Mel Bourden's BIO 33 Blog

Cranial Nerve # 7 the Facial Nerve

2006-05-12T08:28:00.000-07:00

VII Facial Nerve:

nucleus location function cranial exit head region target
of the brain points

pons facial expressions internal auditory muscles on the face
& taste meatus & ant 2/3 of tongue

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

After the Facial Nerve leaves the cranial cavity it becomes 5 smaller branches that fan over the face.

5 Branches of Cranial Nerve VII:

Name Action

Temporal pulls ears forward, raises ears, moves scalp forward, moves eyebrows

Zygomatic closes eyelids, elevates corners of the mouth

Buccal smiling, lips, nostrils

Mandibular Pulls skin of chin upward

Cervical Pulls down corners of mouth

http://www.emedicine.com/ent/topic8.htm

The facial nerve has four components with distinct functions:
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 lcrimal, 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.

Lower Limb...How does it move?

2006-04-10T04:39:00.000-07:00

We now know how the spinal chord and the peripheral nerves are protected and where they are located. Where do they go and how do they help move the lower limb?

The peripheral nerves come off the spinal chord in pairs and each go to a particular region (dermatone). At there destination point there is a link between the neuron's axon terminal and the muscle cell. This is the ..

NEUROMUSCULAR JUNCTION:

the brain sends a signal via the neurons, it travels down the peripheral nerves, and a chemical signal is transferred via sodium which tells the actin and myosin to contract the muscle cell.

the Muscules of the Lower Limb: (http://www.thestretchinghandbook.com/archives/shin-splints.htm)

The skeletal muscles then pull on the bones that they are connected to via tendons.

The bones are connected and move each other via articulations or joints. These are dense fiborous connective tissues.
TYPES OF JOINTS:
Fibrous-
sutures- only in between the skull bones
syndemous- connected by ligament (radius & ulna)
gomphoses- peg in a socket (only teeth)
Cartilaginous-
synchodrosis-hyaline cartilage in long bones (3 bones in 1)
sympheses- fibrocartilage unites bones - pubic symphesis & intervertebral discs.
Synovial-most common0 the movible joint

(http://www.pdrhealth.com/content/rx_drugs/chapters/fgrx04/fgrx0402.GIF)

the last picture for the vertebrae

2006-03-19T14:11:00.000-08:00

thanks to http://www.physiciansplus.net/vertebrae.cfm we can get a good look at the various components of the vertebrae and even see where the spinal chord fits in. So, there we have it, now I know where the peripheral nerves fit in the scheme of things. I hope you do too!

So after many painful minutes of trying to figure out why the html is broken on my last picture I gave up. These 2 pictures are supposed to go under the last section....

Peripheral Nerves- where do they fit it?

2006-03-17T11:46:00.000-08:00

Before I get into the particulars on the peripheral nerves I want to give some background info on the structure of nerve cells, and structure of the vertebral column first. Then I'll fit the peripheral nerves into the equation.

I. All About Nerves Neurons are the cells of the nervous system

3 classes of neurons: (Don't forget S.A.M.E.)

1. Sensory (receptor) neurons (afferent)- they carry the impluses from the sense organs to the brain & spinal chord after receptors detect an internal/external change.
2. Motor Neurons (efferent) -they carry impulses from the brain and spinal Cord to the muscles or glands. In response to impulses, Muscles Contract and Glands Secrete.
3. Interneurons - connect sensory and motor neurons and carry impulses between them. They are found entirely within the Central Nervous System.

The structure of a neuron...

(from http://www.enchantedlearning.com/subjects/anatomy/brain/Neuron.shtml w.enchantedlearning.com/subjects/anatomy/brain/Neuron.shtml)

Helpful hint: Axons send information away from the neuron and the dendrites receive information. Schwann's cells help protect the cell by producing myelin. This allows for an insulated current that is speedy. Now that we have gone over the basics of the neurons here's more about their helper cells...

THE GLIAL CELLS (http://staff.washington.edu/chudler/glia.html)
Astrocyte(Astroglia) -Star-shaped cells that provide physical and nutritional support for neurons: 1) clean up brain "debris" 2) transport nutrients to neurons; 3) hold neurons in place; 4) digest parts of dead neurons; 5) regulate content of extracellular space

Microglia-Like astrocytes, microglia digest parts of dead neurons.

Oligodendroglia-Provide the insulation (myelin) to neurons in the central nervous system.

Satellite Cells-Physical support to neurons in the peripheral nervous system.

Schwann Cells-Provide the insulation (myelin) to neurons in the peripheral nervous system

II. Organization of the Nervous System:

CNS- "command center' where higher level processing takes place

PNS- nerves that go out to target in the body. they are located outside the brain & spinal vertebrea.

A change in external or internal enviroment is detected and the message is sent to the brain. The brain then sends a signal for muscle movement or gland secretion.

Peripheral Nerves:

Cranial nerves: there are 12 pairs the come directly off the brain

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

Nerves	Type	Function
I Olfactory	sensory	olfaction (smell)
II Optic	sensory	vision (Contain 38% of all the axons connecting to the brain.)
III Oculomotor	motor*	eyelid and eyeball muscles
IV Trochlear	motor*	eyeball mu scles
V Trigeminal	mixed	Sensory: facial and mouth sensation Motor: chewing
VI Abducens	motor*	eyeball movement
VII Facial	mixed	Sensory: taste Motor: facial muscle s and salivary glands
VIII Auditory	sensory	hearing and balance
IX Glossopharyngeal	mixed	Sensory: taste Motor: swallowing
X Vagus	mixed	main nerve of the parasympathetic nervous system (PNS)
XI Accessory	motor	swallowing; moving head and shoulder
XII Hypoglossal	motor*	tongue muscles

SPinal nerves : pairs each with a left & a right coming off the spinal chord

Cervical region 8 pairs

C1 & C2- nerves for the head, face, inner & middle ear, sypathetic nerve system, sinuses, eyes, auditory, nerves.

C3 - C8- neck shoulders, thyroid, tonsils, teeth, outer ear,

nose, mouth, vocal chords

Thoracic Region 12 pairs (pretty much goes to all of the vital organs)

T1 -T12-arms, hands, heart, coronary arteries, esophagus, trachea, lungs, broncial tubes, gallbladder, liver, stomach, pancreas, spleen, kidneys, ureters, adrenal glands, sm intestines

Lumbar Region 5 pairs (pretty much goes to the lower parts)

L1 - L5- lrg intestines, appendix, abdomen, bladder, repro organs, ankles, feet

Sacral Region 5 pairs (goes to the dorsal parts)

S1 - S5- hip area, tail bones area, rectum, anus, buttocks.

Now for how they fit it.....

The spinal chord is surrounded by and protected by the bones of the vertebral column. Like the spinal nerves the vertebral column has the same regions, cervical, thoracic, and sacral and the additional coccyx region (or tailbone)

However there are only cervical vertebrae & 8 pairs of nerves. This is because the 1st pair of nerves are above the 1st vertebrae.

Tissues: Types, Classes, Functions, Pictures

2006-02-07T16:07:00.000-08:00

Tissue Classes:

a. Epithelial-
What is it??
it is a set of cells that covers a body surface or lines a body cavity.

What are the functions of it?
- to form a boundary between the environment and the body
-to perform many function - protection, filtration, absorption, excretion, sensory reception

What are its characteristics?
- formed of close packed cells
-fit close to each other, bound together by lateral contacts (ie tight junctions)
-Polarity- have a surface exposed to the body exterior or the cavity of an organ & a lower that attachs to the basal surface
- is supported by connetive tissue (more on this type later)
- avascular- contains no blood vessels
-can regenerate (like when you cut yourself and it heals quite fast)

What are the types of epithelial tissue?

2 Classes = Simple (one layer of cells) & Stratified (more than 1 layer)

3 Common Shapes = Squamous (scale like/flat) , cuboidal (box like) , & columnar (tall & look like columns)

b. Connective
What is it??
-the most wide spread type of tissue in the body

What are the functions of it?
-binds & supports (ie bones support the organs)
-protects (ie the rib bones protect the vital organs by forming a hard cage around them)
-insulates (fat insulates the organs)
-and transports (blood transports nutrients, O2 ect through the body)

What are its characteristics?
-all types are formed from the mesenchyme in embryonic development
-are vascular and have a blood supply
-have an extracellular matrix that allows it to withstand tension, pressure, withstand abuse

What are the types of connective tissue?

(all pictures are from http://washington.uwc.edu/about/faculty/schaefer_w/TissuesPage.htm)

- LOOSE CONNECTIVE- It holds organs in place and attaches epithelial tissue to other underlying tissues

3 components: collagen fibers, elastic fibers, & reticular fibers

-DENSE CONNECTIVE-closely packed, which is found in tendons and ligaments

-SPECIALIZED TYPES:

Adipose- fat tissue stores nutrients

Areolar- stores nutrients, defends vs. infection, holds the body's fliuds

Cartilage- found between dense ct & bone. stands up to both tension & compression

Bone- supports & protects body structure. matrix = inorganic calcium salt + collegen fibers

Blood- matrix = blood plasma transport system

NEURAL TISSUE
What is it??
-the main component of the nervous system that regulates and control body functions
-made up of neurons (highly specialized nerve cells that conduct & generate impluses) & supporting cells

d. Muscle tissue
What is it?
-highly cellular tissues with a great blood supply

What does it do?
-allows for movement & contraction

(http://washington.uwc.edu/about/faculty/schaefer_w/TissuesPage.htm)

What are the types?
-skeletal (medic.med.uth.tmc.edu/.../ muscle/hist-05.htm)

-cardiac

(http://umanitoba.ca/faculties/medicine/units/anatomy/histo/jpg/cardiaccopy.JPG)

-smooth

(http://www.uoguelph.ca/zoology/devobio/210labs/muscle1.html)

issues

2006-02-05T12:50:00.000-08:00

Hello, If anyone knows how to set up Blogger to full intergrate with XHTML or HTML I'd appreciate the info. I designed it all in HTML with pictures, color, ect and after loading had to manually put the images in.

week 2 review

2006-02-05T12:36:00.000-08:00

The Organization of the Human Body in a Nut Shell! <br />

The Organization of the Human Body in a Nut Shell!

The Heirarchy of Life

Molecules

are the smallest parts of a substance made of 2 or more atoms.

Cells

is the smallest structural and functional unit of life

Tissues

is a group of similar cells functioning together

Organs/Structures

are part of organism & consists of 2 or more tissues functioning as a unit
together they can perform a special function.

Organ Systems

are the most complex of the component units of the
human body. A system is an organization of varying numbers
and kinds of organs arranged so together they can perform

complex functions for the body. Ten major systems compose
the human body:

Endocrine

Cardiovascular

Lymphatic

Respiratory

Digestive

Urinary

Reproductive System

Organisms

an individual living unit that is composed of any of the above levels

Environment

The sum of all external conditions affecting the life, development and survival of an organism.

Anatomical Direction

Body Orientation

From the first week of embryonic development on we have the ability to descbride the body
with orientation. The language of anatomical direction is important to be able to accuratly describe
the human body so that anyone can understand th

e exact place in the body that is being referenced.

The body can be sectioned into one of the following three planes. These planes related to the x, y, & z
coordianted in three dimensional space.

Transverse (like slicing a loaf of bread)/crossection. Uses the X/Y space

Saggital (right down the middle dididing the body in 1/2) Uses the Y/Z space

Coronal (divides the body into anterior & posterior sections) Uses X/Z space

Directional Terminology

Superior (cranial, cephalad): above something else, toward the head.

Inferior (caudal): below something else, toward the tail.

Anterior (ventral): toward the front of the body or structure.

Posterior (dorsal): toward the rear or back of the body or structure.

Medial: toward the midline of the body.

Lateral: away from the midline of the body.

Intermediate: between a more medial and a more lateral structure.

Proximal: closer to the point of attachment.

Distal: farther from the point of attachment.

Superficial (external): at or close to the body surface.

Deep (internal): below or away from the body surface.

Body Cavaties

Dorsal Cavity

Includes the Cranial & Spinal cavaites

Ventral Cavity

Includes the Thoracic & Abdominopelvic

Misc.

Oral, Digestive, Orbital, & Synovial

Embryonic Develpment

During the first week of embryonic development the major cells groups are formed.
At 1st the embryo is merely two flat sheets of cells.

The Ectoderm- the outer layer "tube"

later becomes the skin, skeleton, skeletal muscles, & nervous system

The Endoderm- the inner layet/"tube"

later becomes the digestive organs, liver, pancreas, & lungs

Eventually a rod like structure called the notochord is formed. This represents the long
axis of the body. At this point anatomical direction terminology can be used to descbribe
the embryo. The notochord laters becomes the vertebral bodies.

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

1. Melissa Bourden

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