Maintaining Homeostasis & Nervous System Flashcards
What do kidneys do?
-proper ion concentration
- proper water concentration
elimination of urea
- blood pressure
- proper PH`
How does the body acquire nitrogen waste?
by product of protein metabolism in liver
where is ammonia mainly found
aquatic animals like fish
Urea is mainly found in
mammals, sharks and amphibians
Uric acid is mainly found in
insects, reptiles, birds and shelled things
rate the wates from most toxic to least toxic
ammonia, urea, uric
rate wastes from cheap/ easy to take out to hard to take out
ammonia, urea, uric
when talking about kidneys what system are we referring to
excretory system
4 steps of nephrons
filtration
reabsorbtion
secretion
excretory
Steps to a movement
sensory input via affereny cells
intergration(decides whether to respond or not)
motor output efferent cells carry away single
effector
thing actually moves
what is apart of peripheral nervous system
sensory input and motor outout
what is apart of central nervous system
intergration
what is so special about neurons
they ate amitotic
aka they do not divide
Neurons have a high
metabolic rate
they consume a lot sugars and mitochondria stuff
Glia cella are mainly …
support
three types of glial cella
astrocytes
microglia
oligodendrocytes
astrocytes are differnet from the other glial cells bc
they are the most abundant
astocytes…
creates barriers and has highest number if tight junctions to protect neurons
astocytes…
creates barriers and has highest number if tight junctions to protect neurons
astocytes…
creates barriers and has highest number if tight junctions to protect neurons
microglia..
defense system
looks for pathogens and destroys them
oligodendrocytes…
produce myelin sheath that speeds up signal and isolates nerves
autonomic nervous system is controlled by
hypothalamus
a nerve is a
group of neurons bundled together by connective tissue
it can act as protection
what is the longest nerve in the body
the sciatic nerve
resting potential
the membrane potential of a neuron
what number is the resting motaential
avg-== -70 mV
an imbalance of chemicals in any cell will cause a
stimulus
stimulus is apart of what division
afferent division
membane potential stages
resting stage
depolarization
rising phase of action potential
falling phase of action potential
undershoot
resting stage
stimuli causes Na+ channels to open
Depolarization
interior become less negative
Na+ channels open rapidly
r
rising ohase of action potential
K+ slowly open during depolarization
FALLING OHASE OF THE ACTION POTENTIAL
K+ MOVES DOWN ELectrochemical gradient
cell beocme increasingly negative
undershoot
very nergative
below -70
anesthetics…
stop sensations of PNS
usually block voltage gated na+ channels and prevents action potential
analegesic
stop sensation of CNS
the more + strong stimulus means
more frequent action potential
what is the saltatory conuction
increase conduction speed by up to 10x
due to schwann cells surrounding neurons to form myelin sheath
