Human Body Systems

Organ Systems

• MAJOR FUNCTIONS:1. Provide shape & support2. Allows for movement3. Protects tissue & organs4. Stores certain minerals5. Produces blood cells

MAJOR ORGANS:• Skull…protects the brain

• Ribs…protects heart & lungs• Vertebrae…protects the spinal cord

• Femur…produces blood cells in the leg; longest bone in the body• Humerus…produces blood cells in the arm

Skeletal System

MAJOR FUNCTION:1. Allows for body movement by expanding & contracting

3 Types of Muscle Tissue:Skeletal: attached to bone to move the skeleton; EX: bicepSmooth: makes up most organs; EX: stomachCardiac: only found in the heart MAJOR ORGANS: Biceps/Triceps…work together to help move the armQuadriceps/Hamstrings…work together to move the upper leg

Muscular System

Muscles work in pairs!

MAJOR FUNCTION: 1. Responsible for getting O2 IN to the body & removing CO2 FROM the body.

MAJOR ORGANS:• Nostrils…openings in the nose that allow air to enter the body• Trachea…”windpipe”• Larynx…”voice box”• Lungs…contains air sacs (alveoli) where O2 & CO2 exchanged• Diaphragm…dome shape muscle that aids in breathing• Epiglottis…small flap of tissue; closes off respiratory system

when eating & closes off digestive system when talking/breathing

RESPIRATORY SYSTEM

MAJOR FUNCTION: Carries materials (O2, CO2, food, waste, disease fighting cells, hormones) through the body in blood.

MAJOR ORGANS:– Heart…pumps blood throughout the body; separated into 4

chambers (2 atria & 2 ventricles)– Artery…thickest blood vessel; carries oxygen-rich blood AWAY

from the heart – Vein…contains valves to keep oxygen-poor blood going in one

direction—TO the heart– Capillary…thinnest blood vessel; connects arteries to veins

CIRCULATORY SYSTEM

Parts of blood:* platelets…helps in blood clotting* plasma…liquid portion of blood (~55%)* red blood cells (RBC’s)…carry oxygen* hemoglobin…iron containing protein in RBC’s* white blood cells (WBC’s)…produce antibodies to fight infections/diseases

CIRCULATORY SYSTEM

A drop of blood travels through the circulatory system…

Heart Arteries Capillary Veins Heart

MAJOR FUNCTION: Breaks down food into simpler substances for use by the body

MAJOR ORGANS:• Mouth…releases saliva, which helps to break down

starches into simple sugars• Esophagus…muscular tube that connects the

mouth to the stomach• Stomach…j-shape pouch that expands to hold all

the food that is swallowed– pepsin…enzyme that breaks down proteins into amino

acids• Small Intestine…where most digestion occurs &

usable nutrients are absorbed into the bloodstream

• Large Intestine (colon)…where water is absorbed from food & the remaining waste material is prepared for elimination from the body

• Rectum…stores solid waste produced by digestion until the excretory system removes it

A piece of food travels through the body in the following way: Mouth esophagus stomach small large rectum

intestine intestine

MAJOR FUNCTION: Removes wastes (excess water, salts, CO2 and urea) from the body.

MAJOR ORGANS:• Kidney, Urinary Bladder, Skin…cleans/stores/removes liquid

waste• Rectum, Anus…stores/removes solid waste OTHER INFO:• Excretion…process which removes waste from the body• Perspiration (sweat)…rids the body of salts/water; helps to

regulate body temperature

MAJOR FUNCTIONS: • Sends & receives information about the

body’s activities• Monitors & responds to changes in the

environment.

A nerves impulse travels through the body in the following way:

Nerve Spinal cord Brain

• MAJOR ORGANS:• Brain…part of the central nervous system; controls

most functions in the body– Cerebrum…interprets input from the senses; controls

movement of skeletal muscles; carries out complex mental processes

– Cerebellum…coordinates the actions of the muscles; helps maintain balance

– Medulla oblongata…controls involuntary actions (those that occur automatically)

• Spinal Cord…links the brain and most of the nerves• Nerves (Neurons)…allow for feeling

MAJOR FUNCTIONS:1. Body’s defense against disease-causing organisms (pathogens)2. Destroys & removes dead/damaged cells from the body TWO Ways to prevent infectious diseases:• Active Immunity…

– a person’s own immune system produces antibodies– acquired by: (1) having the disease, ex: chicken pox (2) getting a vaccine, ex: polio vaccine– vaccine…consists of pathogens that have been weakened or killed, but

can still trigger the immune system to go into action• Passive Immunity…

– The antibodies come from a source other than the person’s body, ex: from the mother to the unborn baby across the placenta

The body has THREE lines of defense:FIRST line of defense…

• Consists of barriers that keep pathogens from getting into the body– Skin…defends the entire body, until a cut occurs– Mucus, cilia, sneezing, coughing…defends the

respiratory system– Saliva…defends the digestive system; loaded with

“invader-killing” chemicals

SECOND line of defense…

• Inflammatory response occurs—fluid and certain types of white blood cells leak from the blood vessels into nearby tissue, so that the white blood cells can attack the pathogens– Phagocyte…white blood cell that engulfs

pathogens & destroys them by breaking them down

THIRD line of defense…If pathogens get past the second line and is severe enough to

cause a fever…

• Immune system targets specific pathogens• B-cells (WBC’s) produce antibodies (proteins)

that destroy pathogens • T-cells (WBC’s) identify pathogens &

distinguish one kind from another