Chapter 10: Muscles Flashcards
reactive to stimuli from nervous system or environment, generate electrical and mechanical response is called what?
excitability
what are the properties of muscles?
excitability
contractility
extensibility
elasticity
cells actively shorten (contract) upon stimulation, generates tension is called what?
Contractility
cells can lengthen (extend) when pulled is called what?
extensibility
tendency to rebound (recoil) to some resting length after contraction or extension is called what?
elasticity
what are the three muscle types?
skeletal
cardiac
smooth
describe skeletal muscle
cylindrical
multinucleated
obvious striations
arranged in parallel
what type of muscle has to do with voluntary movement?
skeletal
where can you find skeletal muscle?
in skeletal muscles attached to bones or occasionally skin
describe cardiac muscle
branching
striated
uninucleate
have intercalated discs
what type of muscle contracts and propels blood into the circulation and is involuntarily controlled
cardiac
where can cardiac muscle be found
walls of the heart
describe smooth muscle
spindle-shaped cells
central nuclei
no striation
what kind of muscle type propels substances or objects along internal passageways and is under involuntary control?
smooth
where can smooth muscle be found?
walls of hollow organs
what are the general functions of skeletal muscle?
movement maintain posture and body position support soft tissue guard entrances and exits maintain body temp storage of certain organic moleules
what organic molecules does skeletal muscle store?
glucose
amino acids
what is the WHOLE muscle surrounded by?
epimysium
what surrounds a fascicle?
perimysium
what surrounds a muscle fiber?
endomysium
what is the cell membrane of skeletal muscle called?
sacrolemma
what is the muscle form of E.R?
saracoplasmic reticulum
what in the muscle transmits electrical signals?
T-tubules
what is a cylindrical bundle of myofilaments called?
myofibril
ultramicroscopic threadlike structures made up of various protein molecules are called what?
myofilament
what are the two types of myofilaments
thick
thin
what is the main protein in thin myofilaments
actin
what is the protein called that holds thin filaments together
z-line protein
what kind of myofilament do tropomyosin and troponin belong to?
thin myofilaments
what is the main protein found in thick myofilament
myosin
what kind of protein holds thick myofilaments together?
M-line protein
the area between two z-lines that also contains one m-line is called what?
Sarcomere
what is the next bundle that the skeletal muscle holds?
muscle fascicle
what is the next bundle contained in a muscle fascicle?
muscle fibers
what is the next bundle contained by the muscle fiber?
myofibrils
what is the myofibril surrounded by?
sarcoplasmic reticulum
what does the myofibril consist of?
sarcomeres
what connects the thick filaments to the Z-line?
Titin
Neurons that are connected to skeletal muscle cells are called what?
Motor neurons
The place where motor neuron connects to muscle cell is called what?
neuromuscular junction
T/F one motor neuron may contract and stimulate more than one muscle cell (fiber)
T
what makes up a motor unit?
neuron + muscle cell it controls
What does stimulation of the motor neuron cause?
release of Ca2+ from the SR into the cytoplasm
What does Calcium trigger?
the cross bridge cycle
bringing the Z-lines of sarcomeres closer together
what involves interactions of muscle proteins such as actin, myosin, troponin, tropomyosin and requires ATP as an energy source?
Cross bridge cycling
In what ways can skeletal muscle cells vary?
in size
speed of contraction
amount of force
endurance
what are the three fiber types in muscle cells?
type 1 fibers
type 2B fibers
type 2A fibers
what type of fibers are SLOW and OXIDATIVE?
Type 1 fibers
What type of fibers are FAST and GLYCOLYTIC?
Type 2B fibers
What type of fibers are Fast and oxidative?
Type 2A fibers
are type 1 fibers fatigue resistant?
yes
are type 2 B fibers fatigue resistant?
no, they are easily fatigued
are type 2A fibers fatigue resistant?
somewhat
In regards to size, type 1 fibers are ___ and type 2B fibers are ____
small
big
the speed of contraction in Type 1 fibers is ___ and the speed of contraction in Type 2B fibers is ___ and type 2A fibers are ____
Slow
fast
fast
In terms of force generation, Type 1 fibers have ___, Type 2B fibers have ____, and type 2A fibers have ___
Low force
high force
medium force
In a picture type 1 fibers are __ in color, type 2B are ___ in color and type 2A are ___ in color
dark
pale
in-between
The proportion of fiber types is determined by what?
muscle purpose
genetics
activity/training
what are the categories of muscle fiber organization?
Parallel
convergent
circular
Pennate
what are the types of pennate muscle organizations?
unipennate
bipennate
multi-pennate
fibers that run parallel to the long axis of muscle are called what?
parallel muscles
where can you find a parallel muscle?
biceps brachii muscle
fibers converging on a single tendon and muscle and are typically triangular are called what?
convergent muscle
where can convergent muscle be found?
pectoralis muscle
fibers arranged concentrically around opening of rectus are called what?
circular muscle
where can circular muscle be found?
Oricularis oris muscle
fibers that attach to a tendon at an oblique angle are called what?
pennate muscles
fibers that run in an oblique angle to one side of a tendon are called what?
unipennate muscle
fibers that run in a oblique angle on both sides of a tendon are called what?
bipennate muscle
fibers that run in an oblique angle where the tendon branches with the muscle are called what?
multi-pennate
where can uni-pennate muscle be found?
extensor digitorum muscle
where can bipennate muscle be found?
rectus femoris muscle
where can multi-pennate muscle be found?
deltoid muscle
what kind of “discs” does cardiac muscle have?
intercalated discs
what is one important way that cardiac muscle differs from skeletal muscles?
they are electrically interconnected with one another
what do intercalated disks in cardiac muscle contain?
ion channels
do the intercalated discs inhibit electrical activity?
no, they allow it to spread easily from cell to cell so they can contract in unison
T/F Actin and myosin are arranged in sarcomeres or myofibrils in smooth muscle?
F they are not arranged in sarcomeres or myofibrils
what is actin attached to in smooth muscle?
dense bodies scattered throughout cell
how is myosin arranged in smooth muscles?
it is scattered throughout
what is the pattern of smooth muscle contraction?
shortening and twisting
what type of muscle fibers are probably most abundant in smooth muscle?
Type 1 fibers
due to the fact they have slow contraction, and resistant to fatigue
