Chapter 4Chapter 4

Organization of the Organization of the BodyBody

Identify parts of a cell and the specialized Identify parts of a cell and the specialized functions of tissuesfunctions of tissues

Identify the body systemsIdentify the body systems

Describe the functions of the body system Describe the functions of the body system and how they workand how they work

Define the anatomical positions of the Define the anatomical positions of the body body

List the body cavities and the organs List the body cavities and the organs

Identify nine body regionsIdentify nine body regions

Organization of the Human Organization of the Human BodyBody

The body is organized from the The body is organized from the smallest part to the largest part.smallest part to the largest part.

CELLCELL

-simplest structural unit-simplest structural unit

-basic unit of life-basic unit of life

-smallest unit that can live on its -smallest unit that can live on its ownown

CellCellMany cannot be seen with Many cannot be seen with

the naked eyethe naked eyeA cell may be an entire A cell may be an entire

organism or it may be one organism or it may be one of billions of cells that of billions of cells that make up the organismmake up the organism

TissueTissue

- a group of cells with common origin, - a group of cells with common origin, structure, and function.structure, and function.

- cells within a tissue all work toward a - cells within a tissue all work toward a common goal (i.e.: movement, common goal (i.e.: movement, nutrition, etc.)nutrition, etc.)

OrganOrgan

- a group of tissues that have a - a group of tissues that have a common function.common function.

Structural units of the body:Structural units of the body:Cell:Cell:

Body has million of cells that work Body has million of cells that work together to sustain lifetogether to sustain life

consist of a nucleus surrounded by consist of a nucleus surrounded by cytoplasm cytoplasm

It is the fundamental unit of all living It is the fundamental unit of all living things (basic building block)things (basic building block)

Cells multiply by dividing called Cells multiply by dividing called mitosismitosis

Contd:Contd:

Several types of cells Several types of cells Size and shape of cell relates its functionSize and shape of cell relates its function

Examples of some cells in the body:Examples of some cells in the body:

Muscle cells: contractMuscle cells: contract Nerve: conduct electrical impulsesNerve: conduct electrical impulses Epithelial: skin and liningEpithelial: skin and lining Fat cell: contain empty spaces to Fat cell: contain empty spaces to

store fatstore fat

NucleusNucleus

A spheroid body within a cellA spheroid body within a cell Consists of a thin nuclear membrane Consists of a thin nuclear membrane

and genes and chromosomesand genes and chromosomes Responsible for metabolism, growth Responsible for metabolism, growth

and reproduction and reproduction Control center of the cellControl center of the cell

ChromosomesChromosomes

Thread like structures in the cell Thread like structures in the cell nucleusnucleus

Control growth and repairControl growth and repair Control the reproduction of the bodyControl the reproduction of the body Contain regions of DNA called genesContain regions of DNA called genes There are 23 pairs of chromosomes in There are 23 pairs of chromosomes in

every cell except for the egg and sperm every cell except for the egg and sperm which contain 23 unpaired which contain 23 unpaired chromosomes chromosomes

CytoplasmCytoplasm

The substance between the cell The substance between the cell membrane and the nuclear membrane and the nuclear membranemembrane

Jelly like material that is mostly Jelly like material that is mostly waterwater

It is exclusive to the nucleusIt is exclusive to the nucleus Carries on the work of the cellCarries on the work of the cell

Cell membraneCell membrane

Thin layer of tissue which serves as Thin layer of tissue which serves as the wall of the cellthe wall of the cell

Protects the cellProtects the cell Selectively allows substances to pass Selectively allows substances to pass

in and out of the cellin and out of the cell

Tissues:Tissues: groups of similar groups of similar cells working together to do a cells working together to do a

specific jobspecific job

For example:For example: Muscle tissue contractsMuscle tissue contracts Epithelial tissue forms linings and Epithelial tissue forms linings and

covers i.e. skincovers i.e. skin Connective tissue do just that: fat, Connective tissue do just that: fat,

cartilage, bone and bloodcartilage, bone and blood Nerve tissues conduct impulses all Nerve tissues conduct impulses all

over the bodyover the body

TissueTissueEpithelial tissuesEpithelial tissues

The skin and lining surfacesThe skin and lining surfaces Forms the lining of the internal Forms the lining of the internal

organsorgans It protects, absorbs and excretesIt protects, absorbs and excretes

Connective tissueConnective tissue

The fibrous tissue of the bodyThe fibrous tissue of the body Binds together the various parts and Binds together the various parts and

organs of the bodyorgans of the body Eg: bones , tendons cartilageEg: bones , tendons cartilage

Muscle tissueMuscle tissue

Tissue that contractsTissue that contracts Consist of striated (striped) cardiac Consist of striated (striped) cardiac

and smooth muscleand smooth muscle Voluntary is where the movement is Voluntary is where the movement is

under conscious control such as arms under conscious control such as arms and legsand legs

Involuntary is not under conscious Involuntary is not under conscious control, such as heart and digestive control, such as heart and digestive systemsystem

Nerve TissueNerve Tissue

A collection of nerve fibers that A collection of nerve fibers that conduct impulses that control and conduct impulses that control and coordinate body activitiescoordinate body activities

Organ System Organ System

- a group of organs with a special - a group of organs with a special function.function.

- Digestive System, Nervous System, - Digestive System, Nervous System, etc…etc…

OrganismOrganism

- A group of organ systems that at some - A group of organ systems that at some point in time is capable of sustaining life.point in time is capable of sustaining life.

- All organ systems work together in an - All organ systems work together in an organism.organism.

Organs:Organs: structures composed structures composed of several types of tissueof several types of tissue

o An An organorgan (Latin: (Latin: organumorganum, "instrument, , "instrument, tool") is a group of tissues that perform a tool") is a group of tissues that perform a specific function or group of functions. specific function or group of functions.

o Usually there is a Usually there is a mainmain tissue and tissue and sporadicsporadic tissues. The main tissue is the one that is tissues. The main tissue is the one that is unique for the specific organ. unique for the specific organ.

o For example, main tissue in the heart is For example, main tissue in the heart is the myocardium, while sporadic are the the myocardium, while sporadic are the nervous, blood, connective etc.nervous, blood, connective etc.

Systems:Systems:

A set of body organs that A set of body organs that work together for a work together for a common purposecommon purpose

systemssystems

Integumentary systemIntegumentary system Musculoskeletal systemMusculoskeletal system Cardiovascular systemCardiovascular system Gastrointestinal systemGastrointestinal system Respiratory systemRespiratory system Genitourinary systemGenitourinary system Endocrine system’Endocrine system’ Nervous systemNervous system

Body Cavity:Body Cavity: space within the space within the body that contains internal body that contains internal

organsorgans The human body consists of the following cavities:The human body consists of the following cavities: dorsal body cavity dorsal body cavity

– cranial cavity, enclosed by the Skull and contains the cranial cavity, enclosed by the Skull and contains the brain, eyes, and ears. brain, eyes, and ears.

– spinal canal, enclosed by the spine and contains the spinal canal, enclosed by the spine and contains the spinal cord. spinal cord.

– ventral body cavity ventral body cavity thoracic cavity, enclosed by the ribcage and contains thoracic cavity, enclosed by the ribcage and contains

the lungs and heart. the lungs and heart. abdominopelvic cavity abdominopelvic cavity

– abdominal cavity, enclosed by the ribcage and abdominal cavity, enclosed by the ribcage and pelvis and contains the kidneys, ureters, stomach, pelvis and contains the kidneys, ureters, stomach, intestines, liver, gallbladder, and pancreas./pelvic intestines, liver, gallbladder, and pancreas./pelvic cavity, enclosed by the pelvis and contains cavity, enclosed by the pelvis and contains bladder, anus and reproductive system. bladder, anus and reproductive system.

Body cavities and PlanesBody cavities and Planes

The body has two main large cavitiesThe body has two main large cavities Ventral = front of body includes Ventral = front of body includes

thoracic, abdominal, and pelvic thoracic, abdominal, and pelvic cavitycavity

Dorsal = back of body which includes Dorsal = back of body which includes Cranial and Spinal cavityCranial and Spinal cavity

Anatomical PlanesAnatomical Planes Fixed lines of Fixed lines of

reference along reference along which the body is which the body is often divided or often divided or sectioned to sectioned to facilitate viewing of facilitate viewing of its structuresits structures

Allow one to obtain a Allow one to obtain a three-dimensional three-dimensional perspective by perspective by studying the body studying the body from different viewsfrom different views

SagittalSagittal A plane that divides the body into A plane that divides the body into

right and left portionsright and left portions

MidsagittalMidsagittal A plane that vertically divides the A plane that vertically divides the

body or some part of it, into equal body or some part of it, into equal right and left portionsright and left portions

CoronalCoronal Also called frontal; a plane that Also called frontal; a plane that

divides the body into anterior and divides the body into anterior and posterior sections (front and back)posterior sections (front and back)

TransverseTransverse A plane that divides the body into A plane that divides the body into

superior and inferior sections (top superior and inferior sections (top and bottom)and bottom)

Anatomical Anatomical PositionPosition

Standing erect, with Standing erect, with palms and feet facing palms and feet facing forwardforward

Is the standard Is the standard reference point in which reference point in which all positions, all positions, movements, and planes movements, and planes are describedare described

Positions and Positions and DirectionsDirections

Terms of position Terms of position and direction and direction

describe the position describe the position of one body part of one body part

relative to another, relative to another, usually along one of usually along one of

the three major the three major body planesbody planes

Positions and Positions and DirectionsDirections

SuperiorSuperior Refers to a structure Refers to a structure

being closer to the head being closer to the head or higher than another or higher than another structure in the bodystructure in the body

InferiorInferior Refers to a structure Refers to a structure

being closer to the feet or being closer to the feet or lower than another lower than another structure in the bodystructure in the body

Positions and Positions and DirectionsDirections

AnteriorAnterior Refers to a structure Refers to a structure

being more in front than being more in front than another structure in the another structure in the bodybody

PosteriorPosterior Refers to a structure Refers to a structure

being more in back than being more in back than another structure in the another structure in the bodybody

Positions and Positions and DirectionsDirections

MedialMedial Refers to a structure Refers to a structure

being closer to the being closer to the midline or median plane midline or median plane of the body than another of the body than another structure of the bodystructure of the body

LateralLateral Refers to a structure Refers to a structure

being farther away from being farther away from the midline than another the midline than another structure of the bodystructure of the body

Positions and Positions and DirectionsDirectionsDistalDistal

Refers to a structure Refers to a structure being further away from being further away from the the rootroot of the limb than of the limb than another structure in the another structure in the limblimb

ProximalProximal Refers to a structure Refers to a structure

being closer to the being closer to the rootroot of of the limb than another the limb than another structure in that limbstructure in that limb