BIO 351 TEST 3

________: composed of protein myosin that contains two heavy and four light polypeptide chains.

________ in the utricle, saccule, and ampullae of the semicircular canals respond to motion of the head.

________ are organized by motor programs.

________ depends on neurotransmitter released and type of receptor molecules.

________: composed of fibrous protein actin.

Load is greater than the ________ muscle can generate, so muscle neither shortens nor lengthens.

________ to cerebellum impairs standing, walking, or performance of coordinated movements.

________ are wrapped in myelin, which is compact and tight except near the nodes of Ranvier and at focal sites described as "incisures.

________ contain numerous Ca2+ channels that open to allow rapid influx of extracellular Ca2+.

________ spontaneously or in response to chemical stimuli that bind to G protein- linked receptors.

When nervous system stimulates ________, myosin heads are allowed to bind to actin, forming cross bridges, which cause sliding (contraction) process to begin.

Shortening occurs when ________ generated by cross bridges on thin filaments exceeds forces.

________ are spirally arranged, causing smooth muscle to contract in corkscrew manner.

When a(n) ________ passes by, T tubule proteins change shape, causing SR proteins to change shape, causing release of calcium into cytoplasm.

________ can be observed and recorded as a myogram.

________ are specialized cell connections that allow depolarization to spread from cell to cell.

________ contains pouchlike infoldings called caveolae.

________ line: line of protein (myomesin) that bisects H zone vertically.

________: ability to shorten forcibly when stimulated.

________ on a dorsal root that contains cell bodies of afferent spinal nerve neurons.

At the ________ ACh is released by exocytosis of synaptic vesicles at active zones in the nerve terminal.

Actin is polypeptide made up of ________- shaped G actin (globular) subunits.

________: muscle fiber can not be stimulated for a specific amount of time, until repolarization is complete.

________ (responsiveness): ability to receive and respond to stimuli.

Terminologies: Myo, mys, and ________ are prefixes for muscle.

Actin and ________ interact by sliding filament mechanism.

________ in the cleft rapidly terminates transmission by hydrolyzing ACh.

________ consists of axon terminals, synaptic cleft, and junctional folds.

________ flows across the synaptic cleft to reach receptors that are concentrated at the peaks of junctional folds.

________ integrates this information and modifies the motor outflow, exerting a coordinating and smoothing effect on the movements.

________: muscle changes in length and moves load.

________ are offset from each other, resulting in staggered array of heads at different points along thick filament.

________ proteins act as voltage sensors that change shape in response to an electrical current.

________ binding causes either graded (local) potential or action potential.

________ shows hexagonal arrangement of one thick filament surrounded by six thin filaments.

________ has an incidence of 1- 3 people per 100, 000 population.

________: control of voluntary movements, procedural learning, cognition, and emotions.

________: stripes formed from repeating series of dark and light bands along length of each myofibril.

________ does store intracellular Ca2+, but most calcium used for contraction has extracellular origins.

________ (temporal) summation results if two stimuli are received by a muscle in rapid succession.

________ are stimulated by somatic motor neurons.

Axons (long, threadlike extensions of motor neurons) travel from ________ to skeletal muscle.

control of voluntary movements, procedural learning, cognition, and emotions

dark regions

lighter region in middle

line of protein (myomesin) that bisects H zone vertically

lighter regions

coin-shaped sheet of proteins on midline of light I band

composed of fibrous protein actin

composed of protein titin

network of smooth endoplasmic reticulum tubules surrounding each myofibril

area formed from terminal cistern of one sarcomere, T tubule, and terminal cistern of neighboring sarcomere

muscle fiber cannot be stimulated for a specific amount of time, until repolarization is complete

events that transmit AP along sarcolemma (excitation) are coupled to sliding of myofilaments (contraction)

simplest contraction resulting from a muscle fibers response to a single action potential from motor neuron

muscle changes in length and moves load

muscle shortens and does work

muscle lengthens and generates force

proteins that anchor filaments to sarcolemma at regular intervals

responds to stretch only briefly, then adapts to new length

Morphological abnormalities in MG

• Part of the Motor System

• Named “extrapyramidal” to separate it from the tracts that originate in the cortex

• Originates in the brainstem

• Carries motor fibers to the spinal cord

• Responsible for involuntary movement

Peripheral nerve attached to the spinal cord

Axon directed toward central nervous system, conveying sensory information

Nodule on a dorsal root that contains cell bodies of afferent spinal nerve neurons

Axon directed away from the central nervous system, conveying motor commands to muscles and glands.