OCT 509: Anatomy Exam 3

2 bony parts of the head

1. Cranium

2. Face

1 synovial joint of the head

Temporomandibular joint (TMJ)

Temporomandibular joint articulations

Articulation of the mandible with the temporal bone

Mandibular depression

Lowering of the mandible to open the mouth

Mandibular elevation

Raising of the mandible to close the mouth

Protraction (protrusion)

Movement of the mandible anteriorly

Retraction (retrusion)

Movement of the mandible posteriorly

Lateral deviation of the mandible

Movement of the mandible from side to side

All TMJ movements are

bilateral, simultaneous, and identical

*except for lateral deviation

What is unique about the movement of lateral deviation

one TMJ moves laterally while one TMJ moves medially

Normal resting position of the jaw

Position where lips are closed and teeth slightly apart

Normal ROM of mouth opening

2 inches between upper and lower front teeth

Joints of the skull

Articulations of the 8 flat bones of the cranium = synarthrosis joints (sutures)- joints that are fused in adulthood

Joints of the skull in infants and young children

these joints are mobile for expansion of brain and birth, they later fuse in adulthood

Temporalis

A: Bilaterally: elevation, retraction (posterior fibers) of mandible, Unilaterally: lateral deviation of mandible to same side

N: Mandibular branch of trigeminal nerve (CN V)

Masseter

A: Bilaterally: elevation, protrusion of mandible (superficial fibers)

Unilaterally: lateral deviation of mandible to same side

N: Mandibular branch of trigeminal nerve (CN V)

Medial Pterygoid

A: Bilaterally: elevation, protrusion of mandible, Unilaterally: lateral deviation of mandible to opposite side

N: Mandibular branch of trigeminal nerve (CN V)

Lateral Pterygoid

A: Bilaterally: depression, protrusion of mandible, Unilaterally: lateral deviation of mandible to opposite side

N: Mandibular branch of trigeminal nerve (CN V)

Mylohyoid

A: Elevates hyoid and base of tongue. Elevates floor of mouth or depresses mandible when hyoid is stabilized.

N: Branch of trigeminal nerve (CN V)

Geniohyoid

A: Elevates hyoid and base of tongue

N: C1 via hypoglossal nerve (cranial nerve XII)

Stylohyoid

A: Elevates hyoid and base of tongue

N: Branch of facial nerve (cranial nerve VII)

Sternohyoid

A: Depresses hyoid and larynx, stabilizes hyoid bone

N: C1 to C3 via hypoglossal nerve (cranial nerve XII)

Omohyoid

A: Depresses and retracts hyoid and larynx, stabilizes hyoid bone

N: C1-C3 via hypoglossal nerve (CN 12)

Sternothyroid

A: Depresses larynx and thyroid cartilage, thus depressing hyoid by working in conjunction with thyrohyoid

N: C1-C3 via hypoglossal nerve (CN 12)

Digastric

A: Elevates hyoid and base of tongue

N: Mandibular branch of trigeminal nerve (cranial nerve V) and branch of facial nerve (cranial nerve VII)

Thyrohyoid

A: Elevates thyroid cartilage, thus depressing hyoid by working in conjunction with sternohyoid, depresses larynx

N: C1 - C3 via hypoglossal nerve (cranial nerve XII)

Postural influence of a forward head posture

Suprahyoids and infrahyoids lengthen and pull muscles forward

Alters the impact of TMJ and how someone bites, chews, swallows

Aspiration pneumonia

results from breathing food into airways, due to forward head posture and impact on TMJ

Where does the hyoid bone sit

located around C3

Lordosis

excessive anterior convexity

Kyphosis

excessive posterior convexity, “humpback”

Regions with a lordotic curve

Cervical and lumbar regions

Regions with a kyphotic curve

Thoracic and sacral regions

Where do cervical nerve roots exit?

Exit above the associated vertebrae

Where do thoracic nerve roots exit?

Exit below the associated vertebrae

What structure does the spinal cord run through?

Vertebral foramen

Costal facet

3 on each of the thoracic vertebrae, articulate with the ribs

Whiplash injury

Requires use of open mouth x-ray to see if odontoid (dens) is fractured

If fractured, serious consequences due to C1 and C2 having nerves essential for life

C1

Atlas, articulates with cranium superiorly and dens of axis inferiorly, has no body

C2

Axis, has the dens which articulates with C1, has no body

Atlantooccipital joint (AO)

Synovial joint, C1 and occiput, provides movement of flexion, extension, and minimal lateral flexion

Atlantoaxial joint (AA)

Synovial joint, C1 and C2, provides the movement of cervical rotation

True ribs

upper 7 ribs, actually attach to the sternum anteriorly

False ribs

Ribs 8-10, attach indirectly to the sternum via the costal cartilage of the 7th rib

Floating ribs

11th and 12th ribs, have no anterior attachment

Costovertebral facet joints

Joints that are the articulations between ribs and the vertebral bodies

Costotransverse joints

Joint where the tubercle of a rib articulates with a costal facet on the transverse processes of vertebrae

2 parts of a vertebral disk

1. Nucleus pulposus

2. Annulus fibrosus

Water content and nucleus pulposus

Has a high water content, at birth is 80% water

At 60 years it becomes less than 70%

What contributes to the loss of height with aging?

The loss of water content in the nucleus pulposus

Nucleus pulposus

moves as the body moves, with trunk extension this part moves anteriorly and bulges

Herniated disk

this occurs when the annulus fibrosus is weak

the nucleus pulposus is bulging through the annulus fibrosus into the spinal canal

Intervertebral facet joints

Joints that are articulations of the superior facet of the vertebra below with the inferior facet of the vertebra above

The joints found between bodies of vertebrae are

cartilaginous, permit minimal movement

Costochondral joints

Joints where the ribs articulate with the costal cartilage

Nuchal ligament

Prevents excessive vertebral flexion

Ligament that divides inferior to C7 and forms the supraspinal and interspinal ligaments

Anterior longitudinal ligament

attaches to anterior aspect of vertebral bodies and fuses to sacram

Prevents excessive extension

Posterior longitudinal ligament

barrier between intervertebral disc and spinal cord

prevents excessive flexion

Ligamentum flavum

forms the posterior border of vertebral canal

prevents excessive vertebral column flexion

Sternocleidomastoid

A: Bilaterally: head and neck flexion

Unilaterally: lateral neck flexion to same side; rotation of head to opposite side

Accessory muscle of respiration

N: Accessory nerve (cranial nerve XI); 2nd and 3rd cervical nerves

Scalene

A: Bilaterally: neck flexion

Unilaterally: lateral neck flexion to same side

Accessory muscle of respiration

N: 3rd through 8th cervical nerves

Longus colli muscle

Flexes neck, assists in lateral flexion

Longus capitis muscle

Flexes head and upper neck

Rectus capitis anterior

Flexes head, stabilizes AO joint

Rectus capitis lateralis

Laterally bends head, stabilizes AO joint

Suboccipital muscles

Obliquus capitis superior

Obliquus capitis inferior

Rectus capitis posterior minor

Rectus capitis posterior major

Motions of suboccipital muscles

Extension and stabilization of AO joint

*Obliquus capitis inferior stabilizes AA joint

Splenius capitis

A: Bilaterally: head and neck extension

Unilaterally: lateral flexion and rotation of head to same side

N: Middle and lower cervical spinal nerves

Splenius cervicis

A: Bilaterally: neck extension

Unilaterally: lateral flexion to same side

N: Middle and lower cervical spinal nerves

External intercostals

A: Elevate ribs during inhalation

N: Intercostal nerves (T2-T6)

Internal intercostals

A: Depress ribs during exhalation

N: Intercostal nerves (T2-T6)

Rectus abdominis

A: Trunk flexion; compression of abdomen

When pelvis stabilized: depresses ribs

Accessory muscle of respiration

N: 7th through 12th thoracic nerves

External obliques

A: Bilaterally: trunk flexion; compression of abdomen

Unilaterally: trunk lateral flexion and rotation to opposite side

N: 8th-12th intercostal, iliohypogastric, and ilioinguinal nerves

Internal obliques

A: Bilaterally: trunk flexion; compression of abdomen

Unilaterally: lateral trunk flexion and rotation to same side (as this muscle)

N: 8th-12th intercostal, iliohypogastric, and ilioinguinal nerves

Transverse abdominis

A: Compression of abdomen, accessory muscle of respiration

N: 7th-12th intercostal, iliohypogastric, and ilioinguinal nerves

Quadratus lumborum

A: Trunk lateral flexion to same side. Pelvic elevation on same side

N: 12th thoracic and 1st lumbar nerves

3 muscles of the erector spinae

1. Spinalis

2. Longissimus

3. Iliocostalis

3 muscles of the transversospinalis group

1. Semispinalis

2. Rotatores

3. Multifidus

Semispinalis muscle (thoracic portion)

A: Bilaterally: thoracic and cervical extension

Unilaterally: lateral flexion of cervical spine to same side, rotation to opposite side

N: Thoracic spinal nerves

Rotatores

A: Rotation of vertebral column to opposite side

N: Thoracic spinal nerves

Multifidus

A: Bilaterally: Trunk extension

Unilaterally- Trunk lateral flexion to same side, rotation to opposite side

N: Spinal Nerves

Interspinales muscles

A: Neck and trunk extension

N: Spinal nerves

Intertransversarii

A: Neck and trunk lateral flexion to same side

N: Spinal nerves

Diaphragm

A: Inhalation

N: Phrenic nerve (C3, C4, C5)

Respiration

process of gas exchange, supplying oxygen to and removing carbon dioxide from tissues of body

Ventilation

process of moving air in and out of lungs

Thoracic cage

AKA thorax, little to no movement at individual joints here

Made up of sternum, ribs, costal cartilages, and thoracic vertebrae

Elevation and depression of the thoracic cage

Occurs as a result of gliding at the costovertebral and costotransverse joints posteriorly and the chondrosternal joints anteriorly

Movements associated with inhalation and exhalation

Thoracic cage during inhalation

Thoracic cage moves upward and outward, increasing diameter of thoracic cage

Thoracic cage during exhalation

Thoracic cage returns to its starting position by moving downward and inward, decreasing diameter

Bucket handle movement

Handle down against side of bucket = thoracic cage during exhalation

As handle moves upward and away from bucket = thoracic cage during inhalation

Pump handle movement

Refers to change in anterior/posterior diameter of thoracic cage

Inhalation= sternum and ribs move upward and outward (anteriorly)- handle up

Exhalation= ribs and sternum lower to starting position- handle down

Upper airway structures

Nasal cavity, oral cavity, pharynx, larynx

Lower airway structures

Trachea, bronchi, bronchioles, alveoli, lungs

Left lung lobes

2 lobes- upper and lower

only 2 due to providing space for the heart

Right lung lobes

3 lobes- upper, middle, and lower

Intrathoracic volume during inhalation

Diaphragm descends as it contracts, intrathoracic volume increases while intrathoracic pressure decreases

Intrathoracic volume during exhalation

Diaphragm ascends, intrathoracic volume decreases while intrathoracic pressure increases

2 ways of changing intrathoracic volume and pressure

1. Movement of the ribs

2. Movement of the diaphragm

Quiet inhalation

the result of contraction and relaxation of the diaphragm and external intercostals, where the diaphragm does 70% of the effort