homeostasis Flashcards
(38 cards)
what is homeostasis
to keep a stable environment (conditions) despite a fluctuating outer environment
negative feedback (homeostasis)
keeping conditions constant (ex. body temp)
positive feedback
amplifying (ex. giving birth)
what are the two parts of the central nervous system
brain: hind, mid, fron
spinal cord (connected to the hind brain)
where are reflexes received
interneuron (in the spine)
explain how action potential in generated?
what are the parts of a neuron (diagram)
soma (cell body)
axon
pre synaptic membrane (releases neurotransmitters)
- neurotransmitters: diffuse across the synaptic cleft to inhibit or pass forward a signal
synapsis: 2 proximal neurons
dendrites: receiving ends of information
myelin sheath (produced by schwann cells)
nodes of Ranvier: enable saltation of the action potenial
how does the hypothalamus link the nervous and endocrine systems
how do lipid and protein based hormones control transcription?
lipid: pass directly into cells, bind to DNA and act as transcription factors
protein: use a process called transduction, exert influence indirectly
(cascade of chemical reactions including cAMP)
what kind of hormones does the pituitary gland secrete? what are the names and functions of these hormones
tropic hormones (control other endocrine glands)
hGH: human growth hormone
tsh: thyroid stimulating hormone
LH: luteinizing hormone
FSH: follicle stimulating hormone
prolactin: stimulates milk production
ADH: water retention in kidneys (antidiuretic hormone)
oxytocin: stimulates uterine contractions and release of milk by mammary glands
ACTH: stimulates adrenal cortex to secreate glucocorticoids
what do the thyroid and parathyroid glands do?
thyroxine (t4, t3): metabolism
calcitonin: lowers blood calcium
PTH: raises blood calcium
(together they control blood calcium levels)
what gland secretes melatonin?
pineal gland
what does the pancreas do and how?
controls blood sugar levels by secreting insulin (to lower) and glucagon to raise
insulin: secreted by beta cells
glucagon: secreted by alpha cells
what is secreted by the adrenal gland?
adrenal cortex:
- glucacorticods: tissue to raise blood glucose and break down proteins
- mineralcorticods: absorption of Na+ and water by kidneys
- gonadacorticods: secondary sex characteristics
- epinephrine: fight or flight
what does the thymus do and where is it located?
thymosim: development of T-cells for immune response
in the chest, between the lungs and behind the breastbone or sternum
how do secondary sex characteristics develop in males vs females, what glands help with this?
the hypothalamus secretes GnRH which stimulates the secretion of LH and FSH by the pituitary gland. this activates, in males, the testes and in females the ovaries. estrogen are secreted by the ovaries and testosterone by the testes for secondary sex characteristics.
*the female reproductive system is a little more complicated than this**
what is the uterine cycle responsible for?
synchronizing the development of the endometrium (uterine lining) with ovulation
what are the stages of the ovarian cycle
follicular (follicle/support system to the egg + egg) and luteal (corpus luteum)
label the female and male reproductive systems
what does the frontal lobe do
voluntary control and movement such as organizing, initiating and reaching a goal
what does the temporal lobe do
manages emotions, processes info from senses, understanding languages, memories
what does the medulla oblongata/hindbrain do?
maintains homeostasis, reflexes automatic body responses like heart rate, constriction and dialation of blood vessels, deep breathing, swallowing, coughing
what does the cerebellum do?
unconscious movement such as posture, reflezes, body movements. also voluntary motor skills
what does the occipital lobe do?
visual processing and perception such colour, form, motion
