Question | Answer |
step by step process of nervous system | stimulus - Affector - Translate/ interpret - motor output (response) - effector (response) |
Effectors | muscles and glands |
structure of CNS | BRAIN AND SPINAL CORD |
structure of PNS | spinal nerves: 31 pairs
Cranial nerves: 12 pairs |
Afferent neurons | somatic fibers (superficial)
Visceral fibers (deep) |
somatic nervous system | in PNS; motor division; voluntary (skeletal muscle) |
Autonomic nervous system | in PNS; in motor division; involuntary (heart) |
dendrite | fibers on a neuron that receive and then deliver messages to the cell and nucleus. |
axon | sends messages from (away) cell to terminals |
Astrocyte | (star shaped) Most abundant of glia cells; brace neurons; are chemical mops; and ingest excess ions and neurotransmitters; attatch blood cells to neurons |
microglia | not a neuron; phagocytes: ingest harmful substances fro protection and dispose of debris |
ependymal cells | line cavities; circulates cerebrospinal fluid. keeps cilia moving |
oligodendrocyte | only in CNS; can wrap around several nerve fibers at once |
meylin sheath | fatty lipid; wraps tightly around the axon of nerves. Protects neurons; speeds up messages and impulses, and AP |
Schwann cells | attach to only one neuron at a time |
resting potential | plarized; the conditions inside the neuron are different than out |
depolarization | conditions start to become more similar (sodium comes in) everything is inside neuron, initiated by stimulus |
propagation of AP | the upset of conditions inside the neuron because of the depolarization, an action potential starts |
re polarization | protiens open so potassium can flood out in order to restore polarization (stops AP) |
sodium/potassium pump | pumps potassium into cell and sodium out to restore original concentration |
presynaptic neuron | the message sending neuron |
postsynaptic neuron | the message receiving neuron |
4 major regions of the brain | Cerebral hemispheres, diencephalon, cerebellum, stem |
cerebrum | gray and white matter; interpretation for smelling, logic, speech, memory, voluntary movements |
diencephalon | thalamus = relay- determines good or bad
Hypothalamus = hunger, thirst, sex drive, body temp, hearing
Epithalamus = sleep wake cycle |
brain stem | attaches to spinal cord; midbrain= hearing and vision. pons = control breathing. medulla oblongata = hr, bp, vomitting |
cerebellum | 2 hemispheres, coordination of body movements, balance, and equilibrium |
protectors of the CNS | scalp, skin, skull, vertebrae column, meninges |
cerebrospinal fluid | similar to blood plasma; watery cushion, protects and absorbs shock for the brain |
blood brain barrier | least permeable capillaries; fats, resp. gases, alcohol, caffeine, drugs, ect can still get through here |
medulla | senses bad substances before they hit the blood brain barrier and can induce vomitting if needed |
spinal cord anatomy | 17 in long, 1 in wide; 31 pairs.
Foremen magnum = where cord meets brain
Cauda equina = where cord disperses into nerves |
endocrine system | maintain homeostasis. its "organs" = glands |
functions of the endocrine system | cellular metabolism, growth and development, immunity, nutient and h2O balance |
hormone | released by endocrine glands; chemical messages that cause a specific resonse |
receptors in cell membrane | amino acid based: must have acertain protien on membrane to attach to; not lipid soluble |
receptors in nucleus | lipid based: lipid soluble so it can pass through right to the nucleus |
hypothalamus | diencephalon. secretes, releases and inhibits hormones, produces ocytocin and adh |
pituitary gland | stores oxytocin and ADH; 2 lobes, produces prolactin, releases growth homrmone, targets skeletal muscle and long bones |
thyroid gland | releaes thyroid hormone; calcitonin = released when ca+2 level is to HIGH. targets osteoblasts |
parathyroid gland | usually 4; parathyroid hormone = released when Ca+2 levels are to LOW. targets osteoclasts |
thymus | thymosin: maturation of T lyphocytes (immune cells) |
adrenal glands | aldosterone, corisol, epinephrine |
aldosterone | raises na+ level in blood to increase preassure |
cortisol | released when stressed; raises blood sugar and reduces inflammation |
epinephrine | adrenaline; increases BP and heart rate and blood sugar; intensifies memory |
pancreas | regulates glucose levels; glucagon = increases blood sugar - targets: glycogen
Insulin = released to lower blood sugar |