anat 200: appendicular skeleton

Appendicular Skeleton

The system in which bones of the limbs and limb girdles that are attached to the axial skeleton

126

How many bones are in the appendicular skeleton?

Bones within the limbs, and girdle bones that actually attach the limbs.

What is our appendicular system of bones divided into? (hint* 2 bone subtypes)

Upper limbs; Lower limbs

\________________ are important for activities that are are highly mobile. Whereas \_____________ bones are responsible for weight-bearing support and stability, as well as for body locomotion

1. Allows for completion of daily tasks such as dressing up, eating, writing, using a smart phone, etc.

2. Allows for adjustments in body posture.

3.
Allows for mobility of the body.

Describe the functions of the appendicular skeleton.

pectoral girdle (shoulder girdle), arm, forearm and hand

The upper extremity in the organization of the appendicular system is composed of the:

Pelvic girdle, thigh, leg, foot

The lower extremity in the organization of the appendicular system is composed of the:

Pectorial girdle

The bones that attach each upper limb to the axial skeleton form the:

Scapula and Clavicle

The pectoral girdle consists of:

Clavicle

Located in front (anterior) to shoulder, supports the clavicle, also referred to as the collarbone is the:

Scapula

This bone lies on the posterior end of the pectoral girdle, articulates with the humerus. Known as the shoulder blade,.

Superior border, vertebral (medial border), and the axillary border (lateral border)

3 borders of the scapula include:

superior border of scapula

A concave surface, that is the shortest and thinnest border in the scapula.

medial border of scapula

Longest scapular border, extends from superior angle to inferior angle of scapula.

lateral (axillary) border

diagonally oriented, thickest of the borders, extends from lower margin of glenoid cavity, along lateral edge of scapula and to inferior angle.

superior angle of scapula

The angle between superior and medial borders

inferior angle of the scapula

the angle between the medial and lateral (axillary) borders

glenoid cavity (fossa); glenohumeral joint

This scapula bone articulates with the humerus of the arm to form the \_______________

glenohumeral joint

"Ball and socket joint" Located between the head of the humerus (upper arm bone) and the glenoid cavity of the scapula (shoulder blade) Allowing a wide range of movement in the arm, including flexion, extension, abduction, adduction, and rotation.

Scapular spine

Long and prominent ridge that divides posterior aspect of scapula into supraspinatus fossa (above) and infraspinatus fossa (below)

Subscapular fossa, infraspinous fossa, supraspinous fossa

What are the three depressions of the scapula?

Supraspinous fossa

Located on the posterior scapula, above (superior) to scapular spine, narrow

Infraspinous fossa

Located on posteior end of scapula, below (inferior) spine, broad

provide large surface areas for the attachment of muscles that cross the shoulder joint to act on the humerus.

What do the fossae do?

subscapular fossa

Anterior (deep) surface, broad depression of scapula.

coracoid process

Located on lateral end of superior border, this process projects anteriorly and curves laterally. At shoulder level, this process is located inferior to lateral end of clavicle.

attachment site for muscles of the anterior chest and arm.

Function of the coracoid process?

Acromion process; acromioclavicular joint

This bone \___________forms the bony tip of the superior shoulder region and articulates with the lateral end of the clavicle, forming the \___________

Supports scapula, allows freedom of movement, protects the nerves and blood vessles, as they pass b/w trunk and upper limb.

Describe the functions of the clavicle:

medial end, the lateral end, and the shaft.

The clavicle has three regions:

sternal end of clavicle (medial)

articulates with the manubrium of the sternum

lateral end of clavicle

articulates with acromion process of scapula

shaft of clavicle

body of clavicle

sternoclavicular joint

Articulation between the clavicle and the sternum. Allows clavicle and scapula to move in up/down and back and forward movements during shoulder movement.

acromioclavicular joint

articulation between the acromion of the scapula and the acromial (lateral) end of the clavicle

coroclavicular ligament

anchors coracoid process of scapula to lateral clavicle. Supports acromioclavicular joint.

costoclavicular ligament

band of connective tissue that unites the medial clavicle with the first rib

Acromioclavicular joint: allows elevation and depression

Sternoclavicular joint: allows retraction and protraction movement of the shoulder

Glenohumeral joint (also known as the shoulder joint): allows a wide range of movement in the arm, including flexion, extension, abduction, adduction, and rotation

Name the pectoral glid joints and the movements they allocate

Humerus

upper arm bone

head of humerus; glenohumeral joint

This structure of the humerus articulates with glenoid cavity of scapula. It also forms the \_________________

greater tubercle of humerus

located on the lateral side of the proximal humerus

lesser tubercle of humerus

This bone is located on the anterior humerus, serves as an attachment site for shoulder joint

Intertubercular sulcus

This bone is located between the greater and lesser tubercle. It provides passage for the tendon of the biceps muscle.

deltoid tuberosity

site of deltoid muscle attachment; V-shaped on lateral side of humerus shaft.

medial epicondyle of humerus

enlarged projection located on the medial side of the distal humerus

Lateral epicondyle

Smaller bone that is found on the lateral side of the distal humerus.

Olecranon fossa of humerus

Large depression located on the posterior side of the distal humerus. Receives the \__________ of the ulna when elbow is extended.

capitulum of humerus

knob-like structure located on the anterior surface of the distal humerus; articulates with radius bone of forearm.

Trochlea

Pulley bone; articulates with the ulna

joint capsule of glenohumeral joint

thin and weak to allow increased movement at this joint; reinforced by 4 shoulder muscles (rotator cuff)

The four muscles of the shoulder

supraspinatus, infraspinatus, teres minor, subscapularis

Supraspinatus

located on the top of the shoulder blade and is responsible for initiating the movement of lifting the arm away from the body (abduction).

Infraspinatus

located on the back of the shoulder blade and is responsible for externally rotating the arm (turning the arm outward).

teres minor

Also rotates arm laterally; responsible for shoulder stability

Subscapularis

Located at the front of the shoulder blade and is responsible for internally rotating the arm (turning the arm inward)

Ulna

medial bone of the forearm

Radius

lateral bone of the forearm

Trochlar Notch

Proximal end of ulna; articulates with the trochlea of humerus

Coronoid process of the ulna

inferior part of trochlear notch

olecranon of ulna

This structure is located on the superior end of the posterior portion of the proximal ulna

Radial head

proximal end of radius articulates with the capitulum of the humerus

Radial tuberosity

muslce attachment site that is inferior to the neck of the radius.

Radial styloid process

more distally prominant; site of attachment for ligaments that articulates with the lateral side of the wrist.

Ulnar styloid process

distal pointed projection; located medial to the head of the distal ulna

interosseous membrane

unites the ulna and radius bones.

Joint between trochlea
and trochlear notch

Hinge joint is the:

flexion/extension
of forearm

The Hinge joint allows this movement:

condylar

Joint between
capitulum and radial
head

Allows pronation/supination
of forearm

The condylar joint allows for which movements:

(IN ORDER) scaphoid, lunate, triquetrum, pisiform

proximal row of carpals (arranged lateral to medial)

Scaphoid

First of four proximal carpal bones.

Articulates with the radius proximally, the trapezium and capitate distally and lunate medially.

Lunate

Second of 4 proximal bones, articulates with the radius proximally, capitate and hamate distally, scaphoid laterally, and the triquetrum medially.

Triquetrum

Third of proximal carpel bones; articulates with the lunate laterally, the hamate distally.

Pisiform

Last of the 4 proximal bones, articulates with the anterior surface of the triquetrum

trapezium, trapezoid, capitate, hamate

distal row of carpals from lateral to medial

Trapezium

First distal carpel bone articulates with the scaphoid proximally, the first and second metacarpals distally, and the trapezoid medially

Trapezoid

Second of the four distal carpal bones. Articulates with the scaphoid proximally, the second metacarpal distally, the trapezium laterally, and the capitate medially

Capitate

3rd of the 4 distal carpal bones; articulates with the scaphoid and lunate proximally, the trapezoid laterally, the hamate medially, and with the third metacarpal distally

Hamate

articulates with the lunate and triquetrum proximally, the fourth and fifth metacarpals distally, and the capitate laterally

So Long Top Part Here Comes The Thumb

Lateral to medial order: Scaphoid, Lunate, Triquetral, Pisiform, Trapezium, Trapezoid, Capitate, Hamate

Metacarpal

Palm of hand; proximal end of each \_________ bone articulates with one of the distal carpal bones

Base of the thumb; thumb mobility

The first metacarpal bone is located at the \_________________. Important for \___________

second and third metacarpal bones

The most immobile metacarpal bones are:

fourth and fifth metacarpal bone

The metacarpal bones that have limited anterior-posterior mobility. These are important for gripping!

Phalanx Bones

individual finger bones

radiocarpal joint (with scaphoid proximal metacarpal)

The distal end of the radius has a smooth surface for articulation with two carpal bones to form the \_______________

abduction/adduction and flexion and extension

The movements of this radiocarpal joint

Saddle joint

type of joint found at the base of each thumb; allows grasping and rotation and opposition of thumb.

os coxae [pelvic girdle]

the hipbone; formed by the union of the ilium, ischium, and pubis

Ilium

largest part of the hipbone

Ischium

the lower (inferior) posterior portions of the pelvis is the \________. It supports the body when sitting.

Pubis

The medial anterior portion of the pelvis

Iliac crest

superior margin of the ilium

Anterior superior iliac spine

anterior termination of the iliac crest

illiac fossa

shallow depression located on the anteromedial (internal) surface of the upper illium

Auricular surface

area located on the posterior, MEDIAL side of the ilium of the hip bone;

Greater sciatic
notch

large, U-shaped indentation located on the posterior margin of the ilium, superior to the ischial spine

Ischial spine

bony projection from the posterior margin of the ischium that separates the greater sciatic notch and lesser sciatic notch

Ischial tuberosity

Forms the posteior and inferior portion of the hipbone. Aids in sitting behaviour

Acetabulum

large socket located on the lateral side of the hip bone; formed by all three the ilium, pubis, and ischium portions of the hip bone