Podcast
Questions and Answers
What is the functional consequence of the lumbrical muscles' unique origin from the flexor digitorum profundus tendons?
What is the functional consequence of the lumbrical muscles' unique origin from the flexor digitorum profundus tendons?
- They contribute to both flexion at the metacarpophalangeal joints and extension at the interphalangeal joints, facilitating a balanced grip. (correct)
- They primarily stabilize the wrist during forceful finger flexion.
- They solely extend the digits, working antagonistically to the flexor digitorum profundus.
- They exclusively adduct the digits at the metacarpophalangeal joints.
A patient presents with weakness in the abduction of the index and middle fingers, alongside reduced sensation in the web space between the thumb and index finger. Which nerve is MOST likely affected?
A patient presents with weakness in the abduction of the index and middle fingers, alongside reduced sensation in the web space between the thumb and index finger. Which nerve is MOST likely affected?
- Radial nerve
- Axillary nerve
- Ulnar nerve
- Median nerve (correct)
Following a deep laceration on the palmar aspect of the wrist, a patient exhibits an inability to oppose the little finger. Which muscle is MOST likely affected, and what nerve innervates it?
Following a deep laceration on the palmar aspect of the wrist, a patient exhibits an inability to oppose the little finger. Which muscle is MOST likely affected, and what nerve innervates it?
- Abductor digiti minimi; radial nerve
- Palmaris brevis; median nerve
- Opponens digiti minimi; ulnar nerve (correct)
- Flexor digiti minimi brevis; median nerve
A surgeon is planning to harvest the cephalic vein for a coronary artery bypass graft. Which of the following BEST describes the cephalic vein's course in the arm?
A surgeon is planning to harvest the cephalic vein for a coronary artery bypass graft. Which of the following BEST describes the cephalic vein's course in the arm?
In a patient with carpal tunnel syndrome, which of the following muscles would be LEAST affected due to the compression of the median nerve within the carpal tunnel?
In a patient with carpal tunnel syndrome, which of the following muscles would be LEAST affected due to the compression of the median nerve within the carpal tunnel?
A blacksmith strikes his thumb repeatedly with a hammer. Over time, a painful mass develops in the anatomical snuffbox. Damage to what artery is the MOST likely cause?
A blacksmith strikes his thumb repeatedly with a hammer. Over time, a painful mass develops in the anatomical snuffbox. Damage to what artery is the MOST likely cause?
Which statement BEST encapsulates the functional distinction between the dorsal and palmar interossei muscles of the hand?
Which statement BEST encapsulates the functional distinction between the dorsal and palmar interossei muscles of the hand?
A patient is unable to extend their distal interphalangeal joint of the index finger, but metacarpophalangeal and proximal interphalangeal joint extension are intact. Which tendon is MOST likely ruptured?
A patient is unable to extend their distal interphalangeal joint of the index finger, but metacarpophalangeal and proximal interphalangeal joint extension are intact. Which tendon is MOST likely ruptured?
A patient reports losing sensation in the majority of their palm. Which nerve is MOST likely damaged?
A patient reports losing sensation in the majority of their palm. Which nerve is MOST likely damaged?
A concert pianist injures their hand. They can still flex their digits, but are unable to 'even out' the speed at which their fingers are flexed. Which muscle group is MOST likely injured?
A concert pianist injures their hand. They can still flex their digits, but are unable to 'even out' the speed at which their fingers are flexed. Which muscle group is MOST likely injured?
Which structural arrangement within the carpal tunnel increases the risk of median nerve compression, potentially leading to carpal tunnel syndrome?
Which structural arrangement within the carpal tunnel increases the risk of median nerve compression, potentially leading to carpal tunnel syndrome?
How does the superficial palmar arch's primary arterial supply influence surgical decisions in the hand?
How does the superficial palmar arch's primary arterial supply influence surgical decisions in the hand?
What functional implication arises from the flexor digitorum superficialis tendons being located superficially relative to the flexor digitorum profundus tendons in the palm?
What functional implication arises from the flexor digitorum superficialis tendons being located superficially relative to the flexor digitorum profundus tendons in the palm?
Which anatomical structure provides a critical pathway for both vascular and neural elements entering the hand, while also posing a potential site for compression syndromes?
Which anatomical structure provides a critical pathway for both vascular and neural elements entering the hand, while also posing a potential site for compression syndromes?
How might a fracture of the scaphoid bone, located within the carpal bones, have a chance of causing avascular necrosis?
How might a fracture of the scaphoid bone, located within the carpal bones, have a chance of causing avascular necrosis?
What is the functional consequence of the palmar aponeurosis, particularly concerning Dupuytren's contracture?
What is the functional consequence of the palmar aponeurosis, particularly concerning Dupuytren's contracture?
In a laceration proximal to the wrist that severs the ulnar artery, what other arterial structure would play a crucial role in maintaining blood supply to the hand?
In a laceration proximal to the wrist that severs the ulnar artery, what other arterial structure would play a crucial role in maintaining blood supply to the hand?
What anatomical relationship explains why a deep laceration on the palmar aspect of the wrist might spare the superficial palmar arch but risk injury to the median nerve?
What anatomical relationship explains why a deep laceration on the palmar aspect of the wrist might spare the superficial palmar arch but risk injury to the median nerve?
How does the arrangement of tendon sheaths within the wrist facilitate efficient hand function, and what clinical implications arise from this arrangement?
How does the arrangement of tendon sheaths within the wrist facilitate efficient hand function, and what clinical implications arise from this arrangement?
What is the primary biomechanical advantage of the flexor retinaculum's presence at the wrist joint, and how does this relate to carpal tunnel syndrome?
What is the primary biomechanical advantage of the flexor retinaculum's presence at the wrist joint, and how does this relate to carpal tunnel syndrome?
Flashcards
Hand Osteology Components
Hand Osteology Components
Bones in the hand, including the phalanges (fingers), metacarpals (palm), and carpals (wrist).
Flexor Retinaculum
Flexor Retinaculum
A band of connective tissue on the palmar side of the hand that overlies the carpal tunnel.
Carpal Tunnel
Carpal Tunnel
A passageway in the wrist through which tendons and the median nerve pass.
Arterial Blood Supply (Hand)
Arterial Blood Supply (Hand)
Signup and view all the flashcards
Palmar Arches
Palmar Arches
Signup and view all the flashcards
Nerves of the Hand
Nerves of the Hand
Signup and view all the flashcards
Median Nerve
Median Nerve
Signup and view all the flashcards
Flexor Tendon Sheaths
Flexor Tendon Sheaths
Signup and view all the flashcards
Palmar Aponeurosis
Palmar Aponeurosis
Signup and view all the flashcards
Intrinsic Hand Muscles
Intrinsic Hand Muscles
Signup and view all the flashcards
Lumbrical Actions
Lumbrical Actions
Signup and view all the flashcards
Ulnar Nerve (Hand)
Ulnar Nerve (Hand)
Signup and view all the flashcards
Median Nerve (Hand)
Median Nerve (Hand)
Signup and view all the flashcards
Interossei Muscles Actions
Interossei Muscles Actions
Signup and view all the flashcards
Dorsal Interossei Action
Dorsal Interossei Action
Signup and view all the flashcards
Palmar Interossei Action
Palmar Interossei Action
Signup and view all the flashcards
Anatomical Snuffbox Tendons
Anatomical Snuffbox Tendons
Signup and view all the flashcards
Thumb Actions
Thumb Actions
Signup and view all the flashcards
Digits (2nd-5th) Actions
Digits (2nd-5th) Actions
Signup and view all the flashcards
Dorsal Venous Plexus
Dorsal Venous Plexus
Signup and view all the flashcards
Study Notes
- Hand anatomy covers osteology, ligaments, and muscles.
- Also includes the arterial blood flow in the hand, and the path of the nerves.
- Includes the superficial veins of the hand.
Key Hand Anatomy
- The digits are named thumb, index, middle, ring, little, from radial to ulnar.
- Each has carpometacarpal joints (CMC), metacarpophalangeal joints (MCP), and interphalangeal joints.
- The joints of the thumb include interphalangeal (IP) joints.
- Phalanges (phalanx), metacarpals (MC1-5) and carpals make up the bones of the hand.
- The radius and ulna connect to the carpals.
- The scaphoid and lunate are specific carpals identified on both the palmar and dorsal sides.
- The hand is connected to the forearm via the wrist joint.
- The wrist joint includes the carpals, radius, ulna, and metacarpals.
Ligaments and Carpal Tunnel
- Ligaments stabilize the wrist joint.
- The flexor retinaculum forms the roof of the carpal tunnel.
- The carpal tunnel also has an ulnar tunnel.
Arteries and Nerves
- The tendons of forearm muscles continue into the hand.
- The brachial artery branches into the radial and ulnar arteries.
- Arterial blood flow into the palm includes the superficial and deep palmar arches.
- These arches are fed by the ulnar and radial arteries.
- The nerves of the forearm, including the radial, median, and ulnar nerves, proceed into the hand.
- Arteries, nerves, and tendons enter the palm.
Carpal Tunnel Contents
- The carpal tunnel contains the flexor retinaculum, carpal bones, ulnar nerve and artery (within the ulnar tunnel).
- It also contains the digital flexor tendons, flexor digitorum superficialis tendons, and the flexor pollicis longus tendon, plus the median nerve.
Muscles of the Hand
- Tendon sheaths and ligaments are located at the wrist.
- Intrinsic palm muscles are arranged in layers: superficial and middle.
- The palmaris brevis muscle, palmar aponeurosis, flexor retinaculum, and palmaris longus tendon make up the superficial layer.
- The flexor digiti minimi brevis, abductor digiti minimi, flexor pollicis brevis, and abductor pollicis brevis are located in the superficial layer.
- Deeper muscles include the lumbrical muscles, opponens digiti minimi, flexor digiti minimi brevis, adductor pollicis, and flexor pollicis longus tendon.
- Intrinsic muscles are named for the actions they perform.
- Lumbrical muscles flex the metacarpophalangeal joint and extend interphalangeal joints, evening out the speed at which fingers are flexed.
- The ulnar nerve affects all digiti minimi muscles, medial lumbricals, palmaris brevis, and adductor pollicis.
- The median nerve affects most pollicis muscles and lateral lumbricals.
Cutaneous Innervation
- Cutaneous innervation of the skin is provided by the median, ulnar and radial nerves
Posterior Forearm
- The posterior compartment of the forearm includes muscles like the brachioradialis, extensor carpi radialis longus and brevis, and the extensor digitorum muscles.
Dorsal Hand
- On the dorsal side of the hand, interossei muscles abduct and adduct the middle three digits, and also adduct the pinky finger.
- The tendons in the dorsum of the hand include the extensor indicis, extensor pollicis longus and brevis, abductor pollicis longus and extensor digitorum and digiti minimi tendons.
- The anatomical snuffbox contains the extensor pollicis longus and brevis tendons, the abductor pollicis longus and the radial artery.
Muscles
- Anterior/palmar muscles: flexor carpi ulnaris, radialis, digitorum superficialis/profundus, pollicis longus/brevis, palmaris longus/brevis, pronator teres/quadratus, abductor pollicis brevis and digiti minimi, adductor pollicis, opponens pollicis/digiti minimi, interosseous palmar (3), lumbricals (4).
- Posterior/dorsal muscles: extensor carpi ulnaris, radialis longus/brevis, digitorum longus/brevis, pollicis longus/brevis, digiti minimi, indicis, supinator, abductor pollicis longus, interosseous dorsal (4).
Hand Actions
- Thumb abduction: abductor pollicis longus and brevis.
- Digit abduction: interossei.
- Pinky abduction: abductor digiti minimi.
- Thumb adduction: adductor pollicis.
- Digits adduction: interossei.
- Pinky adduction: interossei.
- Thumb opposition: opponens pollicis.
- Digits opposition: interossei.
- Pinky opposition: opponens digiti minimi
Veins
- Superficial veins on the dorsum of the hand include the dorsal venous plexus, cephalic vein, and basilic vein.
- Superficial veins on the anterior upper limb include the cephalic vein, median cubital vein, and basilic vein.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
