Muscles

Flexor Digiti Minimi Brevis

Flexor Digiti Minimi Brevis The structure indicated is the flexor digiti minimi brevis muscle of the foot. The intrinsic muscles on the plantar aspect of the foot are divided into four layers. The flexor digiti minimi brevis muscle is located in the third layer of intrinsic foot muscles. There are three muscles located in this layer: Flexor hallucis brevis Adductor hallucis Flexor digiti minimi brevis Origin: Base of 5th metatarsal Insertion: lateral base of proximal phalanx of little toe Action: flexes little toe at metatarsophalangeal joint Innervation: lateral plantar nerve   Learn more about the anatomy of the foot muscles in …

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flexor digiti minimi brevis

Extensor Carpi Ulnaris

Extensor Carpi Ulnaris The structure indicated is the extensor carpi ulnaris muscle of the forearm. The extensor carpi ulnaris muscle is one of 7 muscles located in the superficial compartment of the posterior forearm. The posterior forearm consists of a superficial and a deep compartment. The superficial compartment contains 7 muscles, whereas the deep compartment contains 5 muscles. The superficial compartment of the posterior forearm includes the following 7 muscles: Brachioradialis Extensor carpi radialis longus Extensor carpi radialis brevis Extensor digitorum Extensor digiti minimi Extensor carpi ulnaris Anconeus The muscles of the posterior compartment of the forearm originate from the …

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extensor carpi ulnaris

Abductor Hallucis

Abductor Hallucis The structure indicated is the abductor hallucis muscle of the foot. The intrinsic muscles on the plantar aspect of the foot are divided into four layers. The abductor hallucis muscle is found in the first layer of muscles. There are three muscles in the first layer: Abductor hallucis Flexor digitorum brevis Abductor digiti minimi The abductor hallucis muscle is located in the medial border of the foot and is responsible for the palpable bulk of muscle that you can feel on the inside of the foot. It inserts via a common tendon, together with the flexor hallucis brevis, onto …

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abductor hallucis

Fibularis Longus

Fibularis Longus The structure indicated is the fibularis (peroneus) longus muscle of the leg. The fibularis longus muscle is one of the muscles of the lateral compartment of the leg. The leg consists of three muscular compartments: anterior, posterior and lateral. The lateral compartment consists of two muscles: Fibularis (peroneus) longus Fibularis (peroneus) brevis The lateral muscles are responsible for eversion of the foot and are innervated by the superficial fibular (peroneal) nerve, which is a branch of the common fibular nerve. The common fibular nerve is a branch of the sciatic nerve and divides into the superficial fibular nerve …

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Fibularis longus

Levator Palpebrae Superioris

Levator Palpebrae Superioris The structure indicated is the levator palpebrae superioris muscle. The levator palpebrae superioris muscle is located in the upper eyelid and is responsible for raising the eyelid. Just like the rectus muscles, and oblique muscles of the eyeball, the levator palpebrae superioris muscle is innervated by the oculomotor nerve (cranial nerve III). The eyelids themselves are supported by the tarsus – in the upper eyelid the superior tarsus, and in the lower eyelid, the inferior tarsus. These structures consist of dense connective tissue. Origin: Roof of the orbit on sphenoid bone, above the optic foramen Insertion: Anterior …

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levator palpebrae superioris

Rectus Capitis Posterior Minor

Rectus Capitis Posterior Minor The structure indicated is the rectus capitis posterior minor muscle. The rectus capitis posterior minor is one of 4 muscles which make up the suboccipital group of back muscles. This group of small muscles are located at the base of the occipital bone in the superior cervical region posteriorly. The four suboccipital muscles are: Rectus capitis posterior major Rectus capitis posterior minor Obliquus capitis inferior Obliquus capitis superior Origin:  spinous process of atlas vertebrae CI Insertion: occipital bone inferior to nuchal line Innervation: posterior ramus of CI Action: Extension of head   Learn more about the …

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Rectus Capitis Posterior Minor

Abductor Pollicis Longus

Abductor Pollicis Longus The structure indicated is the abductor pollicis longus muscle of the posterior forearm. The abductor pollicis longus muscle is one of the muscles located in the deep layer of muscles in the posterior compartment of the forearm. There are 5 muscles in the deep layer of the posterior forearm: Supinator Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus Extensor indicis The abductor pollicis longus muscle, as the name suggests abducts the thumb. Origin: Posterior surface of proximal ulna, radius and interosseous membrane Insertion: Base of 1st metacarpal Innervation: Posterior interosseous nerve Action: Abduction and extension of …

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abductor pollicis longus

Occiptofrontalis

Occipitofrontalis The structure indicated is the frontal belly of the occipitofrontalis muscle. The occipitofrontalis muscle is involved in facial expression and is comprised of two muscle bellies: Frontal belly Occipital belly Contraction of the frontal belly causes wrinkling of the forehead and raising of the eyebrows. Contraction of the occipital belly pulls the scalp back posteriorly. As a muscle of facial expression, the occipitofrontalis muscle is innervated by the facial nerve (cranial nerve VII). In between the frontal and occipital bellies, is an aponeurotic tendon which connects two bellies. Learn more about the muscles of facial expression in this tutorial.

occipitofrontalis - frontal belly

Iliopsoas Muscle

Iliopsoas Muscle The structure indicated is the iliopsoas muscle. The iliopsoas muscle collectively refers to the distal ends of the psoas major and iliacus muscles which exit the pelvis to enter the anterior compartment of the thigh and insert onto the lesser trochanter of the femur. The iliopsoas muscle is the strongest hip flexor. Origin: Iliac fossa and vertebral bodies of T12 to L5 Insertion: Lesser trochanter of femur Innervation: anterior rami of lumbar plexus (L2-L4) Action: Hip flexion, lateral rotation of femur Learn more about the muscles of the anterior compartment of the thigh in this tutorial.

iliopsoas

Pectoralis Minor

Pectoralis Minor The structure indicated is the pectoralis minor muscle. The pectoralis minor muscle lies deep to the much larger, powerful pectoralis major muscle. The pectoralis minor muscle is covered anteriorly by the clavipectoral fascia. This muscle divides the axillary artery into three parts. Part 1 lies proximally to the pectoralis minor, part 2 is the part of the axillary artery covered by the pectoralis minor, and the third part lies distal to the pectoralis minor. The pectoralis minor inserts onto the coracoid process of the scapula. There are three muscles which attach to the coracoid process: Short head of …

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pectoralis minor