Forearm, Hand, Wrist Anatomy

When the bones of the forearm are crossed, it means that the arm is pronated. This is because pronation refers to the rotation of the forearm in such a way that the palm faces downwards or towards the back. Crossing the bones of the forearm is a characteristic movement of pronation, where the radius and ulna (the two bones in the forearm) cross over each other, resulting in the palm facing downwards. Therefore, the statement is true.

The statement is true because the median nerve does indeed pass through the flexor retinaculum. The flexor retinaculum is a band of connective tissue located in the wrist, and it forms a tunnel called the carpal tunnel. The median nerve, along with several tendons, passes through this tunnel. This arrangement allows the median nerve to innervate the muscles of the forearm and hand.

The correct answer is Scaphoid, lunate, triquetrum. This answer is correct because the joint between the distal radius and ulna and the proximal row of carpal bones is known as the radiocarpal joint. The radiocarpal joint is formed by the articulation of the scaphoid, lunate, and triquetrum bones with the distal end of the radius. These three carpal bones form the proximal row of carpal bones and play a crucial role in wrist movement and stability.

The statement is true because the radius is indeed a major forearm bone that plays a significant role in the movement of the wrist joint. As the radius moves, it causes the wrist joint to move as well. This is because the radius is one of the two bones in the forearm that connect to the wrist, along with the ulna. Therefore, any movement of the radius directly affects the movement of the wrist joint.

The given answer is "True" because it directly states that the statement is true.

The ulnar nerve is responsible for innervating the flexor carpi ulnaris muscle and the medial half of the flexor digitorum profundus muscle in the forearm. This means that it provides the necessary nerve signals for these muscles to contract and perform their respective functions. Therefore, the statement is true.

The radial collateral ligament extends from the radial styloid process to the scaphoid bone. The radial collateral ligament is a thick, strong ligament that helps to stabilize the wrist joint. It connects the radius bone in the forearm to the scaphoid bone in the wrist. This ligament plays a crucial role in maintaining the stability and proper alignment of the wrist joint during movements such as flexion, extension, and radial deviation.

The ulnar collateral ligament extends from the ulnar styloid process to the triquetrum and pisiform. This ligament provides stability to the wrist joint and helps prevent excessive movement of the ulna bone. It is located on the medial side of the wrist and is commonly injured in activities that involve repetitive wrist movements or direct impact to the hand.

The radial head plays a crucial role in stabilizing the elbow joint along with the medial collateral ligament (MCL) complex. While the MCL is the primary stabilizer, the radial head acts as a secondary stabilizer. It helps to prevent excessive valgus stress on the elbow joint and provides stability during rotational movements. Therefore, the statement that the radial head is considered a second stabilizer in the elbow with an intact MCL complex is true.

Most activities require a certain degree of pronation and supination of the forearm. Pronation refers to the rotation of the forearm so that the palm faces downwards, while supination refers to the rotation of the forearm so that the palm faces upwards. The statement suggests that the functional range for these movements is 50 degrees in both directions. This means that most activities can be successfully performed within this range of motion. Therefore, the answer "True" indicates that the statement is correct.

opposite

The statement is true because the MCL (medial collateral ligament), capsule, and joint articulation all contribute to resisting valgus stress. Valgus stress refers to a force that pushes the knee joint outward, away from the body's midline. The MCL is a ligament on the inner side of the knee that helps stabilize and prevent excessive movement in this direction. The joint capsule surrounds the knee joint, providing additional support and stability. The joint articulation, which refers to the contact and movement between the bones in the knee joint, also plays a role in resisting valgus stress. Therefore, all three structures work together to share the resistance to valgus stress.

The ligament that connects the MCP joints in the palmar plates of digits 2-5 is called the transverse intermetacarpal ligament. This ligament provides additional stability to the MCP region.

The correct answer is the Capitulum.

The statement suggests that the supinators, muscles responsible for rotating the forearm outward, are stronger than the pronators, muscles responsible for rotating the forearm inward. This implies that the supinators have more strength and power compared to the pronators.

In supination, the ulna and radius are parallel to each other. This means that they are aligned side by side, with their lengths running in the same direction. This position allows for the maximum range of motion in the forearm and hand, enabling activities such as holding objects, writing, and gripping.

The flexor retinaculum is not located proximal to the extensor retinaculum. In fact, it is located distal to the extensor retinaculum.

The statement is true because in the anatomical position, the scaphoid bone is indeed located opposite the lateral area of the radius, while the lunate bone is opposite the medial area + disc. This positioning is consistent with the standard anatomical arrangement of these bones in the human body.

The proximal radio-ulnar joint is classified as a pivot joint because it allows for rotation of the radius bone around the ulna bone. This type of joint is characterized by a rounded bony process that fits into a ring-shaped structure, allowing for rotational movement. In the case of the proximal radio-ulnar joint, the rounded head of the radius bone articulates with the radial notch of the ulna bone, enabling pronation and supination of the forearm.

The sagittal axis runs through the carpal bones from front to back, and the movements conducted in this axis are radial deviation and ulnar deviation. Radial deviation refers to the movement of the hand towards the thumb side of the wrist, while ulnar deviation refers to the movement of the hand towards the pinky side of the wrist. These movements allow for side-to-side movements of the hand and wrist.

The dorsal interossei are a group of muscles located between the metacarpal bones in the hand. These muscles have their origin or attachment points on all of the metacarpal bones. Therefore, the statement that the dorsal interossei has origo on all metacarpals is true.

Supination / pronation is not a movement of the wrist.

The anterior bundle of the MCL-complex tightens in extension.

The correct answer is 170 - 185 degrees in total. This range represents the range of motion (ROM) for pronation and supination. Pronation is the movement of the forearm and hand in which the palm is turned downwards, while supination is the movement in which the palm is turned upwards. The ROM for pronation and supination is typically measured in degrees, and a range of 170 - 185 degrees indicates the total range of motion for these movements.

It is more distal than the extensor retinaculum

The correct answer is 80 - 85 degrees. This range represents the normal range of motion (ROM) of the wrist in flexion, specifically palmar flexion. The wrist is able to flex downwards, towards the palm, allowing for a range of motion between 80 and 85 degrees. This movement is important for various activities that involve bending the wrist, such as grasping objects or performing certain exercises.

They are the most important palmar reinforcements.

Pronator teres.

The lumbricals are a group of muscles in the hand that originate from the flexor digitorum profundus tendons. They pass through the palm and insert into the extensor expansions of the fingers. When they contract, they flex the metacarpophalangeal (MCP) joints and extend the proximal and distal interphalangeal (PIP and DIP) joints. Therefore, the correct answer is "Flexion in the MCP joints and extension in pip and dip."

The adductor pollicis muscle is responsible for adducting the thumb, which means bringing it towards the palm of the hand. The ulnar nerve is responsible for innervating the muscles of the hand, including the adductor pollicis. Therefore, the correct answer is ulnar nerve.

Flexor digitorum profundus (4), flexor digitorum superficialis (4) and flexor pollicis longus (1). Also the median nerve passes through the carpal tunnel.

The ulnar collateral ligament of MCP is stronger than the radial collateral ligament of MCP. This means that it is more resistant to forces that could potentially cause injury or damage to the ligament. The strength of the ulnar collateral ligament allows it to provide stability and support to the MCP joint, which is important for proper hand function and movement.

The wrist joint is classified as an ellipsoid joint because it allows movement in two planes - flexion/extension and abduction/adduction. This type of joint is characterized by an oval-shaped convex surface of one bone fitting into a concave surface of another bone. In the case of the wrist joint, the convex surface of the radius bone articulates with the concave surface of the scaphoid and lunate bones. This arrangement allows for a variety of movements, including bending the wrist forward and backward, as well as moving it from side to side.

Opposite.

The proximal row of carpal bones refers to the group of bones located in the wrist. These bones are arranged in a row, and when viewed from the top, they appear to be convex. This means that the surface of the bones curves outward, creating a rounded shape.

Tunnel/compartment 5 of the extensor retinaculum includes the extensor digiti minimi muscle.

The RADIAL and ulnar artery form connections creating the superficial volar arch and the deep volar arche in the hand.

30 degrees is the correct answer.

The palmar interossei muscles are located in the hand and are responsible for the movement of the fingers. They are specifically involved in the adduction (bringing fingers together) of the fingers. The 2nd, 4th, and 5th digits are the fingers that the palmar interossei muscles act upon, so the correct answer is 2., 4., and 5. digit.

The correct answer is: Dorsal radioulnar ligament, palmar radioulnar ligament, triangular fibrocartilage discus, ulnocarpal ligaments, and extensor carpi ulnaris tendon sheath. This answer is correct because it includes all the components that make up the triangular fibrocartilage complex (TFCC). The TFCC is a structure in the wrist that provides stability and support to the joint. It consists of ligaments (dorsal radioulnar ligament, palmar radioulnar ligament, ulnocarpal ligaments), a fibrocartilaginous disc (triangular fibrocartilage discus), and a tendon sheath (extensor carpi ulnaris tendon sheath).

It cannot slip downwards.

The correct answer is "Anterior bundle, transverse ligament, posterior bundle." This is because the MCL (medial collateral ligament) of the knee consists of three main components: the anterior bundle, which is located towards the front of the knee; the transverse ligament, which runs horizontally across the knee joint; and the posterior bundle, which is located towards the back of the knee. These three components work together to provide stability and support to the knee joint, particularly in preventing excessive inward movement of the knee.

The Metacarpophalangeal joints are classified as saddle joints. Saddle joints are a type of synovial joint that allows movement in multiple directions, including flexion, extension, abduction, adduction, and circumduction. These joints are found in the thumb and enable a wide range of movement, making them highly versatile and important for various manual tasks. The articulating surfaces of saddle joints are shaped like a saddle, with one concave and one convex surface, allowing for a greater range of motion compared to hinge or condyloid joints.

The extensor policis longus tendon runs medial to the dorsal tubercle of Lister's.

It is the joint articulation, followed by the capsule.

Biceps