Courtney's Second Wind

You Want To Talk About Nerves? (hehe!)

2006-05-03T15:18:00.000-07:00

The Trigeminal Nerves

Q.What are the trigeminal nerves?

A. 1.)Largest of cranial nerves

2.) fibers extend from pons to face and divides into three branches (tri)

3.) provides sensory fibers to the face & motor fibers to the chewing muscles.

Q. #1What are the three subdivision of the Trigeminal nerve? Explain.

A. 1.) opthalmic region(v1)

a.) pathway- to ventral midbrain to pons(brain) and also through the superior orbital fissure to the eye

b.) target structure- from skin of anterior scalp, upper eyelid, and nose, and from nasal cavity mucosa, cornea, and lacrimal gland.

c.) type of nueron- sensory afferent

d.) function- corneal reflex

A. 2.) Maxillary region(v2)

a.) pathway- pons through the foramen rotundum to the face

b.) target structure- nasal cavity mucosa, palate, upper teeth, skin of cheek, upper lip, lower eyelid

c.) type of neuron- sensory afferent

d.) function- sensation of pain, touch, and temperature.

A. 3.) Mandibular region(v3)

a.) pathway- through the foramen ovale

b.) target structure(s)-anterior tongue(not taste buds), lower teeth, skin of chin, temporal region of scalp, motor muscles of mastication

c.) type of neuron- sensory (afferent) and motor (efferent)

d.) function- clenching teeth, open mouth against resistence, and move jaw side to side

References

Human Anatomy and Physiology, sixth edition, Pearson Education2004

Trigeminal nerves- www.aw.com

optothalmic- www.med.umch.edu

maxillary- www.dentistry.ouhsc.edu

mandible- www.msu.edu

How The Upper Limbs Work

2006-04-10T11:16:00.000-07:00

Structures That Make Up Our Upper Limbs/Bones

Clavicle
a.) sternal end- attaches to sternal manubrium
b.)acromial end- articulates with scapula
c.) anchors muscle
d.) transmits compression forces from upper limbs to axial skeleton
e.) extremely sensitive to muscle pull

2.) Scapula
a.) flat bones
b.)Made up of three borders
1b.) superior border- shortest, sharpest border
2b.) medial border- parallels vertebral colummn
3b.) lateral border- meets the armpit and ends in Glenoid cavity(articulates with humerus, forming the shoulder joint)
c.) Has three corners
1c.)superior angle and lateral angle join at the inferior angle

3.) Humerus
sole bone of the arm. All markings are to the left.

4.) The Radius and Ulna

The radius(left) is a lateral bone of the forearm that carries the wrist. The head articulates with the pitulum of the humerus. Inferior to the headn is the radial tuberosity where the biceps anchor. Articulates with carpal bones and contributes to the wrist joint.

The Ulna (right) forms the elbow joint with the humerus. It;s two processes the olecranon and coronoid grip trochlea of humerus and form a hinge joint so that our arm is able to flex and extend. Medial to it's haed is a styoloid process, from which ligaments run to the wrist. The head is separated from the wrist by fibrocartilage.

Bones of the Hand
Carpals-(wrist bones)

metacarpals-(palm) Numbered from1-5. Articulate with carpals and phalanges. There is a saddle joint in between metacarpal 1 and the trapezium.

phalanges- fingers or digits numbered 1-5 starting with the thumb.

Joints

Functional Classification of joints( amount of movement at joint)
1.) synarthroses- immovable joint

2.) amphiarthroses- slightly movable joints

3.)diarthroses- freely movable joints

Structural Classification(material binding bones together and if a joint cavity is present)

1.) Fibrous Joints- joined by fibrous tissue, no joint cavity present. The amount of movement allowed depends on the fibers length of the connective tissue. Three types of fibrous joints

Sutures "seems"

Only occur between bones of the skull. during middle age the fibrous connective tissue that binds the skull ossifies into a single unit called synotostoses.

Syndesmoses (bones connected by ligaments)

Connected by a band of connective tissue or ligament. The amount of movement allowed dependson the length of connecting fibers.

Gomphoses

This is a peg in socket firous joint. The only joint of this type is the articulation of tooth in a bony alveolar socket.

Cartilaginous Joints (articulating bones are joined by cartilage)

1.) Synchondroses is hyaline cartilage, this type is mostly found are epiphyseal plates which eventually become synostoses. It can also be found on the first rib and manubrium of the sternum.

2.) Synovial Joints

These joints articulate bones that are separated by fluid containing joint cavities. This joint allows freedom of movement. Most joints of the body fall into this class. Synovial joints have 5 differentiating features
1.) articular cartilage
2.) Joint (synovial )cavity
3.)articular capsul
4.) synovial fluid
5.) reinforcing ligaments

Joints of Upper limbs

1.) Acromiaclavicular- synovial plane contains articular disc

2.)Shoulder-ball and socket

Pivot Joint

in t he upper limb you can find this type of joint at the radioulnar

Hinge joints

Elbow and finger

The only saddle joint we have in the upper limbs is in the carpometacarpal of digit #1

The condyloid joints in the upper limbs are your knuckle and wrist

Plane joints are located: intercarpal and carpometacarpal 2-5

Muscles (or as Stephan would say Muskles hehe!)

Nine Muscles that cross shoulder joint into humerus:

superficial muscles-prime movers of arm movement

- pectoralis major, latissimus dorsi, and deltoid.

Rotator Cuff Muscles(originate on scapula, reinforce shoulder joint)

-supraspinatus, infraspinatus, teres minor, and subscapularis

Teres major- postermedially extends, medially rotates, and adducts humerus, this is the synergist of latissimus dorsi

coracobrachialis- flexes and abducts the humerus, it is the synergist of pectoralis major

Muscles crossing the elbow joint

posterior- triceps brachii(mover of forearm) and anconeus(assists tricep minimally)

anterior-(causes elbow flexion) biceps brachii, brachialis, and brachioradialis

( did not know exact muscles that I am supposed to know of upper and lower limb, perhaps someone can clue me in when commenting on my blog,it has been a rough week, thanks)

How We Are Able To Do Those Things We Love To Do("how the little things really do matter")

Those Special People in My Life

"Upon doing my studies this semester I have not only come to appreciate the miracle of life, but I have come to appreciate the things that are bodies do to make our life wonderful". -Courtney Allard-

Movement

We have the Central Nervous System which is made up of the brain and spinal cord and is the command center of the nervous system. The peripheral nervous system is outside of the cns and is made up of nerves. Spinal nerves carry impulses to and from the spinal cord. Cranial nerves carry impulses to and from the brain. In the PNS the the sensory or afferent, division consists of nerve fibers that send impulses to the CNS from sensory receptors. Sensory fibers sending impulses from the skin, skeletal muscle, and joints are called sommatic afferent fibers and those transmitting impulses from visceral organs are called visceral afferent fibers.

The Motor or Efferent, Division

- tansmits impulses from CNS to effector organs(muscle and glands)

- impulses activate muscles to contract and glands to secrete. This brings about a motor response.

Somatic Nervous System (Voluntary Nervous System) " hmmm, I think I want to wash a car"

- somatic nerve fibers (axons) that conduct impulses from CNS to skeletal muscles. The terminals of somatic

Neuron Type

Multipolar neurons are motor neurons that conduct impulses along the efferent pathways from the CNS to the effector glands and muscles.

Stimulation Of A Neuron And The Miracle Of Movement

A neuron has a electrical impulse that is generated along the length of the axon. This is called the action potential (nerve impulse), and it contols basically everything in the nervous system. The measure of potential energy is called the voltage. Voltage is measured between two points and is called the potential difference. The flow of electrical charge is called the current. When these impulses are sent down the axonal ending of the neuron to its target site, the muscle fiber, the ending splits into a bunch of axonal tetrminals that sprawl over the motor end plate of the muscle fiber. The axonal terminals have mitochondria and synaptic vesicles filled with ACh. The nerve impulse reaches the an axonal terminal , ACh is released by exocytosis, diffuses and and attaches to ACh receptors. This binding action results in the opening of channels (ligand-gated) that allow both Na and K to pass. This whole process produces a end plate potential when Na and K causes muscle interior to dialate. When the end plate potential spreads to other areas of the membrane where it triggers the voltage gated sodium channels to open causing the action potential to stimulate the muscle fiber and causing it to contract. And TAH-DA we have movement!

References of Images

clavicle and scapula- academic.wsc.edu.com

humerus- www.palaeos.com

Ulna- biology.kenyon.edu

Radius- biking.taiiku.tsukuba.com

Carpals- www.vc.tx.us.com

metacarpals- www. octc.kctos.edu

phalanges- classes.kumc.edu

joint of upper limbs- fulton.edzone.net

muscle of upper limb- webschool solutions.com

muscle and joint tissue- www.shoulderdoc.com

popeye- membres.lycos.com

joints- www.nvcc.edu.com

Peripheral Nervous System and the Vertebral Column

2006-03-09T14:37:00.000-08:00

The peripheral nervous system is outside the of the central nervous system. The peripheral nervous system is made up of mostly nerves that run from the brain through the spinal cord. Spinal nerves carry impulses to and from the spinal cord.

Cranial nerves carry impulses to and from the brain.

There are two subdivisions of the Peripheral Nervous System
-A.)The sensory or afferent division
-B.)The motor or efferent division

A.)The Sensory (afferent) division

This subdivision of the Peripheral Nervous System has nerve fibers that sends signals to the central nervous system from sensory receptors located throughout the body. The image to the left are sensory receptors, from www.scientia.org/...gifs/image 1oo.gif.com .

Senory Fibers

1.) Somatic afferent fibers- conveys impulses from the skin, skeletal muscles, and joints.

2.) Visceral afferent fibers- transmits impulses from the visceral organs within the ventral body cavity.

B.) The Motor(Efferent) Division

Part of the Peripheral Nervous System that transmits impulses from the Central Nervous System to effector organs. These impulses are sent to the muscles which activate them to contract, stimulates glands to secrete and what prompts a motor response. There are two systems that make up the motor efferent division.

1.) The Somatic Nervous System

2.) The Autonomic Nervous System

1.) The Somatic Nervous System

Made up of somatic nerve fibers that send impulses from the Central Nervous System to skeletal muscles. This system lets us consciously control our skeletal muscles. (voluntary nervous system

2.) The Autonomic Nervous System

This system is often refered to as the involuntary nervous system. This system has visceral motor nerves that manage the functions of smooth muscle, cardiac muscles, and glands. This system has two subdivisions:

A.)Sympathetic division- mobilizes the body systems during emergency situations.

B.) Parasympathetic division- conseves energy and promotes nonemergency functions.

Nervous Tissues Two Main Cell Types:

1.) Supporting cells- smaller cells that surround and wrap the more delicate neurons.

2.) Neurons- excitable nerve cells that transmit electrical signals.

Neuroglia (glial cells)

These cells provide a supportive scaffolding for neurons so that electrical activities or adjacent neurons do not intefere with each other. Others produce chemicals that guide young neurons to the proper connections, and promote neuron health and growth.

Neuroglia In The CNS

Astrocytes- Their role in making exchanges between capillaries and neurons by taking up glucose from the bloodstream and deliver it to neurons in the form of lactic acid), in aiding the travel of young neurons in synapse formation and in aiding to determine capillary permeability. They mop up leaked potassium ions and recapture relaesed neurotransmitters.

Microglia

Their processes touch close neurons, overlooking their health, and when they sense neurons are troubled or injured they travel towards them. They transform into a special type of macrophage that phagocytes microorganisms or neuronal debris.

Ependymal Cells

www.suu.edu

These cells are referred to as "wrapping garments". They line the central cavities of the brain and the spinal cord. They form a barrier between the cerebrospinal fluid that fills those cavities and the tissue fluid that surrounds the cells of the central Nervous System.

Neuroglia In The Peripheral Nervous System

Two Types:

1.) Satellite Cells -Satellite cells surround neuron cell bodies within ganglia. (ganglia)www.devbrio.com

Their function is still largely unknown

2.) Schwann cells

Surround and form myelin sheaths around larger nerve fibers in the peripheral nervous system. Schwann cells are vital to regeneration of peripheral nerve fibers. (Images from left to right www.betterimages.com and www.owlnet.rice.edu )

Special Characteristics of Neurons

1.) extreme longevity- given proper nutrition cells can live over a hundred years

2.) largely amitotic- cells lose their ability to divide in the nervous system thus causing neurons being unable to replace themselves once they are destroyed. Some areas can reproduce such as the olfactory epithelium and some hippocampal areas.

3.) high metabolic rate- need everlasting supply of oxygen and glucose and cannot live without oxygen.

The Neuron Cell Body

training.seer.cancer.gov

- made up of a translucent round nucleus with a distinct nucleolus encircled by cytoplasm. (also called the perikaryon or soma)

- cell body protein and membrane made up of clustered free ribosomes and rough endoplasmic reticulum. The ER is known as Nissl bodies or Chromatophilic substance, stains dark with dyes.

left Nissl bodies www.northland.cc.mn.us

right ribosomes www.micro.magnet.fsu.edu

- golgi apparatus forms complete circle around nucleus

www.cwx.prenhall.com

Golgi Apparatus

- mitochondria are scattered around other organelles. Bundles of filaments are present which maintain cell shape, these structures are called microtubules and neurofibrils. neurofibrils www.moon.ouhsc.edu

- some neurons have pigment inclusions called lipofuscin

www.kats-korner.com

Lipofuscin

- neuron processes form out of the cell body during embryonic developement. The plasma membrane of the cell acts as " part of the receptive surface" that recieves information from other neurons.

- most cell bodies are located in the CNS which are protected by the bones of the skull and vertebral column.

CNS www.faqs.org/.../neroussystem.html

Clusters of cell bodies in the CNS are called nuclei and where they lie on the the PNS is called ganglia.

Processes

- extend from cell body on neuron

-found in the brain and spinal cord (CNS)

- The PNS is made up mostly of neuron processes. The processes that are make up of bundles of these armlike extensions are called tracts in the CNS and nerves in the PNS.

spinal tracts www..hbu.edu

www.bifsniff.com

Two Types of Neuron Processes

1.) Dendrites

www.dendrites.org

- are located in motor neurons

- main receptive or input regions

-found in the brain areas, specialize in information collection

-convey incoming messages toward the cell body

2.) Axons

www.users.kcn.com

- initial area the axon arises from is called the axon hillock.

- ranges in length

- any long axon is called a nerve fiber

- occasional branches occur in axon and they are called axon collaterals

www.info.med.yale.edu

- the distal endings of the these branches are called axonal terminals, synaptic knobs or boutons

www.unis.org

- Axons generate nerve impulses and transmits them. When impulse reach the axon terminals it causes neurotransmitters to signal chemicals stored in vesicles and releases them into extracellular space.

- neurotransmitters excite or inhibit neurons (or effector cells)

Neurons grouped according to the # of processes

www.faculty.washington .edu

- three or more processes

- most common 99% of neurons belong to this class

- major neuron type of the CNS

- has two processes, an axon and a dendrite

- very rare, found in some special

sense organs such as the retina and olfactory mucousa.

- has a single short process that comes out of the cell body and splits into proximal and distal branches

- found chiefly in ganglia in the PNS where they function as sensory neurons.

The Vertebral Column

www.fotosearch.com

- formed by 26 irregular bones

-serves as axial support of the trunk surrounds and protects the spinal cord and provides attachment points for the ribs and muscles of the back and neck.

- extends from the skull to the pelvis

- consists of 33 vertebrae

www.evolution.com

Five Major Sections

1.) seven vertebrae of the neck are called called cervical vertebrae.

2.) The next 12 are called the thoracic vertebrae

3.) the 5 supporting the lower back are the lumbar

4.) inferior to the lumbar is the sacrum, 5 fused vertebrae

5.) and last is the coccyx which has four fused vertebra

Vertebrae www.courses.vcu.edu

- vertabral column held together by straplike ligaments and trunk muscles

- the major supporting ligaments are called the anterior and posterior longitudinal ligaments

a.) runs down the neck to the sacrum(front & back surfaces of spine)

b.) has a supporting role, prevents prextension of the spine

c.) attaches to the disc

Intevertebral Discs Composed of Two Parts

1.)nucleus pulposus-gives disc elasticity and compressibility

2.) annulus fiberosus- limits expansion of the nucleus pulposus, holds together vertebrae and resists tension of the spine.

All Vertebrae Have A Common Structeral Pattern

- consists of a body or centrum anteriorly and a vertebral arch posteriorly. Arch is a structure formed by two pedicles and two laminae

a.) pedicles- short bony pillars that project from the ventral body

b.)laminae- flattened plates that fuse the median plate, completes the arch

1b.) spinous process- median posterioir projection arising from junction of laminae.

c.) transverse process- extends laterally from each side of the vertebral arch

- disc shaped and vertebral arch form vertebral foramen

- succesive vertebral foramina of the articulated vertebrae form the vertebral canal which the spinal cord passes through

www.instruct.uwo.ca

- Spinous and transverse processes attach muscles that move the vertebral column and for ligaments that stabalize it.

-superioir and inferioir processes stick out superiorly and inferioirly

- pedicles have notches on their superior & inferior borders, making openings between adjacent vertebrae called intervertebral foramina. Spinal nerves coming out of spinal cord pass through these foramae

Epithilial and Connective Tissues, Oh My!

2006-02-06T13:53:00.000-08:00

Epithelial Tissues

Some of the tissues that you see are all epithelial tissues. These cells cover a body surface or lines a body cavity. Epithelium functions include protection, absorption, filtration, excretion, secretion, and sensory reception. Epithelium have distinctive trademarks that segregate them from other tissue types. The epithelial tissue consists of close packed cells. Epithelial cells fit together to form continuous sheets. All epithelia have an apical surface, basal layer, and basal lamina. Although some apical surfaces are smooth, most have microvilli. All epithelial are supported by connective tissue which have a reticular lamina and a basement membrane. There are two different kinds of epithelia such as the simple epithelia and stratified epithelia. The simple epithelia consists of a single cell layer. The stratified epithelia are composed of two or more cell layers.
(images from biology.ucok.edu)

Simple Squamous Epithelium

(image to upper left is from udel.com)

This type of epithelium consists of a single layer of flattened cells with disc shaped nucleus and hardly any cytoplasm. The purpose of this epithelia is to allow the pathway of materials by diffusion and filtration in areas where security is not important. Another function is to secrete lubricating substances into the serosae. The simple squamous epithelium is located in the kidney glomeruli; air sacs of the lungs; lining of the heart, blood vessels, and lymphatic vessels; lining of ventral body cavity.

Simple Cuboidal Epithelium

This epithelium is made up of a single layer of cubelike cells with large, spherical central nuclei. The purpose of this epithelium is to secrete and absorb and it is located in kidney tubules; ducts and secretory parts of small glands. It is also found on the ovary surface.

Simple Columnar Epithelium

Simple Columnar epithelium is made up of a single layer of tall cells with round to oval nuclei; some cells bear cilia; the layer may contain mucos secreting unicellular glands (goblet cells). Goblet cells secrete a protective lubricating mucus and are named for their goblet shaped "cups" of mucus that occupy most of the apical cell volume. The simple columnars purpose is absorption; secretion of mucus, enzymes, and other substances. The ciliated type propels mucus by cilliary action. The noncilliated type lines a good portion of the digestive tract, gallbladder, and excretory ducts of some glands. The cilliated type lines small bronchi, uterine tubes, and some regions of the uterus.

Pseudostratified Columnar Epithelium

This type of epithelium is a single layer of cells that have contrastive heights, some do not reach the free surface. The nucleus of this epithelium is seen at differing levels and may contain goblet cells and have cillia. The purpose of this epithelium is secretion, mostly mucus and to propel this mucus by cilliary action. The noncilliated type of pseudostratified columnar are located in male sperm carrying ducts and ducts of large glands. The ciliated type of epithelium are located in the trachea and most of the upper respitory tract.

Stratified squamous epithelium

This type of epithelium is made up of several cell layers. It's free surface is made up of squamous cells, and cells within the deeper layers are made up of cuboidal or columnar cells. The purpose of this type of epithelium is protection. It protects underlying tissues in areas subjected to abrasion. This epithelium is found in areas subjected to wear and tear and are easily regenerated in areas such as esophogus, mouth, and vagina (nonkeratinized). Keratinized areas forms the epidermis of the skin. Keratin is a tough protective protein.
Stratified Cuboidal and Columnar Epithelium
(left to right

The Stratified cuboidal epithelium is very seldom in the body and it is found in some of the larger glands such as sweat glands and mammory glands. Where you can find these type of epithelia there are usually two layers of cuboidal cells. The stratified columnar epithelium also has a reserved abundance in the body. There is small amounts that are found in the pharynx, the male urethra, and lining some glandular ducts. This epithelium appears to be seen in sites or junctions between two other types of epithelia.

Transitional Epithelium

This form of epithelium forms the lining of hollow urinary organs, which stretch as they fill with urine. This epithelium resembles both stratified squamous and stratified cuboidal; basal cells are cuboidal or columnar; surface cells are squamous like, depending on the degree of the organ stretch.

Glandular Epithelium

A gland consists of one or more cells that make and secrete a certain product. This product is called secretion which can refer to the glands product and the process of making and releasing the product. Glands are categorized as endocrine ("internally secreting") or exocrine ("externally secreting") depending where they release their product, and as unicellular or multicellular based on the cell number making up the gland.

Endocrine Glands

Endocrine glands are sometimes called ductless glands because they eventually lose their ducts. Endocrine glands secrete hormones that through certain processes go into the extracellular matrix. The hormones then travel to the blood or lymphatic fluid and go to specific organs. Each hormone signals its specific organ to respond in some characteristic way." Endocrine glands are structerally diverse, so one description does not fit all". Their secretions also vary in substance(s). Not all endocrine glands are all epithelial based, chapter 16 talks more about this differentiation of structure and function.

Exocrine Glands

Exocrine glands are alot more abundant than endocrine glands, and their products are similier. All exocrine glands secrete their materials onto body surfaces or into body cavities. Exocrine glands are located where you have mucus, sweat, oil, and salivary glands, the liver, the pancreas, and many more.
(image from www.city.ac.uk/Tissue/Tissue1_2003.html)

Unicellular Exocrine Gland Image from www.fofweb.com
The only significant example of a unicellular gland is the goblet cell.

Goblet cells are scattered in the epithelial lining of the intestinal and respitory tracts. In humans, all of the glands produce mucin. Mucin is a complex glycoprotein that dissolves in water when secreted. When it has dissolved, mucin forms mucus. Mucus protects and lubricates surfaces.

Multicellular Exocrine Glands

( Image from sacs.vetmed.ufl.edu)

Multicellular exocrine glands are fundamentally more perplexing than unicellular glands. They have two primary parts: an epithelium derived duct and a secretory unit made up of secretory cells. Connective tissue surrounds the secretory unit and supplies it with blood vessels and nerve fibers, and makes up a fiberous capsule which reaches into the gland proper and divides the gland into lobes. Multicellular glands are either simple or compound glands according to their duct structure. Simple glands have unbranched ducts, and compound glands have a branched duct. These glands are broken down a little bit more into secretory units which are tubular , alveolar, and tubuloalveolar. Tubular is if the secretory cells form tubes. Alveolar is if the secretory cells form small flasklike sacs. Tubuloalveolar is if they have both types of secretory units. There are also different ways of secreting substances and they are also labeled or described by function. Merocrine glands are located in the pancreas, most sweat glands, and salivary glands belong to this class. Holocrine glands aggregate their product within them until they rupture. Sebaceous glands (oil) of the skin is a prime example of holocrine. Apocrine glands accumulate their product, only beneath the free surface. The apex of the cell eventually pinches off and releases secretory granules and a tiny bit of cytoplasm. The cell at this point repairs its damage and begins this cycle again.
Connective Tissues

The four main classes of connective tissue

1.) Connective tissue proper

2.) Cartilage

3.) Bone tissue

4.) blood

Common Characteristics

1.) Common origin- all connective tissues are derived from mesenchyme

2.) Degrees of vascularity- connective tissues run the whole realm of vascularity

3.) Extracellular matrix- the matrix is capable of withstanding weight, great tension, and endure abuses that no other tissue would be able to endure.

Structeral Components of Connective Tissue

1.) Ground substance- fills spaces between cells and contains fibers. It is made up of cell adhesion protiens, and proteoglycans which serve primarily as a connective tissue glue that allows connective tissue cells to attach themselves to matrix elements. The ground substance holds alot of fluids and where nutrients and other dissolved substances can diffuse between blood capillaries and cells.

2.) Fibers- provide support. There are three different types of fibers

a.)Collagen fibers- these fibers are extremely tough and provide a high degree of strength (also called white fibers)

b.) Elastic fibers- contain elastin which enables them to stretch and recoil. Elastic fibers are found in the skin, lungs, and blood vessel walls. (also called yellow fibers)

c.) Reticular fibers- surrounds small blood vessels and support soft tissue of organs. In the basement membrane of epithelial tissues, and around capillaries there is a more abundant supply because it allows more give than larger collagen fibers.
Each major Class of Connective Tissue Has a cell Type

1.) Connective Tissue Proper/ Fibroblast

2.) Cartilage/Chondroblast

3.) Bone/Osteoblast

4.) Blood/ Hematopoietic stem cell

Embryonic Connective Tissue: Mesenchyme

image diagram from connection.lww.comimage fromwww.udel.edu

Mesenchyme is the first evident tissue formed from the mesoderm germ layer. It arises in the earliest weeks of embryonic development and eventually it specializes in making up connective tissues. Mucous connective tissue is derived from mesenchyme, it supports the umbilical cord of the fetus.

Connective Tissue Proper

Subclasses

1.)Loose Connective Tissue

2.) Dense Connective Tissue

Connective Tissue Proper; loose connective tissue, areolar

image from home.mc.ntu.edu.tw

This type of tissue has a gel like matrix with all three fiber types. The cells that make up this tissue are fibroblasts, macrophages, mast cells, and some white blood cells. The function of this tissue type is to wrap and cushion organs. Its macrophages eat up bacteria. Playing an important role in inflammation it holds and conveys tissue fluid. Areolar is widely scattered under the epithelia. It packages organs, forms the lamina propria of mucous membranes, and surrounds capillaries.

Connective Tissue Proper: loose connective tissue, adipose

image from science.EJC.edu

Adipose tissue is dominately made up of adipocytes which are fat cells. This tissue has a nucleus but it is pushed to the side by large fat droplets. Adipose tissue is very vascularized. Adipose tissue usually builds up in subcutaneous tissue, where it also acts as a shock absorber and insulation(prevents heat loss in the body). Other sites where there is a build up of fat are areas such as surrounding the kidneys, behind eyeballs, abdomen and hips. This adipose is sometimes called white fat. Adipose tissue is also refered to as brown fat , the difference is white fat stores certain nutrients and brown fat uses the nutrients to generate heat to warm the body.

Connective Tissue Proper:loose connective tissue, reticular

image from erl.pathology.iupui.edu

This tissue type is said to resemble areolar tissue(personally I don't see the great similarity), but anywho the only fibers in its matrix are reticular fibers, which form a delicate network along which reticular cells lie scattered. Reticular fibers are formed in the lymphoid organs (lymph nodes, bone marrow, and spleen.

Connective Tissue Proper;Dense Connective Tissue, dense regular

image from www.lima.ohio-state.edu/academics/biology

This tissue type attaches muscles to bones or to muscles, attaches bones to bones. This tissue is tough against stress when it is pulled and great force is applied in one direction. Dense regular is located on tendons, most ligaments, and aponeuroses. This tissue contains closely packed bundles of collagen fibers running in one direction. Between collagen fibers there are rows of fibroblasts that are always making fibers and sufficient ground substance. This tissue type is poorly vascularized.

Connective Tissue Proper: dense connective tissue, dense irregular

image from www.mnhe.com

In reading about this tissue type it is to my understanding that the bundles of collagen fibers are much more thick and they are arranged irregularly. This tissue type is located in the body where you would have great tension applied in all directions like the dermis of your skin, the submucousa of your digestive tract, and in fiberous capsules of organs or joints.

Cartilage

Hyaline Cartilage

image from www.montgomerycollege.edu
Hyaline cartilage supports and reinforces, has expansive cushioning properties, and resists compressive stress. "This type of cartilage forms most of the embryonic skeleton; covers the ends of long bones in the joint cavities; forms costal cartilages of the ribs; cartilages of the ribs; cartilages of the nose, trachea, and larnyx". This tissue type contains a large amount of collagen fibers, although you cannot see them that well and the matrix appears to be "glassy".

Cartilage: elastic

Elastic cartilage is similier to hyaline cartilage but it contains more elastic fibers in the matrix. Elastic cartilage forms the skeleton of the ear and epiglottis. This particular cartilage maintains the shape of a structure while allowing great flexibility.

Cartilage Fibrocartilage image from science.tjc.edu

This type of cartilage is found where hyaline cartilage meets a true ligament or tendon. This type of cartilage has rows of chondrocytes that which alternate with rows of thick collagen fibers. This cartilage type is found in between intervertbral discs; pubic symphysis; and at the discs of the knee joints. Being able to succumb compressive shock.

Others: Bone

image from www.mc.maricopa.edu

Bone is made up of calcified matrix containing many collagen fibers. Mature bone cells are called osteocytes and they reside within the lacunae within the matrix. Bone supports and protects, provides levers for muscles, stores calcium and other minerals and fat. Marrow inside of the bone is the primary area for blood cell formation.

Others:blood

image from www.hoxworth.org

Blood is classified as a connective tissue because it is derived from mesenchyme and consists of blood cells. Blood transports nutrients, respitory gases, wastes and other substances throughout the body within blood vessels.

Courtney's Second Wind
1.)Courtney Allard

2.)born in Fall River MA on February 7,1982, raised in Somerset

3.)I like Joe, Patsy Cline, it depends on what mood I am in.

4.)I live with my fiancee, if I could go back I would be living at home with my parents while I went to school. I have a interesting biological family that I have known for five years now and I have an adoptive family who I love to death.(My view on the whole parent situation it is not who gave birth to you, it is the people that raise you and put up with all your crap, anyone can make babies.

5.)I am here at B.C.C to try to get into the nursing program.

6.) I work for a company called People Incorporated. You might have had Bob Canuel as an instructer here at B.C.C, he is the CEO and President of our company.(he has made alot of great changes!) I am a house manager in one of our houses in residential services. If anyone is looking for a job this is a great job to have while you are going through college or if you wish to further your career in Human Resources. If you have any questions please feel free to contact me by email at callard11@mail.bristol.mass.edu

posted by Courtney Allard @ 2:01 PM 0 comments

How The Little things Really Do Matter

2006-01-30T18:58:00.000-08:00

The Miracle of Life

where it all began

As I sit here and reflect about how life begins, it just simply blows my mind. Life is such complicated but precious gift that is given to us. The thing that makes life so appreciative is the complexity of being existant. Our bodies are machines that have to keep us at a balanced level(homeostasis) so that we can live. Within our bodies we have more little machines that have their each individual tasks and responsibilities. Do you know how we repay our bodies for all the hard work they do? We poison them and abuse them by smoking, drinking, drugging, we pollute our environments with toxic wastes in our waters, we build factory's and pollute the air that we breath with chemicals, and give each other diseases. I could go on and on with oodles of things we do that harm ourselves and others. It's amazing how our bodies are built to defeat those everyday things that we may come in contact with. Our bodies can only take so much abuse and thats when things go wrong with it and we may find our selves sick or even in the hospital. Appreciation of our own life and our bodies is important before bringing another individual into this world. In my readings I have come to the realization that I need to start off by changing the way I live. I want to live a long and happy life.

The preliminary stage of the structural formula of life begins with atoms. Atoms are the foundation of matter from which molecules are derived. Molecules in turn combine to form organelles. Organelles are the essential ingredient of the microscopic cell.

Each cell in the human body has it's own purpose and importance to every subdivision of our body. The creatures that we are is marvelous because the heiarchy does not stop here, it continues to a level called the tissue level. The tissue level has four component tissue types that make up the human being and they are epithilium, muscle, connective tissue and nervous tissue.

(from left to right: epithilium, connective tissue, muscle, and nervous tissue.HEHE!)

Each of these four tissue types has an essential attribute to the human body. An organ is a diverse structure that is made up of at least two tissue types.

Ladies and Gentlemen We have An Organ!

Four different tissue types is a more commonplace that performs a specific function for the body. (Did I just say four!Just kidding, I couldn't find anymore tissues.) The liver, the brain, bloodvessels, and the brain are all organs that we have and they are very special because each individual organ can carry out tasks that no other organ can. All of our organs put together is called our organ system. The Cardiovascular system, integumentary, skeletal,muscular, nervous,endo crine, respiratory, digestive, lymphatic, urinary, and reproductive system are all organ systems that make up our body.

When our Organ systems work together as one unit it has formed a living human being and this is called the organismal level.

Fetal Developement

The embryonic membranes that form during the first two to three weeks of developement are the amnion, yolk sac, allantois, and chronion. The amnion becomes a sac that fills with fluid. As the embryonic disc curves to form the tubuler body, the amonion curves with it. Ultimately, the sac developes all the way around the embryo, broken only by the umbillical cord. The amniotic sac protects the embryo against trauma, and keeps a homeostatic temperature. The fluid within the sac prevents fastly growing parts from fusing. The yolk sac hangs from the embryo and forms part of the gut, produces blood cells and blood vessels and is the place of primordial germ cells that travel into the emryos body to seed the gonads. The allantois forms on the outside of the yolk sac to dispose of excreta. The allantois in humans is the foundation for the umbilical cord that connects the embryo to the placenta. The fully developed umbilical cord embraces a root of embryonic tissue, the umbilical arteries and vein, and is surrounded by amniotic membrane. Pending week 3 the two layered embryonic disc becomes a three layered embryo in which the primary germ layers form. The layers consist of the ectoderm, mesoderm, and endoderm, this process is called granulation. Granualation arises when a raised notch appears on the the dorsal side of the embryonic disc and activates the axis of the embryo, this is called the primitive streak. Cells that are on the surface of the embryonic disc and travel and enter the groove of the primary germ layer, the endoderm. The cells that form on the upper and the lower surfaces are called the surfaces. The cells that stay on the embryos dorsal surface are the ectoderm. The cells from the mesoderm beneath the primitive streak accumulate forming a rod od mesodermal cells called the notochord. This is the first axial support of the embryo. The three original germ layers promote as the primitive tissues fom which all body organs will develop. The ectoderm the "outer skin" accommodates architecture of the nervous system and the skin epidermis. The endoderm the "inner skin" is the framework for the epithelial linings of the digestive, respiratory, and urogential systems, and coinciding glands. The mesoderm is the middle skin that outlines fundamentally everything else. Both ectoderm and the endoderm incorporate mostly of cells that are solidly connected to each other and are said to be epithelia. Gastrulation outlines the primary foundation of the embryo and establishes the moment for the preparation of organogenesis which is the composition of body organs and organ systems. At the conclusion of the embryonic period all the adult organ setup. The primary supreme episode in organogenesis is neurulation which is the contrast of ectoderm that procreates the brain and the spinal cord. this operation is induced by chemical signals from notochord, the rod of the mesoderm thatnspecifies the body axis. The ectoderm overlying the notochord thickens and forms the neural plate, and then begins to flexture innate as a neural groove, which designs neural folds. The predominant compass of the neural folds bind together and a neural tube, but it shortly falls off into the body. At the top of the neural tube it becomes the brain and the excess evolves into the spinal cord. The allied neural crest cells travel and develop the cranial, spinal, and sympathetic ganglia, to the medulla of the adrenal gland, and give away to various connective tissue. At the consummation of the first month of developement the three primary brain vesicles and are apparent. At the conclusion of the second month the cerebral hemispheres cover the top of the brain stem and all brain inclinations are obvious. Uttermost the existing ectoderm combining the surface layer of the embryonic body seperates into the epidermis. The embryo grows and folds into a cylindrical shape. In the process of the embryo growing the endoderm gas formed a tube, this is called the primitive gut. The primitive gut forms the the epithilial lining of the gastrointestinal tract. The organs of the GI tract, and oral and anal openings perforate. The pharyngeal endoderm forms the thyroid, parathyroids, and thymus. The liver and the pancreas derive from intestinal mucosa. The endoderm forms the epithilium of the mucosal lining of the hollow organs of the digestive and respiratory tracts. The mesodermal distinction is the manifestation of the notochord in the embryonic disc. Three mesodermal aggregates appear on either side of the notochord. Mesodermal blocks embrace the notochord. Small clusters of mesoderm which are called somites double into sheets of lateral mesoderm. Somites have three working parts and they are sclerotome, dermatome, and myotome. The sclerotome produces the vertebre and rib at a certain level. Dermatome forms the skin and the dorsal part of the body. The myotome forms the skeletal muscles of the kneck , body trunk, and the muscles of the limbs. The intermediate mesoderm forms the gonads and kidneys. The lateral mesoderm plates: the somatic mesoderm and the splanchnic mesoderm. Somatic mesoderm help to form the skin in the ventral body region. Mesenchymal cells contribute to the heart and blood vessels and most connective tissues. Splanchnic mesodermal cells form smooth muscle, connective tissues, and serousal coverings.

8 Weeks

At 8 weeks at the end of embryonic developement the head is nearly as large as the body. At this point all major brain regions are present and the first brain waves in the brainstem.The liver is excessivly large and begins to form blood cells. At this stage there are limbs are present, fingers and toes are developed. The process of ossification has began and muscle contraction have started to occur. The cardiovascular system at this point is fully functional and has been pumping blood since the fourth week.

9-12 week

At this point the head is still dominent, the body is still enlarging, the brain continues to grow, the spinal cord grows, and the retina in the eye is existant. Facial characteristics are showing, epidermis and dermis are visible. The liver is pronounced, the palate is fusing, endodermal glands are fully matured. Visceral organs have developed smooth muscle. The blood cell composition has begun in bone marrow. Notochord deteriation and ossification speeds up, all limbs are bonded. The sex of the baby is ready to be determined.

13-16 weeks

At this point of developement the cerebellum is becoming unmistakable, common sensory organs are distinguished, eyes and ears acquire there distinctive position and shape, motor functions such as blinking and sucking movement of lips happen. The face begins to looks human and the head begins to develop outward. At this time meconium is gathering, and GI tract has reached the point of full maturity. The kidneys have achieved conventional hierachy. Ultimately bones are now obvious and joint cavities are noticeable

17-20 weeks

The vernix caseosa is covering the body at this brink of developement, the fetal position has been taken because of space circumference. The limbs on the fetus are reaching concluding dimensions. Significance occurs when the mother of baby can feel unpremediated muscular activity of the fetus.

21-30 weeks

This is the duration of abundant cumulation in weight. The myelination of cord begins and the fetuses eyes are unsealed. Distal limb bones have begun to ossify. The fetuses skin is wrinkled and red; fingernails and toenails exist tooth enamel is evolving on the primary tooth. The body is lean and and is appropriately symmetrical. The bone marrow is now a key site for for blood cell developement. The scrotum is fully matured in males.

30-40 weeks

At the final stage of development the skin is a whitish pink, fat laid down in subcutaneous tissue

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2006-01-26T17:04:00.000-08:00