Chapter 11. Muscular Tissue Assignment

The junctional folds of the neuromuscular junction are the site of ______ receptors?

Acetylcholine

The protein found in muscle cells that stores and releases oxygen needed is called?

myoglobin

When stimulated , muiscles cells will respond with _____ changes across the plasma membrane.

Electrical

Aerobic respiration produces _____ ATP than glycolysis.

more

what is found in thin filiaments?

1. Tropomyosin

2. F actin

3. troponin

How do smooth muscle myocytes differ from cardiocytes?

Smooth muscle myocytes have no T tubules while cardiac muscles do.

The characteristic that allows muscles to pull on bones and organs to create movement is called?

Contractility

What are two contractile proteins found in a myofibil?

1. Actin

2. Myosin

Which describe smooth muscle tissue?

1. uninucleate

2. mom - striated

The process of muscle excitation is a series of events that permit an impulse from a nerve to generate a polarization change called ------ potential in a muscle fiber.

Action Potential

The volatage meassured across the muscle cell at rest is about -90 M V Action Potential and is called the resting membrane.

potential

In what type of contraction does the internal tension build until it overcomes resistance and the muscle moves the load?

Isotonic

the steps of muscle relaxation in order.

1. The nerve signal ceases

2. AChE breaks ACh down

3. Active transport pumps in the sarcoplasmic reticulum begin to pump calcium back into the cisternae

4. Calcium releases from troponin

5. Tropomyosin covers the myosin binding sites.

Walls of the heart consist of ____ muscle tissue.

cardiac

The partial contraction of a resting muscle is known as which of the following?

muscle tone

The energy needed for short bursts of intense activity is provided by what?

1. Creatine Phosphate

2. ATP

what does excitation involce?

The generation of action potentials, and occur in both neurons and muscle fibers.

The progressive weakness and loss of contractibility that results from prolonged use of the muscles is known as muscle ?

fatigue

what are characteristics of cardiac muscle?

1. It has large stores of glycogen

2. it uses aerobic respiration almost exclusively

3. it is rich in myoglobin

what is the role of acetylchoinesterase?

It breaks down ACh, ending muscle stimulation.

What type of contraction maintians joint stability and posture.

isometric contraction

The portion of a myofibril from one Z disc to the next is called?

sarcomere

What are two regulatory proteins found in a myofibril?

1. troponin

2. tropomyosin

which proteins makes up the thick filaments of a myofibril.

myosin

The prevailing theory regarding muscle contraction is called ___ ____ theory?

Sliding filament theory

Which describes cardiac muscle tissue?

1. Striated

2. usually uninucleate

3. branching

All of the muscle fibers innervated by a single nerve fiber constitute a _______?

motor unit

When muscles stretch and recoil, they recoil to a shorted length. what is the property called?

elasticity

A synapse is the point where a nerve fiber meets a target cell. When the target cell is a muscle fiber, this type of synapse is called a _______ junction.

Neuromuscular junction

Which of the following occur during the relaxation phase of muscle contraction?

1. Calcium levels in the sarcoplasm fall

2. muscle tension declines

3. myosin releases the thin filaments

skeletal muscle exhibits alternating light and dark bands called?

Striations

How does muscle contraction occur?

the overlapping of myofilaments increases.

what is muscle tone?

The partial contraction of resting muscles.

What are the functions of smooth muscle ?

1. To constrict or dilate blood vessels to control pressure.

2. To move material through the digestive tract.

3. To regulate pupil diameter.

Which types of muscle tissue are considered involuntary?

1. cardiac

2. smooth

The neurotransmitter used in a neuromuscular junction is?

Acetylcholine

When a muscle is at rest, what molecule blocks the active sites on the actin molecules?

tropomyosin

Which are the characteristics of cardiac muscle cells?

1. they are resistant to fatigue

2. they contract nearly in unison

3. they contract with regular rhythm

within skeletal muscle cells , what extends from one Z disc to the next and constitutes one contractile until?

1. sarcomere

The voltage measured across the muscle cell at rest is about -90mv and is called the resting membrane?

resting membrane potential

Which describe smooth muscle?

1. smooth muscle has little SR

2. Smooth muscle has no T- tubules

3. smooth muscle is uninucleate

The type muscle contraction in which there is a change in length , but no change in tension is called ______ contraction.

Isotonic contraction

calcium is stored within the _____ ______ of a skeletal muscle cell.

sarcoplasmic reticulum

heart rate and contraction strength are controlled by ?

autonomic nervous system

Which affect twitch strength ?

1. Temperature of the muscle

2. How stretched the muscle was just before it was stimulated

3. Muscle fatigue

4. Stimulation frequency

actions that require physical strength typically involve ?

large motor units

a record of the timing and strength of a muscles contraction is called?

myogram

in the heart, what triggers the wave of electrical excitation that causes the heart to contract?

pacemaker

which are chacteristics of cardiac muscle?

1. it has large stores of glycogen

2. it is rich in myoglobin

3. it uses aerobic respiration almost exclusively.

what is the immediate trigger for the contraction of smooth muscle.

calcium ions

the minimum voltage necessary to generate an action potential ?

The threshold

what is the H band of a sarcomere?

a region within the A band that lacks thin filaments

Tonic contraction of ____ muscle plays an important role in maintain blood pressure and in keeping the intestine partially contracted.

smooth

what is the perimysium of a muscle?

the connective tissue layer covering individual bundles of muscle fibers.

Which three situations lead to fatigue in long duration exercise?

1. electrolyte loss

2. fual depletion

3. central fatigue

a muscle fiber shortens and generates force during the ____ period of a muscle twitch.

Contraction

fibers that are well adopted to aerobic respiration are called _____ twitch fibers?

Slow

where is single unit smooth muscle found ?

1. wall of stomach

2. wall of bladder

3. wall of uterus

Action potentials spread across the sarcolemma and continue down which structures into the sarcoplasm?

t tubules

which type of muscles contract more strongly?

warm

Muscle tissue is typically slow to contract and slow to relax?

smooth

discs are the thickened notched ends of the cardiac muscle cells which contain gap junctions.

intercalated

temporal summation to a state of fluttering contraction known as what?

incomplete tetanus

During repolarization ____ ions diffuse out of the cell, changing the membrane potential back to negative value.

potassium

what occurs when calcium binds to troponin?

The troponin tropmyosin complex changes shape and exposes the myosin binding sites (active site)

muscle tissue is typically slow to contract and slow to relax

smooth

what is the function of T tubules

to stimulate the terminal cisternae to release calcium

muscle cells contain _____ a starch like carbohydrate that provides energy during intense exercise.

Glycogen

at the synaptic knob of the motor neuron, calcium stimulates exoctosis of the synaptic vesicles to release the neurotransmitter ____ into the synapse.

Acetylcholine

The glycogen lactic acid system utilizes what molecules as fuel to generate ATP?

glucose

what causes skeletal muscle cells to be striated?

the alternating light and dark regions of the sarcomeres

what results in a weak contraction?

1. an over stretched muscle

2. an over contracted

once threshold has been reached a muscle fiber will contract fully, is know as what law.

all or none

during contraction the cooked myosin head binds to an exposed active site on the actin protein of the filament to form a cross bridge.

Actin

twitch strength varies with how stretched the muscle was just before the current stimulus.

true

the cross bridge created by the binding of a myosin head to an active site on an actin filament is broken by binding

ATP

which two types of muscle tissue can be autorhythmic?

1. smooth

2. cardiac

which process produces the most ATP?

aerobic respiration

contracting muscles against a load that resists movement is called?

Resistance

fatigue resistance is improved by _____ exercise which enhances the delivery and use of oxygen.

aerobic

each muscle fiber innervated by which of the following?

one motor neuron

where does the end plate potential occur?

motor end plate

actin and myosin serve what functions?

1. internal transport

2. chromosome movement

3.cellular movement

in muscle what does the source of ATP depend upon?

duration of exercise

on a myogram the stimulus and the twitch is known as the ______ period.

Latent

what is true the light bands in skeletal muscle.

they are called I bands in skeletal muscle.

the portion of a myofibril from one z disc to the next is called?

Sarcomere

infolding of the sarcolemma called transverse tubules are associated with two terminal cisternae. forming a unit called a?

Triad

the build up of lactic acid in the sarcoplasm has very little effect on twitch strength

true

the innermost layer of connective tissue that surrounds each muscle fiber is called?

Endomysium

complete (fused) _____ is the continuous forceful contraction in a muscle with no relaxation between stimuli

Tetanus

what happens when calcium ions bind to troponin?

tropomyosin moves off the active site on actin

the synaptic knob does not touch the muscle fiber but is separated by which structure?

synaptic cleft

which is not naturally seen in the muscles of the body?

complete tetanus

in an NMJ after acetylcholins diffuses across the synaptic cleft where does it bind to ligand gated channels

on the sarcolemma

the quick up and down voltage shift from negative to positive created by the movement of NA+ and K + across the cell membrane

action potential

what are smaller motor units used for?

fine motor control

cadiac muscle cells are considered ____ because they contract rhythmically and independently.

autorhythmic

what do neurons ans muscle cells have in common?

their membrane undergo voltage changes when stimulated.

As the myosin head releases the thin ilament muscle tesion declines during what is reffered to as the _____ phase of a muscle twich.

relaxation