Z00 3733 UCF FINAL EXAM !!

Know the parts of the sternum and rub. For the rib, know which structures articulate with the body and transverse process of the vertebrae.

Manubrium→ jugular notch, clavicular notch, articulates with 1st rib

Between manubrium and body articulates = sternal angle, where 2nd rib articulates with sternum

Body = articulates with the 3rd, 4th, 5th, 6th, and 7th ribs

posterior

(dorsal) toward or at the back of the body; behind

• The vertebra is posterior to the heart

anterior

(ventral) toward or at the front of the body

• The sternum is anterior to the heart

superior

cranial) toward the head end or upper part of a structure or the body; above

• The head is superior to the abdomen

inferior

(caudal) away from the head end or toward the lower part of a structure or the body; below

• The intestines are inferior to the liver

proximal

closer to the origin of the body part or the point of attachment of a limb to the body trunk •

The elbow is proximal to the wrist

distal

farther from the origin of a body part or the point of attachment of a limb to the body trunk

• The knee is distal to the thigh

rostral

toward the nose

caudal

toward the tail

Neurons/Neuroglia In PNS:

- Satellite Cells: Form the myelin sheath around soma in the ganglia

Surround neuron cell bodies within ganglia

- Schwann Cells: Form myelin sheath around axons

- Sensory (Unipolar & Bipolar Cells)

neurons/neuroglia in the CNS

- Astrocytes, microglia, ependymal

- Oligodendrocytes, interneurons & Motor (Multipolar Cells)

astrocytes

are the most abundant glial cell type

-Sense when neurons release glutamate

-Extract blood sugar from capillaries for energy

-Take up and release ions to control the environment around neurons

-Involved in synapse formation in developing neural tissue

-Produce molecules necessary for neuronal growth (BDTF)

-Propagate calcium signals involved with memory

microglia

Are the smallest and least abundant glial cell

- Phagocytes—the macrophages of the CNS

- Engulf invading microorganisms and dead neurons

- Derive from blood cells called monocytes

- Migrate to CNS during embryonic and fetal periods

ependymal

Line the central cavity of the spinal cord and brain o Bear cilia—help circulate the cerebrospinal fluid

oliogendrocytes

have few branches o Wrap their cell processes around axons in CNS

▪ Produce myelin sheaths in the CNS

Know the organizational structure of skeletal muscles

1. Epimysium

2. Perimysium

3. Fascicles

4. Endomysium

5. Muscle Fibers/Cells

6. Myofibrils

Skeletal Muscles & their nerves

Organized into bundles of muscle fibers (cells) called fascicles, surrounded by connective tissue (epimysium, perimysium, endomysium).

- Nerves: Consist of bundles of axons (nerve fibers), organized into fascicles, an

Epimysium

dense regular connective tissue surrounding entire muscle

Perimysium

surrounds each fascicle (group of muscle fibers)

Endomysium

a fine sheath of connective tissue wrapping each muscle cell

Understand how a neuron interacts with a skeletal muscle fiber to cause a contraction; know the importance of the neuromuscular junction

Nerve ending releases neurotransmitter (Acetylcholine) to skeletal muscle cells --> travels Synaptic Cleft and binds with receptors --> Action Potential occurs --> enacts the process of producing the release of Ca2+ --> Binds with Actin in the myofibrils and interacts with Myosin --> being muscle contraction

Connective tissue sheaths are continuous with tendons

When muscle fibers contract, the pull is exerted on all layers of connective tissue tendon

- Sheaths provide elasticity and carry blood vessels and nerves

Muscle Actions and Interactions

- prime mover (agonist): has major responsibility for a certain movement

- antagonist: opposes or reverses a movement

- synergist: helps the prime mover by adding extra force & by reducing undesirable movements

-Fixator ▪ A type of synergist that holds a bone firmly in place

Muscles and Nervous Tissue

- Muscle normally contracts because it is stimulated by nervous impulses coming from neurons. Muscle and nervous tissue form units called MOTOR UNITS.

- The axon of a neuron branches repeatedly, and each of these branches controls one muscle fiber.

▪ Therefore, each muscle fiber receives a branch of an axon, and each axon (therefore neuron) innervates more than one muscle fiber.

Motor Unit

One neuron + muscle fibers that it controls o Motor units vary in size according to location. Usually, 1 neuron will control 150 muscle fibers. However, in large muscles, such as in the leg, 1 neuron may control as many as 2000 fibers.

- In other locations where more delicate and precise movement is needed, such as in the eyes and fingers, 1 neuron may control only 2 to 3 muscle fibers.

The neuron does not come in direct contact with the muscle tissue.

The area where the nervous tissue meets the muscle fiber is called the NEUROMUSCULAR JUNCTION.

- The terminal end of the axon interacts with the motor-end-plate of the sarcolemma that surrounds an individual muscle fiber/cell.

Know the two types of bone ossification, and when each occurs during growth and development; which bones are developed through each physiological method

Intramembrane Ossification (Membrane Bones): Happens during fetal development, flat bone is developed (skull, clavicle, etc), derives from mesenchyme

Endochondral Ossification (Other Bones): Happens in all stages of life, helps with bone repair, derives from hyaline cartilage

intramembranous ossification

- Direct ossification At about 5-6 weeks of development, mesenchyme forms a fibrous connective tissue membrane around the brain and where the mandible and clavicles will be. Mesenchymal cells become osteochondral progenitor cells that then become osteoblasts.

- Think stem cells, then cells differentiate and become more specialized Osteoblasts produce "matrix," aka bone, then mature into osteocytes due to a decrease in oxygen. In humans, this type of ossification occurs only in the flat bones of the skull, mandible and clavicles. ________________

1. Ossification centers appear in the fibrous connective tissue membrane.

Selected centrally located mesenchymal cells cluster and differentiate into osteoblasts, forming an ossification center.

2. Bone matrix (osteoid) is secreted within the fibrous membrane and calcifies.

-Osteoblasts begin to secrete osteoid, which is calcified within a few days

-Trapped osteoblasts become osteocytes

3. Woven bone and periosteum form

- Accumulating osteoid is laid down between embryonic blood vessels in a random manner. The result is a network (instead of lamellae of trabeculae called woven bone

-Vascularized mesenchyme condenses on the external face of the woven bone and becomes the periosteum

4. Lamellar bone replaces woven bone, just deep to the periosteum. Red marrow appears.

- Trabeculae just deep to the periosteum thicken and are later replaced with mature lamellar bone, forming compact bone plates

- Spongy bone (diploe), consisting of distinct trabeculae, persists internally, and its vascular tissue becomes red marrow.

Bones

- Support - provide hard framework

- Movement - skeletal muscles use bones as levels

- Protection of underlying organs

- Mineral storage - reservoir for important minerals

- Blood cell formation - bone contains red marrow

- Energy metabolism - osteoblasts secrete osteocalcin

▪ Bone-building

compact bone

Hard, dense bone tissue that is beneath the outer membrane of a bone

- Organized with osteons

spongy (cancellous) bone

Layer of bone tissue that has many small spaces and is found just inside the layer of compact bone.

-Organized Found within flat bones and within the epiphyses (ends) of long bones o Trabeculae—little "beams" of bone

Where would you expect to find red bone marrow?

within the trabeculae of spongy bone

Found in spongy bone, especially in flat bones like the pelvis, ribs, sternum, and in the epiphyses of long bones like the femur.

osteomalacia

Bone inadequately mineralized (doesn't harden completely)

Rickets

occurs in children, analogous to osteomalacia, weakened and bowed legs, and malformation of the head and ribs (caused by dietary Vit D and calcium phosphate deficiency).

- In adults called Osteomalacia.

- Softening of the bones due to defective bone mineralization, often caused by vitamin D deficiency.

Osteoporosis

decline in bone mass in which bone reabsorption outpaces bone deposit (will typical occur to women after menopause due to estrogen that helps maintain bone density)

-characterized by low bone mass, bone reabsorption (breakdown) outpaces bone deposition, occurs in most of women after menopause due to decreased estrogen (secretion of estrogens helps maintain bone density)

- Leads to weakened bones and increased fracture risk

Osteosarcoma

a form of aggressive bone cancer that usually develops in the long bones of the body, commonly in teenagers and young adults

arthritis

Numerous joint-damaging diseases: inflammation of the joints

Rheumatoid arthritis

An autoimmune disease.

▪ The body attacks CARTILAGE and SYNOVIAL MEMBRANES of joints. There will be inflammation of the joint, swelling, pain. If this type of arthritis is not treated, the synovial membranes become thicker and produce more fluid (water on the knee). Destruction of the cartilage leads to the bones within the joint ossifying together.

Osteoarthritis

Degenerative joint disease, more common than Rheumatoid Arthritis.

▪ Onset associated with aging.

▪ There is deterioration of the articular cartilage with osteoarthritis, but no synovial membrane involvement. There is inflammation, pain and decrease in the use of the joint.

Gouty Arthritis

A metabolic disease.

▪ Uric acid is a waste product produced by the cells, and much of it will be excreted through urine. When a person has gout, they will be producing too much uric acid - more than can be excreted. The uric acid will build up in the blood and some will form salt crystals that deposit in the joints, causing pain and decrease in motion. Bones can also fuse because the crystals will wear away at the cartilage.

▪ Kings Disease

clinical significance of atherosclerosis.

what is it & how it forms?

Narrowing of the arterial wall due to lipid deposition, formed by fat/lipid entering in arterial wall

- What it is: A condition where plaque (composed of fat, cholesterol, and other substances) builds up in the arterial walls, narrowing and hardening them.

-How it forms: Begins with damage to the endothelium (lining) of blood vessels, which allows cholesterol and other substances to accumulate and form plaques. Over time, this reduces blood flow and can lead to heart attack or stroke

***HEAD AND NECK**

Know the blood supply and drainage of the head and neck beginning with the aortic arch and ending with the superior vena cava. Make sure to include the Circle of Willis and its branches

Starts from the common carotid artery and vertebral arteries (Circle of Willis) that bring blood up in the head and is drained out into the internal jugular (FACIAL blood supply comes from the external/internal carotid artery where facial artery SUPPLIES and facial vein DRAINS to jugular vein

What does the internal carotid artery include (2)

Opthalmic artery

Circle of willis

Circle of Willis, how many branches

· Anterior cerebral artery

· Anterior communicating artery

o Forms part of the cerebral arterial circle

· Middle cerebral artery

Within the meninges, where would you find cerebral spinal fluid (CSF)? How is CSF "produced?" How is CSF recycled back into the blood?

-CSF is located within the subarachnoid space in the brain and spinal cord

-CSF is produced by the Choroid Plexus; in choroid plexuses in the brain ventricles

Protection of the Brain

skull, meninges, CSF, blood brain barrier

Cerebral meninges

- Both brain and spinal cord are covered by meninges.

- Dura, arachnoid, and pita maters

Functions of meninges

-Cover and protect the CNS

-Enclose and protect the vessels that supply the CNS

-Contain the cerebrospinal fluid

§ Between pia and arachnoid maters

What is the importance of the choroid plexus? Where is it located?

produces cerebrospinal fluid (CSF) via the ependymal cells that line the ventricles of the brain and serves as a barrier in the brain separating the blood from the CSF, known as the blood-CSF barrier.

- Modified ependymal cells interacting with capillary endothelium

- This allows for CSF to be filtered from the blood

- Located in the ventricles

- CSF is recycled back into the blood through the Fira sinuses via the sagittal sinus

-composed of ependymal cells surrounding capillaries

Know the Clinical significance of hydrocephalus

Excess buildup of CSF in the ventricle system (due to overproduction or decreased reabsorption of CSF)- Diagnosed w/ notable swelling is seen in children (mainly) and adults - Treated by installing a shunt and valve that connects the abdominal cavity and swelled location to drain CSF

- Accumulation of excess CSF within the ventricular system

- Either from the overproduction of CSF or decreased reabsorption

clinical significance of meningitis

Inflammation of the meninges-Diagnosed w/ CSF-Treated by having patient curl in fetal position, locate the L4 and L5 vertebrae in which a catheter is placed to reach the subarachnoid space, and proper medication is given whether it be due to viral or bacterial infection

- Infected cerebral spinal fluid and swollen tissue

How could the facial artery and cavernous sinus be involved in the development of encephalitis or meningitis?

can be exposed to bacteria, viruses, and pathogens as it delivers blood. The cavernous sinus sets up neural tissue to be exposed to any kind of pathogen that may have been picked up in drainage and can lead to meningitis or encephalitis- Facial vein is extremely important since this allows a direct connection to cavernous sinus through which infection may get into skull

Cranial Nerves names and how many?

12 CN

- Filaments of olfactory nerve

- Optic nerve

- Oculomotor nerve

- Trochlear nerve

- Trigeminal nerve

- Abducens nerve

- Facial nerve

- Vestibulocochlear nerve

- Glossopharyngeal nerve

- Vagus nerve

- Accessory nerve

- Hypoglossal nerve

Cranial Nerve

- Attach to the brain and pass-through specific foramina of the skull

- Numbered from I to XII

- Cranial nerves I and II attach to the forebrain

**All others attach to the brain stem

- Primarily serve head and neck structures

**The vagus nerve (X) is the only cranial nerve that extends into the abdomen

olfactory nerve

CN 1

Sensory: Visceral VS

Sense of smell

optic nerve

CN 2

Sensory: Somatic SS

Vision

oculomotor nerve

CN 3

Motor: Somatic (SM) and Visceral (VM)

SM function: Move extraocular (extrinsic eye) muscles:

-superior rectus, medial rectus, inferior rectus, and inferior oblique

VM: constrict the pupil

trochlear nerve

CN 4

Motor: Somatic (SM)

Innervate superior oblique muscle

trigeminal nerve and pathways of divisions

- Attach to the brain and pass-through specific foramina of the skull

- Numbered from I to XII

- Cranial nerves I and II attach to the forebrain

o All others attach to the brain stem

- Primarily serve head and neck structures

o The vagus nerve (X) is the only cranial nerve that extends into the abdomenCN 5

- Attach to the brain and pass-through specific foramina of the skull

- Numbered from I to XII

- Cranial nerves I and II attach to the forebrain

o All others attach to the brain stem

- Primarily serve head and neck structures

o The vagus nerve (X) is the only cranial nerve that extends into the abdomen

Move muscles of mastication (v3): temporalis,masseter, lateral and medial pterygoids, movestensor tympani in middle ear(V3), and sensoryinnervation of the face

V1-superior orbital fissure

V2

V3

abducens nerve

CN 6

Motor: Somatic (SM)

innervate lateral rectus

facial nerve

CN 7

Both: Sensory and Motor function:

SS (general), VS (general; taste), SM & VM

Move mimetic muscles of the face (all facial muscles except the muscles of mastication), move stapedius in the middle ear, sense of taste,influeces salivary glands

Sensory function

-Special visceral sensory from taste buds on anterior two-thirds of tongue

Somatic motor function

-Five branches—innervate facial muscles

Visceral motor function

-Innervation of lacrimal glands, submandibular and sublingual salivary glands

5 Branches of the facial Nerve

TZBMC

Temporal

Zygomatic

Buccal

Mandibular

Cervical

vestibulocochlear nerve

CN 8

Sensory: SS(hearing; equilibrium) and "some" SM

Sense of hearing and balance

Vestibular branch: SS equilibrium

Cochlear branch: SS hearing

glossopharyngeal nerve

CN 9

Both: Sensory and Motor function:

SS (general), VS (general; taste), SM & VM

Sense of taste, move pharyngeal muscles,influences salivary glands

Sensory function

-Special visceral sensory from taste buds on posterior one-third of tongue

-General visceral sensory

****Posterior one-third of tongue

****Pharyngeal mucosa

****Chemoreceptors in carotid body

****Baroreceptors of carotid sinus

vagus nerve

CN 10

Both: Sensory and Motor function:

SS (general), VS (general; taste), SM & VM

Sense of taste, moves levator veli palatini nearthe middle ear, visceral innervation of internalorgans

accessory nerve

CN 11

Motor: SM

innervates the trapezius muscle in the upper back and the sternocleidomastoid muscles on the neck

hypoglossal nerve

CN 12

Motor: SM

innervates the intrinsic and extrinsic muscles of the tongue

aid tongue movement during feeding, swallowing, and speech

Know the names, locations, and innervation for all mimetic muscles (Spoiler alert: they are ALL innervated by CN VII- facial nerve)

Scalp

-1. Epicranious (occipitofrontalis): wrinkles in the forehead; astonishment

Eyelids

-1. Corrugator Supercilli: vertical folks, protects against light; thinker's brow

2. Orbicularis Oculi (orbital/palpebral/lacrimal): lateral folds; concern

Nasal

-1. Nasalis

Mouth

-1. Orbicularis Oris: closing mouth, sucking shape w/contraction

2. Zygomaticus Minor

3. Zygomaticus Major: lifts corners of mouth up; laughter/pleasure

4. Risorius: w/ zygomaticus major, produces nasolabial folds; laughing muscle

5. Levator Labii Superioris6. Depressor Labii Inferioris: pulls lower lip down; perseverance7. Levator Anguli Oris: lifts corners of mouth; self confidence8. Depressor Anguli Oris: pulls corners of mouth down, sadness9. Buccinator: blows air out mouth, keeps mucous membrane free from folds10. Mentalis: chin lip furrow; doubt/indecision11. Platysma: tenses anterior neck skin

Mimetic muscles function, innervation, and names of the 4 muscle groups

radiate into the skin of the face and the head; their contraction causes displacement of the skin

Innervation: All mimetic muscles by Facial nerve (cranial nerve CN VII)

4 muscle groups:

• Scalp

• Region of eyelid

• Nasal region (only nasalis)

• Mouth region

Muscles of the Scalp

Epicranius:

• Has 2 bellies: Frontal and Occipital, connected by an aponeurosis

Function: Produces wrinkles in forehead and gives facial expression of astonishment

Region of Eyelid Muscles

Orbicularis Oculi:

-3 parts: Orbital , Palpebral and Lacrimal

-Function: produces folds in lateral angle of the

eye, expression of Worry and concern.

Corrugator supercilli:

-Function: Pulls the skin and eyebrow down and medially.

-Produces vertical folds. Protects against light. Thinker's brow expression

Innervation:

All mimetic muscles by Facial nerve (CN VII)

Nasal Region

Nasalis

Mouth Region

1. Orbicularis Oris:

----Function: contraction closes the mouth, strong contraction gives a sucking shape

2. Buccinator:

- Quadrilateral in shape.

- Origin: mandible at 1st or 2nd molar region. Forms the pterygomandibular raphe. Extends to angle of the mouth and forms the lateral wall of its vestibule

- Function: enables air to be blown out of the mouth; keeps the mucous membrane of the cheek free of folds

Zygomaticus Major:

Origin: zygomatic bone

Insertion: angle of mouth

Function: lifts the corner of the mouth upward, giving expression of laughter or pleasure

3. Zygomaticus Minor:

- Origin: zygomatic bone

- Insertion: nasolabial groove

4. Risorius: (laughing muscle)

- Function: together with zygomatic major it produces the nasolabial folds

5. Levator labii superioris:

- Origin: Infraorbital margin to skin of upper lip

6. Lavator anguli oris:

- Function: lifts the angle of the mouth, giving expression of self confidence

7. Depressor anguli oris:

- Function: pulls the angle of the mouth downwards and produces expression of sadness

8. Depressor labii inferioris:

- Function: pulls the lower lip down, giving expression of perseverance

9. Mentalis:

- Function: chin-lip furrow, giving expression of doubt and indecision.

10. Platysma:

- Function: tenses skin in the anterior neck

**All mimetic muscles are innervated by facial nerve (CN VII)

What is the sensory innervation of the face?

Trigeminal nerve (CN5) from the three branches (ophthalmic, maxillary, and mandibular)

• Derived from branches of the Trigeminal (CN V) nerve: Ophthalmic (V/1), Maxillary (V/2) and mandibular (V/3) branches

• Maxillary branch supplies lower eyelid, cheek, lateral nasal, upper lip and anterior temporal regions by Infraorbital nerve

Sensitivity of the 3 branches can be tested by pressing nerves

• This is a vertical line, 2-3 cm lateral to midline

Horner's syndrome

Classic triad (miosis/constricted pupil, partial ptosis, loss of hemifacial sweating - anhidrosis)

results from damage of pre or post sympathetic fibers to face

Causes: injury to nerve, carotid artery, stroke, lesion in brain stem, or tumor in lung

Direct and consensual light reflex

constriction of ipsilateral and contralateralpupil when a light is shone into one eye. It shows the function of CN III and also theoptic pathway. These reflexes may be lost in head trauma.

Pupillary dilation due to CN III palsy may be due to tumors or an aneurysm

Glaucoma

optic neuropathy, retinal ganglion cell loss, and blindness due to impaireddrainage of the aqueous humor from the Schlemm's canal. Leads to increasedintraocular pressure and increased retinal blood flow

cataracts

progressive degeneration and opacity of the lens which leads to impairedvision and blindness; due to the deposition of aggregated proteins

Know the names, locations, and innervations of the muscles of mastication

- all innervated by mandibular n

CN V; trigeminal nerve; 3 branches

(• 3 branches: ophthalmic, maxillary, and mandibular)

Masseter, Temporalis, Lateral pterygoid,Medial Pterygoid

Masseter

powerfully closes the jaw by elevating the mandible

Origin: Zygomatic arch

Insertion: masseteric tuberosity of mandible

Has 2 parts: Superficial (oblique fibers) and deep (vertical fibers)

Function: powerfully closes the jaw by elevating the mandible

Innervation: Mandibular division of CN V

Temporalis

strongest elevator of lower jaw

Origin: temporal fossa as far as inferior temp line

Insertion: by a strong tendon to coronoid process of mandible and mandibular ramus

Function: strongest elevator of lower jaw

Innervation: Mandibular division of CN V

lateral pterygoid

mandibular movements (guiding muscle)

• Has 2 parts

Function: mandibular movements (guiding muscle)

Innervation: lateral pterygoid nerve, CN V

medial pterygoid

elevates mandible and pushes it forward, rotational movement

• Runs at right angles to the lateral pterygoid

• Has 2 parts: Angle of mandible is between this muscle and the masseter

Function: elevates mandible and pushes it forward, rotational movement

Innervation: Medial pterygoid nerve, CN V

Know the location and function of the paranasal sinuses

• Covered by a mucous membrane (pseudostratified ciliated epithelium) with motile cilia, and glands,

• Rich in vasculature to purify, moisten and warm/cool the air in order to protect the lungs

• They add resonance to the sound and make the head lighter

Frontal sinus

Ethmoidal air cells

Sphenoidal sinus

Maxillarry sinus

Frontal sinus:

drains into the middle meatus via frontonasal duct

Ethmoidal air cells:

in ethmoidal labyrinth between orbit and nasal cavities, 3 sets:

• Posterior cells: drain into superior meatus

• Anterior cells: drain into the middle meatus

• Middle cells: drain on or above ethmoidal bulla in the middle meatus

Sphenoidal sinus:

drains into sphenoethmoidal recess

Maxillary sinus:

is the largest, in maxilla, drains into semilunar hiatus of the middle meatus

Know the contents of the middle ear

"tympanic cavity"

Auditory Ossicles: three bones, that with the tympanic membrane, transmit the sound across middle ear to the internal ear

-Malleus

-Incus

-Stapes

malleus, incus, stapes (auditory ossicles), tensor tympani muscle, stapedius

contents of inner ear

cochlea, vestibule, semicircular canals

• Composed of a membranous Labyrinth covered by very hard bony Labyrinth in Petrous part of the temporal bone

• The bony Labyrinth contains a clear, aqueous fluid, called perilymph, in which the membranous labyrinth is suspended; membranous labyrinth is filled with endolymph

• Labyrinth is part of the Vestibular Apparatus or Organ of Balance

• The Apparatus also contains the membranous saccule and utricle; both carry sensory epithelium the Macula Sacculi and Macula Utriculi

What is the location, innervation and function of the tensor tympani ?

Helps keeps the tympanic membrane tense so that sound can reverberate (Innervation: CN.V)

- Insertion: handle of malleus

- Innervation: Trigeminal nerve (mandibular branch)

- Function: tenses the tympanic membrane

What is the location, innervation and function of the stapedius muscles?

Help regulate sound transmission (Innervation: CN.VII)

- Insertion: neck (head) of stapes

- Innervation: Facial nerve (CN VII)

- Function: Levers the foot plate of stapes out of the oval window and dampens the sound

Which is important in the development of hypercusis?

increased sensitivity to sound due to loss of stapedius muscle function (helps to dampen sound stimuli)

facial nerve paalysis • causes loss of function of stapedius muscle and loss of dampening sound stimuli, leading to Hyperacusis (an increased sensitivity to sound)

What is the Clinical significance of Otis externa and Chronic Otitis media? How is a myringotomy used to treat the later of the two conditions?

otitis externa = infection of the outer ear

Causes: swimmer's ear that causes an irritation to occur, build up of wax

Elderly patients need particular care because innervation of this area by Vagus and Glossopharyngeal nerve

treatment: medication

** less severe

Otis externa

• Lesions within the canal may cause nausea or vomiting

• Sensory afferents of the canal carried by the vagus and glossopharyngeal nerves contain parasympathetic fibers to the upper GI tract

• Similarly, removal of cerumen my cause a gag reflex or cough

• In elderly patients, such stimulation may lead to cardiac arrest via the carotid reflex

What is the Clinical significance Chronic Otitis media?

Severe or chronic infection that occurs in MIDDLE ear

More common in children because of eustachian tube at 90 degree angle in children (vs. straight eustachian tube in adults) which does not allow middle ear infection to drain down into throat which keeps the infectious material in the ear

• Chronic infections like swimmer's ear may lead to bony hyperplasia and a narrowing of the meatus

myringotomy

Tubes can be put in ear for drainage -- incision/rivet made in tympanic membrane for tube (about 6-8 weeks for healing and then tube pops out

Placing of tube, which ONLY treats otitis media

Can be a complication of measles

• an incision made through the tympanic membrane to insert a tube for drainage of secretions and pus in severe and/or chronic cases of otitis media

Sternocleidomastoid

CN XI accessory,

Origin: sternum and clavicle

Insertion: Mastoid process and superior nuchal line

Function: Unilateral contraction turns the head to opposite side and bends it ipsilaterally; Bilateral contraction lifts the head

• Participates in respiration

Innervation: Accessory nerve (CN XI) and C2-C3