2024 Human Anatomy and Dissection Day 9 PDF

2024 Human Anatomy and Dissection : Day 9 Forearm and hand （Anterior: Flexors） ぜん わん て 前腕と手 ぜんわん くっきん （前面：屈筋） Goals of this lesson Students must understand and be able to describe: 1. The flexor muscles of...

2024 Human Anatomy and Dissection : Day 9 Forearm and hand （Anterior: Flexors） ぜん わん て 前腕と手 ぜんわん くっきん （前面：屈筋） Goals of this lesson Students must understand and be able to describe: 1. The flexor muscles of the forearm and the structure of the flexor retinaculum. ぜんわん くっきん ぐん くっきん したい こうぞう （前腕屈筋群と屈筋支帯の構造） 2. The structures of the tendon sheath of the hand. て けんしょう （手の腱鞘の構造） 3. The arteries and nerves of the hand. どうみゃく しんけい （手の動脈と神経） Flexor muscles of the forearm ぜんわん くっきん ぐん 前腕屈筋群 Flexor muscles of the forearm Muscles of the arm are separated into anterior （flexor） and posterior （extensor） compartments by layers of fascia, intermuscular septa, interosseous membrane（骨間膜：こっかん まく）, and bone. Muscles in the anterior compartment of the forearm classified to 3 layers: superficial, intermediate, and deep. *Generally, these muscles are associated with movements of the wrist joint, flexion of the fingers including the thumb, and pronation. Gray's Anatomy for Students, Fifth Edition Reference 2024.10.15 Major branches of the brachial plexus There are 5 major branches from the brachial plexus, which are Musculocutaneous n., Median n., Ulnar n. （3 anterior） and Radial n., Axillary n. （2 posterior）. Lateral cord Musculocutaneous n. （筋皮神経：きんぴ しんけい） Median n. （lateral root） （正中神経：せいちゅう --） Posterior cord Radial n. （橈骨神経：とうこつ --） Axillary n. （腋窩神経：えきか --） Medial cord Flexor muscles of Median n. （medial root） the forearm and hand Ulnar n. （尺骨神経：しゃっこつ --） Netter Collection of Medical Illustrations: Musculoskeletal System, Part I - Upper Limb, Second Edition  Median n. ・Motor flexor in forearm ・Thenar muscles in hand Nerve innervation of anterior forearm and hand Flexors of the forearm are basically innervated by median nerve. Intrinsic muscles* of the hand are basically innervated by ulnar nerve. ＊ Intrinsic muscle（内在筋：ないざいきん） Ulnar n. A muscle that has both its origin and insertion within a struct ・Motor intrinsic ure, as intrinsic muscles of the tongue, eye, hand, or foot. muscles in forearm ・Flexor carpi ulnaris and medial half of e.g. Thenar muscles（母指球筋：ぼしきゅう--） flexor digitorum profundus in forearm Gray's Anatomy, Forty Second edition  Right forearm （Anterior: Flexors） Nerve innervation of anterior forearm Flexors of the forearm are basically innervated by median nerve. Exceptions are flexor carpi ulnaris （尺側手根屈筋：しゃくそく しゅこん くっ きん） and ulnar half of the flexor digitorum profundus（深指屈筋：しんし --）. Those are innervated by ulnar nerve. Netter Collection of Medical Illustrations: Musculoskeletal System, Part I - Upper Limb, Second Edition Nerve innervation of anterior forearm Flexors of the forearm are basically innervated by median nerve. Exceptions are flexor carpi ulnaris （尺側手根屈筋：しゃくそく しゅこん くっ きん） and ulnar half of the flexor digitorum profundus（深指屈筋：しんし --）. Those are innervated by ulnar nerve. Right forearm Netter Collection of Medical Illustrations: （Anterior: Flexors） Musculoskeletal System, Part I - Upper Limb, Second Edition Superficial flexors of the forearm There are 4 muscles in the superficial layer. Flexor carpi ulnaris （尺側手根屈筋：しゃくそく しゅこん くっ きん） Palmaris longus （長掌筋：ちょう しょう --） Flexor carpi radialis （橈側手根屈筋：とうそく しゅこん --） Pronator teres （円回内筋：えん かいない --） Those muscles have a common origin from the medial epicondyle （内側上顆：ないそく じょうか） of the humerus. Except for the pronator teres, extend distally from the forearm into the hand. Right forearm Netter Collection of Medical Illustrations: （Anterior: Flexors） Musculoskeletal System, Part I - Upper Limb, Second Edition Flexor carpi ulnaris（尺側手根屈筋） Origin: Humeral head: Medial epicondyle of humerus Ulnar head: Olecranon（肘頭：ちゅうとう） Insertion: Pisiform bone（豆状骨：とうじょう こつ） Metacarpal V（第5中手骨：ちゅうしゅ --） Function: Flexor of the wrist Palmaris longus（長掌筋） Insertion: Palmar aponeurosis（手掌腱膜：しゅしゅう けんまく） Function: Flexor of the wrist Flexor carpi radialis（橈側手根屈筋） Insertion: Metacarpals II, III （第2,3中手骨） Function: Flexor of the wrist Pronator teres（円回内筋） Origin: Humeral head: Medial epicondyle of humerus Ulnar head: Ulna Insertion: Radius Right forearm Function: Pronation （Anterior: Flexors） Gray's Anatomy for Students, Fifth Edition  Nerve innervation of Anterior forearm Flexors of the forearm are basically innervated by median nerve. Exceptions are flexor carpi ulnaris （尺側手根屈筋：しゃくそく しゅこん くっ きん） and ulnar half of the flexor digitorum profundus（深指屈筋：しんし --）. Those are innervated by ulnar nerve. Right forearm （Anterior: Flexors） Netter Collection of Medical Illustrations: Musculoskeletal System, Part I - Upper Limb, Second Edition Intermediate flexors of the forearm There are only 1 muscle in the intermediate layer. Flexor digitorum superficialis （浅指屈筋：せんし くっ きん） Right forearm （Anterior: Flexors） Netter Collection of Medical Illustrations: Musculoskeletal System, Part I - Upper Limb, Second Edition Flexor digitorum superficialis（浅指屈筋） Origin: Humero-ulnar head: Medial epicondyle of humerus Radial head: oblique line of radius Insertion: Middle phalanges of fingers 2 – 5（第2-5中節骨：ちゅうせつ こつ） Function: Flexes PIP joints of the index, middle, ring, and little fingers. Flex MP joints of the same fingers and the wrist joint Right forearm （Anterior: Flexors） Gray's Anatomy for Students, Fifth Edition  Deep flexors of the forearm There are 3 deep muscles in the anterior compartment of the forearm: Flexor digitorum profundus （深指屈筋：しん し くっきん） Flexor pollicis longus （長母指屈筋：ちょう ぼし --） Pronator quadratus （方形回内筋：ほうけい かいない --） Right forearm （Anterior: Flexors） Netter Collection of Medical Illustrations: Musculoskeletal System, Part I - Upper Limb, Second Edition Flexor digitorum profundus（深指屈筋） Origin: Ulna and Interosseous membrane Insertion: Distal phalanges of fingers 2 – 5（第2-5 末節骨） Function: Flexes DIP joints of the index, middle, ring, and little fingers. Flex MP joints of the same fingers and the wrist joint. Flexor pollicis longus（長母指屈筋） Origin: Radius and Interosseous membrane Insertion: Distal phalanges of thumb（母指末節骨） Function: Flex IP joints of the thumb Flex MP joints of the thumb Pronator quadratus（方形回内筋） Origin: Ulna Insertion: Radius Function: Pronation Right forearm （Anterior: Flexors） Gray's Anatomy for Students, Fifth Edition  Nerve innervation of anterior hand Intrinsic muscles of the hand are basically innervated by ulnar nerve. Exceptions are 3 thenar muscles （母指球筋：ぼし きゅう --） in the thenar eminence（母指球） and 1st, 2nd lumbricals（虫様筋：ちゅうよう --）. Those are innervated by median nerve. Left hand （Anterior: Flexors） Gray's Anatomy, Forty Second edition Arteries of the forearm ぜんわん どうみゃく （前腕の動脈） Radial artery（橈骨動脈） runs parallel to the radial nerve. Ulnar artery（尺骨動脈） branches anterior interosseous artery （前骨間動脈：ぜん こっかん どうみゃく）. Ulnar artery runs parallel to the ulnar nerve（尺骨神経）. Anterior interosseous artery run parallel to the anterior interosseous nerve（前骨間神経）, which is branch of the median nerve（正中神経）. Right forearm （Anterior: Flexors） Netter Collection of Medical Illustrations: Musculoskeletal System, Part I - Upper Limb, Second Edition Flexor retinaculum and carpal tunnel くっきん したい しゅこん かん （屈筋支帯と手根管） Flexor retinaculum is a fibrous band on the palmar side of the hand near the wrist. It arches over the carpal bones（手根骨） of the hands, covering the carpal arch and forming the carpal tunnel（手根管）. The 4 structures pass through the tunnel. Flexor digitorum profundus （tendon） Flexor digitorum superficialis （tendon） Flexor pollicis longus （tendon） Median nerve. Right hand （Anterior: Flexors） Gray's Anatomy for Students, Fifth Edition All the tendons of the flexor digitorum profundus and flexor digitorum superficialis are surrounded by a single synovial sheath（腱鞘：けんしょう）. Separate sheath surrounds the tendon of the flexor pollicis longus. Median nerve is anterior to the tendons in the carpal tunnel. Right forearm （Anterior: Flexors） Gray's Anatomy for Students, Fifth Edition  Reference “Clinical tips” Carpal tunnel syndrome 手根管症候群：しゅこんかん しょうこうぐん Carpal tunnel syndrome： One of the tendons or tissues in the carpal tunnel is inflamed or swollen and puts pressure on the other structures in the tunnel, including the median nerve. Carpal tunnel syndrome is the most commonly reported nerve entrapment syndrome. Symptoms of carpal tunnel syndrome include tingling sensations and muscle weakness in the https://www.nhk.or.jp/kenko/atc_268.html palm. しびれ：Numbness Treatments: Steroids injection, surgical release 手根管：Carpal tunnel of the transverse carpal ligament. 靱帯：ligament 正中神経：Median nerve 炎症：Inflammation 骨膜：Periosteum Layers in palm しゅしょう そう こうぞう （手掌の層構造） Layers in hand The superficial layer of the hand is the palmar aponeurosis（手掌腱膜：しゅしょう けんまく）. * You can observe Palmaris brevis（短掌筋：たんしょう --） Netter Collection of Medical Illustrations: Musculoskeletal System, Part I - Upper Limb, Second Edition Layers in hand In the deep layer of the hand, there are tendons of extrinsic muscles （partly in synovial sheath） with the intrinsic muscles of the hand. Layers of the intrinsic muscles are 1. Thenar/hypothenar muscles 2. lumbricals 3. Adductor pollicis 4. Palmar/dorsal interosse * Just inferior to the aponeurosis, there are superficial arterial arch （浅掌動脈弓：せんしょう どうみゃく きゅう）. Netter Collection of Medical Illustrations: Musculoskeletal System, Part I - Upper Limb, Second Edition Intrinsic muscles of the hand て ないざい きん （手の内在筋） Thenar muscles （母指球筋：ぼし きゅう きん） All thenar muscles are innervated by median nerve. Flexor pollicis brevis （短母指屈筋：たん ぼし くっ --） Abductor pollicis brevis （短母指外転筋：たん ぼし がいてん --） Opponens pollicis （母指対立筋：ぼし たいりつ --） Damage to median nerve cause ape hand（猿手：さる て）. It is an inability to abduct the thumb. Gray's Atlas of Anatomy Thenar muscles （母指球筋：ぼし きゅう きん） All thenar muscles are innervated by median nerve. Flexor pollicis brevis （短母指屈筋：たん ぼし くっ --） Abductor pollicis brevis （短母指外転筋：たん ぼし がいてん --） Opponens pollicis （母指対立筋：ぼし たいりつ --） Damage to median nerve cause ape hand（猿手：さる て）. It is an inability to abduct the thumb. Gray's Anatomy for Students, Fifth Edition Hypothenar muscles （小指球筋：しょうし きゅう きん） All hypothenar muscles are innervated by ulnar nerve. Flexor digiti minimi brevis （短小指屈筋：たん しょうし --） Opponens digiti minimi （小指対立筋：しょうし たいりつ --） Abductor digiti minimi （小指外転筋：しょうし がいてん --） Gray's Atlas of Anatomy Lumbricals （虫様筋：ちゅうよう きん） Lumbricals are innervated by ulnar nerve （3,4） and median nerve （1,2）. Origin: Tendons of flexor digitorum profundus Insertion: Extensor hoods of fingers 2 – 5 Function: Flex MP joints while extending IP joint Gray's Anatomy for Students, Fifth Edition Adductor pollicis （母指内転筋：ぼし ないてん きん） Adductor pollicis is innervated by ulnar nerve. This muscle has 2 heads. Origin: Transverse head: metacarpal III Oblique head: capitate and bases of metacarpals II and III Insertion: Proximal phalanx of thumb Function: Adducts thumb Gray's Anatomy for Students, Fifth Edition Interosseous muscles （骨間筋：こっかん きん） All interosseous muscles are innervated by ulnar nerve. Palmar interossei Function: Adduction of the fingers Dorsal interossei Function: Abduction of the finger Dorsal Interossei (Palmar View), Palmar Interossei (Palmar View), Right Hand. Right Hand. Gray's Anatomy for Students, Fifth Edition Arteries of the palm て どうみゃく （手の動脈） There are two arterial arch, the superficial palmar arch（浅掌動脈弓：せんしょう どうみゃく きゅう） and the deep palmar arch（深掌動脈弓：しんしょう --）, exist in the palm. Ulnar artery mainly supplies the superficial palmar arch. Radial artery mainly supplies the deep palmar arch. * Radial artery once cross dorsally at the wrist and back to the palm. Gray's Anatomy for Students, Fifth Edition  Reference “Clinical tips” Allen test アレン テスト Allen test is a medical sign used in physical examination of arterial blood flow to the hands. The hand is normally supplied by blood from both the ulnar and radial arteries. The arteries forms arches in the hand. Thus, if the blood supply from one of the arteries is cut off, the other artery can supply adequate blood to the hand. A minority of people lack this dual blood supply. You need this test before you perform catheter. Dermatome of the hand （手のデルマトーム） Most of the intrinsic muscles of the hand are innervated by the ulnar nerve. However, dermatome of the hand is more complicated. Dermatome of the hand is mix of ulnar nerve, median nerve, and radial nerve. Netter Collection of Medical Illustrations: Musculoskeletal System, Part I - Upper Limb, Second Edition  Reference “Clinical tips” Digital block （指の麻酔：ゆび の ますい） Digital block is one of the most common nerve block techniques. It is frequently used in the emergency department. Needle should be inserted at a point on the dorsolateral aspect of the base of the finger. It is contraindication（禁忌：きんき* ） to use epinephrine added anesthetics to digital local anesthesia. ＊ 禁忌（きんき） 人体に悪影響を及ぼす危険がある薬剤の配合や 治療法を避けて行わないようにすること。 Anatomical procedures （解剖手順） Anatomical procedures （Day 9） Forearm 1. Identify the antebrachial fascia. Open it in its middle, reflect bilaterally. 2. Dissect out and identify the brachioradialis and the superficial flexor muscles, which are the pronator teres, the flexor carpi radialis, the palmaris longus, the flexor carpi ulnaris, and the flexor digitorum superficialis. * Clear the borders of the bellies and the tendons of those muscles. 3. Incise the palmaris longus at its tendon, reflect the muscle and the tendon. Along with any remaining tendon, excise the palmar aponeurosis. Also incise the tendon of the flexor carpi radialis and reflect it superiorly to identify the insertion of the pronator teres. 4. Incise and open the palmar carpal ligament without damaging tendons, arteries, or nerves. 5. Dissect out the entire median nerve. You may incise the pronator teres which is penetrated by the median nerve. Also incise the flexor digitorum superficialis. 6. Dissect out and observe pairs of artery and nerve, which are the radial AV, the anterior interosseous AV, and the ulnar AV. With the median nerve, ] identify which nerves innervate which muscles. 7. Dissect out the deeper layer muscles, which are the flexor pollicis longus, the flexor digitorum profundus, and the pronator quadratus. Hand 1. With the scalpel and the forceps, excise the skin. 2. Dissect out tendons of the flexor digitorum superficialis and the flexor digitorum profundus. Incise the tendons of those muscles at the palmar carpal ligament (after you finish step 4 of forearm region). Then dissect out the lumbrical muscles. 3. Dissect out and identify the thenar muscles, which are the flexor pollicis brevis, the abductor pollicis brevis, and the opponens pollicis. First, identify the flexor pollicis brevis and the abductor pollicis brevis with the branch of the median nerve. Then incise the origin of those muscles and identify the opponens pollicis. 4. Dissect out and identify the hypothenar muscles, which are the flexor digiti minimi brevis, the abductor digiti minimi, and the opponens digiti minimi. First, identify the flexor digiti brevis and the abductor digiti minimi. Then incise the origin of those muscles and identify the opponens digiti minimi. 5. Dissect out the median nerve and identify the branches to the lumbrical muscles (The radial half. The ulnar half of the lumbrical muscles are innervated by the ulnar nerve). 6. Then identify the ulnar artery and the superficial palmar branch of the radial artery. Observe those arteries form the superficial palmar arterial arch. 7. Dissect out the deep palmar arch. It receives the main branch from the radial artery, which can be observed between the metacarpal bones of digits I and II. Goals of this lesson Students must understand and be able to describe: 1. The flexor muscles of the forearm and the structure of the flexor retinaculum. ぜんわん くっきん ぐん くっきん したい こうぞう （前腕屈筋群と屈筋支帯の構造） 2. The structures of the tendon sheath of the hand. て けんしょう （手の腱鞘の構造） 3. The arteries and nerves of the hand. どうみゃく しんけい （手の動脈と神経）