyroid hormone (PTH)
low levels of calcium may result in…
Tetany: convulsive contractions of skeletal muscles.
too much calcium may result in…
kidney stones
hyposecretion of growth hormone during adulthood…
acromegaly → Growth plates have fused, so long bones can no longer increase in length. Bones in jaw, forehead, fingers, and toes increase in width → broadening of facial features.
diabetes insipidus
The posterior gland does not secrete enough ADH/the kidney does not respond to ADH.
high urine outputs
ADH
causes increased permeability of water into the nephron.
Aldosterone
stimulated by low blood pressure. causes Na+ to be reabsorped in the nephrons. water follows by osmosis –> higher blood pressure.
prostaglandins
hormones that have a pronounced effect on a small localized area
