Kendra's A&P Blog

Facial Nerve

2006-05-07T18:32:00.000-07:00

Cranial Nerve VII

Facial Nerves
-a large nerve that innervates muscles of facial expression along with other things

Allowes for facial movements to show emotion!

Without her facial nerves this adorable look of surprise would be impossible to achieve!

This Picture shows where CnVII the facial nerve comes off of the brain stem.

1.Temporal Branch
2.Zygomatic Branches
3.Parotid Duct
4.Buccal Branches
5.Marginal Mandibular Branch
6.Cervical branch
7. Main trunk of Facial Nerve

The cell bodies of these primary afferent neurons reside in the geniculate ganglion:

Brancial motor(special visceral efferent):
Supplies the muscles of facial expression; posterior belly of digastric muscle; stylohyoid, and stapedius.

Visceral motor(general visceral efferent):
Parasympathetic innervation of the lacrimal, submandibular, and sublingual glands, as well as mucous membranes of nasopharynx, hard and soft palate

Special sensory(special afferent):
Taste sensation from the anterior 2/3 of tongue; hard and soft palates.

General sensory(general somatic afferent):
General sensation from the skin of the concha of the auricle and from a small area behind the ear.

(http://info.med.yale.edu/caim/cnerves/cn7/cn7_1.html)

The Peripheral Nervous System

2006-03-20T13:06:00.000-08:00

The Peripheral Nervous System( PNS)
- consists of sensory and motor neurons
sensory ( afferent) neurons- carry impulses toward the CNS
There are three ways to classify sensory receptors : 1.) by the type of stimulus they detect 2.)by their body location and 3.) by their structural complexity.

motor(efferent) neurons-carry impulses away from the CNS to muscles and glands.

The peripheral nervous system is split into two subdivisions
somatic nervous system and the autonomic nervous system

Somatic Nervous System

There are twlve pairs of cranial nerves and 31 pairs of spinal nerves

CANIAL NERVES
-two pairs attach to the forebrain, the rest originate from the prain stem. Other than the vagus nerves, which extend into the abdomen, cranial nerves serve only head and neck structures.

Nerves Type Function
Olfactory/ sensory/ smell
Optic /sensory/vision
Oculomotor/ motor/ eyelid and eyeball muscles
Trochlear/ motor/ eyeball muscles
Trigeminal /mixed/ sensory: facial and mouth sensation motor: chewing
Abducens/ motor/ eyeball movement
Facial /mixed/ Sensory:taste Motor: facial muscles and salivary glands
Vestibulocochlear/ motor/ hearing and balance
Glossopharyngeal /mixed/ Sensory: taste Motor: swallowing
Vagus /mixed/ main nerve of the parasypathetic nervous system (PNS)
Accessory /motor/ swallowing; moving head and shoulder
Hypoglossal /motor/ tongue muscles

(http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/P/PNS.html )

SPINAL NERVES
There are thirty one pairs of spinal nerves, each containing thousands of nerve fibers, arise from the spinal cord and supply all parts of the body except the had and some areas of the next. All are mixed nerves
These nerves are named according to their point of issue from the spinal cord

There are 8 pairs of cerviacal spinal nerves( C1-C8), 12 pairs of thracic nerves( T1-T12), 5 pairs of lumbar nerves(L1-L5), 5 pairs of scral nerves(S1-S5) and one pair of coccygreal nerves(C0)

All of our conscious awareness of the external eviroment and motor activity to cope with it operate in this somatic division of the PNS

Autonomic Nervous System

-this is the system of motor neutons that innervates smooth and cardiac muscle and glands. The ANS gives blood to needed areas, speeds and slows heart rate, adjustse blood pressure and body temperature, and increases or decreases stomach secretions. It is larglely an involuntary system.

The Autonomic Nervous System is subdivided into the Parasympathetic

The Sympathetic Nervous System

2006-02-12T22:55:00.000-08:00

TISSUES

Types:

Epithelial
Connective
Muscle
Nervous

Epithelial Tissue

Special Characteristics of Epithelium

Cellularity. Epithelial tissue is compose almost entirely of close-packed cells. Only a tiny amoount of extracellular materiall lies in the narrow spaces between them.
Specialize contacts. Epithelial cells fit close together to form continuous sheets. Adjacent cells are bound together at many points by lateral contacts, including tight junctions and desmossomes.
Polarity. All epithelia have an apical surface, an upper free surface exposed to the body exterior or the cavity of an internal organ, and a lower attached basal surface. Cell regions near the apical surface differ from those near the basal surface in both structure and function.
Supported by connective tissue.All epithelial sheets rest upon and are supported by connective tissue. Just deep to the basal lamina is the reicular lamina, a layer of extracellular material containing a fine network of collagen protein fibers that "belongs to the underlying connective tissue.
Avascular but innervated. Epithlium is supplied by nerve fibers(innervated) but contains no blood vessels(avascular). These cells are nourished by the blood vessels of the underlying connective tissue.
Regeneration. Epithelium has a high regenerative capacity. As long as epithelial cells receive adequate nutrition, they can replace lost cells rapidly by cell division.

Classification of Epithelia

Simple Epithelia-composed of a single cell later, found where absorption and filtration occur and a thin epithelial barrier is desirable

ex.simple squamous

Stratified epithelia- consisting of two or more cell layers stacked one on top of the other, are common in high abrasion areas where protection is important.

ex. Stratified squamous

Squamous-flattened and scalelike; nucleus is a flattened disc

Simple squamous:

Function:

Location:

Stratified Squamous:

Function:

Location:

Cuboidal are boxlike, approximately as tall as they are wide and the nucleus is sperical

Simple Cuboidal

Function:

Location:

ex. simple cuboidal

Columnar- tall and column shaped and the nucleus is elongated from top to bottem and usually located close to the cell base.

Simple Columnar

Function:

Location:

ex. Simple Columnar

Pseudo stratified columnar - single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain goblet cells and bear cilia.

Function:

Location:

Transitional- Resembles both stratified squamous and stratified cuboidal; basal cells cuboidal or columnar;surface sells dome shaped or squamouslike, depending on degree of organ stretch.

Function:

Location:

Kendra's Intro Information

2006-01-23T07:31:00.000-08:00

Kendra Parker
Taunton, Ma- May 20 1986
The Used
General Education requirement for dental hygeine
Two sisters(31) and one Brother(27)

Digital Native Score: 8/10