Title: Muscles
1Muscles
- function, actions and
- identification of
- major superficial muscles, some conditions and
treatments
2types of muscles
- Three structurally and functionally distinct
types of muscle are found in vertebrates - smooth muscle,
- skeletal muscle and
- cardiac muscle.
3functions of skeletal muscles
- movement
- posture
- heat production
- shape
- facial expressions
- chewing, swallowing
- reflexes
4naming skeletal muscles
- Skeletal muscles are named according to
structural and/or functional characteristics. - Location - temporalis (temporal bone) and
tibialis anterior (front of tibia) - Size - maximus (largest), minimus (smallest),
longus (longest), brevis (shortest) - Shape deltoid (triangular), trapezius
(trapezoid), serratus (saw-like edge)
5more on naming muscles
- Direction of fibers rectus (parrallel to
midline), transverse (perpendicular to midline),
oblique (diagonal to midline) - Number of origins biceps (2), triceps (3),
quadriceps (4) - Origin and insertion sternocleidomastoid is
named for the two places of origin as well as its
insertion. - Action what the muscle does when at work.
6actions of skeletal muscles
- flexion-movement that decreases the angle _at_ a
joint - extension-movement that increases the angle _at_ a
joint.
7abd and add
- abduction-movement of an appendage away from the
midline. - adduction-movement of an appendage towards the
midline.
8rotation
- rotation -turning around the longitudinal axis _at_
a joint. Can only occur at a pivot (radio-ulna /
neck) or ball socket (shoulder / hip) joint. - circumduction-Is a movement found _at_ ball socket
(hip shoulder) and condyloid joints (wrist /
ankle / knuckles).
9supination - pronation
- supination -medial rotation of the forearm at the
Radio Ulna joint, so the palms face up. - pronation -Lateral rotation of forearm at the
Radio Ulna joint, so the palms face down.
10inversion - eversion
- inversion - twisting of the foot so that the sole
faces inward. - eversion - Twisting of the foot so that the sole
faces outward.
11dorsiflexion and plantar flexion
- dorsiflexion toe towards the knee using
tibialis anterior - plantar flexion point toes using gastrocnemius
12shoulder girdle movements
- elevation - Upward movement of the shoulder
girdle. - depression - Downward movement of the shoulder
girdle..Depression - protraction and retraction are all movements
associated with the shoulder girdle.
13movements
- 1. Lateral rotation
- 2. medial rotation
- 3. Supination
- 4. Pronation
- 5. Eversion
- 6. Inversion
- 7. Adduction
- 8. Abduction
14 What do you know
about these muscles?
- Flexor carpi ulnaris
- Extensor carpi radialis
- Latissimis dorsi
- Transversus abdominis
- Rectus femoris
- Deltoid
- Trapezius
- Orbicularis oris, Orbicularis oculi
- Sternocleidomastoideus
15skeletal muscle facts
- Skeletal muscle consists of very long tubular
cells. The average length of skeletal muscle
cells in humans is about 3 cm (sartorius muscle
up to 30 cm, stapedius muscle only about 1 mm).
Their diameters vary from 10 to 100 µm. - Skeletal muscle fibres contain many peripherally
placed nuclei.Up to several hundred rather small
nuclei with 1 or 2 nucleoli are located just
beneath the plasma membrane.
16facts, continued
- Skeletal muscle fibres show in many preparations
characteristic cross-striations. It is therefore
also called striated muscle. - Skeletal muscle is innervated by the somatic
nervous system. - Skeletal muscle makes up the voluntary muscle.
17what students of anatomy learn about the skeletal
muscles
- over 600 named muscles in human
- makes up 40-50 of body weight
- the physiology of muscle action
- name, location, action, origin, insertion and
often the nerve that serves the muscle
18striatedmuscle tissue
19the players
- myofibrils contract instantly if ATP and Ca2
is added to them, meaning that it is these single
myofibrils which are the force generators in
muscle cells.
20sarcomere
- Striated sarcomeres are separated by Z-discs.
Two Z-discs bound a sarcomere in the direction of
stretching. Thin filaments made of Actin are
attached to each of these discs and extend
towards each other inside the sarcomere. They do
not overlap in the sarcomeres striated form. In
this case there is a dark band visible between
the Z-discs. This is made up of the thick Myosin
filaments which overlap partially with the thin
Actin filaments which extend into a light half of
the I-Band region left and right of the dark
A-band.
21contraction shorten
- When Myofibrils contract the thin and thick
filaments move past each other. Each sarcomere
unit of the myofibrils shortens proportionally to
the muscle contraction. Upon contraction, it is
the light bands which shorten whereas the dark
bands do not change in length. This is explained
by the Actin filaments sliding into the dark
region of Myosin filaments.
22thick and thin
- Actin - the thin filaments
- Myosin - the thick filaments
-
23 24structure of skeletal muscle
25contraction
During contraction, actin fibers are pulled
inward a) pulling is by "hooks" on myosin
(myosin heads) b) hooks bend, using energy of
ATP c) each hook pulls, releases, pulls again
until muscle is contracted d) calcium (Ca2)
ions signal this to start -Ca2 into muscle
starts contraction -during relaxation, Ca2 is
transported out Â
26nerves and muscles
27muscle ends
- origin-stationary end, the anchor
- insertion- moved end
- belly- the area in between
28CAUTION
- NOTE These pictures are intended to provide a
virtual tour of the lab models and specimens.Â
They are not intended to substitute for
classroom/lab learning. They are simply
supplemental material for you to use as reminders
of what you should study or have already studied.
29superficial muscles
- Muscles which occupy the layer closest to the
surface of the skin are called superficial
muscles. These are easily displayed on a person
who has developed their physique for show or
physical performance.
30major muscles of face
- frontalis
- orbicularis oculi
- nasalis
- temporalis
- orbicularis oris
- zygomaticus major
- masseter
- mentalis
- levator labii superioris
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32Facial muscles around the mouth, directions of
muscle contraction
- A levator labii superioris
- B zygomaticus minor
- C zygomaticus major
- D risorius
- E depressor anguli oris
- F labii inferioris,
- G orbicularis oris
33muscles of mastication
- temporalis
- medial and lateral pterygoids
- masseter
34masseter
- masseter and directions of the lower jawbone
movement
35 sternocleidomastoid
- sternocleidomastoid muscle is the main muscle
on the side of the neck.
36neck pain
- The trapezius muscle is the one that tenses up
most often. When you see people reaching back to
massage their shoulders, it is the trapezius
muscle that they are trying to loosen. - The other two muscles that have a tendency to
tighten up are the sternocleidomastoid (often
called the sterno-mastoid) and the scalene
muscles. - Keep it Moving! The neck is by far the most
mobile portion of the spine. Its ROM is generally
70 to 90 degrees.
37bones of the neck, review
- The bones of the neck are called the cervical
vertebrae. - Every mammal on earth, even the giraffe, has 7
of them. In humans, the cervical vertebrae are
obviously a lot smaller than those of giraffes.
They are also a lot smaller than the vertebrae of
the other areas of the human spine. -
38neck pain?
- Our necks need to use their mobility in order
to maintain it. They work best when they can
consistently move into and out of their full
range of motion in a gentle - that is, not a
jarring - way.
39non-used necks injuries
- We rotate our necks fully when we look over
our shoulder and then back the car down the
driveway. We extend our necks completely when we
look up at the ceiling. - The fact that we do not do these things often
is one of the major reasons why our necks cause
us problems. On occasion, when its essential for
the neck to move to an extreme range of motion,
it cant cope with the job. Thats when injuries
occur.
40muscles of the back
41trapezius
- The trapezius covers a large section of the
upper back. It conceals the upper part of the
shoulder blade.
42latissimus dorsi
- The latissimus dorsi occupy the middle back on
either side. - The gluteus maximus make up the back of the
buttocks.
43abdominal muscles
- 4 muscles of the abdominal area
- rectus abdominis
- external oblique
- internal oblique NS
- transversus abdominis NS
44muscles of the arm
45superficial muscles of the chest and front of the
arm.
- The shoulder muscles are called deltoids. These
triangular muscles define the upper shoulders - biceps brachii are easily recognizable large
bumps on the upper inside of the arm - The pectoralis muscles span the chest
46superficial muscles of the posterior arm
- triceps brachii extends the arm,
straightening the elbow
47leg muscles
48anterior muscles of the thigh
- Quads extensor of knee
- rectus femoris
- vastus lateralis
- vastus medius
- vastus intermedialis
- sartorius cross leg
- gracilis adducts leg
49posterior muscles of the thigh
- The hamstring muscle group comprises three
muscles - biceps femoris
- semitendonosus
- semimembranosus
- The action of these muscles is to bend the
knee and extend the hip.
50adductors of the thigh
- adductor magnus, longus, brevis and the
pectineus, make up the adductor group. -
- Groin pulls are a strain at the attachment of
the adductors to the pubic bone.
51 major muscle of lower leg - anterior
- tibialis anterior flexes the foot pulls foot
toward the knee
52muscles of lower leg -posterior - calf muscles
- gastrocnemius is the calf muscle which are each
divided into two hemispheres. - soleus
53soleus and Achilles tendon
- This picture illustrates the relationship
between the superficial gastrocnemius muscle, the
deeper soleus muscle and the large Achilles
tendon which is visible attaching to the heel.
54atrophy - hypertrophy
- no use
- average use
- increased use
55muscle twitch
- cycle of contraction and relaxation
- latent phase
56tetany
- Tetany-stimuli is so fast that muscle cannot
relax - stays contracted - (tetanus - bacterial toxin interferes with
motor neuron function, uncontrolled stimulation)
57chondromalacia (runner's knee)
- Wearing away and/or softening of the articular
cartilage, tissue that covers and protects the
underside of the patella, the bottom end of the
femur, and top end of the tibia. It absorbs
stress to the knee joint and allows the patella
to track smoothly in its femoral groove.Causes
Typically, excessive running Symptoms Pain
around the patella (kneecap), usually occurring
on the medial (inner) side and below (inferior
aspect of the patella).
58doctor and PT
- Recommended Treatment R.I.C.E. - Rest, Ice,
Compression, Elevation. Reduce activity to
promote healing. Avoid downhill runs especially.
Strengthen surrounding muscles with a
professionally recommended program. Apply Ice for
10-15 minutes after each workout to reduce
inflammation and pain. (If any skin irritation or
adverse reaction occurs due to icing, see your
medical doctor). A proper stretching (Quadriceps,
Iliotibial Band) routine is highly recommended
pre and post workouts. As with any orthopedic
injury, a consultation with a sports medicine
professional is recommended.
59hamstring strain/tear
- occurs when excessive or repetitive stress
causes tearing of the muscle fibers in the
hamstring.Causes Tight hamstring muscles,
muscle imbalance, sudden movement, and repetitive
strain are all common types of hamstring
injuries. Symptoms A sharp pain may be felt in
the hamstring when a serious strain or tear
occurs. This often happens during such action as
an explosive move in basketball or a quick
sprint. If you feel a deep ache in the hamstring
area it may be a less severe strain or minor
tear.
60intramuscular injection
- intramuscular injection delivers medicine
directly into the muscle - deltoid
- gluteus medius
61injections
62muscular disorders
- Atrophy
- decrease in size of muscle fibers
- Disuse atrophy - bedridden individuals, casts
- Denervation atrophy - loss of nerves and muscle
function - Muscular Dystrophy - (Duchenne MD)
- Loss of muscle fibers
- Linked to young males (ages 3-5)
- Lacking certain protein thus allows too much
Ca into cell this leads to cell death and
replacement with scarring
63muscular disorders
- Myasthenia gravis
- autoimmune disease
- antibodies bind to ACh receptors
- atrophy of muscle fibers
- drugs that keep levels of ACh high are used
64what happens in rigor mortis?
- Ca pumps run out of ATP
- Ca cannot be removed
- continuous contraction
- eventually tissues break down
65muscles of the face, review
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68references
- Link Publishing
- www.linkpublishing.com
- Texas Tech University
- www.biol.ttu.edu/Z2403/large20AP20pics
- humanback.htm
- PE World
- http//www.peworld.org/anatomy/muscles.htm
- Pro Tech Athletics
- www.pro-tecathletics.com/ kneeinjuries.htm
- Insite Fitness
- www.insitefitness.com.au/