Bio Exam 3

Front 1

plasma membrane of a muscle fiber

Back 1

sarcolemma

Front 2

cytoplasm of a muscle fiber

Back 2

sarcoplasm

Front 3

an energy-storage polysaccharide abundant in muscle

Back 3

glycogen

Front 4

oxygen-storing red pigment of muscle

Back 4

myoglobin

Front 5

tunnel-like extension of the sarcolemma extending from one side of the muscle fiber to the other; conveys electrical signals from the cell surface to its interior

Back 5

t tubule

Front 6

smooth ER of a muscle fiber; a calcium reservoir

Back 6

sarcoplasmic reticulum

Front 7

dilated ends of sarcoplasmic reticulum adjacent to a t tubule

Back 7

terminal cisternae

Front 8

thick filament

Back 8

myosin; 11 nm in diameter

Front 9

thin filament

Back 9

actin, troponin, and tropomyosin. 5-6 nm in diameter

Front 10

distance from one z disc to the next; contractile unit of a muscle fiber

Back 10

sarcomere

Front 11

cell bodies of motor neurons are located in:

Back 11

spinal cord and brainstem

Front 12

denervation atrophy

Back 12

nerve is severed, then the muscle becomes paralyzed

Front 13

muscle twitch

Back 13

less than 10 stimuli/second
muscle tension remains the same with each stimulation event

time for relaxation!

Front 14

treppe

Back 14

stimulation frequency increased to 10-20 stimuli/second
increasing tension due to insufficient time to remove all the Ca from the sarcoplasm
still time for relaxation

Front 15

wave summation

Back 15

stimulation frequency 20-40 stimuli/second

relaxation does not occur

each new wave is added to the previous wave

Front 16

incomplete tetany

Back 16

40-50 stimuli/second until ultimately the contractions of the muscle fiber "fuse" and that lacks any relaxation

Front 17

tetany

Back 17

formed after incomplete tetany, becomes one continuous smooth contraction

if stimulation continues muscle will fatigue

Front 18

nervous system stimulation does not exceed ___ stimuli/second

Back 18

25

Front 19

anaerobic fermentation

Back 19

ATP produced without oxygen

ATP yield is minimal

produces lactic acid

Front 20

aerobic respiration

Back 20

high ATP yield

requires continuous oxygen

uses glucose and fatty acids

Front 21

Phosphogen system is an _______ ATP source

Back 21

immediate

gives up to 10-15 seconds of sprinting

Front 22

2 enzymes in phosphogen system & what they do

Back 22

myokinase - takes from one ADP and transfers it to another, makes ATP and AMP

creatine kinase - takes from a creatine phosphate and transfers it to an ADP, makes creatine and an ATP

Front 23

muscle RMP

Back 23

-90mV

Front 24

depolarization

Back 24

muscle becomes less negative (after Na+ rushes in)

Front 25

repolarization

Back 25

return to RMP, becomes more negative (when K+ moves out)

Front 26

hyperpolarization

Back 26

muscle becomes too negative (slow closing of Na+ channels)

Front 27

crossbridge formation:

Back 27

myosin heads attach to exposed myosin binding sites of actin.

Front 28

power stroke:

Back 28

myosin head swivels and pulls the thin filament a small distance past the thick filament toward the center of the sarcomere.

Front 29

What molecule binds to the myosin head in order to release it from actin?

Back 29

ATP

Front 30

Myasthenia Gravis

Back 30

autoimmune disease where antibodies attack NMJ, binding ACh receptors together in clusters.
Receptors are removed by the muscle.
Muscle fatigues quickly & muscle weakness ensues.
Some patients die quickly and others live a normal lifespan

Front 31

Sarin

Back 31

organophosphorus compound, results in spastic paralysis
potent inhibitor of AChE
ACh continues to act on the muscle and it never relaxes
death can ensue as soon as one minute
Symptoms:
SLUDGE

Front 32

SLUDGE (sarin symptoms)

Back 32

salivation, lacrimation (tears), urination, gastrointestinal distress, emesis (vomiting)

Front 33

endomysium

Back 33

thin sleeve of areolar CT, surrounds each muscle fiber

Front 34

perimysium

Back 34

thicker CT sheath, wraps muscle fibers into fascicles

Front 35

epimysium

Back 35

fibrous sheath, surrounds entire muscle

Front 36

fascia

Back 36

sheet of CT that separates neighboring muscles from each other and from subQ

Front 37

Ohm's law

Back 37

current = voltage/resistance

Front 38

4 segments of a neuron

Back 38

Receptive segment: receive stimuli to excite neuron (chemically gated)
Initial segment: axon hillock, deciding factor on whether or not to fire (voltage-gated)
Conductive segment: axon & its branches (voltage Na+ & K+)
Transmissive segment: synaptic knob (voltage-gated Ca++)

Front 39

avascular necrosis

Back 39

loss of blood supply, death of bone tissue

Front 40

subluxation

Back 40

joint only partly out of place

Front 41

Ligaments of the knee joint

Back 41

Patellar ligament: contains sesamoid bone of patella, attaches to tibial tuberosity from the quadriceps muscle

ACL (anterior cruciate ligament): from anterior tibia to posterior femur, prevents anterior translation of tibia on the femur

PCL: from the posterior tibia to the anterior femur. prevents posterior translation of the tibia on the femur (twice as strong as ACL)

Medial collateral ligament (MCL): prevents valgus (knee coming inward, medially)

LCL: prevents varus (knees outward, laterally)

Front 42

Divisions of CNS

Divisions of PNS

(and subdivisions)

Back 42

CNS: brain and spinal cord

PNS: sensory division and motor division

Sensory (afferent) division: carries signals from receptors to the CNS. Divided into somatic & visceral.

Somatic sensory: signals from body parts to CNS

Visceral sensory: signals from organs to CNS


Motor (efferent) division: signals from CNS to body's effectors. Divided into somatic and visceral.

Somatic motor: carries signals to skeletal muscles. Voluntary, as well as involuntary somatic reflexes

Visceral motor (Autonomic nervous system): carries signals to glands, cardiac muscle, and smooth muscle. Involuntary, unconscious. 2 divisions.

Sympathetic division of ANS: arouses body for action...accelerating heartbeat, increasing respiration, inhibiting digestion

Parasympathetic division of ANS: calms body: slows heartbeat, stimulates digestion

http://www.google.com/imgres?imgurl=http://apbrwww5.apsu.edu/thompsonj/Anatomy%2520%26%2520Physiology/2010/2010%2520Exam%2520Reviews/Exam%25203%2520Review/14-01_ANSinNvsSys_1.jpg&imgrefurl=http://www.apsu.edu/thompsonj/Anatomy%2520%26%2520Physiology/2010/2010%2520Exam%2520Reviews/Exam%25203%2520Review/CH%252011%2520Divisions%2520of%2520the%2520Nervous%2520System.htm&h=600&w=620&sz=53&tbnid=QVBTicqzuVdgPM:&tbnh=90&tbnw=93&zoom=1&usg=__QfFangWDxR0bZ6djWyJ6huI-ZGQ=&docid=I0A9NnmS3q24SM&sa=X&ei=BUWCUoGQMc3a4AOfj4GABA&ved=0CDIQ9QEwAQ

Front 43

What forms the blood brain barrier?

Back 43

astrocytes

Front 44

Oligodendrocytes

Back 44

have a bulbous body with many armlike processes...each process reaches out to a nerve fiber and spirals around it like electrical tape, forming the myelin sheath in the CNS

Front 45

microglia

Back 45

macrophages of the CNS

Front 46

Multiple sclerosis

Back 46

Antibodies attack oligodendrocytes
deteriorate and are replaced by hardened scar tissue.
sclerosis = hardening
usually between 20 and 40 years old
no cure

Front 47

Tay Sachs disease

Back 47

hereditary disorder...results from abnormal accumulation of a glycolipid in the myelin sheath due to a lack of lysosomal enzyme.
Most victims die by the age of 3-4 years

Front 48

gaps between segments of myelin sheath

Back 48

nodes of Ranvier

Front 49

short section of nerve fiber between the axon hillock and the first glial cell:

Back 49

initial segment

*axon hillock + initial segment = trigger zone

Front 50

T or F: unmyelinated fibers in PNS are enveloped in Schwann cells

Back 50

True.
They just aren't wrapped many times around

Front 51

speed at which a nerve signal travels along a nerve fiber depends on:

Back 51

diameter of the fiber and the presence or absence of myelin

Front 52

an electrical potential is:

Back 52

a difference in the concentration of charged particles between one point and another.

Front 53

electrical current

Back 53

flow of charged particles from one point to another

Front 54

RMP of skeletal muscle

RMP of neurons

Back 54

charge difference across the plasma membrane...
Neurons: -70mV Skeletal muscle: -90mV

K+ in ECF and Na+ in ICF reach an equilibrium, which ends in an RMP of -70mV

Front 55

Steps of an action potential

Back 55

1. sodium ions arrive at the axon hillock and depolarize the membrane at that point..appears as a steadily rising local potential
2. Local potential must rise to threshold (-55mV), minimum needed to open voltage-gated channels
3. Neuron fires (produces an action potential). Voltage-gated Na+ channels open quickly and keep opening and depolarizing the membrane, more channels open in a positive feedback loop that makes the membrane voltage rise rapidly
4. When potential passes 0mV, Na+ channels start closing, voltage peaks at +35mV.
5. By the time the voltage peaks, slower K+ channels open and K+ exits the cell. This repolarizes the membrane and returns it to negative numbers.
6. K+ channels are slow to close, so the membrane voltage drops to more negative than RMP (hyperpolarization).
7. RMP gradually restored

Front 56

Na+ and K+ location changes during action potential

Back 56

Na+ starts outside the cell and moves quickly inside the cell. K+ slowly moves out of the cell.

Front 57

Compare/contrast local & action potentials

Back 57

Local: produced by gated channels on the dendrites and soma.
Action: produced by voltage-gated channels on the trigger zone and axon.
Local may be depolarizing or hyper polarizing.
Action potential always depolarizing
Local: graded; proportional to stimulus strength
Action: all or none; either does not occur or exhibits the same peak voltage regardless of stimulus strength
Local: reversible; returns to RMP if stimulation ceases before threshold is reached
Action: irreversible; goes to completion if it begins
Local: local; has effects for only a short distance
Action: self-propogating; has effects a great distance from point of origin
Local: decremental; grows weaker with distance
Action: nondecremental; maintains strength regardless of distance

Front 58

EPSP

Back 58

excitatory postsynaptic potential

Na+ flows into the cell, neutralizing some of the negative charge on the inside of the membrane..depolarizes a little

Front 59

IPSP

Back 59

inhibitory postsynaptic potential

Cl- flows into the cell and makes the cytosol more negative (or K+ flows out)

Front 60

Temporal summation

Back 60

occurs when a single synapse generates EPSPs so quickly that each is generated before the previous one fades..allows the EPSPs to add up over time to a threshold voltage that triggers an action potential.

pg 467

Front 61

Spatial summation

Back 61

occurs when EPSPs from several synapses add up to threshold at the axon hillock

pg 467

Front 62

facilitation

Back 62

process where one neuron enhances the effect of another

Front 63

presynaptic inhibition

Back 63

opposite of facilitation; one presynaptic neuron suppresses another one.

Front 64

Types of neural circuits

Back 64

diverging: 1 input, turning into many outputs
converging: many inputs, turning into 1 output
reverberating: 1 input, recirculating and ending in 1 output (looped)
parallel after-discharge: 1 input diverges to stimulate several chains of neurons, but they converge to make 1 output.

Front 65

ability of a muscle to stretch under tension

ability of a muscle to return to its original length after being stretched

Back 65

extensibility

elasticity

Front 66

The elasticity of skeletal muscle fibers is primarily due to the presence of:

Back 66

titin

Front 67

T tubules are extensions of the ______ in skeletal muscle

Back 67

sarcolemma

Front 68

length-tension relationship

Back 68

force of contraction is dependent on degree of stretch of the muscle prior to stimulation

Front 69

T or F: smooth muscles have T tubules

Back 69

FALSE

Front 70

Fusiform cells are found in:

Back 70

smooth muscles

Front 71

____ ions are concentrated in the _____________ while muscle fibers are at rest

Back 71

Ca++ ions, sarcoplasmic reticulum

Front 72

motor unit:

Back 72

a motor neuron and all the muscle fibers it innervates

Front 73

Closer look at excitation-contraction:

action potential in muscle

Back 73

Stimulation of a muscle fiber opens Na+ channels; influx of Na+, depolarization..
Action potential is generated in the sarcolemma next to the end plate.
Action potential is propogated along the sarcolemma
Action potentials travel down T tubules, and Ca++ channels in nearby terminal cisternae open and release Ca++ into sarcoplasm.
Ca++ binds to troponin molecules on thin filaments and contraction begins.

Front 74

Somatic sensory receptor signals go to:

Back 74

CNS, then to skeletal muscle by way of somatic motor neurons

Front 75

Visceral receptors (use ANS) and go to:

Back 75

visceral effectors by way of autonomic motor neurons