ANAPHY SKELETAL SYSTEM PART 2

comprises The Appendicular Skeleton in Detail, They types of Joints ETC

Appendicular Skeleton

It is composed of 126 bones of the Appendages (Limbs)

Bone Structures of the Appendicular Skeleton

Pectoral Girdle, Upper Limbs, Pelvic Girdle, Thigh, Legs

Pectoral Girdle

-Connects the upper limbs to the axial skeleton

-Consists of 4 main bones, the 2 scapulae and the 2 clavicles

Clavicle

Also known as the collarbone, it is a long, S-Shaped Bone that lies horizontally across the front of the shoulder just in front of the first rib.

Its function is to act as a brace to hold the arm away from the top of the thorax and help prevent shoulder dislocation

Structurally has three main Anatomical Parts:

1. Medial (sternal) end

2. Lateral (Acrominal) end

3. Shaft

Sternal End of the Clavicle

Attaches to the Manubrium of the Sternum, forming the sternoclavicular joint

Acrominal End of the Clavicle

articulates with the Acromion of the Scapula, forming the acroclavicular joint

Shaft of the Clavicle

The prominent and visible part of the Clavicle—commonly known to be prone to be fractured.

Scapula

Also known as the Shoulder blade, it is a flat, triangular bone located on the posterior side of the shoulder surrouned by muscles. This allows it to move freely across the back of the Thoracic Cage.

Has:
Three borders (Superior, Medial, and Lateral) and;
Three Angles (Superior, inferior, and lateral)

Glenoid Cavity

Contained in the Lateral Angle of the Scapula, this is a shallow socket that articulates with the head of the humerus to form the glenohumeral joint

Supraglenoid and Infaglenoid tubercles

This is located above and below the Glenoid Cavity seving as attachment points for arm muscles.

Acromion Process

This is the enlarged lateral end of the spine of the scapula. It connects with the clavicle laterally at the acromioclavicular joint

Coracoid Process

This is a beaklike process pointing laterally over the top of he shoulder and anchors some of the muscles of the arm.

Contains the Supra-scapular Notch—a nerve passageway

Bones of the Upper Limbs

These are the 30 separate bones that form the skeletal framkework of each upper arm including the:

• Arm

• Forearm and;

• Hand

Together, these bones create the framework for movement at the shoulder, elbow, and wrist, while also providing attachment sites for muscles that control the hand and arm

Humerus

This bone forms the entire arm. This is also the longest and largest bone of the upper limb.

Head of the Humerus

is the large, rounded head that faces upward, medially, and slightly backward—articulating with the glenoid cavity of the scapula to form the shoulder joint

Anatomical Neck of the Humerus Head

The immediately inferior section of the Humerus head which separates the head of the humerus from the rest of the bone as well as provides attatchment for the joint capsule.

The Greater Tubercle of the Humerus Head

This is the tubercle of the humerus head that is located laterally and has areas for muscle attachment

The Lesser Tubercle of the Humerus Head

This is the tubercle located on the anterior side of the humerus head, this also serves as a muscle attachment site.

Intertubercular Groove

known as the bicipital groove, this is located in between the greater and lesser tubercle that allows passage of the tendon of the biceps brachii muscle

Surgical Neck of the Humerus

This is located below the two tubercles—connecting the upper end of the humerus to its shaft. it is also a common site of fractures

Shaft of the Humerus

Is the long part of the humerus. It is cylindrical in its proximal section and becomes flatter towards the distal section

Deltoid Tuberosity

Along the lateral side of the shaft, this is a triangular and roughened area where the deltoid muscle attaches to.

Trochlea

Located in the distomedial end of the Humerus, it is a spool-like part that articulates with the ulna.

Capitulum

Located in the distolateral end of the humers, it is a ball-like part that articulates with the radius

Olecranon Fossa

On the posterior surface, at the distal section of the humerus, it is a deep, triangular depression that receives the olecranon of the ulna when the elbow is extended

Coronoid Fossa

Located on the anterior surface, at the mediodistal section of the humerus, it is a small depression that receives the coronoid process of the Ulna during flexion

Radial Fossa

Located on the anterior surface, at the laterodistal section of the humerus, it is a small depression that receives the Radial styloid process during flexion

Medial Epicondyle

Located at the mediodistal end of the humerus, this serves as the attachment site for forearm flexor muscles. It is also relatively bigger in size than its counterpart

Lateral Epicondyle

Located at the Laterodistal end of the humerus, it serves as the attachment site for forearm extensor muscles. it is also relatively smaller in size than its counterpart.

Ulna

The medial bone of the forearm

Proximal end of the Ulna

This is the thinck, hooklike, top part of the ulna that forms the elbow joint with the humerus

Olecranon

Located at the proximal end of the ulna, this is the large, prominent curved process that acts as the lever for the elbow joint—forming the visible tip of the elbow.

Trochlear Notch

This is the large, C-shaped depression created by the olecranon and the coronoid process. It is responsible for gripping and articulating the trochlea of the humerus.

Coronoid Process

This is the protruding process that forms the lower part of the trochlear notch. This is is what tucks into the coronoid fossa of the humerus during flexion.

Ulnar Tuberosity

Located right below the coronoid process, this projection is a rough area for muscle attachment such as the brachialis

Radial Notch

Located on the lateral side of the ulna, this projection is where the head of the radius articulates to form the proximal radioulnar joint

Shaft of the Ulna

The long portion of the ulna that gradually becomes smaller towards its distal end.

Interosseous Border of the Ulna

This is located at the shaft of the ulna where the interosseous membrane attaches and connects to the ulna to the radius

Styloid Process of the Ulna

It is a small, bony projection that anchors the crucial ligaments and cartilage needed to keep the pinky-side of the wrist joint stable.

Head of the Ulna

It is the rounded bump found at the distal end of the Ulna acting as a stationary pivot point that the radius sweeps around to follow forearm rotation

Styloid Process of the Ulna

This is the small, pointed peg-like projection on the distal end of the ulna. It is the visible bump on the pinky-side of the wrist. This anchors the ligaments and cartilage needed to keep the lateral side of the wrist joint stable

Radius

It is the lateral bone of the forearm, located on the thumb side. This bone has 3 surfaces and 3 anglles—allowing it to rotate around the ulna during forearm movements

Head of the Radius

This is a disc shaped head with a shallow depression on top, which articulates with the capitulum of the humerus, its outer surface is smooth and articulates with the radial notch of the ulna, forming the proximal radioulnar joint

Neck of the Radius

Separates the head of the radius to the shaft and the distal end of the radius

Radial Tuberosity

A rough oval-shaped projection that serves as a muscle attachment point located just bellow the neck of the radius

Shaft of the Radius

This is the long slightly curved section of the radius. It becomes wider towards its distal end

Interosseous border of the Radius

Located in the radial shaft, it provides attachment for the interosseous membrane that connects the radius to the ulna

Distal end of the Radius

It is the wide, large bottom portion of the radius on the thumb-side of the forearm that forms the primary connection point for your wrist joint

Ulnar Notch

Located on the medial side of the distal end of the radius, it articulates with the head of the ulna to form the distal radioulnar joint

Styloid process of the Radius

Located on the lateral side of the distal end of the radius, this is a pointed projection that provides attachments for ligaments supporting the wrist

Bones of the Hand

Consists of 8 carpal bones, 5 metacarpal bones, and 14 phalanges

Carpal Bones

These 8 bones make up the wrist and the base of the hand

Acronym for the 8 Carpal Bones

Some Lovers Try Positions That They Can’t Handle

(Scaphoid) (Lunate) (Triquetrum) (Pisiform) (Trapezium) (Trapezoid) (Capitate) (Hamate)

Proximal Row Carpal Bones

Scaphoid, Lunate, Triquetrum, and Pisiform

Distal Row Carpal Bones

Trapezium, Trapezoid, Capitate, Hamate

Scaphoid

Largest of the 4 proximal row carpal bones that is shaped like a boat

Lunate

one of the proximal row carpal bones that has a crescent shape

Triquetrum

one of the proximal row carpal bones that looks like a pyramid

Pisiform

one of the proximal row carpal bones that is small rounded and lies infront of the triquetrum

Trapezium

one of the distal row carpal bones that has a groove on its front surface and forms a saddle shaped joint with the first metacarpal

Trapezoid

The smallest of the distal row carpal bones and is also wedge-shaped

Capitate

Largest of the distal row carpal bones and sits in the center of the wrist

Hamate

The wedge shaped and has a hook like projection out of all the distal row carpal bones

Metacarpal bones

are the bones of the palm that are numbered 1 to 5 starting from the thumb. These bones also lie between the carpal bones and finger bones

First Metacarpal

the metacarpal bone belonging to the thumb. This is short, strong and more mobile than the other metacarpal bones

Second Metacarpal

The metacarpal bone belonging to the index finger

Third metacarpal

the metacarpal bone belonging to the middle finger

Fourth Metacarpal

The metacarpal bone belonging to the ring finger that helps with strong grippign actions

Fifth metacarpal

The metacarpal bone belonging to the pinky finger that helps with srong gripping actions

Base of the Metacarpal

Part of the metacarpals that connects with the carpal bones as well as sometimes with the neighboring metacarpals

Shaft of the metacarpal

Part of the metacarpals that are slightly curved with rough areas for muscle attachments

Head of the metacarpal

Part of the metacarpals that connects with the proximal phalanx of each finger and forms the knuckles

Phalanges

Bones of the fingers and thumb containing 14 bones

Number of Phalanges of the Thumb

2, proximal and distal

Number of Phalanges of Fingers 2-5

3, proximal, medial, distal

Interphalangeal Joints

The joints between the phalanges

Pelvic Girdle

This is the bones of the pelvis that form a largely immobile structure to function as a weight-bearing framework for the whole body.

Hip Bone

the large, curved bone that forms the lateral and anterior parts of the pelvis consisting of the:

-ilium

-ischium and;
-pubis

Acetabulum

Located on the lateral side of the hipbone, this is a cup-shape cavity where the ilium, ischium and the pubis meet. it aslo forms part of the hip joint

Obturator Foramen

A large opening located between the ischium and the pubis which serves as a site for muscle attachment

Ilium

The superior and largest part of the hip bone and hasa broad, fan-like shape—extending upward from the acetabulum and forms the lateral boundary of the greater pelvis.

Iliac Crest

The upper border of the ilium that is curved and can be felt along the waist

Iliac Fossa

A large smooth depression located at the internal surface of the ilium

Greater Sciatic Notch

Located on the posterior border of the ilium, it is a large indentation that helps form an opening for the passage of structures from the pelvis to the lower limb

Ischium

This is the posteroinferior part of the hip bone which plays and important role in supporting the body when sitting down

Ischial Tuberosity

The large roughened area of the ischium which bears the body’s weight in the seated position. This projection also serves as an attachment point for muscles.

Lesser Sciatic Notch

Located above the ischial tuberosity, this is a smooth, concave indentation on the posterior border of the ischium of the hip bone.

Pubis

This bone forms the anterior part of the hip bone.

Pubic Body

The medial portion of the pubis.

Pubic Symphysis

a slightly movable cartilaginous joint located at the front of the pelvis—connecting the left and right pubic bodies.

Superior Pubic Ramus

This connects the pubis to the ilium.

Inferior Pubic Ramus

This extends downward and joins the ischial ramus to form the ischiopubic ramus

Pelvis

Composed of 4 bones: the two hip bones, the sacrum, and the coccyx. Its main functions are to support the weight of the upper body, transfer this weight to the lower limbs, provide attachment for muscles, and protect the pelvic organs.

Greater Pelvis

The broad, upper part of the pelvis that is associated with teh abdominal cavity

Lesser Pelvis

The lower, narrower part of the pelvis that contains the pelvic Organs

Pelvic Brim

The boundary between the greater and lesser pelvis

The pelvic inlet

The upper opening of the lesser pelvis formed by the pelvic brim. is anterosuperior

Pelvic outlet

the lower opening of the lesser pelvis. is posteroinferior

Sacrum

The large, triangular bone formed by the fusion of the 5 sacral vertebrae located at the base of the vertebral column, It also forms the posterior part of the pelvis

The Sacral base

The upper end of the sacrum that articulates with the 5th lumbar vertebra