Muscular System Flashcards
tissue or organ of the animal body
characterized by the ability to contract, usually in
response to a stimulus from the nervous system
muscle
it is a result of alternating contraction and
relaxation of muscles.
motion
constitute about 40-50% of the total body
weight of adult.
muscle tissue
The study of muscle is
myology
*Muscle is the contractile tissue of the body and
is derived from the ____ layer of
embryonic germ cells.
mesodermal
contain contractile filaments that
move past each other and change the size of the
cell.
muscle cells
function of muscle
produce force and cause motion
Muscles can cause either ___of the
organism itself or movement of ____ organs
locomotion
internal
type of muscle tissue
skeletal
cardiac
smooth
muscle attached to bones
skeletal muscle
Function is to move bones thus creating movement.
skeletal muscle
- It is striated, contains alternating dark and light bands.
- It is voluntary or it can be controlled at will.
skeletal muscle
It is cylindrical in shape and contain numerous nucleus
located in their periphery
skeletal muscle
Speed of contraction is ___ to ___ in skeletal muscle
fast to slow
do skeltal muscle have rhythmic contraction
no
- Forms the wall of the heart.
cardiac muscle
- Striated, contains alternating dark and light bands.
- Involuntary or it is not controlled at will.
cardiac muscle
- It has a rhythm in contraction.
- Branching in shape, and contain a centrally located nucleus.
cardiac muscle
Possess the intercalated discs, which are unique only to them
cardiac muscle
connect one
muscle fiber to another
intercalated discs
It provides a route for quick muscle action potentials
throughout the heart.
cardiac muscle
Located in the walls of hallow internal structures.
smooth muscle
- It is not striated.
- It is involuntary.
smooth muscle
- Fusiform or spindle shape cells that possess a centrally located
nucleus.
smooth muscle
- It provides movement of substances in the hallow organs. (ex.
Peristalsis in the GI tract)
smooth muscle
Speed of contraction is very slow.
* It has rhythmic contraction in some part of the body (GI tract)
smooth muscle
function of the muscle (4)
- Producing body movements
- Stabilizing body positions
- Storing and moving substances within the body
- Generating heat
PROPERTIES OF MUSCLE TISSUE (4)
- Electrical excitability
- Contractility
- Extensibility
- Elasticity
The ability to respond to certain stimuli by producing
electrical signals such as action potential.
electrical excitability
Is the ability of muscle tissue to contract forcefully when
stimulated by an action potential.
contractility
Is the ability of muscle to stretch without being
damaged.
extensibility
- The ability of muscle tissue to return to its original
length and shape after contraction or extension.
elasticity
It is a sheet or broad band of fibrous connective tissue that
supports and surrounds muscle and other organs of the body.
fascia
It separates the muscle from the skin
supreficial fascia
- It contains adipose tissue that insulates the body.
superficial fascia
fascia that lines the body walls and the limbs
deep fascia
It allows free movement of muscles, carries nerves, blood
vessels, and lymphatic vessels.
deep fascia
a fills the space between muscles
deep fascia
Three layers of connective tissue extend from the
deep fascia these are
epimysium
perimysium
endomysium
connective tissue that covers the entire muscle
epimysium
covers fascicle
perimysium
covers muscle fibers
endomysium
entire muscle -> fascicle -> muscle fiber -> myofibril -> sarcomere
+1
- A dense layer of collagen fibers that surrounds the entire
muscle.
epimysium
It separates the muscle from surrounding tissues and organs
epimysium
Surrounds group of 10 to 100 or more individual bundles of
muscle fibers called a fascicle
perimysium
e individual bundles of
muscle fibers
fascicle
Surrounds the individual skeletal muscle fibers (fascicle) and interconnects
adjacent muscle fibers
endomysium
Scattered between the endomysium and the muscle fibers are ____
sattelite cells
embryonic stem cells that function in the repair of damaged muscle
tissue
satellite cells
narrow bans of connective tissue that connec muscles to bone
tendons
bands of connective tissue that join bone to bone
ligaments
bands of connective tissue that attach flat muscle to another muscle or to several bones
aponeuroses
It is the attachment of the
muscle tendons or
aponeuroses to the
stationary bone, which is
usually proximal.
origin
- It is the attachment of the
other muscle tendons or
aponeuroses to the
movable bone which is
usually distal.
insertion
It is the prime
mover. A muscle that causes
a desired action; contracting.
agonist
It is a muscle
simultaneously relaxing as
the agonist is contracting
antagonist
. It is a muscle
involved in addition to
agonists and antagonists,
which serve to steady a
movement, thus, preventing
unwanted movements and
helping the prime mover
functions more efficiently
synergist
parallel muscle term
rectus
transverse muscle term
transversus
attachd to the temporal bone
temporalis
largest muscle
maximus
smallest muscle
minimus
long bone
longus
short bone
brevis
two origins
biceps
three origins
triceps
triangular
deltoid
rhomboid
rhomboideus
o: scapula
i: deltoid ridge of humerus
scapulohumeralis
bends or flexes a part; decreases the angle at a joint
flexor
straightens or extends a part; usually increases the angle of a joint
extensor
moves a bone away from the midline or axis of the body
abductor
moves a bone closer to the midline
adductor
produces an upward or superiorly directed movement
levator
produces a downward or inferiorly directed movement
depressor
decreases the size of an opening
sphincter
increases the size of the opening
dilator
moves a bone around its longitudinal axis
rotator
rotator that turns a part dorsad or upward
supinator
rotator that turns a part ventrad or upward
pronator
makes a body part more rigid
tensor
is a condition in which an organism forms or possesses a
linear series of body segments.
metamerism
is the segmented appearance
created by the epaxial and hypaxial muscles
metamerism
bundles of muscle fibers.
myomeres
separate myomeres horizontally
myosepta
separate myomeres vertically
myocommata
dorsal side muscle and support the body, also move the head
and tail (extend from the skull to the tip of the tail), these muscles aid in stride length
epaxial muscle
ventral side muscle and are dominant in tetrapods, aid in
respiration
hypaxial muscle
include the skeletal muscles of the
trunk and tail.
axial muscle
extend forward beneath the
pharynx as hypobranchial muscles
and muscles of the tongue
axial muscle
are present in orbits as extrinsic
eyeball muscles
axial muscle
- are metameric
- are segmental because of their
embryonic origin; arise from
segmental mesodermal somites
axial muscles
consists of a series of segments (myomeres) separated by myosepta
axial musculature
serve as origins and insertions for segmented muscles
myosepta
Myomeres are divided into dorsal and ventral masses by a horizontal septum that
extends between the transverse processes of the vertebrae:
which animal
fish
Epaxials = below/above the septum
above
above/below the septum
hypaxials
below
separate the myomeres of the 2 sides of the body
middorsal and midventral septa
(midventral septum is called the
linea alba
have epaxial and hypaxial masses, and these retain some evidence
of metamerism
tetrapads
Modifications:
❑epaxials are elongated bundles that extend through many body segments and that are
located below the expanded appendicular muscles required to operate the limbs
❑hypaxials of the abdomen have no
myosepta and form broad sheets of muscle
❑hypaxials are oriented into oblique, rectus, and transverse bundles
tetrapods
lie along vertebral column dorsal to transverse processes and lateral to
neural arches
epaxial of tetrapods
extend from base of the skull to tip of the tai
epaxials
epaxials are obviously
metameric and are referred to
as the dorsalis trunci
urodeles and some lizards
superficial epaxial bundles form long muscles that extend over many body
segments; deep bundles are still segmented
group of animals
higher tetrapods
- lies on transverse processes of
vertebrae; includes the longest epaxial
bundles
group of muscles!
longissimus group
lateral to longissimus and spinalis
* arises on ilium and inserts on dorsal
ends of ribs or uncinate processes
iliocostalis group
- lies close to neural arches
- connects spinous processes or
transverse processes with those several
vertebrae anteriorly
spinalis group
- intervertebral
- remain segmented
- connect processes (spinous,
transverse, and zygapophyses) of
adjacent vertebrae
shortest bundles
oblique (external and internal), transverse, and rectus muscles
Muscles that form longitudinal bands in roof of body cavity (subvertebral muscles)
hypaxials
- ribs developed in myosepta along entire length of the trunk
- urodeles still have myosepta the length of the trunk (but ribs no longer form in all of them)
group of animals?
early amphibians and reptiles
- myosepta and ribs are restricted to the thorax (so abdominal muscles are not segmented)
- hypaxials form 3 layers: external oblique, internal oblique, and transverse (in the thorax region:
external and internal intercostals, which play an important role in respiration, and transverse
muscle)
group of animals?
modern amniotes
weakly developed in most fish; ‘stronger’ in tetrapods
rectus muscles
- support ventral body wall and aid in arching the back
rectus musacles
(typically extends from the anterior end of the sternum to
the pelvic girdle
what muscle
rectus abdominis
- underneath and against transverse processes of vertebrae
- includes the psoas and iliacus in the lumbar region and the longus colli in the neck
- less developed in the thorax and none in the tail
sub vertebral muscles
do short epaxials perform same function as in fish
yes
attach to and move the skull
what bundle of epaxials
most anterior bundles
arch and support the vertebral column
short and long bundles
hypaxials used chiefly for swimming
aquatic urodeles
hypaxials that assist in locomotion
group of animals
urodeles?
muscles that are reduced in volume in tetrapods compared to fish
hypaxials
now support contents of abdomen, assist in respiration
(especially intercostal muscles), and assist epaxials in bending vertebral column
(rectus muscles)
which muscle and group of animals
hypaxials
tetrapods
- hypobranchials extend forward
from pectoral girdle and insert on
mandible, hyoid, and gill cartilages - hypobranchials strengthen floor of
pharynx and assist branchiomeric
muscles in elevating floor of
mouth, lowering jaw, and extending
gill pouches
group of animals?
fish
- hypobranchials stabilize and move
hyoid apparatus and larynx - the tongue of amniotes is a ‘sac’
anchored to hyoid skeleton and filled
with hypobranchial muscle
group of animals?
tetrapods
- move fins or limbs
appendicular muscles
originated on the axial skeleton and inserts on
the girdles or skeleton of the limbs.
extrinsic
originates on the girdle as proximal muscles
and inserts on distal parts.
intrinsic
appendicular muscles serve mostly as stabilizers; intrinsic muscles
are limited in number and undifferentiated.
group of animals?
fish
- appendicular muscles are much more complicated than in fish
- greater leverage required for locomotion on land
- jointed appendages require complex muscles
tetrapods
Dorsal group of the forelimbs that arise on:
* fascia of trunk in lower
tetrapods
* skull, vertebral column, and
ribs to a point well behind the
scapula in higher tetrapods and
converge on the girdle and limb
2 muscles
trapezius
lattisimus dorsi
s are the connection between muscles and
when the muscles then activate together they can enhance
the stability of your body.
muscle slings
e requires no such muscular anchoring because it is attached directly to the
vertebral column (as a result, the volume of extrinsic muscle is relatively small in posterior
limbs).
pelvic girdle
most develop from hypaxial blastemas in the body wall
* referred to as secondary appendicular muscles because it was not
their original function to operate appendages
* chief extrinsic muscles of forelimbs of tetrapods include: scapular
deltoid, latissimus dorsi, rhomboideus, serratus ventralis, and
pectorals
extrinsic appendicular muscle
- form from blastemas within the limb bud
- called primary appendicular muscles
intrinsic appendicular muscles
appendicular muscles of ___ are much more complex than in fish
amphibians
appendicular muscles of ___ are more numerous and diverse than in amphibians; better support of body and
increased mobility of distal segments of the limbs
reptiles
appendicular muscles of ___ are - intrinsic musculature is reduced; pectoralis (downstroke muscle) and
supracoracoideus (upstroke muscle) are enlarged
birds
appendicular muscles of ___ aresimilar to reptiles but more diverse
mammals
- associated with the pharyngeal arches
- series of skeletal and smooth muscles
- adductors, constrictors, and levators operate jaws plus successive gill arches
branchiomeric muscles
read table
+1 for understanding
operate the jaws (adductor mandibulae and
intermandibularis)
madibular arch
muscles of 1st arch operate jaws
* adductors of mandible:
❑ masseter and temporalis
❑ pterygoid
❑ digastric
group of animals
tetrapods?
- move hyoid arch
- aid in hearing (stapedial muscle)
- assist in moving lower jaw (e.g., digastric)
muscle of hyoid arch
muscle that aid in hearing
stapedial muscle
muscle that aid in lmoving lower jaw
digastric
constrictors above and below gill chambers plus levators
(including the cucullaris) that compress and expand the gill pouches
group of animals
shark
- muscles reduced; operculum plays important role in
respiration
group of animals
bony fish
muscles further reduced; in the muscles of 3rd and successive arches
which group of animal?
tetrapods
- used for swallowing
stylopharyngeus
intrinsic muscles of the larynx
voicebox
gives rise to trapezius, cleidomastoid, and
sternocleidomastoid muscles of amniotes
cucullaris
- originate (usually) on the skeleton and insert on the underside of the dermis
- striated
- move skin of amniotes
extrinsic integumentary muscle
- entirely within the dermis
- found in birds and mammals
- mostly smooth muscles
intrinsic integumentary muscle
example of extrinsic integumentary muscle
platysma
example of intrinsic integumentary muscle
arrector pili muscle
- consist of a number of electric discs (up to 20,000) piled in either vertical or
horizontal columns - each disc (electroplax) is a large coin-shaped cell
- evolved several times in a variety of fish (good example of convergent evolution)
electric organs
Functions of electric organs:
defense
communication
locating prey (electrolocation)
