A and P exam 3 Vocab

6.5, 9, 10

z discs

narrow, plate-shaped regions of dense material that separate one sarcomere from the next

a band

dark, middle part of sarcomere that extends entire length of thick filaments and includes those parts of thin filaments that overlap thick filaments

I band

lighter, less dense area of sarcomere that contains remainder of thin filaments but no thick filaments. A Z disc passes through the center of each I band.

H Zone

narrow region in center of each A band that contains thick filaments but no think filaments.

M line

region in center of H zone that contains proteins that hold thick filaments together at center of sarcomere,

Thermogenesis

Function of muscular tissue. Heat production from the contraction of muscular tissue. Ex.) involuntary contraction of skeletal muscles, AKA shivering, increases the rate of heat produ

Locomotion

function of muscular tissue, to produce body movement.

Stabilize body position/ maintain posture

function of muscular tissue

Storage and movement of substances

function of muscular tissue. Storage: sphincters, movement of substances: pumping blood, blood flow, digestion, propelling gametes, urine, lymph.

Excitability

main characteristic of muscle tissue, Responsiveness and the ability to recieve and respond to stimuli.

Contractility

main characteristic of muscle tissue, ability to shorten forcibly when stimulated.

Extensibility

main characteristic of muscular tissue, ability to be stretched.

Elasticity

main characteristic of muscular tissue, ability to recoil to resting length,

smooth muscle

arrector pilli

cardiac and smooth muscle

only has one nucleus

skeletal muscle

has long, cylindrical, unbranched cells

cardiac muscle

contains both gap junctions and desmosomes

smooth muscle

contains calmodulin instead of troponin

cardiac muscle

cells contain intercalated discs

skeletal muscle

contains all 3 CT coverings (epimysium, perimysium, endomysium )

skeletal and cardiac muscle

contains sarcomeres

smooth muscle

cells form sheets and layers that contract in different orientation

skeletal muscle

voluntary control

cardiac and smooth muscle

involuntary control

smooth muscle

has slow, sustained muscle contractions. Ex.) peristalsis, which is involuntary

skeletal muscle

used to maintain posture and stabilize joints

skeletal and cardiac

Has transverse (T) tubules that deliver the electrical signals into the cells

cardiac muscle

exclusively uses aerobic respiration, think oxygenated blood

smooth and cardiac muscle

Uses mostly extracellular calcium ions to cause muscle contraction

cardiac and smooth muscle

cells are self-excitable/auto-rhythmic

cardiac muscle

cannot undergo tetany

skeletal muscle

uses mostly INTRAcellular calcium ions to cause muscle contraction.

tropomyosin

What muscle protein directly covers the myosin-binding sites on the actin molecules. ADD PHOTO HERE

troponin

Which muscle tissue is associated with actin, is made of 3 parts, and can bind to Calcium

acetylcholine

what neurotransmitter is used to stimulate skeletal muscle contraction

calcium

What ion enters the MOTOR AXON TERMINAL to cause the release of neurotransmitter?

acetylcholine

What neurotransmitter is released FROM the motor axon terminal INTO the synaptic cleft once calcium ions enter.

Sodium

When the neurotransmitter, acetylcholine, binds to the receptors on the motor end plate, it cause WHAT channels to open

sodium, depolarization

stimulation of a muscle cell causes WHAT ions to enter the cell which leads to WHAT

calcium

Once an action potential reaches the sarcoplasmic reticulum, WHAT ions are released into the sarcoplasm

myosin

troponin changes shape, which moves tropomyosin out of the way of WHAT in order to bind to actin. Who does tropomyosin cok-block?? :(

ATP binds to myosin

When BLANK binds to BLANK, myosin heads detach from the binding sites on actin

A band

Which region of the sarcomere does not shorten during muscle contraction

cross bridges form between MYOSIN and ACTIN and pulls the actin (thin) filaments inwards, causing contraction.

When ATP turns to ADP + phosphate, what is the energy being used for in the contraction cycle?

isometric contraction

contraction where muscle does NOT increase length when load increases

oxygen debt

the amount of oxygen needed to restore a muscle to its pre-exercise state

creatine phospahte

unique molecule in muscle that provides a phosphate to produce quick energy

anaerobic metabolism

production of energy when oxygen is not available

inability to maintain the force of muscle contraction despite stimulation

muscle fatigue

muscle twitch

single individual muscle contraction due to one stimulus

muscle tone

constant state of partial muscle contraction

motor unit

motor neuron plus all of the muscle fibers it stimulates

isotonic contraction

contraction where muscle CHANGES length when it contracts due to increased tension

tetanus

prolonged muscle contraction

diarthrotic

most of the freely moveable joints of the body could be classified FUNCTIONALLY as

Structural type

synovial, cartilaginous, and fibrous

structural subtype

ball and socket, condyloid, hinge, modified hinge, pivot, plane, saddle, symphysis, synchondrosis, suture, syndesmosis

Functional type

diarthrosis, synarthrosis, amphiarthrosis

H band

In the center of each A band, contains only thick filaments

contractile proteins

myosin and actin, generate force during contraction

regulatory proteins

troponin and tropomyosin, helps switch the contraction process on/off

myosin

has head and tail. The head has two binding sites: an actin binding site, an ATP binding site.

Actin

main component of thin filament. One each of these molecules there is a myosin-binding site, where a myosin head can attach

sliding filament model of contraction

during contraction, thin filaments slide past thick filaments, causing actin and myosin to overlap more. Myosin pulls on actin, causing thin filaments to slide inward.

neuromuscular junction

the specialised synapse - connection point - between a motor neuron and a skeletal muscle fiber.

Excitation contraction coupling

the sequence of events by which transmission of an action potential alond the sarcolemma leads to the sliding of myofilaments.

skeletal and cardiac

striations present

muscle tissue with many nuclei

skeletal

muscle tissue with 1 or 2 nuclei

cardiac

muscle tissue with 1 nuclei

smooth

epimysium

dense irregular CT surrounding entire muscle, may blend with fascia.

perimysium

dense irregular CT surrounding fascicles (groups of muscle fibers)

endomysium

fine reticular fibers surrounding each muscle cell ( = muscle fiber)

myofibril

threadlike contractile elements w/in sarcoplasm of muscle fiber that extend the entire length of fiber, composed of myofilaments

order of skeletal muscle anatomy

fascia, epimysium, muscle, perimysium, fascicles, endomysium, sarcolemma, muscle fibers, myofibrils, thin and thick filaments.

aponeurosis

sheetlike fibrous connective tissue

tendon

ropelike CT

fascicle

group of muscle fibers

sarcolemma

muscle fiber plasma membrane

sarcoplasm

muscle fiber cytoplasm

glycosomes

glycogen storage

myoglobin

oxygen storage

sarcomere

smallest contractile unit (functional unit) of muscle fiber

transverse (T) tubules

tube formed by protrusion of sarcolemma into cell interior, increases membrane surface area. Acts as voltage sensors, will change shape in response to an electrical current.

Muscle contraction depends on

latent period

excitation-contraction coupling event - no muscle tension seen

period of contraction

cross bridges form b. myosin and actin - tension increases

period of relaxation

calcium ions reentry into the sarcoplasmic reticulum, tension drop and contraction ends as ACh is broken down.

refractory period

time bn twitches when muscle cannot respond due to loss of excitability.

wave (temporal) summation

2 stimuli are received by a muscle in rapid succession. muscle fibers arent getting time to relax bn stimuli so twitches increase in force w each stimuli

oxidative fibers

use aerobic pathways (red fiber)

glycolytic fibers

use anaerobic glycolysis (white fibers)

slow oxidative skeletal fiber

red, low intensity, endurance activities, eg maintaining posture

fast oxidative skeletal fiber

red-pink, medium intensity activities, eg sprinting or walking

fast glycolytic skeletal fibers

white, short term intense of powerful movements, eg hitting a baseball

cardiac muscle

contains endomysium and perimysium

smooth muscle tissue

contains only endomysium

has regulator proteins of contraction: troponin and tropomysin

skeletal and cardiac

has calmodulin and myosin light chain kinase as regulator proteins

smooth muscle

hypertrophy

increase in muscle size