The upper limb bones form a complex structure, enabling a wide range of motion and dexterity. From the to the , each bone plays a crucial role in supporting and moving the and .
These bones connect through various joints, allowing for different types of movement. Understanding the anatomy and function of upper limb bones is essential for grasping how we perform everyday tasks and complex movements.
Bones of the Upper Limb
Bones of the upper limb (part of the appendicular skeleton)
S-shaped bone articulates with manubrium of sternum medially and of laterally
Functions as strut to hold upper limb away from trunk
Scapula
Triangular, flat bone located on posterior aspect of thorax
Key features include spine (prominent posterior ridge), acromion (lateral extension of spine articulating with clavicle), glenoid cavity (shallow socket articulating with head of ), and coracoid process (anterior projection serving as attachment point for muscles and ligaments)
Long bone of arm with rounded proximal head articulating with glenoid cavity of scapula
Greater and lesser tubercles serve as attachment points for rotator cuff muscles
is roughened lateral surface area for attachment of deltoid muscle
Medial and lateral epicondyles are distal projections serving as attachment points for muscles
Lateral bone of forearm with proximal head articulating with of humerus and radial notch of
is roughened medial surface area for attachment of biceps brachii tendon
Distal serves as attachment point for brachioradialis muscle and ligaments
Medial bone of forearm with proximal forming point of elbow and serving as attachment point for triceps brachii muscle
Anterior articulates with of humerus
Distal styloid process serves as attachment point for ulnar collateral ligament of wrist
Eight small bones arranged in proximal (, , , ) and distal (, , , ) rows forming wrist
Five bones forming palm of hand numbered I-V from lateral to medial
Phalanges
Bones of fingers with each having three (proximal, middle, distal) except thumb which has two (proximal, distal)
Articulations of upper limb bones
Articulation between sternal end of clavicle and manubrium of sternum
Saddle-type synovial joint allowing limited multi-planar movement
Acromioclavicular joint
Articulation between acromion of scapula and acromial end of clavicle
Articulation between glenoid cavity of scapula and head of humerus
Ball-and-socket synovial joint allowing wide range of multi-planar motion
Articulation between trochlea of humerus, of ulna, and head of consisting of humeroulnar (hinge-type allowing flexion/extension) and humeroradial (pivot-type allowing rotation during pronation/supination) joints
Articulation between head of radius and radial notch of ulna
Pivot-type synovial joint allowing rotation of radius during pronation/supination
Articulation between head of ulna and ulnar notch of radius
Pivot-type synovial joint allowing rotation of radius during pronation/supination
Wrist (radiocarpal) joint
Articulation between distal radius and proximal carpal row
Condyloid-type synovial joint allowing flexion, extension, abduction, adduction of hand
Articulations between adjacent carpal bones
Plane-type allowing limited gliding movements
Articulations between distal carpal row and metacarpal bases
Plane-type synovial joints except thumb carpometacarpal joint which is saddle-type allowing wider range of motion
Articulations between metacarpal heads and proximal phalanx bases
Hinge-type synovial joints allowing flexion and extension
Carpal tunnel anatomy and significance
Narrow passageway on palmar wrist aspect bordered by carpal bones (floor) and (roof)
Contains median nerve and flexor tendons of fingers and thumb
Functional significance
Allows passage of median nerve and flexor tendons from forearm to hand
Protects median nerve and flexor tendons from damage during wrist movements
Clinical relevance: syndrome
Compression of median nerve within carpal tunnel
Causes include flexor tendon inflammation (repetitive strain) and conditions reducing carpal tunnel size (wrist fractures, arthritis, pregnancy)
Symptoms are pain, numbness, tingling in thumb, index, middle, lateral half of ring finger and thenar muscle weakness and atrophy in severe cases
Diagnosed by clinical exam (, ) and nerve conduction studies
Treated conservatively with wrist splinting, NSAIDs, corticosteroid injections or surgically by carpal tunnel release (transverse carpal ligament division to decompress median nerve)
Upper Limb Anatomy: Bone Landmarks and Structural Features
(e.g., humerus, radius, ulna) have specific structural features:
Diaphysis: shaft of the bone
Epiphyses: proximal and distal ends of the bone
Metaphyses: regions between diaphysis and epiphyses
serve as important attachment points for muscles, ligaments, and tendons:
Processes: bony projections (e.g., coracoid process of scapula)
Tuberosities: roughened areas for muscle attachment (e.g., )
Tubercles: small, rounded projections (e.g., greater and lesser tubercles of humerus)
Synovial joints in the upper limb allow for various types of movement:
Lined with synovial membrane producing synovial fluid for lubrication
Surrounded by joint capsule for stability and protection
Key Terms to Review (114)
Acromion: The acromion is a bony projection on the superior aspect of the scapula that forms the highest point of the shoulder. It is an important anatomical landmark that serves as the attachment site for several muscles and ligaments, and is a crucial component of the shoulder joint complex.
Anatomical neck: The anatomical neck of a bone is the slightly constricted region immediately distal to the head of the bone, found commonly in the humerus of the upper limb. It marks the location where the bone's epiphysis (head) meets its diaphysis (shaft), serving as a key point for muscle attachment and articulation with other bones.
Anatomy of Selected Synovial Joints: The anatomy of selected synovial joints examines the structure and function of the most movable type of joint found in the human body, focusing on components like bones, cartilage, synovial fluid, joint capsule, and ligaments. It is essential for understanding how these joints facilitate movement and maintain stability across different parts of the body.
Appendicular Skeleton: The appendicular skeleton is the part of the human skeletal system that is composed of the bones of the upper and lower limbs, as well as the girdles that attach the limbs to the axial skeleton. It is responsible for facilitating movement and providing support for the body's extremities.
Arm: In the context of anatomy and physiology, particularly within the chapter on the appendicular skeleton, the arm refers to the region of the upper limb between the shoulder and the elbow. It is primarily composed of a single long bone, the humerus, which connects to muscles and joints enabling a wide range of motion.
Bicipital groove: The bicipital groove, also known as the intertubercular sulcus, is a deep indentation located between the greater and lesser tubercles on the humerus bone in the upper arm. It serves as a pathway for the tendon of the long head of the biceps brachii muscle to attach to the scapula.
Bone Landmarks: Bone landmarks are distinct anatomical features on the surface of bones that serve as reference points for identifying the location and orientation of bones and their associated structures. These landmarks are critical for understanding the skeletal system, particularly in the context of the bones of the upper limb.
Capitate: The capitate bone is the largest carpal bone located in the center of the wrist, playing a crucial role in the wrist's complex movements and stability. It articulates with multiple bones to facilitate hand motion and support.
Capitate: The capitate is one of the eight carpal bones located in the wrist, specifically positioned at the center of the proximal row of the carpal bones. It is the largest carpal bone and plays a critical role in wrist movement and stability, connecting the hand to the forearm and facilitating various hand functions.
Capitulum: The capitulum is a round knob-like structure on the distal end of the humerus that articulates with the radius in the forearm. It facilitates elbow and forearm movement by connecting to the radius.
Carpal bone: Carpal bones are the eight small bones that make up the wrist, connecting the hand to the forearm. They are arranged in two rows of four bones each, helping in the complex movements of the wrist.
Carpal tunnel: The carpal tunnel is a narrow passageway located on the palm side of your wrist, which is formed by bones and ligaments. This tunnel protects the main nerve to your hand and the tendons that bend your fingers.
Carpal Tunnel: The carpal tunnel is an anatomical structure located at the base of the palm, formed by the carpal bones and the transverse carpal ligament. It is the passageway through which the median nerve and flexor tendons of the fingers travel from the forearm to the hand, playing a crucial role in the function and dexterity of the upper limb.
Carpals: The carpals are a group of eight small bones located in the wrist region, forming the connection between the forearm and the hand. These bones play a crucial role in the overall structure and function of the upper limb, as they facilitate the intricate movements and flexibility required for various manual tasks.
Carpometacarpal Joints: The carpometacarpal joints are a series of synovial joints located between the distal row of carpal bones and the proximal ends of the metacarpal bones in the hand. These joints facilitate the complex movements and flexibility required for dexterous hand function.
Clavicle: The clavicle, commonly known as the collarbone, is a long bone that serves as a strut between the shoulder blade and the sternum or breastbone. It plays a critical role in providing structural support and facilitating movement within the pectoral (shoulder) girdle.
Clavicle: The clavicle, also known as the collarbone, is a long, slender bone that connects the shoulder blade (scapula) to the sternum (breastbone). It is an essential part of the pectoral girdle, which forms the attachment point for the upper limb to the axial skeleton.
Coronoid fossa: The coronoid fossa is a shallow depression located on the anterior surface of the distal end of the humerus, where it accommodates the coronoid process of the ulna during forearm flexion. It plays a crucial role in elbow joint movement by allowing the arm to bend smoothly.
Coronoid Process: The coronoid process is a bony projection on the ulna, one of the two bones in the forearm. It is an important anatomical feature that plays a crucial role in the mechanics of the elbow joint and the range of motion of the upper limb.
Coronoid process of the ulna: The coronoid process of the ulna is a triangular eminence projecting forward from the anterior proximal portion of the ulna, one of the two bones in the forearm. It serves as a point of attachment for several muscles and ligaments, playing a crucial role in elbow joint stability and motion.
Deltoid tuberosity: The deltoid tuberosity is a rough, raised area on the middle of the humerus (the long bone of the upper arm) where the deltoid muscle attaches. It serves as an anchor point allowing for muscle attachment which facilitates arm movement and stability.
Deltoid Tuberosity: The deltoid tuberosity is a rough, V-shaped area on the lateral surface of the humerus bone, located just distal to the midpoint of the bone. It serves as the attachment site for the deltoid muscle, a major muscle responsible for shoulder movement and stability.
Development of the Appendicular Skeleton: The development of the appendicular skeleton involves the formation and growth of the bones that make up the limbs, shoulders, and pelvic areas of the human body. It is a crucial aspect of fetal growth and continues to develop through childhood into early adulthood.
Distal radioulnar joint: The distal radioulnar joint is a pivot type of synovial joint located between the distal ends of the radius and ulna bones in the forearm, allowing for pronation and supination movements of the hand. It plays a crucial role in enabling the wrist to move and rotate with flexibility.
Distal Radioulnar Joint: The distal radioulnar joint is the articulation between the distal ends of the radius and ulna bones in the forearm. It is a pivotal joint that allows for the rotational movements of the forearm, enabling pronation and supination of the hand.
Elbow joint: The elbow joint is a synovial joint that connects the upper arm bone (humerus) with the two bones of the forearm (radius and ulna), allowing for flexion and extension as well as limited rotation. It is a hinge type of joint supported by muscles, ligaments, and tendons to facilitate movement and stability.
Elbow Joint: The elbow joint is a hinge-type synovial joint that connects the upper arm (humerus) to the forearm (radius and ulna). It allows for flexion, extension, and a small degree of rotation of the forearm.
Flexor retinaculum: The flexor retinaculum is a strong, fibrous band that stretches across the front of the carpal tunnel at the wrist, holding the tendons of the flexor muscles in place. It assists in the smooth movement and operation of these tendons as they contract and relax during hand movements.
Forearm: The forearm is the region of the upper limb located between the elbow and the wrist, comprising two long bones, the radius and the ulna, which support movements and function of the hand. It plays a crucial role in various motions such as rotation, flexion, and extension of the wrist and hand.
Glenohumeral joint: The glenohumeral joint is the ball-and-socket joint where the head of the humerus fits into the shallow socket of the scapula, allowing a wide range of movement for the upper arm. It is a key component of the shoulder's flexibility and stability.
Glenohumeral Joint: The glenohumeral joint, also known as the shoulder joint, is the main joint of the shoulder that allows for a wide range of motion in the upper limb. It is a ball-and-socket type of synovial joint formed by the articulation between the rounded head of the humerus and the shallow, cup-like glenoid cavity of the scapula.
Greater tubercle: The greater tubercle is a prominent area of bone located on the lateral side of the humerus, just below the head of the humerus. It serves as an attachment point for several muscles of the shoulder.
Greater Tubercle: The greater tubercle is a bony prominence located on the proximal end of the humerus, the upper arm bone. It serves as an attachment site for several important muscles involved in the movement and stabilization of the shoulder joint.
Hamate: The hamate is one of the eight small bones that make up the carpal bones in the wrist, distinguished by its unique hook-like projection on its palmar side. It plays a critical role in the complex movements and stability of the hand.
Hamate: The hamate is one of the eight carpal bones that make up the wrist. It is located on the ulnar (little finger) side of the hand and is responsible for several important functions in the upper limb.
Hand: The hand is part of the human body at the end of the arm, consisting of the wrist, palm, and fingers. It is made up of 27 bones, including the carpals (wrist bones), metacarpals (palm bones), and phalanges (finger bones).
Head of the humerus: The head of the humerus is the rounded, proximal end of the humerus bone that fits into the glenoid cavity of the scapula, forming part of the shoulder joint. It facilitates arm rotation and movement by articulating with the shoulder girdle.
Head of the radius: The head of the radius is the round, disc-shaped part at the top end of the radius bone, which is one of the two bones in the forearm. It articulates with the capitulum of the humerus and the radial notch of the ulna, enabling rotation and bending movements at the elbow.
Head of the ulna: The head of the ulna is the distal (far) end of the ulna bone, which is one of the two long bones in the forearm. It articulates with the wrist bones, specifically with the ulnar notch of the radius and articular disc of the wrist, facilitating wrist movement.
Hook of the hamate bone: The hook of the hamate bone is a bony projection on the palmar side of the hamate bone, which is one of the eight small carpal bones in the wrist. It serves as an attachment point for ligaments and tendons in the hand.
Humerus: The humerus is the long bone in the upper arm that runs from the shoulder to the elbow, connecting with both the scapula at the shoulder joint and the radius and ulna at the elbow joint. It plays a critical role in both the mobility and stability of the upper limb.
Humerus: The humerus is the upper arm bone, connecting the shoulder to the elbow. It is the longest, largest, and strongest bone in the upper limb and plays a crucial role in the structure and function of the arm and shoulder.
Intercarpal Joints: The intercarpal joints are a series of small, gliding synovial joints located between the carpal bones in the wrist. These joints facilitate the complex movements and flexibility of the wrist, allowing for a wide range of motion and dexterity of the hand.
Interosseous border of the radius: The interosseous border of the radius is the lateral edge of the radius bone in the forearm that faces towards the ulna, providing an attachment site for the interosseous membrane that connects the radius and ulna bones. This feature is crucial for forearm stability and movement, facilitating actions such as pronation and supination.
Interosseous border of the ulna: The interosseous border of the ulna is a specific edge on the ulna bone in the forearm that serves as an attachment site for the interosseous membrane, which spans between the ulna and radius. This border runs longitudinally along the length of the ulna, facing towards the radius.
Interosseous membrane of the forearm: The interosseous membrane of the forearm is a fibrous sheet that connects the radius and ulna bones, facilitating the transmission of forces and providing stability to the forearm. It also serves as an attachment site for some muscles of the forearm.
Interphalangeal joint: An interphalangeal joint is a hinge joint located between the phalanges (bones) of the fingers and toes. These joints allow for the bending and straightening movements of the fingers and toes.
Interphalangeal Joints: The interphalangeal joints are the hinge-like synovial joints located between the phalanges, or finger and toe bones, that allow for flexion and extension of the digits. These joints are essential for the dexterity and range of motion in the hands and feet.
Intertubercular groove (sulcus): The intertubercular groove, also known as the sulcus, is a long, narrow depression located on the humerus bone of the upper arm. It serves as a pathway for the tendon of the long head of the biceps brachii muscle to attach to the scapula.
Lateral epicondyle: The lateral epicondyle is a bony prominence located on the outer side of the humerus, just above the elbow joint. This structure serves as an important attachment point for muscles and ligaments in the forearm, particularly those involved in wrist extension and forearm supination. Its significance extends to conditions such as lateral epicondylitis, commonly known as 'tennis elbow', highlighting its role in both anatomy and clinical contexts.
Lateral epicondyle of the humerus: The lateral epicondyle of the humerus is a small, bony protrusion located on the outer (lateral) side of the lower end of the humerus, just above the elbow joint. It serves as an attachment point for muscles and ligaments of the forearm.
Lateral supracondylar ridge: The lateral supracondylar ridge is a prominent bony ridge located on the distal end of the humerus that serves as an attachment point for muscles and ligaments. It runs above the condyle on the outer side of the humerus, providing structural support and facilitating joint movement.
Lesser tubercle: The lesser tubercle is a small, rounded protrusion found on the humerus (the bone of the upper arm), specifically located on the anterior (front) side. It serves as an attachment site for one of the muscles of the rotator cuff, the subscapularis muscle.
Lesser Tubercle: The lesser tubercle is a bony projection on the anterior surface of the proximal humerus, the upper arm bone. It serves as an attachment point for the tendon of the subscapularis muscle, which is responsible for internal rotation of the shoulder joint.
Long Bones: Long bones are a type of bone classified by their elongated, cylindrical shape. They are the primary bones found in the appendicular skeleton, specifically in the upper and lower limbs, and are responsible for providing structure, support, and facilitating movement.
Lunate: The lunate is a crescent-shaped carpal bone found in the proximal row of the wrist, between the scaphoid and triquetrum bones. It articulates with the radius in the forearm and plays a crucial role in wrist movement and stability.
Lunate: The lunate is one of the eight carpal bones located in the wrist, forming part of the proximal row of the carpal bones. It is a small, crescent-shaped bone that plays a crucial role in the structure and function of the upper limb.
Medial Epicondyle: The medial epicondyle is a bony projection on the distal end of the humerus bone, located on the medial side of the elbow joint. It serves as an attachment point for several important ligaments and tendons that are crucial for the function and stability of the upper limb.
Medial epicondyle of the humerus: The medial epicondyle of the humerus is a bony protrusion located on the inner (medial) side of the humerus at its lower end, near the elbow. It serves as an attachment point for the muscles and ligaments involved in movement and stabilization of the forearm.
Metacarpal bone: The metacarpal bones are the five long bones located in the palm of the human hand, connecting the wrist to each of the fingers. They are numbered from one to five starting with the thumb side of the hand.
Metacarpals: The metacarpals are a group of five bones located in the palm of the hand, connecting the wrist to the fingers. These bones play a crucial role in the structure and function of the hand, providing a stable foundation for the fingers and enabling various hand movements.
Metacarpophalangeal joint: The metacarpophalangeal joint is the articulation between the metacarpal bones of the hand and the proximal bones of the fingers. These joints allow for the movement and flexion that enables gripping and manipulation of objects.
Metacarpophalangeal joints: Metacarpophalangeal joints, commonly known as MCP joints, are the articulation points between the metacarpal bones of the hand and the proximal phalanges of the fingers. These joints play a crucial role in hand function, allowing for a wide range of movements essential for gripping and manipulating objects, and they are classified as synovial joints that facilitate various types of body movements.
Midcarpal joint: The midcarpal joint is a compound joint in the wrist that allows for the complex movements of the hand, formed between two rows of carpal bones. It plays a critical role in enabling the hand to flex, extend, and perform circular motions.
Neck of the radius: The neck of the radius is a narrow area located just distal to the head of the radius, connecting it to the radial shaft in the human forearm. This part allows for the rotation and stability necessary for arm movement.
Olecranon: The olecranon is the bony prominence at the posterior end of the ulna, the larger of the two bones in the forearm. It is a key anatomical feature that plays a crucial role in the structure and function of the elbow joint.
Olecranon fossa: The olecranon fossa is a deep, triangular depression located on the posterior aspect of the humerus, just above the trochlea. It accommodates the olecranon process of the ulna when the arm is fully extended.
Olecranon process: The olecranon process is a prominent, pointed projection at the upper end of the ulna, part of the elbow joint where it connects with the humerus. It serves as an attachment point for muscles and ligaments that enable elbow movement.
Phalanges: The phalanges are the bones that make up the fingers and toes. They are the distal bones of the upper and lower limbs, responsible for the fine motor movements and dexterity of the hands and feet.
Phalanx bone of the hand: The phalanx bones of the hand are small long bones forming the skeleton of the fingers and thumb, comprising three bones (proximal, middle, and distal phalanges) in each finger and two in the thumb. These bones support digital movement and dexterity.
Phalen's Test: Phalen's test is a clinical examination technique used to diagnose carpal tunnel syndrome, a condition characterized by compression of the median nerve in the wrist. It involves flexing the wrist and observing for the development of numbness or tingling in the fingers, which indicates potential nerve impingement.
Pisiform: The pisiform is a small, pea-shaped carpal bone located in the proximal row of the carpus, on the ulnar side of the hand. It articulates only with the triquetrum and acts as a sesamoid bone, embedded within the tendon of the flexor carpi ulnaris muscle.
Pisiform: The pisiform is a small, pea-shaped bone located on the medial side of the wrist, forming part of the proximal row of carpal bones. It is one of the eight carpal bones that make up the wrist joint, connecting the forearm to the hand.
Pollex: The pollex is the anatomical term for the thumb, which is the first digit of the human hand. It has a unique range of motion, including opposition, that allows it to touch the other fingers, aiding in grasping and manipulation.
Proximal radioulnar joint: The proximal radioulnar joint is a pivot type of synovial joint located between the radius and ulna bones near the elbow, allowing for the rotation of the forearm. It plays a crucial role in enabling movements such as turning the palm up or down.
Proximal Radioulnar Joint: The proximal radioulnar joint is the synovial joint located between the proximal end of the radius and the ulna, allowing for the rotational movements of the forearm. It is a crucial component of the upper limb's skeletal structure and a key joint in the overall function of the upper extremity.
Radial fossa: The radial fossa is a shallow depression located on the anterior surface of the distal end of the humerus, where it accommodates the head of the radius when the forearm is flexed. It plays a significant role in elbow joint flexibility and stability.
Radial notch of the ulna: The radial notch of the ulna is a small, shallow depression located on the lateral side of the coronoid process of the ulna, where it articulates with the head of the radius to form part of the proximal radioulnar joint. This structure allows for the pivoting motion necessary for pronation and supination of the forearm.
Radial tuberosity: The radial tuberosity is a bony prominence located on the radius bone of the forearm, near the elbow, where the biceps muscle attaches. It serves as an anchor point for the tendon of the biceps brachii muscle, facilitating arm flexion and supination.
Radial Tuberosity: The radial tuberosity is a bony prominence located on the proximal end of the radius, the lateral bone of the forearm. It serves as the attachment site for the biceps brachii tendon, a major flexor and supinator muscle of the forearm.
Radiocarpal joint: The radiocarpal joint is a synovial joint formed between the distal end of the radius and the proximal row of carpal bones in the wrist. It allows for movements such as flexion, extension, abduction, and adduction of the wrist.
Radiocarpal Joint: The radiocarpal joint, also known as the wrist joint, is a synovial joint located between the distal end of the radius bone in the forearm and the proximal row of carpal bones in the wrist. It is a pivotal joint that allows for a wide range of motion in the hand and wrist.
Radius: The radius is one of the two long bones in the forearm, running parallel to the ulna, and plays a critical role in wrist and arm movement. It extends from the lateral side of the elbow to the thumb side of the wrist, enabling rotational motion of the forearm.
Radius: The radius is one of the two bones that make up the forearm, located on the lateral (thumb) side. It is responsible for rotating the forearm and wrist, allowing for a wide range of motion in the upper limb.
Scaphoid: The scaphoid is one of the small bones in the wrist (carpal bones) situated between the hand and forearm on the thumb's side. It plays a crucial role in movement and stability of the wrist.
Scaphoid: The scaphoid is a small, boat-shaped carpal bone located on the radial side of the wrist, connecting the distal row of carpal bones to the proximal row. It plays a crucial role in the mobility and stability of the wrist joint.
Scapula: The scapula, also known as the shoulder blade, is a flat, triangular bone that forms the posterior part of the pectoral girdle. It is a key component of the skeletal system, playing a crucial role in the structure and function of the upper limb.
Shaft of the humerus: The shaft of the humerus is the long, cylindrical middle portion of the humerus, which is the upper arm bone connecting the shoulder to the elbow. It serves as an attachment site for several muscles and supports the arm's weight and movement.
Shaft of the radius: The shaft of the radius is the long, central part of the radius bone in the forearm, extending from below the head near the elbow to just above the wrist where it widens to form part of the wrist joint. It serves as a major structural component of the forearm, providing attachment sites for muscles and supporting movements of the wrist and hand.
Shaft of the ulna: The shaft of the ulna is the long, narrow, central portion of the ulna bone, extending from the elbow to the wrist. It provides structural support and surface area for muscle attachment in the forearm.
Sternoclavicular joint: The sternoclavicular joint is a pivotal articulation point where the clavicle (collarbone) meets the sternum (breastbone) at the base of the neck. It is one of the major joints that facilitate shoulder movement and upper limb flexibility.
Sternoclavicular Joint: The sternoclavicular joint is the articulation between the medial end of the clavicle and the manubrium of the sternum. It is the only bony connection between the upper limb and the axial skeleton, and it plays a crucial role in the movements and stability of the pectoral girdle.
Styloid Process: The styloid process is a slender, bony projection that extends downward from the temporal bone of the skull. It serves as an attachment point for several muscles and ligaments involved in the movements of the head, neck, and upper limb.
Styloid process of the radius: The styloid process of the radius is a pointed, bony projection located at the distal end of the radius bone in the forearm. It serves as an attachment point for ligaments that support the wrist joint.
Styloid process of the ulna: The styloid process of the ulna is a pointed, bony projection located at the distal end of the ulna, near the wrist. It serves as an attachment point for ligaments of the wrist.
Subscapular fossa: The subscapular fossa is a concave depression located on the anterior (frontal) surface of the scapula bone, serving as the attachment site for the subscapularis muscle. It plays a critical role in arm and shoulder movement by allowing for muscle attachment and facilitating upper limb mobility.
Surgical neck: The surgical neck is a narrowed section just below the head and tubercles of the humerus bone, where it transitions to the shaft. This area is prone to fractures and is a common site for surgical intervention in case of injury.
Synovial Joints: Synovial joints are the most common and complex type of joint in the human body. They are characterized by a fluid-filled cavity surrounded by a capsule, allowing for a wide range of motion and smooth articulation between bones. Synovial joints play a crucial role in the movement and function of the upper and lower limbs, as well as the development and types of body movements.
Tinel's Sign: Tinel's sign is a clinical test used to assess the presence of nerve irritation or compression, particularly in the context of peripheral nerve injuries or entrapment syndromes. It is a useful diagnostic tool for evaluating the condition of a nerve and determining the potential for nerve regeneration.
Transverse carpal ligament: The transverse carpal ligament is a strong band of connective tissue that spans across the wrist, forming the roof of the carpal tunnel. This ligament is crucial as it protects the median nerve and the flexor tendons that pass through the tunnel, ensuring proper function and movement of the hand. It connects to various carpal bones and contributes to the structural integrity of the wrist.
Trapezium: The trapezium is one of the eight carpal bones in the wrist, specifically located at the base of the thumb near the radial side of the hand. It plays a crucial role in thumb movement and wrist stability.
Trapezium: The trapezium is a small, irregularly shaped carpal bone located on the radial side of the wrist, between the scaphoid and the first metacarpal bone. It plays a crucial role in the mechanics and mobility of the thumb within the context of the bones of the upper limb.
Trapezoid: The trapezoid is one of the eight carpal bones located in the wrist, specifically positioned within the second row and playing a crucial role in the hand's mobility and functionality. It articulates with the second metacarpal bone to facilitate movement and support to the structure of the hand.
Trapezoid: The trapezoid is a small, irregularly shaped bone located in the wrist, part of the carpus. It is one of the eight carpal bones that connect the forearm to the hand, playing a crucial role in the complex movements and stability of the wrist joint.
Triquetrum: The triquetrum is one of the eight small carpal bones located in the wrist, specifically on the ulnar side where it articulates with the pisiform, lunate, and hamate bones. It plays a crucial role in the complex movements and stability of the wrist.
Triquetrum: The triquetrum is one of the carpal bones located in the wrist, specifically in the proximal row of the carpals. It is a small, pyramidal-shaped bone that plays an important role in the structure and function of the hand and wrist.
Trochlea: The trochlea is a grooved, spool-like structure on the distal end of the humerus that articulates with the ulna in the elbow joint. It allows for the hinging movement of the forearm.
Trochlear notch: The trochlear notch is a large, concave indentation located at the proximal end of the ulna, which articulates with the trochlea of the humerus to form the elbow joint. This structure allows for the wide range of motion necessary for forearm movement.
Ulna: The ulna is one of the two long bones in the forearm, located on the side opposite the thumb and running parallel to the radius. It forms a major part of the elbow joint and articulates with the humerus at its larger end, known as the olecranon.
Ulna: The ulna is one of the two bones that make up the forearm, located on the little finger side. It is responsible for several important functions related to the skeletal system, joint anatomy, and upper limb movement.
Ulnar nerve: The ulnar nerve is one of the major nerves of the arm, responsible for innervating (supplying with nerves) parts of the hand and facilitating muscle movement and sensation in the forearm and hand. It runs from the shoulder to the hand, passing through areas such as the inner elbow (often referred to when talking about hitting your "funny bone").
Ulnar notch of the radius: The ulnar notch of the radius is a small, shallow depression located on the distal end of the radius bone, where it articulates with the head of the ulna to form part of the distal radioulnar joint. This anatomical feature plays a crucial role in allowing for the rotation of the forearm.
Ulnar tuberosity: The ulnar tuberosity is a bony prominence found on the proximal end of the ulna, one of the two long bones in the forearm. It serves as an attachment point for the brachialis muscle, which plays a key role in flexing the elbow.
Upper Limb Anatomy: Upper limb anatomy refers to the structural organization and arrangement of bones, joints, muscles, nerves, and blood vessels in the upper extremity, including the shoulder, arm, forearm, wrist, and hand. This region of the body is crucial for a wide range of functions such as reaching, grasping, and manipulating objects, making it essential for daily activities and overall mobility.