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Body Systems Overview

Body Systems work together:

• If you damage one system, you may damage several…for example, smoking

irritates the lungs and destroys the cells of the immune system

Levels of Organization Chemical

• Atoms & molecules

Building blocks of

matter

Cellular

Smallest independent unit of life

Tissue:

Consist of similar cells working

together to perform a specific

function

Epithelial Tissue

Lines body cavities Covers body surfaces

Protection, secretion, Absorption

Connective Tissue

Fills in spaces Binds & supports other

tissues Dense, loose, blood, bone

Muscular Tissue Contracts & provides

movement Skeletal

-skeletal muscles Cardiac

-wall of heart Smooth

- wall of internal organs

Nervous Tissue

Conducts electrical

impulses

Brain, spinal cord,

peripheral nerves

Organ

Lung

Group of tissues

working together to perform a specific

function

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Organ System

respiratory system

Group of organs working together to

perform a specific

function

Organism

Group of organ systems

working together to perform a specific

function (maintain life)

There are 11 organ systems in the human body

Skeletal System

Major Functions:

• It provides shape

and support

• Enables you to

move

• Protects your

internal organs

• Produces blood

cells

• Stores certain

materials until your

body needs them

Main Parts:

• Bones

• Tendons connect

bones to muscles.

• Ligaments connect

bone to bone.

• Cartilage cushions

places where bones

connect and offers

flexibility.

Muscular System

Major Functions:

• Your muscles

control all

movements of the

body tissues,

organs and bones.

Main Parts:

Three types of muscle

tissue

• skeletal muscle

• smooth muscle

• cardiac muscle

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Circulatory (cardiovascular) System

Main Functions:

Transport

• Oxygen

• Nutrients

• Waste

throughout the

body

Main Parts:

• Heart

• Blood Vessels

• Aorta

• Arteries

• Arterioles

• Capillaries

• Venules

• veins

• Blood

Respiratory System

Main Functions:

• Moves oxygen

from the outside

environment into

your body

• Removes carbon

dioxide and water

from your body.

Main parts:

• Nose

• Mouth

• Pharynx

• larynx

• Trachea

• Lungs

• Bronchi

• Bronchioles

• alveoli

• Diaphragm

Digestive System

Main Functions:

• Breaks down food

into molecules the

body can absorb.

• Passes these

molecules into the

blood to be

carried

throughout the

body.

• Eliminates solid

wastes from the

body.

Main Parts:

• Mouth

• Pharynx

• Esophagus

• Stomach

• Small intestine

• Large intestine

• Rectum

• Anus

• Pancreas

• Gall bladder

• liver

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Excretory system

Main Functions:

• Collects wastes

produced by cells

and removes these

wastes from your

body. The removal

process is known as

excretion.

Main Parts:

• Kidney

• Ureter

• Bladder

• urethra

Integumentary System

Main functions:

• Covers body and

prevents water loss.

• Protects body from

injury and infection.

• Helps regulate body

temperature.

• Eliminate wastes

• Gathers information

about the

environment

• Produce vitamin D

Main parts:

• Skin

• Nails

• hair

Immune system

Main Functions:

• Protect you from

foreign invaders.

• Special cells react to

each kind of pathogen

with defensive tactics

targeted specifically

at that type of

pathogen. • A pathogen is a bacterium,

virus, or other

microorganism that can

cause disease.

Main parts:

• White blood

cells that target

specific

pathogens are

called

lymphocytes.

• T-cells and B-

cells are two

major types of

lymphocytes.

Each type has a

specific job.

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Lymphatic System

Main Functions:

• Extensive

drainage network

that helps keep

bodily fluid

levels in balance

and defends the

body against

infections.

• Filters out

organisms that

cause disease,

produces certain

white blood cells

and generates

antibodies

Main parts

• Network of

lymphatic vessels

that carry lymph —

a clear, watery fluid

that contains

protein molecules,

salts, glucose, urea,

and other

substances —

throughout the

body.

• Works closely with

the immune system

and the circulatory

system.

• Spleen stores many

of the white blood

cells needed for the

immune response.

Endocrine System

Main Functions:

• Maintain a stable

environment within

the body or

homeostasis.

• The hormones also

help the body to

regulate:

o Growth

o Sexual

development

o Metabolism

o Sugar, salt and

fluid levels in

the blood

Main Parts:

• Hypothalamus

• Pituitary gland

• Other glands

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Reproductive System

Main Functions:

– Make gametes

(egg and

sperm) and

hormones

– Fertilization

of the egg

with sperm

– Differ

structures in

male to

female with

different

functions.

Main Parts:

Male

• Testes

• Scrotum

• Sperm ducts

• Urethra

• Prostate and

other glands

• penis

Female

• Ovaries

• Fallopian tubes

• Fimbriae

• Uterus (womb)

• Cervix

• vagina

Feedback Mechanisms

▪ Homeostasis is maintained by the endocrine system through the use of

various feedback mechanisms.

▪ A feedback mechanism is in use when the biological reaction is actually

being controlled by the end products of that reaction.

▪ Negative feedback loop are most common.

• original stimulus reversed

• most feedback systems in the body are negative

• used for conditions that need frequent adjustment

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Receptor

Structures that monitor

a

controlled condition and

detect changes

Control center

determines next action

Effector

receives directions from

the

control center produces

a

response that restores

the

controlled condition

TYPES OF FEEDBACK

NEGATIVE POSITIVE

• Restores homeostasis

• Response opposite of stimulus • Brings levels back to normal

• Continues to disrupt homeostasis • Response reinforces stimulus

• Example – uterine contractions during childbirth

• Rare

Receptors

• detect stimulus

Effectors

• Muscles or glands

• Produce response

Homeostasis

Response

• Feedback

• Restores homeostasis

Disruption produces stimulus

Control center

• Brain or spinal cord

• Receives information from receptors

• Sends messages to effectors