Posterior Of thigh

s a group, the muscles of the posterior compartment of the thigh are called the hamstrings. To be called a hamstring, the muscle must arise from the ischial tuberosity. The hamstrings are: biceps femoris (long head) semimembranosus semitendinosus hamstring part of the adductor magnus (not shown in the diagram)

Nerves

The muscles of the posterior compartment of the thigh are innervated by the tibial (medial) part of the sciatic nerve.  The short head of the biceps is innervated by a branch of the common peroneal nerve.

Arteries

The arteries of the posterior compartment of the thigh arise from two major arteries: inferior gluteal (upper posterior compartment) perforating branches of the profunda femoris

Table of Muscles

Muscle	Origin	Insertion	Action	Nerve Supply
biceps femoris, long head	ischial tuberosity	head of fibula	flexes and laterally rotates leg, extends thigh	tibial part of sciatic nerve
biceps femoris, short head	shaft of femur	head of fibula	flexes and laterally rotates leg	common peroneal nerve
semitendinosus	ischial tuberosity	upper part medial surface of tibia	flexes and medially rotates leg; extends thigh	tibial part of sciatic
semimembranosus	ischial tuberosity	medial condyle of tibia;  forms oblique popliteal ligament	flexes and medially roates leg; extends thigh	tibial part of sciatic
adductor magnus (hamstring part)	ischial tuberosity	adductor tubercle of femur	extends thigh	tibial part of sciatic

Popliteal Fossa

The popliteal fossa is an anatomical region behind the knee with certain identifiable boundaries.

Start by identifying the bony background of the popliteal fossa and then visualizing the boundaries. The bones of the popliteal fossa are: femur medial condyle lateral condyle tibia medial condyle lateral condyle The boundaries are: superior and medial - semitendinosus (ST) inferior and medial - medial head of gastrocnemius (MG) superior and lateral - biceps femoris (B) inferior and lateral - lateral head of gastrocnemius (LG)
The muscles and contents of the popliteal fossa are: Muscles semitendinosus biceps femoris medial head of gastrocnemius lateral head of gastrocnemius Arteries popliteal artery - continuation of femoral artery superior medial and lateral genicular arteries inferior medial and lateral genicular arteries Nerves tibial nerve common peroneal nerve
With the nerves and arteries removed and the muscles reflected, you now identify the structures making up the floor of the popliteal fossa: posterior surface of femur posterior surface of tibia oblique popliteal ligament popliteus muscle

Table of Muscles

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Medial Thigh

Anterior Leg & Dorsum of Foot

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Head and Neck Musculature

Muscle Regions of the Body:

• Head and neck
• Trunk, front and back
• Brachium, antibrachium & hand
• Thigh, leg & foot

Return to the Muscle Starting Point 


Muscle Groups within this Region:

• Suboccipital
• Prevertebral
• Anterolateral Neck
• Superficial Neck
• Anterior Neck
• Epicranial
• Muscles of Facial Expression
• Muscles of Mastication
• Extraocular
• Laryngeal

Links Related to this Region:

• TMJ Tutorial

Suboccipital Musculature

 

Obliquus capitis inferior

• Origin: spinous process of axis (C2)
• Insertion: transverse process of atlas (C1)
• Action: rotates the head to the contracted side
• Blood: muscular branches of vertebral artery
• Nerve: suboccipital nerve, (dorsal rami C1)

Obliquus capitis superior

• Origin: transverse process of atlas (C1)
• Insertion: between superior and inferior nuchal line of occiput
• Action:
  
  
  
  
  
  1. bilaterally extends the head
  2. laterally flexes to the contracted side
• Blood: muscular branches of vertebral artery
• Nerve: suboccipital nerve, (dorsal rami C1)

Rectus capitis posterior major

• Origin: spinous process of axis (C2)
• Insertion: inferior nuchal line (lateral to minor)
• Action:
  
  
  
  
  
  1. bilaterally extends the head
  2. rotates the head to the contracted side
• Blood: muscular branches of vertebral artery
• Nerve: suboccipital nerve, (dorsal rami C1)

Rectus capitis posterior minor

• Origin: posterior tubercle of atlas (C1)
• Insertion: inferior nuchal line (adjacent to midline)
• Action: bilaterally extends the head
• Blood: muscular branches of vertebral artery
• Nerve: suboccipital nerve, (dorsal rami C1)

Prevertebral Musculature

 

Longus colli

• Origin: lower anterior vertebral bodies and transverse processes
• Insertion: anterior vertebral bodies and transverse processes several segments above
• Action: flexes the head and neck
• Blood: muscular branches of the aorta
• Nerve: ventral rami C2-C6

Longus capitis

• Origin: upper anterior vertebral bodies and transverse processes
• Insertion: anterior vertebral bodies and transverse processes several segments above
• Action: flexes the head and neck
• Blood: muscular branches of the aorta
• Nerve: ventral rami C1-C3

Rectus capitis anterior

• Origin: anterior base of the transverse process of the atlas
• Insertion: occipital bone anterior to foramen magnum
• Action: flexes the head
• Blood: muscular branches of the aorta
• Nerve: ventral rami C2,3

Rectus capitis lateralis

• Origin: transverse process of the atlas
• Insertion: jugular process of the occipital bone
• Action: bends the head laterally
• Blood: muscular branches of the aorta
• Nerve: ventral rami C2,3

Anterolateral Neck Musculature

 

Anterior scalene

• Attachment A: anterior tubercles of transverse processes of C3-C6
• Attachment B: 1st rib
• Action:
  
  
  
  
  
  if transverse process fixed:
  1. elevates the ribs for respiration
     if ribs fixed:
  2. rotates to side opposite of contraction
  3. laterally flexes to the contracted side
  4. bilaterally flexes the neck
• Blood: inferior thyroid artery (branch of the thyrocervical trunk)
• Nerve: ventral rami C3-C6

Scalenus minimus (may be absent)

• Attachment A: anterior tubercles of transverse processes of C6 & 7
• Attachment B: 1st rib and/or supraplural membrane
• Action:
  
  
  
  
  
  if transverse process fixed:
  1. elevates the ribs for respiration
     if ribs fixed:
  2. rotates to side opposite of contraction
  3. laterally flexes to the contracted side
  4. bilaterally flexes the neck
• Blood: ascending cervical artery
• Nerve: variable (cervical and brachial plexus)

Middle scalene

• Attachment A: transverse processes of all cervical vertebrae
• Attachment B: 1st rib (behind anterior scalene)
• Action:
  
  
  
  
  
  if transverse process fixed:
  1. elevates the ribs for respiration
     if ribs fixed:
  2. rotates to side opposite of contraction
  3. laterally flexes to the contracted side
  4. bilaterally flexes the neck
• Blood: ascending cervical artery
• Nerve: ventral rami C3-C8

Posterior scalene

• Attachment A: posterior tubercles of transverse processes of C5 & C6
• Attachment B: 2nd and/or 3rd rib
• Action:
  
  
  
  
  
  if transverse process fixed:
  1. elevates the ribs for respiration
     if ribs fixed:
  2. rotates to side opposite of contraction
  3. laterally flexes to the contracted side
  4. bilaterally flexes the neck
• Blood: ascending cervical artery
• Nerve: ventral rami C5-C7

Superficial Neck Musculature

 

Sternocleidomastoid

• Origin: (two heads)
  
  
  
  
  
  1. manubrium of sternum
  2. medial portion of clavicle
• Insertion: mastoid process of temporal bone
• Action:
  
  
  
  
  
  1. rotates to side opposite of contraction
  2. laterally flexes to the contracted side
  3. bilaterally flexes the neck
• Blood:
  
  
  
  
  
  1. occipital artery
  2. superior thyroid artery
• Nerve:
  
  
  
  
  
  1. motor: spinal accessory (XI cranial)
  2. sensory: ventral rami of C2,(C3)

Platysma

• Origin: subcutaneous skin over delto-pectoral region
• Insertion: invests in the skin widely over the mandible
• Action:
  
  
  
  
  
  1. depress mandible and lower lip
  2. tenses the skin over the lower neck
• Blood: superficial vessels of the neck
• Nerve: cervical branch of facial nerve (VII cranial)

Anterior Neck

 

Sternohyoid

• Origin:
  
  
  
  
  
  1. posterior aspect of manubrium
  2. sternal end of clavicle
• Insertion: body of hyoid
• Action:
  
  
  
  
  
  1. depresses hyoid & larynx
  2. acts eccentrically with the suprahyoid muscles to provide them a stable base
• Blood:
  
  
  
  
  
  1. inferior thyroid artery (primary)
  2. superior thyroid artery
• Nerve:
  
  
  
  
  
  1. upper portions: superior root of ansa cervicalis, C2
  2. lower portions: inferior root of ansa cervicalis, C2,3

Omohyoid

• Attachments:
  
  
  
  
  
  1. superior belly: hyoid bone (lateral to sternohyoid)
  2. inferior belly: superior scapular border (medial to suprascapular notch)
• both bellies meet at the clavicle & are held to the clavicle by a pulley tendon
• Action:
  
  
  
  
  
  1. depresses hyoid & larynx
  2. acts eccentrically with the suprahyoid muscles to provide them a stable base
• Blood:
  
  
  
  
  
  1. inferior thyroid artery (primary)
  2. superior thyroid artery
• Nerve:
  
  
  
  
  
  1. upper portions: superior root of ansa cervicalis, C2
  2. lower portions: inferior root of ansa cervicalis, C2,3

Sternothyroid

• Origin: posterior aspect of manubrium
• Insertion: oblique line of thyroid cartilage
• Action:
  
  
  
  
  
  1. depresses hyoid & larynx
  2. acts eccentrically with the suprahyoid muscles to provide them a stable base
• Blood:
  
  
  
  
  
  1. inferior thyroid artery (primary)
  2. superior thyroid artery
• Nerve:
  
  
  
  
  
  1. upper portions: superior root of ansa cervicalis, C2
  2. lower portions: inferior root of ansa cervicalis, C2,3

Thyrohyoid

• Origin: oblique line of thyroid cartilage
• Insertion: body of hyoid
• Action:
  
  
  
  
  
  1. depresses hyoid
  2. may assist in larynx elevation
• Blood:
  
  
  
  
  
  1. inferior thyroid artery (primary)
  2. superior thyroid artery
• Nerve:
  
  
  
  
  
  1. upper portions: superior root of ansa cervicalis, C2
  2. lower portions: inferior root of ansa cervicalis, C2,3

Stylohyoid

• Origin: styloid process of temporal bone
• Insertion: lateral margin of hyoid (near greater horn)
• Action:
  
  
  
  
  
  1. pulls the hyoid superiorly & posteriorly during swallowing
  2. fixes the hyoid bone for infrahyoid action
• Blood: facial & occipital artery
• Nerve: facial nerve (VII cranial)

Digastric

• Attachments:
  
  
  
  
  
  1. post belly: mastoid process of temporal bone
  2. anterior belly: digastric fossa of internal mandible
• both bellies meet and attach at the lateral aspect of body of hyoid by a pulley tendon
• Action:
  
  
  
  
  
  1. open mouth by depressing mandible
  2. fixes hyoid bone for infrahyoid action
• Blood: branches of the external carotid
• Nerve:
  
  
  
  
  
  1. posterior belly: facial nerve (VII cranial)
  2. anterior belly: mylohyoid nerve

Mylohyoid

• Origin: inner surface of mandible off the mylohyoid line
• Insertion:
  
  
  
  
  
  1. body of hyoid
  2. along midline at mylohyoid raphe
• Action:
  
  
  
  
  
  1. elevates the hyoid bone
  2. raises floor of mouth (for swallowing)
  3. depresses mandible when hyoid is fixed
• Blood: lingual artery
• Nerve: mylohyoid nerve (branch of mandibular division, V3 cranial)

Geniohyoid

• Origin: inner surface of the mandible off the mental spines
• Insertion: body of hyoid (paired muscles separated by a septum)
• Action:
  
  
  
  
  
  1. elevates the tongue
  2. depress the mandible
  3. works with mylohyoid
• Blood: lingual artery
• Nerve: branch from C1 (following hypoglossal nerve)

Epicranial Musculature

 

Occipitalis (2 bellies)

• Origin:
  
  
  
  
  
  1. lateral 2/3 of superior nuchal line
  2. external occipital protuberance
• Insertion: galea aponeurosis, over the occipital bone
• Action: draws back the scalp to raise the eyebrows and wrinkle the brow
• Blood: occipital artery
• Nerve: posterior auricular branch of facial nerve

Frontalis (2 bellies)

• Origin: galea aponeurosis, anterior to the vertex
• Insertion: skin above the nose and eyes
• Action: draws back the scalp to raise the eyebrows and wrinkle the brow
• Blood: ophthalmic artery
• Nerve: temporal branch of facial nerve

Muscles of Facial Expression

 

Orbicularis oculi

• Origin:
  
  
  
  
  
  1. orbital portion: nasal process of frontal bone
  2. palpebral portion: palpebral ligament
  3. lacrimal portion: lacrimal crest of lacrimal bone
• Insertion: circumferentially around orbit meeting in palpebral raphe
• Action: powerfully closes the eye
• Blood: ophthalmic artery
• Nerve: zygomatic branch of facial nerve

Corrugator supercilii

• Origin: frontal bone just above the nose
• Insertion: skin of the medial portion of the eyebrows
• Action: draws the eyebrows downward and medially
• Blood: ophthalmic artery
• Nerve: zygomatic branch of facial nerve

Orbicularis oris

• Origin:
  
  
  
  
  
  1. alveolar border of maxilla
  2. lateral to midline of mandible
• Insertion:
  
  
  
  
  
  1. circumferentially around mouth
  2. blends with other muscles
• Action:
  
  
  
  
  
  1. closes the lips
  2. protrudes the lips
• Blood: facial artery
• Nerve: buccal branch of facial nerve

Levator labii superioris alaeque nasi

• Origin: frontal process of maxilla
• Insertion:
  
  
  
  
  
  1. upper lip muscles
  2. nasal cartilage
• Action:
  
  
  
  
  
  1. elevates the upper lip
  2. flares the nostrils
• Blood: facial artery
• Nerve: buccal branch of facial nerve

Levator labii superioris

• Origin: medial 1/2 of infraorbital margin
• Insertion: upper lip muscles
• Action: elevates the upper lip
• Blood: facial artery
• Nerve: buccal branch of facial nerve

Zygomaticus minor

• Origin: zygomatic bone, posterior to maxillary-zygomatic suture
• Insertion: skin of the upper lip
• Action: elevates the upper lip
• Blood: facial artery
• Nerve: buccal branch of facial nerve

Zygomaticus major

• Origin: anterior to zygomatic-temporal suture
• Insertion: modiolus (angle of the mouth)
• Action: lifts and draws back the angle(s) of the mouth (as in smiling)
• Blood: facial artery
• Nerve: buccal branch of facial nerve

Risorius (may be absent)

• Origin: parotid fascia
• Insertion: modiolus (angle of the mouth)
• Action: draws the mouth laterally (as in smiling)
• Blood: facial artery
• Nerve: buccal branch of facial nerve

Levator anguli oris

• Origin: maxilla, inferior to infraorbital foramen
• Insertion: modiolus (angle of the mouth)
• Action: lifts the angle(s) of the mouth (as in smiling)
• Blood: facial artery
• Nerve: buccal branch of facial nerve

Buccinator

• Origin:
  
  
  
  
  
  1. posterior alveolar process of maxilla
  2. posterior alveolar process of mandible
  3. along the pterygomandibular raphe
• Insertion: modiolus
• Action: compresses the cheek(s)
• Blood: facial artery
• Nerve: buccal branch of facial nerve

Depressor anguli oris

• Origin:
  
  
  
  
  
  1. along the oblique line of mandible
  2. lateral aspect of mental tubercle of the mandible
• Insertion: modiolus
• Action: lowers the angle(s) of the mouth (as in frowning)
• Blood: facial artery
• Nerve: mandibular branch of facial nerve

Depressor labii inferioris

• Origin:
  
  
  
  
  
  1. mandible, between symphysis and mental foramen
  2. along oblique line of the mandible
• Insertion: skin of the lower lip
• Action: draws the lower lip downward and laterally
• Blood: facial artery
• Nerve: mandibular branch of facial nerve

Muscles of Mastication

 

Masseter

• Origin:
  
  
  
  
  
  • Superficial:
    
    
    
    
    
    1. zygomatic process of the maxilla
    2. inferior border of zygomatic arch
  • Intermediate: inner surface of zygomatic arch
  • Deep: posterior aspect of inferior border of zygomatic arch
• Insertion:
  
  
  
  
  
  • Superficial:
    
    
    
    
    
    1. angle of mandible
    2. lateral surface of mandibular ramus
  • Intermediate: ramus of mandible
  • Deep:
    
    
    
    
    
    1. superior ramus of mandible
    2. coronoid process of mandible
• Action:
  
  
  
  
  
  1. closes the lower jaw (clenches the teeth)
  2. may deviate mandible to opposite side of contraction
• Blood: masseteric artery
• Nerve: masseteric nerve

Medial pterygoid

• Origin:
  
  
  
  
  
  1. medial surface of lateral pterygoid plate of the sphenoid
  2. palatine bone
  3. pterygoid fossa
• Insertion:
  
  
  
  
  
  1. inner surface of mandibular ramus
  2. angle of the mandible
• Action:
  
  
  
  
  
  1. closes the lower jaw (clenches the teeth)
  2. can protrude the mandible in combination with the lateral pterygoid
• Blood: medial pterygoid artery
• Nerve: medial pterygoid nerve

Lateral pterygoid

• Origin:
  
  
  
  
  
  1. Superior head: lateral surface of the greater wing of the sphenoid
  2. Inferior head: lateral surface of the lateral pterygoid plate
• Insert together:
  
  
  
  
  
  1. neck of the mandibular condyle
  2. articular disk of the TMJ
• Action:
  
  
  
  
  
  1. deviates mandible to side opposite of contraction (during chewing)
  2. opens mouth by protruding mandible (inferior head)
  3. closes the mandible (superior head)
• Blood: lateral pterygoid artery
• Nerve: lateral pterygoid nerve

Extraocular Musculature

 

Levator palpebrae superioris

• Origin: inferior aspect of the lesser wing of sphenoid (adjacent to the common annular tendon)
• Insertion:
  
  
  
  
  
  1. medial and lateral walls of the orbit
  2. superior tarsus
• Action: elevates the eyelid
• Blood: branches of ophthalmic artery
• Nerve: oculomotor nerve (III cranial)

Lateral rectus

• Origin:
  
  
  
  
  
  1. common annular tendon (which comes off the body and lesser wing of sphenoid)
  2. margins of the optic canal
• Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
• Action: abducts eye
• Blood: branches of ophthalmic artery
• Nerve: abducens nerve (VI cranial)

Medial rectus

• Origin:
  
  
  
  
  
  1. common annular tendon (which comes off the body and lesser wing of sphenoid)
  2. margins of the optic canal
• Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
• Action: adducts eye
• Blood: branches of ophthalmic artery
• Nerve: oculomotor nerve (III cranial)

Superior rectus

• Origin:
  
  
  
  
  
  1. common annular tendon (which comes off the body and lesser wing of sphenoid)
  2. margins of the optic canal
• Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
• Action:
  
  
  
  
  
  1. elevates
  2. medially rotates
  3. adducts the eye
• Blood: branches of ophthalmic artery
• Nerve: oculomotor nerve (III cranial)

Superior rectus

• Origin:
  
  
  
  
  
  1. common annular tendon (which comes off the body and lesser wing of sphenoid)
  2. margins of the optic canal
• Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
• Action:
  
  
  
  
  
  1. elevates
  2. medially rotates
  3. adducts the eye
• Blood: branches of ophthalmic artery
• Nerve: oculomotor nerve (III cranial)

Inferior rectus

• Origin:
  
  
  
  
  
  1. common annular tendon (which comes off the body and lesser wing of sphenoid)
  2. margins of the optic canal
• Insert: posterior to the sclerocorneal junction (each muscle inserting along its own directional axis)
• Action:
  
  
  
  
  
  1. depress
  2. laterally rotates
  3. adducts the eye
• Blood: branches of ophthalmic artery
• Nerve: oculomotor nerve (III cranial)

Superior oblique

• Origin: body of sphenoid
• Insert: upper lateral quadrant of the posterior half of the sclera (via the trochlea, as a pulley)
• Action:
  
  
  
  
  
  1. depress
  2. medially rotates
  3. abducts the eye
• Blood: branches of ophthalmic artery
• Nerve: trochlear nerve (IV cranial)

Inferior oblique

• Origin: orbital surface of maxilla
• Insert: lower lateral quadrant of the posterior half of the sclera (via the suspensory ligament, as a pulley)
• Action:
  
  
  
  
  
  1. elevates
  2. laterally rotates
  3. abducts the eye
• Blood: branches of ophthalmic artery
• Nerve: oculomotor nerve (III cranial)

Laryngeal Musculature

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