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 levels of organizationof organization::

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

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

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

Lets look at tissues first...Lets look at tissues first...

four major types of tissues in the human four major types of tissues in the human body:body:

EPITHELIALEPITHELIAL:: covers body surfaces and covers body surfaces and lines body cavitieslines body cavities

CONNECTIVECONNECTIVE:: binds and supports body partsbinds and supports body parts MUSCULARMUSCULAR:: causes parts to movecauses parts to move NERVOUSNERVOUS:: responds to stimuli and responds to stimuli and

transmits impulses from one body part to transmits impulses from one body part to anotheranother

EPITHELIAL TISSUES: EPITHELIAL TISSUES: covers body, lines cavitiescovers body, lines cavities

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

Types:Types:

1.1. Squamous Squamous EpitheliumEpithelium: : Function in Function in protection, protection, diffusion, filtration. diffusion, filtration. Made of Made of flatflat cells cells. . Lines Lines alveolialveoli and and walls of walls of capillariescapillaries, , 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 microvillimicrovilli or or ciliacilia to aid to aid function. e.g. lining of function. e.g. lining of intestine, oviduct lining, intestine, oviduct lining, lining of uterus.lining of uterus.

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

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

PSEUDOSTRATIFIED COLUMNAR

Simple SquamousSimple Squamous

Function Function

Filtration, Filtration, diffusion, osmosisdiffusion, osmosis

Location Location

Oral cavity, Oral cavity, lining of blood lining of blood vesselsvessels

Simple CuboidalSimple Cuboidal

FunctionFunction

Secretion, Secretion, absorptionabsorption

LocationLocation

Surface of Surface of ovaries, linings ovaries, linings of kidney of kidney tubulestubules

Simple ColumnarSimple Columnar

FunctionFunctionProtection, Protection, secretion, secretion, absorptionabsorption

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

Pseudostratified ColumnarPseudostratified Columnar FunctionFunction

Protection, Protection, secretion, secretion, movement of movement of mucus and mucus and sex cellssex cells

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

Stratified SquamousStratified Squamous

FunctionFunction

ProtectionProtection

LocationLocation

Outer 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 fill up spacesspaces

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 found between cells) usually made cells) usually made up of either up of 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 tissues, hold organs in place, fat organs in place, fat storagestorage

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 ligamentsligaments (connect bones to (connect bones to other joints.other joints.

CartilageCartilage

has flexible has flexible matrix rich matrix rich in protein in protein and fibers. and fibers. e.g. nose, e.g. nose, ears, 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 liquidliquid called called plasmaplasma..

Muscle Tissue: Contracts Muscle Tissue: Contracts for Movementfor Movement

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

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

Skeletal MuscleStriated, Voluntary

Smooth Musclenon-striated, Involuntary

Cardiac MuscleStriated, Involuntary

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

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

CARDIAC MUSCLECARDIAC MUSCLE: : striatedstriated, , involuntaryinvoluntary, forms , forms heart muscleheart muscle. . Found only in the heart. Can Found only in the heart. Can contract quickly, and beats your contract quickly, and beats your whole life through.whole life 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 conduct electrical & chemical messages along special cells called messages along special cells called neurons. Composed of neurons. 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 axons and dendrites are nerve fibers. Bundles of nerve fibers are fibers. Bundles of nerve fibers are called 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 : a single cell, or a collection of cells that cells that secretesecrete something something

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

ii.ii. EndocrineEndocrine glandsglands: secrete : secrete chemicals (especially chemicals (especially hormoneshormones) into ) into bloodstreambloodstream (e.g. pituitary gland, (e.g. pituitary gland, pancreas secretes insulin into the blood).pancreas secretes insulin into 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. protect, and nourish nerve cells. They provide nutrients to the They provide nutrients to the neurons and help keep the tissue neurons and help keep the tissue free of debris.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 tissuestypes of tissues (usually (usually more).more).

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

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

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

stratified squamous epithelialstratified 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 produce here produce melaninmelanin, , responsible for responsible for skin colourskin colour. . Keratin proteinKeratin protein hardens skin hardens skin cells. (cells. (Hair & nailsHair & nails are made of are made of tightly packed keratinized cells).tightly packed keratinized cells).

DermisDermis: : middle layermiddle layer. . Loose Loose connective tissueconnective tissue with many with many elasticelastic fibersfibers. . Sweat glandsSweat glands, , nerve endings, blood vessels, nerve endings, blood vessels, and and hair follicleshair follicles 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 specific functions. (e.g. digestive system).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 organ systems contribute to maintaining a stable internal environment a 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