Anatomy of the Carpus and Hand
36 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which carpal bone is most commonly fractured?

  • Pisiform
  • Scaphoid (correct)
  • Hamate
  • Trapezium

What is a major complication of a scaphoid fracture due to its blood supply?

  • Avascular necrosis (correct)
  • Bone marrow edema
  • Fracture nonunion
  • Cartilage damage

What type of fracture occurs at the first carpometacarpal joint?

  • Colles' fracture
  • Smith's fracture
  • Greenstick fracture
  • Bennet's fracture (correct)

What anatomical structure tends to pull the metacarpal shaft proximally when a Bennet's fracture occurs?

<p>Abductor pollicis longus tendon (A)</p> Signup and view all the answers

Which carpal bone articulates with the base of metacarpal III?

<p>Capitate (D)</p> Signup and view all the answers

Which nerve innervates the medial two lumbricals?

<p>Ulnar nerve (C)</p> Signup and view all the answers

What is the primary function of the lumbricals?

<p>Flex MCPJ and extend IPJ (A)</p> Signup and view all the answers

Which muscle is part of the hypothenar group?

<p>Flexor digiti minimi (D)</p> Signup and view all the answers

What is the major function of the adductor pollicis?

<p>Adduction of the thumb (B)</p> Signup and view all the answers

Which group of muscles is responsible for the abduction and adduction of the fingers?

<p>Interossei (A)</p> Signup and view all the answers

What is one of the primary learning outcomes regarding the wrist and hand?

<p>Revise the osteology and joints of the wrist and hand (B)</p> Signup and view all the answers

Which movements are specifically associated with the thumb?

<p>Abduction, adduction, and opposition (D)</p> Signup and view all the answers

Which bones are part of the proximal row of the carpal bones?

<p>Scaphoid, lunate, triquetrum, and pisiform (B)</p> Signup and view all the answers

What structure contains long tendons of the forearm flexors within the hand?

<p>Carpal tunnel (B)</p> Signup and view all the answers

Which clinical aspect is highlighted in the learning outcomes?

<p>Common neurovascular injuries within the hand (B)</p> Signup and view all the answers

Which thenar muscles are primarily responsible for thumb opposition?

<p>Opponens pollicis (B)</p> Signup and view all the answers

Which layer of the palm is involved in the organization of the palmar spaces?

<p>Deep fascia layer (B)</p> Signup and view all the answers

What is the orientation of thumb movements relative to digit III?

<p>90° to the movement of digits (D)</p> Signup and view all the answers

Which nerve innervates the muscles of the hypothenar eminence?

<p>Deep motor branch of the ulnar nerve (C)</p> Signup and view all the answers

What does the mid-palmar compartment primarily contain?

<p>Long flexor tendons, lumbricals, and palmar arches (A)</p> Signup and view all the answers

What is the primary shape characteristic of the palmar aponeurosis?

<p>Triangular (C)</p> Signup and view all the answers

What condition is characterized by a thickening of the palmar fascia leading to fixed positions of fingers?

<p>Dupuytren's contracture (B)</p> Signup and view all the answers

Which structure is NOT found in the thenar eminence?

<p>Lumbricals (B)</p> Signup and view all the answers

Which structure prevents the bowing of flexor digitorum tendons?

<p>Synovial sheaths (C)</p> Signup and view all the answers

What is the function of the intrinsic muscles of the hand?

<p>Facilitate finger abduction and adduction (B)</p> Signup and view all the answers

Which of the following best describes the function of the fibrous flexor tendon sheaths?

<p>Anchor the long flexor tendons to the phalanges (C)</p> Signup and view all the answers

What would likely result from a damaged recurrent motor branch of the median nerve?

<p>Loss of thumb opposition (D)</p> Signup and view all the answers

What is the role of the radial bursa in the hand?

<p>Encases flexor tendons from the forearm (C)</p> Signup and view all the answers

Which artery mainly supplies blood to the hand?

<p>Radial artery (B), Ulnar artery (D)</p> Signup and view all the answers

What structure does the extensor hood primarily serve as an attachment for?

<p>Lumbricals (A)</p> Signup and view all the answers

Which test is used to assess arterial blood flow in the hand?

<p>Allen's Test (C)</p> Signup and view all the answers

What is primarily formed by the anastomosis of the deep branch of the ulnar artery and the radial artery?

<p>Deep palmar arch (D)</p> Signup and view all the answers

Which of the following arteries is NOT a contributor to the superficial palmar arch?

<p>Radialis indicis artery (C)</p> Signup and view all the answers

Which band does the extensor hood NOT divide into?

<p>Medial band (C), Dorsal band (D)</p> Signup and view all the answers

Where does the ulnar artery enter the hand?

<p>Between the pisiform and hook of hamate (C)</p> Signup and view all the answers

What is the function of the lumbricals regarding finger movement?

<p>Flex MCP and extend IP joints (C)</p> Signup and view all the answers

Flashcards

Carpal Bones

The eight small bones that form the wrist joint.

Scaphoid, Lunate, Triquetrum

Three of the eight carpal bones in the proximal row.

Thumb Abduction/Adduction

Moving the thumb away from or towards the other fingers.

Thumb Opposition

Touching the thumb to the other fingers, crucial for grasping.

Signup and view all the flashcards

Carpal Tunnel

A narrow passageway in the wrist formed by bones and ligaments.

Signup and view all the flashcards

Thenar and Hypothenar Eminences

Muscle groups at the base of the thumb and little finger, respectively.

Signup and view all the flashcards

Intrinsic Hand Muscles

Muscles located entirely within the hand, crucial for fine movements.

Signup and view all the flashcards

Long Tendons of Forearm Flexors

Tendons that pass through the hand; important for bending the fingers

Signup and view all the flashcards

Scaphoid fracture

Most common carpal fracture, typically across the long axis at the "waist".

Signup and view all the flashcards

Scaphoid fracture risk

Fracture compromises blood supply, potentially causing avascular necrosis of proximal part of the bone (due to retrograde blood movement).

Signup and view all the flashcards

Bennett's fracture

Fracture at the 1st carpometacarpal joint (base of the thumb).

Signup and view all the flashcards

Carpometacarpal joint

Synovial joint (saddle type) connecting carpal bones to metacarpal bones.

Signup and view all the flashcards

Abductor pollicis longus tendon

Tendon that inserts at the base of the thumb's metacarpal, involved in abduction and pulling metacarpal proximally.

Signup and view all the flashcards

Lumbrical Action

Lumbricals flex the metacarpophalangeal (MCP) joint and extend the interphalangeal (IP) joints.

Signup and view all the flashcards

Lumbrical Innervation

The lateral two lumbricals are innervated by the median nerve, while the medial two lumbricals are innervated by the ulnar nerve.

Signup and view all the flashcards

Hypothenar Group

The hypothenar group includes the flexor digiti minimi, abductor digiti minimi, and opponens digiti minimi, all innervated by the deep motor branch of the ulnar nerve.

Signup and view all the flashcards

Thenar Group

The thenar group includes the flexor pollicis brevis, abductor pollicis brevis, and opponens pollicis, all innervated by the recurrent motor branch of the median nerve.

Signup and view all the flashcards

Interosseous Muscles

The dorsal interossei abduct the fingers, while the palmar interossei adduct the fingers. Both are innervated by the deep motor branch of the ulnar nerve.

Signup and view all the flashcards

Hypothenar eminence muscles

Three muscles located in the hypothenar eminence, controlled by the deep motor branch of the ulnar nerve.

Signup and view all the flashcards

Thenar eminence muscles

Three muscles of the thumb, innervated by the recurrent motor branch of the median nerve.

Signup and view all the flashcards

Mid-palmar space contents

Long flexor tendons from the forearm, lumbricals, and palmar arches are located in the mid-palmar space.

Signup and view all the flashcards

Digital tendon sheaths (FDP and FDS)

Sheaths that surround tendons 2, 3, and 4, helping prevent bowing and connected with the 5th digital sheath.

Signup and view all the flashcards

FPL tendon sheath

The sheath that encompasses the flexor pollicis longus (FPL) tendon to the wrist.

Signup and view all the flashcards

Palmar aponeurosis

A strong, flat tendon that's a condensation of deep palm fascia. It divides into slips to connect to flexor tendon sheaths and deep palm ligaments.

Signup and view all the flashcards

Dupuytren's contracture

A benign condition causing the palmar fascia to thicken and progressively fix finger position, usually affecting the 4th and 5th digits.

Signup and view all the flashcards

Flexor Retinaculum

Also known as the transverse carpal ligament, the flexor retinaculum is a structure found in the wrist.

Signup and view all the flashcards

Ulnar bursa

A sac, near the wrist, that provides support and lubrication around the tendons.

Signup and view all the flashcards

Extensor Hood

A fibrous structure formed by tendons of the extensor digitorum and extensor pollicis longus, covering the proximal phalanx, then dividing into a central band and two lateral bands. It serves as an attachment point for lumbricals, dorsal interossei, and palmar interossei, contributing to finger flexion and extension.

Signup and view all the flashcards

Extensor Digitorum Tendons

Tendons of the extensor digitorum muscle that extend the four fingers, forming part of the extensor hood structure.

Signup and view all the flashcards

Extensor Pollicis Longus Tendon

Tendon of the extensor pollicis longus muscle, contributing to the extensor hood, responsible for extending the thumb.

Signup and view all the flashcards

Lumbricals

Intrinsic hand muscles that flex the metacarpophalangeal (MCP) joint and extend the interphalangeal (IP) joints of the fingers.

Signup and view all the flashcards

Dorsal Interossei

Intrinsic hand muscles that abduct (spread) the fingers, also contributing to MCP flexion and IP extension.

Signup and view all the flashcards

Palmar Interossei

Intrinsic hand muscles that adduct (bring together) the fingers, also contributing to MCP flexion and IP extension.

Signup and view all the flashcards

Superficial Palmar Arch

An arterial network in the palm, formed primarily by the superficial branch of the ulnar artery, providing blood to the fingers.

Signup and view all the flashcards

Deep Palmar Arch

An arterial network in the palm, formed primarily by the radial artery, providing blood to the thumb and index finger, and anastomosing with the deep branch of the ulnar artery.

Signup and view all the flashcards

Study Notes

Carpus and Hand

  • The lecture covers body movement and function of the carpus (wrist) and hand.
  • Learning outcomes include: revision of wrist and hand osteology and joints, muscles in the thenar and hypothenar eminences, long tendons of forearm flexors, carpal tunnel and its contents, common neurovascular injuries, clinically relevant landmarks, and intrinsic muscles/neurovascular structures.
  • Various anatomical texts are recommended for further study, including clinical atlases, Gray's Anatomy, essential clinical anatomy, and Netter's Atlas.

Movements of the Hand

  • Abduction and adduction of fingers occur around digit III.
  • Movement of the thumb is at 90 degrees to the movement of the fingers.

Movements of the Thumb

  • Abduction, adduction, and opposition are distinct thumb movements.

Bones of the Wrist

  • Proximal row includes scaphoid, lunate, triquetrum, and pisiform.
  • Distal row includes trapezium, trapezoid, capitate, and hamate.
  • Key features of each bone are mentioned.

Scaphoid Fracture

  • The scaphoid is the most commonly fractured carpal bone.
  • Fractures typically occur across the "waist" of the bone.
  • Blood supply to the scaphoid is distal to proximal, which can lead to risk of avascular necrosis.

Bennett's Fracture

  • This is a fracture of the first carpometacarpal joint (CMC joint) of the thumb.
  • The synovial joint is saddle-shaped.
  • The abductor pollicis longus tendon plays a role in stabilizing and abducting the thumb.

Hypothenar and Thenar Eminences

  • Hypothenar eminence contains three muscles of the little finger, innervated by the deep branch of the ulnar nerve.
  • Thenar eminence contains muscles of the thumb, innervated by the recurrent branch of the median nerve.

Compartments of the Hand

  • Midpalmar compartment contains long flexor tendons, lumbricals, and palmar arches.
  • Hypothenar eminence contains three little finger muscles.
  • Thenar eminence contains muscles for the thumb.

Synovial Sheaths

  • Fibrous sheaths (e.g., FDP and FDS) hold tendons to phalanges, preventing bowing.
  • FPL tendon sheath is also noted.

Fascia of the Hand

  • Includes palmar aponeurosis (a condensation of deep fascia), palmar carpal ligament, and flexor retinaculum.
  • Flexor retinaculum (transverse carpal ligament) is mentioned.
  • Structures described are palmar aponeurosis, palmar carpal ligament, and flexor retinaculum

Palmar Aponeurosis

  • A triangular-shaped condensation of deep palmar fascia.
  • Anchored to flexor retinaculum, divides into slips for insertions; fibrous flexor tendon sheaths and deep transverse ligaments.

Dupuytren's Contracture

  • A benign fibroproliferative disorder of the palmar fascia.
  • Fascia thickens, causing fingers to flex and become fixed.
  • Often affects the fourth and fifth digits.
  • Surgery may be required to relieve symptoms.

Intrinsic Muscles of the Hand

  • Hypothenar group, thenar group, and lumbricals are intrinsic muscles innervated by various nerve branches.

Lumbricals

  • Arise from the FDP tendon.
  • Insert into the radial side of the MP joints and extensor hood.
  • Lateral lumbricals receive innervation from the median nerve; medial lumbricals from the ulnar nerve.

Dorsal and Palmar Interossei

  • Dorsal interossei abduct fingers.
  • Palmar interossei adduct fingers.
  • Both are innervated by the deep branch of the ulnar nerve.

Extensor Hood

  • Tendons of extensor digitorum and extensor pollicis longus expand over the proximal phalanx.
  • Serves as an attachment for lumbricals, dorsal interossei, and palmar interossei, and for flexing MCP and extending IP.

Blood Supply

  • Ulnar artery and radial artery supply blood to the hand.
  • Ulnar artery is anterior to the flexor retinaculum between the pisiform and hook of the hamate.
  • Radial artery curves around scaphoid/trapezium and anastomoses with deep branch of the ulnar artery.

Allen's Test

  • Used to assess collateral circulation of the radial and ulnar arteries.
  • The radial artery is most commonly used for testing access.

Surface Anatomy

  • Superficial arch is at the level of the tip of the thumb.
  • Deep arch is at the base of the extended thumb.

Carpal Tunnel Syndrome

  • Any lesion (e.g. inflammation, infection, fluid retention, or arthritis) causing compression of the median nerve in the carpal tunnel can cause symptoms.
  • Symptoms include median nerve compression, paraesthesia, and loss of function in the hand.
  • Clinical presentation, diagnostic work up, and treatment are not included.

Cutaneous Innervation

  • Various nerves (e.g., axillary, radial, musculocutaneous, and median) provide sensation to different regions of the arm/hand.

Dermatomes

  • Dermatomes are mapped skin regions, and their related segments of the spinal cord and peripheral nerves.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Description

This quiz focuses on the anatomy and movements of the carpus and hand. Students will explore the osteology of the wrist, muscle groups, and common neurovascular injuries related to hand function. It is essential for understanding clinical applications and anatomical landmarks.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser