ANAT 3651 Musculoskeletal System

Functions of muscles

Thermoregulation, maintains posture, movement, controls movement of materials through our body

Types of muscles

Skeletal, smooth, cardiac

Skeletal muscle

Location: throughout body, most attach to bones

Function: voluntary movement

Appearance: very long, cylindrical cells; striations; peripherally located multinucleated cells

Smooth muscle

Location: GI tract, vascular tissues

Function: contraction causes controlled movement of material; involuntary movement

Appearance: short, fusiform (spindle-shaped); lacks striations; single, central nucleus

Cardiac muscle

Location: muscle of the heart (myocardium)

Function: contracts heart to pump blood; involuntary movement

Appearance: short, bifurcated; striations; centrally located mono- or binucleated; intercalated discs

What is this?

Cardiac muscle tissue

What is this?

Smooth muscle tissue

What is this?

Skeletal muscle tissue

Skeletal muscle organization

Myofibrils—>muscle fibers—>fascicles—>muscle tissues

Epimysium

Connective tissue surrounds whole muscle

Perimysium

Connective tissue surrounds fascicles

Endomysium

Connective tissue surrounds muscle fibers

When is an attachment considered an origin?

When it is the less mobile attachment and when it is the proximal attachment when in extremities

When is an attachment considered an insertion?

When it is the more mobile attachment and when it is the distal attachment when in extremities

Joint

The place of contact between two or more bones (articulation)

In terms of joints, more planes of motion= ___ stability

Reduced

How do joints increase stability?

Add muscular support and ligamentous attachment

Types of joints

Fibrous, cartilaginous, synovial

Types of fibrous joints

Gomphosis, Sutures, Syndesmosis

Types of cartilaginous joints

Synchondrosis and symphysis

Types of synovial joints

Planar, hinge, pivot, saddle, condylar, ball and socket

Gomphosis joints

Type of fibrous joint; immobile, small amounts of dense connective tissue, ex. teeth and sockets

Suture joints

Type of fibrous joint; immobile, small amounts of dense connective tissue, ex. skull bones

Syndesmosis joints

Type of fibrous joint; slightly mobile, large amounts of dense connective tissue, ex. interosseous membranes between radius-ulna and tibia-fibula

Synchondrosis joints

Type of cartilaginous joint; immobile, connected by hyaline cartilage, ex. 1st rib-manubrium, epiphyseal plates

Symphysis joints

Types of cartilaginous joint; slightly mobile, connected by fibrocartilage, ex. pubic symphysis, intervertebral discs

Planar joints

Type of synovial joint; non-axial, ex. intercarpal and intercarpal joints

Hinge joints

Type of synovial joint; uniaxial, ex. elbow joint and interphalangeal joints

Pivot joints

Type of synovial joint; uniaxial, ex. radioulnar joint and atlantoaxial joint

Condylar joints

Type of synovial joint; biaxial, ex. metatarsophalangeal joints and metacarpophalangeal joints

Saddle joint

Type of synovial joint; biaxial, ex. 1st thumb and carpometacarpal joint

Ball and socket joints

Type of synovial joint; multiaxial, ex. shoulder and hip joints

Flexion

Decreases angle at a joint (usually anterior movement)

Extension

Increases angle at a joint (usually posterior movement)

Abduction

Movement away from the midline

Adduction

Movement towards the midline

Rotation

Around a central axis

Lateral (external) rotation

Rotate outward

Medial (internal) rotation

Rotate inward

Supination

Rotate palm anteriorly

Pronation

Rotate palm posteriorly

Inversion

Sole of foot inward

Eversion

Sole of foot outward

Elevation

Moving superiorly

Depression

Moving inferiorly

Protraction

Move anterior

Retraction

Move posterior

Tuberosity

Type of bone marking; large rounded projection, may be rounded

Crest

Type of bone marking; narrow ridge of bone, usually prominent

Trochanter

Type of bone marking; very large, blunt, irregularly shaped process (the only examples are on the femur)

Line

Type of bone marking; narrow ridge of bone, less prominent than a crest

Tubercle

Type of bone marking; small, rounded projection or process

Epicondyle

Type of bone marking; raised area on or above a condyle

Spine

Type of bone marking; sharp, slender, often pointed projection

Process

Type of bone marking; any bony prominence

Head

Type of bone marking; bony expansion carried on a narrow neck

Facet

Type of bone marking; smooth, nearly flat articular surface

Condyle

Type of bone marking; rounded articular projection, often articulates with a corresponding fossa

Foramen

Type of bone marking; round or oval opening through a bone

Groove

Type of bone marking; furrow

Fissure

Type of bone marking; narrow, slitlike opening

Notch

Type of bone marking; indentation at the edge of a structure

Fossa

Type of bone marking; Shallow basinlike depression in a bone, often serving as an articular surface

Meatus

Type of bone marking; canal-like passageway

Sinus

Type of bone marking; cavity within a bone, filled with air and lined with mucous membrane

Components of the axial skeleton

Skull, hyoid, vertebral column, thoracic cage

Components of the appendicular skeleton

Pectoral girdle and upper extremity, pelvic girdle and lower extremity

Upper and lower limbs are known as what?

Serial homologues

During limb development, upper limbs rotate 90 degrees ___ and lower limbs rotate 90 degrees ___

1. Laterally, medially

Components of the pectoral girdle

Clavicle and scapula

How can the scapula move?

Elevation/depression, abduction/adduction

What is the glenohumeral joint?

Shoulder

Bony parts of the glenohumeral/shoulder joint

Scapula (glenoid fossa; socket) and head of humerus (ball)

What type of joint is the glenohumeral/shoulder joint?

Ball and socket

Ligaments found in the glenohumeral/shoulder joint

Glenohumeral joint and coracohumeral joint

Ways the shoulder can move

Flexion/extension, abduction/adduction, medial rotation/lateral rotation

Bony parts of the elbow joint

Trochlea (humerus)+trochlear notch (ulna) (medial)

Capitulum (humerus)+head of radius (lateral)

What type of joint is the elbow joint?

Hinge joint

Ways the elbow can move

Flexion/extension

Bony parts of the radio-ulnar joint

Radius and ulna

What type of joint is the radioulnar joint?

Pivot joint

Ways the radioulnar joint can move

Pronation/supination

Carpals (proximal then distal row)

Scaphoid, lunate, triquetral, pisiform, trapezium, trapezoid, capitate, hamate

Bony parts of the wrist joint

Distal radius and carpals

What type of joint is the wrist joint

Condylar

What ways can the wrist joint move?

Abduction (radial deviation)/adduction (ulnar deviation), flexion/extension

What type of joints are the metacarpo-phalangeal joints?

Condylar

What ways can the metacarpo-phalangeal joints move?

Abduction/adduction, flexion/extension

What type of joints are the interphalangeal joints?

Hinge joints

What ways can the interphalangeal joints move?

Flexion/extension

Muscles that move the scapula

Trapezius, rhomboids, levator scapulae, pectoralis minor, serratus anterior

Origin, insertion, and action of the trapezius

Origin—> occipital bone and spinous process of vertebrae

Insertion—> scapular spine, acromion, and distal clavicle

Action—> elevates, depresses, adducts scapula

Origin, insertion, and action of rhomboids

Origin—> spinous processes of vertebrae

Insertion—> medial border of scapula

Action—>adducts scapula

Origin, insertion, and action of levator scapulae

Origin—> transverse processes of vertebrae

Insertion—> superior angle of scapula

Action—> elevate scapula

Origin, insertion, and action of pectoralis minor

Origin—> ribs

Insertion—> coracoid process of scapula

Action—> depress scapula

Origin, insertion, and action of serratus anterior

Origin—> ribs

Insertion—> medial border of scapula

Action—> abduct scapula

Muscles that move the arm

Flexors (pectoralis major, coracobrachialis)

Extensors (latissimus dorsi, teres major)

Abductor (deltoid, supraspinatus)

Rotator cuff (SITS; supraspinatus, infraspinatus, teres minor, subscapularis)

Origin, insertion, and action of pectoralis major

Origin—> sternum and clavicle

Insertion—> greater tubercle of humerus

Action—> flex, adduct arm at shoulder

Origin, insertion, and action of coracobrachialis

Origin—> coracoid process of scapula

Insertion—> proximal humerus

Action—> flex and adduct arm at shoulder

Origin, insertion, and action of latissimus dorsi

Origin—> spinous process of vertebrae and iliac crest

Insertion—> lesser tubercle of humerus

Action—> extend, adduct arm at shoulder