Muscle Tissue - Drage Homepage
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Transcript Muscle Tissue - Drage Homepage
Primary Function
of the Muscular System
Locomotion
movement of substances through the body
structure and support for organs and tissues
Muscle Tissue: 3 Types
Muscle Tissue enables the movement of
body structures. Smooth, Cardiac, Skeletal
Muscle Types: Smooth Muscle
Smooth muscle is
non-striated, and
acts in a number of
involuntary processes
in the body. Some of
these processes
include:
Muscle Types: Smooth Muscle
allows the expansion and contraction of arteries
and veins
lines the bladder and reproductive tracts
lines the entire gastrointestinal tract
Did you know?...
Tiny smooth muscle fibers in the skin
called Arrector pili are responsible for
“goose bumps.”
Muscle Types: Cardiac Muscle
Cardiac muscle
(heart muscle) is
striated but functions
involuntarily. It is
solely responsible for
propelling blood
throughout the body.
Muscle Types: Skeletal Muscle
Skeletal muscle is striated, and
associated with voluntary movement. It
also provides structure and support for
organs and tissues.
Anatomy of skeletal muscles
tendon
Muscle
Fascicle
Skeletal
muscle
Skeletal
muscle
fiber (cell)
How Do Muscles Work?
Individual muscle fibers are
composed of small cylindrical
structures called myofibrils.
The functional component
within the myofibril is called
the sarcomere.
Within the sacromere,
protein filaments called actin
and myosin allow the cell to
expand and contract in a
3 step process:
3 Steps
1) Before the muscle is stimulated, actin and myosin
filaments partially overlap one another.
2) A nerve cell releases a signal which causes the actin
and myosin filaments to “slide” along one another and
overlap even more.
3) This contracts the myofibril and subsequently the
entire muscle cell. When the nervous signal changes, the
filaments relax and return to their original state.
Muscle
fiber
sarcomere
Z-line
myofibril
Actin
myosin
Thin myofilament
Myosin molecule of
thick myofilament
Sarcomere
Actin and Myosin: A Closer Look
Access the website below (skip to sections 6-10)
and complete the tutorial.
http://www.wiley.com/college/pratt/0471393878/st
udent/animations/actin_myosin/actin_myosin.swf
Action Potentials and the
Neuromuscular Junction
1.
Impulse arrives at axon terminal
Ca+ ions rush in activating
synaptic vesicles
2.
3.
4.
Synaptic vesicles fuse with cell
membrane of axon terminal
ACh released
ACh binds with motor end
plate: deplorization occurs
Impulse travels through
T-tubules & SR
Actin, Myosin, and Action Potentials
Putting it all Together…
Access these online
animations to help visualize
these processes…
The Neuromuscular Junction
http://tinyurl.com/the-neuromuscularjunction
Action Potential and Muscle Contraction
http://tinyurl.com/5qox4x
Sarcomere Contraction
http://tinyurl.com/sarcomerecontraction
Did you Know?
If you check out a standard lass,
Muscles are a third of her body mass.
Muscle
(~35%)
BODY COMPOSITION
The Muscular System:
Key Components
Muscles move body parts because they’re
attached to bones by strips of dense
connective tissue called tendons.
Skeletal Muscle: Key Concepts
The place where muscle attaches to a stationary
bone is called the “origin.” The place where the
same muscle attaches and “pulls” is called the
“insertion.”
Origin
Insertion
Skeletal Muscle: Key Concepts
Skeletal muscle can
be characterized as
either “extensors”
(causing a joint to
straighten or
extend), or a
“flexor” (causing a
joint to bend or flex).
Challenge question
How are
tendons
different from
ligaments?
Basic Muscle
Groups
You Need to
Know!
Basic Muscle
Groups
You Need to
Know!
Basic Muscle
Groups
You Need to
Know!
Naming Skeletal Muscles
Direction of
Muscle
Fibers
Location
Action
Skeletal
Muscle
Origin
&
Insertion
Size
Shape
Number
Of
Origins
Naming Muscles: By
Direction of Muscle Fibers
(Relative to the Midline)
RECTUS = parallel to the
midline
Rectus Abdominus
TRANSVERSE =
perpendicular to midline
Transverse Abdominus
OBLIQUE = diagonal to
midline
External Oblique
Naming Muscles: Location
Structure near
which muscle is
found
FRONTALIS =
near FRONTAL
bone
OCCIPITALIS =
near OCCIPITAL
bone
Naming Muscles: Size
Relative Size of Muscle
MAXIMUS = largest
MEDIUS = middle
Fibularis Longus
BREVIS = short
Gluteus Minimus
LONGUS = longest
Gluteus Medius
MINIMUS = smallest
Gluteus Maximus
Fibularis Brevis
TERTIUS = shortest
Fibularis Tertius
Naming Muscles: Number of Origins
Number of tendons of
origin
BICEPS = Two
Biceps Brachii
Biceps Femoris
TRICEPS = Three
Triceps Brachii
QUADRICEPS =
Four
Quadriceps Femoris
Naming Muscles: Shape
Relative Shape of the
Muscle
DELTOID = triangular
shape Δ
TRAPEZIUS = trapezoid
shape
SERRATUS = sawtoothed ♒
RHOMBOIDEUS =
rhomboid shape
TERES = round ○
Naming Muscles: Action
NAME
FLEXOR
EXTENSOR
ACTION
EXAMPLE
Decrease angle at a joint
Flexor Carpi Radialis
Increase angle at a joint
Extensor Carpi Ulnaris
ABDUCTOR
Move bone away from
midline
Abductor Pollicis Longus
ADDUCTOR
LEVATOR
Move bone toward midline
Adductor Longus
Produce upward movement
Levator Scapulae
DEPRESSOR
Produce downward
movement
Depressor Labii Inferioris
SUPINATOR
Turn palm upward/anterior
Supinator
PRONATOR
Turn palm
downward/posterior
Pronator Teres
Cateorigizing muscles by
the Actions they Facilitate
Prime mover– muscle with the major
responsibility for a certain movement
Antagonist – muscle that opposes or
reverses a prime mover
Synergist – muscle that aids a prime
mover in a movement and helps prevent
rotation
Fixator – stabilizes the origin of a prime
mover
Examples
__________
__________
__________
__________
Head & Neck Muscles
Head & Neck Muscles
Frontalis: elevate
Orbicularis Oculi: close
eyebrows
eyelid
Zygomaticus: draw
angle of lip upward
Buccinator: draws
cheeks against teeth
Orbicularis Oris: closes
mouth
Platysma: draws lower
lip down & back
Cranial Aponeurosis:
connects frontalis to
occipitalis
Temporalis: elevates
mandible
Occipitalis: draws scalp
back
Masseter: elevates
mandible
Sternocleidomastoid:
Flexes head
Draws head toward
shoulder
Key Muscles of Facial Expression
Smiling Muscles
Orbicularis Oculi
Nasalis
Levator Labii
Superioris
Levator Anguli
Superioris
Zygomaticus
Risorius
Frowning Muscles
Frontalis
Orbicularis Oris
Depressor Anguli Oris
Depressor Labii
Inferioris
Mentalis
Platysma
Muscles of the Axial Skeleton
Erector Spinae:
maintain posture
of back/extension
Semispinalis
Multifidus
Rotatores
Respiratory Muscles
Spinalis
Longissimus
Iliocostalis
Oblique Muscles:
rotation of the
vertebrae
Diaphragm
External Intercostals
Internal Intercostals—deep
breaths
Abdominal Muscles
External Obliques
Internal Obliques
Transverse Abdominus
Rectus Abdominus
Muscles of the Axial
Skeleton
Muscles of Scapular Stabilization
Trapezius:
Retraction
Elevation
Depression
Upward Rotation
Rhomboid—retraction
Levator Scapular—Elevation
Pectoralis Major—Protraction
Serratus Anterior—Protraction
Anterior Muscles of Shoulder
Deltoid
Pectoralis Major
Flexion/Extension
Abduction/Adduction
Internal’External Rotation
Adduction
Flexion
Extension
Internal Rotation
Biceps Brachii—Flexion
Posterior Muscles of
Shoulder
Teres Major
Latissimus Dorsi
Adduction
Extension
Internal Rotation
Adduction
Extension
Internal Rotation
Triceps Brachii
Adduction
Extension
Rotator Cuff Muscles
(SITS)
Supraspinatus
Abduction
Infraspinatus
External Rotation
Teres Minor
External Rotation
Internal Rotation
Subscapularis
Muscles of the
Elbow/Forearm
Triceps Brachii—
Bicep Brachii—
Extension
Brachialis—Flexion
Brachioradialis—
Flexion
Supination
Flexion
Pronation
Pronator Teres
Pronator Quadratus
Supinator Longus
Muscles of the Wrist &
Hand
Flexor Carpi
Ulnaris
Flexor Carpi
Radialis
Flexor Digitorum
Extensor Carpi
Ulnaris
Extensor Carpi
Radialis
Extensor
Digitorum
Anterior (Palmar) View
Posterior (Dorsal) View
Muscles of the Hip: Anterior
Medial/Adductor Muscles:
Adductor Magnus
Adductor Longus
Adductor Brevis
Gracilis
Anterior Muscles
Iliopsoas—Flexion
Pectineus—
Flexion
Adduction
Sartorius—
Flexion
Lateral Rotation
Muscles of the Hip: Gluteal
Gluteus Maximus—
Gluteus Medius—
Gluteus Minimus—
** Gluteus Minimus is under
the Gluteus Medius
Extension
Abduction
Abduction
Tensor Fasciae
Latae—
Flexion
Abduction
Muscles of Anterior Thigh
“Quadriceps”
Rectus Femoris—
Hip flexion
Knee extension
Vastus Lateralis—
knee extension
Vastus Medialis—knee
extension
Vastus Intermedius—
knee extension
Sartorius—
Hip & Knee Flexion
Lateral Hip Rotation
**Vastus Intermedius is
beneath Rectus Femoris
Muscles of Posterior Thigh
“Hamstrings”
Responsible for
Knee Flexion & Hip
Extension
Semimembranosus
Semitendinosus
Biceps Femoris
Gastrocnemius
Knee Flexion
Muscles of the Lower Leg
Anterior Compartment
Posterior Compartment
Tibialis Anterior — Dorsiflexion &
inversion
Extensor Digitorum Longus
Fibularis Tertius — dorsiflexion &
eversion
Gastrocnemius — plantarflexion,
knee flexion
Soleus — plantarflexion
Lateral Compartment
Fibularis Longus — plantarflexion
& eversion
Fibularis Brevis — plantarflexion
& eversion
Can you think of different ways in which
the muscular system works with other
body systems to maintain homeostasis?
Aerobic vs.
Anaerobic Exercise
Muscle contraction requires ATP. When oxygen
is present in sufficient amounts, the normal
processes of glycolysis and cellular
respiration can take place (aerobic).
However, if oxygen is not present in large
enough quantities to sustain vigorous muscle
contraction, only a small amount of ATP is
generated through glycolysis; and lactic acid
forms in the absence of cellular respiration
(anaerobic).
Pop
Quiz!
Identify
Skeletal
muscle groups
1-14
“That’s All Folks!”
More to come…