Physiology Midterm 1

Front 1

epithelial tissue

Back 1

selective secretion and absorption of ions and organic molecules, and for protection. located at surfaces of body and individual organs, and hollow structures within body

Front 2

connective tissue

Back 2

connect and support structures of the body. some are found in loose meshwork of cells and fibers underlying most epithelial layers.

Front 3

nerve tissue

Back 3

specialized to initiate and conduct electrical signals, over long distances.

Front 4

muscle tissue

Back 4

specialized to generate the mechanical forces that produce movement. may be attached through other structures to bones and produce movements of the limbs or trunk. may be attached to skin, may surround hollow cavities- heart.

Front 5

plasma membrane

Back 5

covers the cell surface.

Front 6

hydrophobic/philic, amphipathic

Back 6

hate water- CH chains of phospholipid tails/water loving-polar heads of phospholipid. both water loving and hating.

Front 7

integral membrane proteins

Back 7

closely associated with membrane lipids and cannot be extracted from the membrane without disrupting the lipid bilayer. amphipathic.

Front 8

peripheral membrane proteins

Back 8

NOT amphipathic, do not associate with nonpolar regions of the lipids in the interior of the membrane. located at the membrane surface where they are bound to the polar regions of the integral membrane proteins.

Front 9

simple diffusion

Back 9

hydrophobic enough molecules to get through phospholipid bilayer.

Front 10

facilitated diffusion

Back 10

down a concentration gradient. no energy required. eg. glucose entry into most body cells-transport protein changes shape without energy.

Front 11

net flux

Back 11

difference between the two one-way fluxes.

Front 12

primary active transport

Back 12

against a concentration gradient (creates one), direct slipping of ATP

Front 13

secondary active transport

Back 13

against a concentration gradient, energy provided by another molecule's gradient. almost always in exchange for Na+

Front 14

ion channels

Back 14

selective for certain ions, gated by electrical/chemical/mechanical.

Front 15

endo/exocytosis

Back 15

require ATP and many membrane proteins. bulk movement of macroscopic particles or large proteins into and out of cells.

Front 16

facilitated diffusion

Back 16

move particles down concentration gradient

Front 17

osmosis

Back 17

water can cross most cell membranes due to channels called aquaporins.

Front 18

absolute refractory

Back 18

region of the membrane, when during the AP, a second stimulus, no matter how strong, will not produce a second AP. voltage-gated Na channels either already open or have proceeded to inactivated state.

Front 19

relative refractory

Back 19

following absolute refractory period, there's an interval during which a second AP can be produced, but only if the stimulus strength is considerably greater than usual.

Front 20

node of ranvier

Back 20

AP occur only here, where myelin coating is interrupted and the concentration of voltage-gated Na channels is high.

Front 21

myelin

Back 21

causes saltatory conduction. speeds up neurons, for motor neurons or when have sharp pain.

Front 22

voltage-gated

Back 22

changes in membrane potential can cause movement of charged regions on a channel protein, altering its shape.

Front 23

mechanically- gated

Back 23

physically deforming (stretching) the membrane may affect the conformation of some channel proteins.

Front 24

ligand-gated

Back 24

binding of specific molecules to channel proteins may directly or indirectly change the shape of channel protein.

Front 25

acetylcholine ACh

Back 25

NT in peripheral nervous system at the neuromuscular junction and in the brain. excitatory NT

Front 26

nicotine

Back 26

hydrophobic structure allows rapid absorption. binds tightly. receptors mediate EPSPs within glanglia of the autonomic nervous system, and presynaptic facilitation of excitatory NTs release at widespread synapses in brain

Front 27

muscarine

Back 27

mushroom poison. these receptors couple with G proteins, which then alter the activity of different enzymes and ion channels. prevalent at synapses in brain and junctions of neurons that innervate many glands and the heart.

Front 28

graded potential

Back 28

amplitude varies with size of event, can be summed, has no threshold, has no refractory period, decreases with distance, duration varies ith initiating conditions, can be depolarization or hyper, depends on ligand channels or other chem/physical changes.

Front 29

receptor potential

Back 29

in afferent neurons, the initial depolarization to threshold is achieved by a graded potention, which is generated in the sensory receptors at the peripheral ends of the neurons.

Front 30

adaptation

Back 30

process that decreases in receptor sensitivity, which results in a decrease in AP frequency in an afferent neuron despite a stimulus of constant strength.

Front 31

afferent

Back 31

PNS, somatic sensory, visceral sensory, special sensory

Front 32

efferent

Back 32

PNS, somatic motor, autonomic motor (sympathetic, parasympathetic, enteric)

Front 33

presynaptic inhibition

Back 33

decreases depolarization and neurotransmitter release

Front 34

presynaptic facilitation

Back 34

increases depolarization and NT release.

Front 35

interneurons

Back 35

connect neurons within CNS. integrate efferent and afferent divisions of the PNS in the CNS.

Front 36

pre/postsynaptic IPSP

Back 36

NT binds to receptor, ligand-gated channels open, either K+ out or Cl- in, net effect is either hyperpolarization (if K+) or prevent depolarization (Cl-).

Front 37

pre/postsynaptic EPSP

Back 37

postsynaptic- NT binds to receptor, ligand-gated channels open, cations flow through (mainly Na+), K+ leaves, net effect is depolarization.

Front 38

spatial summation

Back 38

2 neurons firing at same time

Front 39

temporal summation

Back 39

1 neuron firing, close in time

Front 40

dorsal, ventral roots

Back 40

where groups of afferent fibers enter the spinal cord from peripheral nerves.

Front 41

ventral roots

Back 41

where axons of efferent neurons leave the spinal cord.

Front 42

phosphatases

Back 42

facilitates dephosphorylation accomplished by a second class of enzymes. mechanism for removing the phosphate group and returning the protein to its original shape.

Front 43

G-proteins

Back 43

protein complex bound to receptor located on cytosolic surface of plasma membrane. reversibly binds guanosine with nucleotides. interact with membrane ion channels.

Front 44

adenylyl cyclase

Back 44

enzyme that catalyzes the conversion of ATP molecules to cAMP- acts as second messenger.

Front 45

corpus callosum

Back 45

cortex layers of left and right cerebral hemispheres, although largely separated by a deep longitudinal division, are connected by a massive bundle of nerve fibers.

Front 46

signal transduction

Back 46

diverse sequences of events between receptor activation and cellular responses. stimulus is transformed into a response.

Front 47

phosphorylation

Back 47

phosphate group, which has net negative charge, is covalently attached by a chemical reaction, where a phosphate group is transferred from one molecule to another.

Front 48

somotopic map

Back 48

where neurons of the motor cortex that control muscle groups in various parts of the body are arranged anatomically, relative sizes of body structures are proportional to the number of neurons dedicated to their motor control.

Front 49

cerebral cortex

Back 49

cerebral hemispheres, consisting of an outer shell of gray matter, and an inner layer of white matter, composed primarily of myelinated fiber tracts.

Front 50

occipital, temporal, parietal, frontal lobes

Back 50

cortex of each cerebral hemisphere is divided into four lobes. highly folded.

Front 51

cerebellum

Back 51

little brain

Front 52

forebrain- cerebral hemispheres

Back 52

contain cerebral cortex: perception, generation of skilled movements, reasoning, learning and memory. contain subcortical nuclei, which participate in coordination of skeletal muscle activity

Front 53

forebrain- thalamus

Back 53

acts as a synaptic relay station for sensory pathways on their way to the cerebral cortex, participates in control of skeletal muscle coordination, plays a key role in awareness

Front 54

forebrain- hypothalamus

Back 54

regulates anterior pituitary gland, water balance, eating/drinking behavior, reproductive system, circadian rhythms, autonomic nervous system and body temp. participates in generation of emotional behavior, reinforces certain behaviors

Front 55

brain stem- pons, medulla

Back 55

CNS, contains all fibers passing between the spinal cord, forebrain and cerebellum. contains the reticular formation and integrating centers for cardiovascular and respiratory activity, and contains nuclei for cranial nerves.

Front 56

Somatic motor

Back 56

PNS, efferent division, body's skeletal muscles.
from CNS to skeletal muscles, signal travels along 1 neuron (autonomic travels through 2)

Front 57

somatic sensory

Back 57

PNS, afferent division, touch, pressure, heat, cold, muscle force and position, pain. cold and warmth receptors

Front 58

visceral sensory

Back 58

PNS, afferent division, blood pressure, oxygen levels, osmolarity

Front 59

special sensory

Back 59

PNS, afferent division, vision, hearing, taste, smell

Front 60

Autonomic motor

Back 60

PNS, efferent division, sympathetic and parasympathetic. Both para/sympa are tonically (constantly) active. effects on organs are opposite.
from CNS to smooth/cardiac muscles, glands or GI neurons, signal travels on preganglionic fiber, to a ganglion, and through a postganglionic fiber.

Front 61

Sympathetic nervous system

Back 61

PNS (autonomic motor, efferent), thoracic area of spine, activates processes facilitating physical exertion and inhibits processes that do not help, generalized. eg: heart and blood vessels, slows digesting. "fight or flight" passes through pre and postganglionic neurons from CNS to destination

Front 62

Parasympathetic nervous system

Back 62

PNS (autonomic motor, efferent), brainstem and sacral area of spine, activates processes that help during the resting state and inhibit processes that aid in physical exertion, discrete. eg: digesting. "rest and digest" passes through pre and postganglionic neurons from CNS to destination

Front 63

Norepinephrine

Back 63

receptors on on presynaptic terminals strongly modulate synthesis and release of this neurotransmitter. nerve fibers that release this NT is called adrenergic fibers (adrenaline)

Front 64

Fick's law (flux equation)

Back 64

magnitude of net flux is directly proportional to difference in concentration across membrane (C0-Ci); surface area of membrane A, and membrane permeability coefficient P: J=PA(C0-Ci)

Front 65

Body fluid compartments

Back 65

26 L ICF (water)
11 L interstitial fluid
3 L plasma
2 L ECF

Front 66

Botulinum toxin

Back 66

destroys SNAREs at EPSPs (botox- paralyzes muscles)

Front 67

Tetanus toxin

Back 67

destroys SNAREs at ISPS, anaerobically makes tetanus toxic. Ca mediated exocytosis causes jaw muscles to contract

Front 68

second messenger system

Back 68

substances that enter or are generated in the cytoplasm as a result of receptor activation by first messenger. second messengers diffuse throughout the cell to serve as chemical relays from the plasma membrane to the biochemical machinery inside the cell.

Front 69

cAMP

Back 69

activated adenylyl cyclase catalyzes conversion of cytosolic ATP molecules to cyclic AMP- acts as a second messenger to trigger the sequence of events leading to cell's ultimate response of the first messenger.

Front 70

labeled lines

Back 70

every location on body has a dedicated pathway. eg: temperature wire- only fires to brain if hot/cold. if touch this wire, feel hot/cold even if not actually! labeled lines terminate in regoins of the brain dedicated to each area.

Front 71

phantom limb

Back 71

neurons from amputated limb are still present in brain. labeled lines firing to brain inappropriately.

Front 72

Rapid adaptation (phasic)

Back 72

stimulus intensity is the same over time. APs are few at first, but not after a bit. when stimulus removed, APs fired again. eg: sit down in chair- don't need to keep being told that you're sitting

Front 73

Slow adaptation (tonic)

Back 73

stimulus is same over time. lots of APs at first, but then fewer and farther apart. when stimulus removed, no AP. eg: knowing where arms are when sitting still/falling asleep.

Front 74

sciatic nerve pain

Back 74

eg: leg hurts, but not because it is injured, because pinched nerve in spinal cord.

Front 75

overlapping receptive fields

Back 75

have 3 neurons, stimulus is on middle neuron, all 3 overlap. middle neuron has highest AP frequency, bordering neurons have small APs

Front 76

lateral inhibition

Back 76

enhances acuity- precision of localizing a stimulus. exaggerates location of stimulus to help locate it. neurons cancel each other out to enhance contrast to allow stimulated neuron to be felt. a;odfhvafdg

Front 77

receptor potential

Back 77

graded potentials. bigger stimulus means more APs, not higher AP.

Front 78

pre-ganglionic neurons

Back 78

first neuron from CNS to ganglion.

Front 79

post-ganglionic neurons

Back 79

second neuron passing between ganglia and effector cells (smooth or cardiac muscles, glands or GI neurons)

Front 80

pacinian corpuscle

Back 80

pressure receptor touches with probe on nerve with capsule. rapidly adapting (phasic) response. told touched, and when touch removed.
probe on nerve without capsule, slowly adapting (tonic) response. constantly being told it was being touched.

Front 81

long-term potentiation

Back 81

1. high frequency APs in presynaptic cell
2. glutamate released
3. glutamate binds to AMPA and NMDA channels
4. Na+ entry depolarizes cell
5. depolarization drives Mg2 out of NMDA
6. Ca2 entry activates second messenger system
7. long-lasting increase in glutamate receptors and sensitivity
8. long-lasting increase in glutamate synthesis and release from presynaptic cell

Front 82

NMDA

Back 82

recognizes glutamate during stressful events, help remember better