Homeostatic control mechanism

-the factor that is being regulated

Homeostatic control mechanism

-detects changes in the enviornment from a particular set point

Homeostatic control mechanism

-receives information from the sensors and makes a decision about waht needs to be done

Homeostatic control mechanism

-make changes according to the information they receive from the integrating center

-blood clotting

-contractions of the uterus during childbirth

-most disease due to disturbance of __

-ability to maintain decreases with age

span the entire width of plasma membrane

-function as transporters, channels, receptors, carriers

partially embedded on either side of plasma membrane

-function as enzymes, structural support, receptors

there are no bonds b/w the lipids and proteins tht make up the plasma membrane

-not fixed in space so parts can move

short cell surface projections with motile properties

increase surface area

very small, finger-like extensions of the plasma membrane

-act as receptors

-provide structural support

-help transport molecules across membrane

cellular region b/w organelles and plasma membrane

-includes the cytosol and organelles

small granules composed of protein and RNA

-site of protein synthesis (integral proteins)

entensive, enclosed network of membrane with ribosomes on surface

-packages proteins and distributes them to other organelles

-membrane system composed of tubules with no ribosomes attached

-site of lipid and steroid synthesis

-stores calcium in some cell types

stack of smooth membrane sacks with associated vesicles

-modifies proteins received from the rough ER and packages them into vesicles

double membrane structure

-make energy currency = ATP

mRNA to proteins

-mRNA serves as tenplate

tRNA brings amino acids to ribosome

-takes place in cytoplasm

movement of a substance across a membrane from higher concentration to lower concentration

-moves down concentration gradient

-does not require energy in form of ATP

-movement of substance across a membrane from lower to higher concentration

-requires ATP

-lipid soluble substances (lipophilic)

-very small polar molecules

-concentration difference across membrane

-temp of the solution

-permeability of membrane

-surface area of membrane

movement of large, polar substances across plasma membrane by carrier proteins (integral proteins)

-ATP not needed (moved by concentration gradient)

must be difference in solute concentration across the membrane

-membrane must be selectively permeable to water but not the solute

pressure required to prevent osmosis

indirect measure of solute concentration of a solution

requires ATP

requires a carrier molecule

-directly utilizes energy released by hydrolysis of ATP

-Ca++ ATPase

-Na+/K+ ATPase

-high population of integral proteins and voltage-gated sodium channels

-APs propigated here

most common type of neuron

-motor neuron (efferent)

found in CNS

connect afferent to efferent neurons

process information (signals)

helps to maintain normal external enviornment around neurons

-helps to maintain the blood brain barrier

line cavities of the brain and spinal cord

-make CSF

-open when a substance binds to a receptor on the channel to allow ion to move down their concentration gradients

-respond to NTs

-esp important in dendrites

-most Na+

-contained in excitatory cells (neurons and muscles)

-positive feedback

-essential for producing AP

phase of AP - ions moving through passive (K+) channels to maintain RMP

-Na+/K+ ATPase maintains concentrations

AP phase - stimulus depolarizes the membrane by acting on chemically-gated channels resulting Na+ moving into the neruon

-if threshold reached AP initated

-AP phase - once threshold reached, many more voltage-gated Na+ channels open = depolarization

-continues untill AP peaks

AP phase - Voltage-gated Na+ channels close "inactivation"

-voltage-gated K+ channels open=leads to repolarization

-ions flow from one cell to another

-adjacent cells joined together by gap junctions (connexins) that permit direct passage of ions from one cell to next

smooth and cardiac muslce

-1 AP reaches presynaptic terminal

2-depolarization activates voltage-gated Ca++ channels resulting in influx of CA into presynaptic terminal

3-Ca+ triggers fusion of vesicular membrane with axon membrane leading to release of NT into synaptic cleft via exocytosis

neuron has cell body in CNS and synapses with a second neuron at an autonomic ganglion outside the CNS

-interneurons

this neuron extends from the autonomic ganglion to the effector cells

-efferent neurons

sympathetic ganglia

3 sympathetic ganglia that lie in the abdominal cavity

-celiac ganglia, superior (and inferior) mesenteric ganglia

-synapse with postganglionic nerve fibers at a paravertebral ganglion at the spinal cord where they enter

-branch once reach paravertebral ganglion and synapse with postganglionic symp. nerve fibers located at differnt levels in chain

-pass without interruption though the paravetrebral symp ganglia and synapse with a postganglionic symp nerve fiber at a prevertebral ganglion

-originate in paravetrebral or prevertebral ganglia

-relatively long compared to preganglionic fibers 9except those synapse in prevertebral ganglia)

-innervate effector cells

single preganglionic fiber branches to synapse with many postganglionic fibers at different levels on symp chain

-acts to amplify signal

-located on sympathetic and parasympathetic postganglionic nerurons

-NMJ

-found on effector cells stimulated by sympathetic postganglionic neurons

-2 types (alpha and beta) 1and2