1. Muscular System

2. Muscles in Humans
There are approximately 650 muscles in the human body, each performing a unique role.
Muscles are the driving force behind the musculoskeletal systems, enabling us to sit, stand, walk, talk and do anything else that requires movement.
They also keep our heart beating and help us breathe.
In order to function, they must be able to react to stimuli, contract, extend and return to their normal shape.

3. Muscular System Muscles are responsible for all types of body movement
3 basic muscle types are found in the body
Skeletal muscle
Cardiac muscle
Smooth muscle

4. Characteristics of Muscles
Muscle cells are elongated (muscle cell = muscle fiber)
Contraction of muscles is due to the movement of microfilaments
All muscles share some terminology
Prefix myo refers to muscle
Prefix mys refers to muscle
Prefix sarco refers to flesh

5. Nervous system to muscles
Within the nervous system, nerve impulses travel from neuron to neuron along complex nerve pathways. The junction between the parts of two such neurons is called a "synapse.“
If a sufficient amount of the substance (called "neurotransmitter") is released, the membrane is stimulated, and a nerve impulse is triggered

6. Neuromuscular junction occurs when a nerve cell contacts a muscle 

7. Comparison of Types of Muscle

8. Types of Muscle, cont.

9. Myofilaments
Muscle cells are unique because of the contractible protein fibers, called myofilaments, within them. 
the filaments of myofibrils constructed from proteins are of two types, thick and thin.
Thin filaments consist primarily of the protein actin.
Thick filaments consist primarily of the protein myosin.
Muscle contraction occurs because of the myosin filaments pull on actin filaments

10. Skeletal Muscle Characteristics
Most attach to bones by tendon
Cells are multinucleate
Striated—have visible binding
Voluntary
Cells surrounded & bundled by connective tissue

11. Smooth Muscle Characteristics
Has no striations
Spindle-shaped cells
Single Nucleus
Involuntary—no conscious control
Found mainly in the walls of hollow organs

12. Characteristics of Cardiac Muscle
Has striations
Usually has a single nucleus
Joined to another cardiac muscle cell
Involuntary
Found only in the heart
Connects cytoplasm between 2 cells (Gap junction)
Gap junctions are responsible for electrochemical and metabolic coupling. They allow Each heart muscle cell is coupled to its neighbors electrically by tiny holes, producing depolarization of the heart muscle

13. Skeletal Muscle Functions of Skeletal Muscle
Produce Movement
Maintain posture
Stabilize joints
Generate Heat
Sites of Muscle Attachment
Bones
Cartilage
Connective tissue coverings
Muscle Fibers blend into a connective tissue attachment
Tendon—cordlike structure
Aponeurosis—sheet-like structure
Properties of Muscle
Irritability – ability to receive and respond to a stimulus
Contractibility – ability to shorten when an adequate stimulus is received
Extensibility – ability to lengthen when an adequate stimulus is received
Elasticity – ability to return to normal shape

14. Anatomy of a Muscle Cell
Each fiber is built up from smaller strands called myofibrils, and each myofibril contains interlaced filaments of muscle proteins.

16. Naming Skeletal Muscles

17. 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

18. Location Structure near which muscle is found
FRONTALIS = near FRONTAL bone
OCCIPITALIS = near OCCIPITAL bone

19. Size Relative Size of Muscle MAXIMUS = largest MEDIUS = middle
Gluteus Maximus
MEDIUS = middle
Gluteus Medius
MINIMUS = smallest
Gluteus Minimus
LONGUS = longest
Fibularis Longus
BREVIS = short
Fibularis Brevis
TERTIUS = shortest
Fibularis Tertius

20. Number of Origins Number of tendons of origin BICEPS = Two
Biceps Brachii
Biceps Femoris
TRICEPS = Three
Triceps Brachii
QUADRICEPS = Four
Quadriceps Femoris

21. Shape Relative Shape of the Muscle DELTOID = triangular shape Δ
TRAPEZIUS = trapezoid shape  SERRATUS = saw-toothed ♒
RHOMBOIDEUS = rhomboid shape 
TERES = round ○

22. Origin & Insertion Origin – attachment to an immoveable bone
Insertion – attachment to a movable bone
ILIO COSTALIS= attaches to the ilium & ribs (costal = ribs)

23. Action NAME ACTION EXAMPLE FLEXOR EXTENSOR ABDUCTOR ADDUCTOR LEVATOR
Decrease angle at a joint
Flexor Carpi Radialis
EXTENSOR
Increase angle at a joint
Extensor Carpi Ulnaris
ABDUCTOR
Move bone away from midline
Abductor Pollicis Longus
ADDUCTOR
Move bone toward midline
Adductor Longus
LEVATOR
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

24. Types of Muscle--Actions
Prime mover (Agonist) – 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

25. Head & Neck Muscles

26. Head & Neck Muscles Frontalis: elevate eyebrows 
Orbicularis Oculi: close 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

27. Muscles of Mastication
Masseter: elevates mandible
Temporalis: elevates mandible
Medial pterygoid: elevates mandible
Lateral pterygoid: depresses mandible

28. 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

29. Muscles of the Axial Skeleton

30. Muscles of the Axial Skeleton
Intrinsic Muscles
Erector Spinae: maintain posture of back/extension
Spinalis
Longissimus
Iliocostalis
Oblique Muscles: rotation of the vertebrae
Semispinalis
Multifidus
Rotatores
Muscles of Quiet Respiration
Diaphragm
External Intercostals
Internal Intercostals—deep breaths
Abdominal Muscles
External Obliques
Internal Obliques
Transverse Abdominus
Rectus Abdominus
Quadratus Lumborum

31. Muscles of Scapular Stabilization
Trapezius:
Retraction (M)
Elevation (S)
Depression (I)
Upward Rotation (S, M)
Rhomboid—retraction
Levator Scapular—Elevation
Pectoralis Major—Protraction
Serratus Anterior—Protraction

32. Anterior Muscles of Shoulder
Deltoid
Flexion (A, M)/Extension (P, M)
Abduction (M)/Adduction (A)
Internal (A) /External Rotation (P)
Pectoralis Major
Adduction
Flexion
Extension
Internal Rotation
Biceps Brachii—Flexion

33. Posterior Muscles of Shoulder
Teres Major
Adduction
Extension
Internal Rotation
Latissimus Dorsi
Triceps Brachii

34. Rotator Cuff Muscles (SITS)
Teres Minor
External Rotation
Subscapularis
Internal Rotation
Supraspinatus
Abduction
Infraspinatus
External Rotation

35. Muscles of the Elbow/Forearm
Triceps Brachii—Extension
Bicep Brachii—
Flexion
Supination
Brachialis—Flexion
Brachioradialis—
Pronation
Pronator Teres
Pronator Quadratus
Supinator Longus

36. 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

37. Muscles Of Hip: Anterior Muscles

38. Muscles of Hip: Anterior Muscles
Medial/Adductor Muscles:
Adductor Magnus
Adductor Longus
Adductor Brevis
Gracilis
Anterior Muscles
Iliopsoas—Flexion
Pectineus—
Flexion
Adduction
Sartorius—
Lateral Rotation

39. Muscles of Hip: Gluteal Muscles
Gluteus Maximus—Extension
Gluteus Medius—Abduction
Gluteus Minimus—Abduction
Tensor Fasciae Latae—
Flexion
Abduction
** Gluteus Minimus is under the Gluteus Medius

40. 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

41. Muscles of Posterior Thigh
“Hamstrings”
Responsible for Knee Flexion & Hip Extension
Semimembranosus
Semitendinosus
Biceps Femoris
Gastrocnemius
Knee Flexion

42. Muscles of the Lower Leg
Anterior Compartment
Tibialis Anterior—Dorsiflexion & inversion
Extensor Digitorum Longus
Fibularis Tertius—dorsiflexion & eversion
Posterior Compartment
Gastrocnemius—plantarflexion, knee flexion
Soleus—plantarflexion
Lateral Compartment
Fibularis Longus—plantarflexion & eversion
Fibularis Brevis—plantarflexion & eversion

43. Throwing Movement

44. Running & Kicking

45. Tendinitis Inflammation of tendons and of tendon-muscle attachments
Many patients report stressful situations in their life in correlation with the beginnings of pain which may contribute to the symptoms. If the symptoms of tendinitis last for several months or longer it is probably tendinitis.

46. Muscular Diseases Muscular Dystrophy
Muscular Dystrophy (MD) is a group of genetic diseases that cause the muscle fibers to become easily damaged.
There are over one dozen different types, but the most common general symptoms are muscle weakness, lack of coordination and loss of mobility.
The most severe type, Duchenne's muscular dystrophy, can cause mental retardation and primarily affects young boys.
MD is diagnosed through genetic tests, muscle biopsies, blood tests that measure for high levels of creatine kinase and ultrasounds.
There is no cure for MD but it can be treated to reduce the severity with physical therapy, medication, surgery and special braces.

47. Muscular Diseases Compartment Syndrome
Compartment syndrome occurs when too much pressure builds up in and around the muscles.
It can result from crushing injuries, extended pressure on a blood vessel, swelling inside a cast or complications from surgery.
Symptoms include severe pain, a feeling of fullness or tightness in the muscle and a tingling sensation.
Numbness indicates cellular death and it may be difficult to restore full function once it reaches that point. Surgery to relieve the pressure is usually required.

48. Fibromyalgia
is a medical disorder characterized by chronic widespread pain and allodynia, a heightened and painful response to pressure
Fibromyalgia is estimated to affect 2–4% of the population, with a female to male incidence ratio of approximately 9:1
Fibromyalgia is considered a controversial diagnosis, due to lacking scientific consensus to its cause
Signs and symptoms:
Muscle spanms, weakness, nerve pain, muscles twitching, palpitations, bowel disturbances, sleep disturbances, short/long term memory, impaired speed performace, inability to multitask, anxiety, depression, RA, headaches, etc…

49. Mitochondrial Myopathies
On biopsy, the muscle tissue of patients with this disease category usually demonstrate 'ragged red' muscle fibers.
These 'ragged red' fibers contain mild accumulations of glycogen and neutral lipids, and may show an increased reactivity for succinate dehydrogenase and a decreased activity for cytochrome c oxidase.
Examples of Mitochondrial myopathy include:
varying degrees of cognitive impairment and dementia
lactic acidosis (breakdown food)
strokes
transient ischemic attacks
hearing loss
Dysmotility (digestive muscles don’t work)
weight loss
cardiac conduction defects