Human Body OrganizationHuman Body Organization

By Mr. By Mr. CarmichaelCarmichael

Levels of OrganizationLevels of Organization

The human body has several The human body has several levels of levels of organizationorganization ::

Cells of the same type joined together are Cells of the same type joined together are called called TISSUESTISSUES

Different Tissues are joined together to Different Tissues are joined together to form form ORGANSORGANS

Various organs are arranged into an Various organs are arranged into an ORGAN SYSTEMORGAN SYSTEM

Lets look at t issues f irst...Lets look at t issues f irst...

four major types of tissues in the human body:four major types of tissues in the human body: EPITHELIALEPITHELIAL :: covers body surfaces and covers body surfaces and

lines body cavitieslines body cavities CONNECTIVECONNECTIVE :: binds and supports body binds and supports body

partsparts MUSCULARMUSCULAR :: causes parts to movecauses parts to move NERVOUSNERVOUS:: responds to stimuli and transmits responds to stimuli and transmits

impulses from one body part to anotherimpulses from one body part to another

EPITHELIAL TISSUES: EPITHELIAL TISSUES: covers body, l ines cavit iescovers body, l ines cavit ies

covers entire body covers entire body surface and most of the surface and most of the body's inner cavities.body's inner cavities.

outer epidermis (skin) outer epidermis (skin) protects from injuryprotects from injury and and drying outdrying out

inner epidermal tissue, on inner epidermal tissue, on internal surfaces protects, internal surfaces protects, secretes mucus (e.g. secretes mucus (e.g. along digestive tract)along digestive tract)

Types:Types:

1.1. Squamous Squamous EpitheliumEpithelium : : Function in protection, Function in protection, diffusion, filtration. diffusion, filtration. Made of Made of f latf lat cells cells . . Lines Lines alveolialveoli and and walls of walls of capil lariescapil laries , , blood vesselsblood vessels ..

Capillary Structure

Cuboid EpitheliumCuboid Epithelium

function in function in secretionsecretion and and absorptionabsorption , , protectionprotection . . cubecube shaped cells. e.g. shaped cells. e.g. line kidney tubules, line kidney tubules, surface of ovaries.surface of ovaries.

Lining of Kidney

Columnar EpitheliumColumnar Epithelium column-shaped. Often have column-shaped. Often have

microvi l l imicrovi l l i or or ci l iacil ia to aid to aid function. e.g. lining of function. e.g. lining of intestine, oviduct lining, lining intestine, oviduct lining, lining of uterus.of uterus.

Each type can exist as a single Each type can exist as a single layer or be layer or be stratif iedstratif ied (layers (layers stacked on top of each other). stacked on top of each other). e.g. mouth, nose, vagina lined e.g. mouth, nose, vagina lined by stratified squamous by stratified squamous epithelium.epithelium.

Pseudostratif ied Pseudostratif ied ColumnarColumnar : appear to be : appear to be layered but is really just one layered but is really just one layer of cells. e.g. lining of layer of cells. e.g. lining of respiratory tract.respiratory tract.

PSEUDOSTRATIFIED COLUMNAR

Simple SquamousSimple Squamous

Function Function Filtration, Filtration,

diffusion, osmosisdiffusion, osmosis

Location Location Oral cavity, lining Oral cavity, lining

of blood vesselsof blood vessels

Simple CuboidalSimple Cuboidal

FunctionFunctionSecretion, Secretion, absorptionabsorption

LocationLocationSurface of Surface of ovaries, linings of ovaries, linings of kidney tubuleskidney tubules

Simple ColumnarSimple Columnar

FunctionFunctionProtection, Protection, secretion, secretion, absorptionabsorption

LocationLocationLining of Lining of Uterus, tubes Uterus, tubes of the digestive of the digestive tracttract

Pseudostratified ColumnarPseudostratified Columnar FunctionFunction

Protection, Protection, secretion, secretion, movement of movement of mucus and sex mucus and sex cellscells

LocationLocationLinings of Linings of respiratory respiratory passages, passages, various tubes various tubes of the of the reproductive reproductive systemssystems

Stratified SquamousStratified Squamous

FunctionFunctionProtectionProtection

LocationLocationOuter layers Outer layers of skin, of skin, vagina, and vagina, and anal canalanal canal

CONNECTIVE TISSUECONNECTIVE TISSUE : connects : connects

organsorgans FunctionsFunctions bind bind

structures structures togethertogether

fill up spacesfill up spaces provide provide

support and support and protectionprotection

store fatstore fat

StructureStructure

cells in connective cells in connective tissue usually in tissue usually in MATRIXMATRIX (a (a non-non-cellularcellular material material found between cells) found between cells) usually made up of usually made up of either either collagencollagen or or elastinelastin ..

Cell withinMatrix

ElastinFiber

CollagenFiber

Structure of Loose Connective Tissue

Types of Connective Tissue:Types of Connective Tissue:

1.1. LooseLoose : join : join tissues, hold organs tissues, hold organs in place, fat storagein place, fat storage

FibrousFibrous

bundles of bundles of collagencollagen fibers, fibers, very strongvery strong . . Used in Used in tendonstendons (connect muscle to (connect muscle to bone) and bone) and l igamentsligaments (connect bones to (connect bones to other joints.other joints.

Carti lageCarti lage

has flexible has flexible matrix rich in matrix rich in protein and protein and fibers. e.g. fibers. e.g. nose, ears, nose, ears, vertebrae, vertebrae, ends of ends of bones.bones.

BoneBone ::

rigid connective rigid connective tissue. Matrix of tissue. Matrix of calcium salts.calcium salts.

BloodBlood

5.5. : matrix is : matrix is l iquidliquid called called plasmaplasma ..

Muscle Tissue: Contracts for Muscle Tissue: Contracts for MovementMovement

muscle tissue is composed of fibers made muscle tissue is composed of fibers made of of actinactin and and myosinmyosin proteins (among proteins (among other “helper” proteins) whose interaction other “helper” proteins) whose interaction is responsible for is responsible for movementmovement ..

There are 3 Distinct Types:There are 3 Distinct Types:

Skeletal MuscleStriated, Voluntary

Smooth Musclenon-striated, Involuntary

Cardiac MuscleStriated, Involuntary

SKELETAL MUSCLESKELETAL MUSCLE : : str iatedstriated (alternating light and dark bands) (alternating light and dark bands) attached to bones, used for movement, attached to bones, used for movement, voluntary controlvoluntary control . Can contract . Can contract quickly and strongly but will fatigue in quickly and strongly but will fatigue in time.time.

SMOOTH MUSCLESMOOTH MUSCLE : : non-striatednon-striated , , involuntary controlinvoluntary control , found in walls of , found in walls of internal organs, intestine, stomach, blood internal organs, intestine, stomach, blood vessels. Contracts more slowly, but can vessels. Contracts more slowly, but can contract over a longer period of time.contract over a longer period of time.

CARDIAC MUSCLECARDIAC MUSCLE : : striatedstriated , , involuntaryinvoluntary , forms , forms heart muscleheart muscle . . Found only in the heart. Can contract Found only in the heart. Can contract quickly, and beats your whole life quickly, and beats your whole life through.through.

Nervous Tissue: Conduct Nervous Tissue: Conduct Electrochemical MessagesElectrochemical Messages

specialized tissue that forms specialized tissue that forms nervesnerves , , brainbrain , , spinal cordspinal cord

conduct electrical & chemical messages conduct electrical & chemical messages along special cells called neurons. along special cells called neurons. Composed of Composed of cell bodycell body , , dendritesdendrites (conduct messages (conduct messages toto cell body), cell body), axonaxon (send messages (send messages awayaway from cell body). from cell body).

axons and dendrites are nerve fibers. axons and dendrites are nerve fibers. Bundles of nerve fibers are called Bundles of nerve fibers are called nervesnerves ..

Nerves Nerves conduct messagesconduct messages to and to and from spinal cord, brain, and sense from spinal cord, brain, and sense organs to register organs to register sensationsensation and and trigger muscle movementtrigger muscle movement ..

Cell BodyAxon

Dendrite

Synaptic Endings

Structure of a Neuron (in this case, a motor neuron)

What are Glands?What are Glands?

GlandGland : a single cell, or a collection of cells that : a single cell, or a collection of cells that secretesecrete something something

i .i . Exocrine glandsExocrine glands : secrete into : secrete into ductsducts . e.g. . e.g. the gall bladder is an exocrine gland because it the gall bladder is an exocrine gland because it secretes bile in a duct. Sweat glands are secretes bile in a duct. Sweat glands are exocrine glands.exocrine glands.

i i .i i . EndocrineEndocrine glandsglands : secrete chemicals : secrete chemicals (especially (especially hormoneshormones ) into ) into bloodstreambloodstream (e.g. (e.g. pituitary gland, pancreas secretes insulin into pituitary gland, pancreas secretes insulin into the blood).the blood).

GLIALGLIAL cells are cells that surround cells are cells that surround nerve cells. They help to support, nerve cells. They help to support, protect, and nourish nerve cells. They protect, and nourish nerve cells. They provide nutrients to the neurons and help provide nutrients to the neurons and help keep the tissue free of debris.keep the tissue free of debris.

ORGANS: Tissues working ORGANS: Tissues working togethertogether

organs (e.g. the heart) are organs (e.g. the heart) are made up of made up of one or more one or more types of t issuestypes of t issues (usually (usually more).more).

SKINSKIN is also an example of an is also an example of an organ. It is your largest organ, organ. It is your largest organ, and has several tissue layers.and has several tissue layers.

Skin Skin coverscovers body surfaces, body surfaces, gives gives protectionprotection from water from water loss and invasion by loss and invasion by microorganisms, contains microorganisms, contains sense organssense organs , helps to , helps to regulate body temperature Skin regulate body temperature Skin is made up of is made up of Three LayersThree Layers ..

EpidermisEpidermis : is : is outer layerouter layer . . Composed of Composed of

stratif ied squamous epithelialstratif ied squamous epithelial cells. cells.

Basal cellsBasal cells at base of this layer at base of this layer produce new cells. produce new cells.

PigmentPigment cells ( cells (melanocytesmelanocytes ) here ) here produce produce melaninmelanin , responsible for , responsible for skin skin colourcolour . . Keratin proteinKeratin protein hardens skin hardens skin cells. (cells. (Hair & nai lsHair & nai ls are made of tightly are made of tightly packed keratinized cells).packed keratinized cells).

DermisDermis : : middle layermiddle layer . . Loose Loose connective t issueconnective t issue with many with many elasticelastic f ibersfibers . . Sweat glandsSweat glands , nerve endings, , nerve endings, blood vessels, and blood vessels, and hair fol l icleshair fol l icles located here.located here.

SubcutaneousSubcutaneous LayerLayer : : bottom bottom layer.layer. Loose connective tissue Loose connective tissue containing adipose cells (fat!)containing adipose cells (fat!)

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Human Organ SystemsHuman Organ Systems

each located in specific location, with each located in specific location, with specific functions. (e.g. digestive system).specific functions. (e.g. digestive system).

many internal organ systems enclosed many internal organ systems enclosed within within coelomcoelom , a cavity within the body., a cavity within the body.

organ systems contribute to maintaining a organ systems contribute to maintaining a stable internal environment stable internal environment ((homeostasishomeostasis ). e.g. Temp, pH, ). e.g. Temp, pH, [glucose], blood pressure.[glucose], blood pressure.

1. Digestive convert food to usable nutrients

2. Circulatory transport of necessary molecules to cells

3. Immune defense against invading pathogens

4. Respiratory gas exchange

5. Excretory gets rid of metabolic wastes

6. Nervous & Sensory regulation and control, response to stimuli, processing information

7. Muscular & Skeletal support and movement

8. Hormonal regulation of internal environment, development

9. Reproductive producing offspring