9 - Anatomy of the Hand Flashcards
What are the three parts of the hand?
Carpus (Wrist)
Metacarpus
Digits (Fingers and thumb)
How many carpal bones are there?
8
How many metacarpal bones are there?
5
How many phalanges are there?
14
3 in each finger
2 in thumb
Proximal Row
Scaphoid - S
Lunate - L
Triquetral - Tr
Pisiform - P
Distal Row
Trapezium - Tm
Trapezoid - Td
Capitate - C
Hamate - H
Which carpal bones make up the proximal row?
Scaphoid
Lunate
Triquetral
Pisiform
Which carpal bones make up the distal row?
Trapezium
Trapezoid
Capitate
Hamate
Which carpal bones articulate with the distal radius?
Scaphoid & Lunate
Which is the most commonly injured carpal bone?
Scaphoid
What is important about a fracture to the scaphoid bone?
Part of the radial artery enters the scaphoid bone - if you fracture the bone you can cut off its blood supply causing necrosis.
What mnemonic helps you remember the order of the carpal bones?
Some Lovers Try Positions That They Cant Handle
What type of bone is the pisiform? What inserts into it?
Sesamoid bone
Flexor Carpi Ulnaris inserts into it
What are the four parts of a metacarpal?
Head
Neck
Shaft
Base
How many metacarpals are there?
5
What are the three types of a phalange?
Proximal
Intermediate (not in the thumb)
Distal
Name 5 joints of the hand
Wrist
Carpal (midcarpal)
Carpometacarpal
Metacarpophalangeal
Interphalangeal
What is the name of the joints between the carpal bones?
Carpal / Midcarpal / Intercarpal
What is the name of the joint between the carpel bones and the metacarpals?
Carpometacarpal joints
What’s the name of the joint between the metacarpals and the phalanges?
Metacarpophalangeal joints. (MCP joints)
What is the name of the joints between the phalanges?
Interphalangeal joints
What type of joint is found between the carpals?
Synovial plane joints
Why is there limited intra-carpal movement?
Because the carpals are in a capsule which is reinforced by several ligaments.
What type of joint are the carpometacarpal joints?
Synovial planar joints
Which are the most mobile of the carpometacarpal joints?
Little finger and thumb
What is special about the carpometacarpal joint of the thumb?
It is a saddle joint which allows a wide range of mobility, including opposition of the thumb.
What type of joint is the metacarpophalangeal joint?
Condylar synovial joint
What movement is permitted by the MCP Joints?
Everything except rotation is limited.
What are the MCP joints reinforced by?
Palmar ligaments
Deep transverse metacarpal ligaments
Collateral ligaments
Which MCP joint is reinforced differently to the others?
The thumb
How is the thumb MCP joint reinforced?
By ulnar and radial collateral ligaments
What is another term for the MCP joint?
The knuckles
Which finger is deemed to be the axis for adduction and abduction of the fingers?
The middle finger
Abduction and adduction of the fingers occurs at which joint?
The MCP joints
Which muscle is responsible for abduction of the fingers?
Dorsal interosseous
Which muscle is responsible for adduction of the fingers?
Palmar interosseous
What is the mnemonic to remember which muscles abduct and adduct the fingers?
PAD DAB
Palmar Adduct
Dorsal Abduct
What type of joint are in the interphalangeal joints?
Hinge synovial joints
What reinforces the interphalangeal joints?
Collateral and volar (palmar) ligaments
What movement is permitted at the interphalangeal joints?
Flexion & extension only
How many interphalangeal joints are found in the thumb?
1
Which muscles are responsible for flexion of the fingers at the metacarpophalangeal joints?
Flexor Digitorum Profundus
Flexor Digitorum Superficialis
Interossei
Which muscles are responsible for flexion of the fingers at the proximal interphalangeal joints? (PIPJs)
Flexor Digitorum superficialis
Which muscles are responsible for flexion of the fingers at the distal interphalangeal joints? (DIPJs)
Flexor Digitorum Profundus
What is the function of the lumbricals?
Flexion of MCPJs and extension of PIPJ & DIPJs.
Which are the main muscles which allow extension of the fingers at the MCPJ, PIPJ and DIPJs?
Extensor Digitorum
Interossei
Which are the accessory muscles which allow extension of the fingers?
Extensor Indicis (Index finger)
Extensor Digiti Minimi