Body Systems

Nervous System• Carries messages to and from the

brain and spinal cord and all other parts of the body

• Main Parts:– Central Nervous System:• Brain• Spinal Cord

– Peripheral Nervous System:• Consists of all nerves that branch out

from central nervous system to muscles, skin, internal organs, and glands

Central Nervous System

• Brain:– Control center of the body– Weighs about 3 lbs– Can store more information than

all libraries in the world– Creates ideas, controls thinking,

reasoning, movement, and emotions

Cerebellum: controls and coordinates muscle

activity. Helps maintain balance

Brain Stem: Controls functions of internal

organs

Cerebrum: controls ability to think, memorize, and learn. Determines personality and

intelligence

• Spinal Cord:– Thick column of nerve cells that

extends from the brain through spinal column.

– Carries messages to and from your brain and body

Central Nervous System

Cardiovascular System

• Transports nutrients, gases, hormones, and cellular waste products throughout body.

• Main Parts:– Blood– Blood Vessels– Heart

Blood• Carries nutrients, oxygen, carbon

dioxide, and cellular waste products to and from cells

• Plasma:– Liquid component (95% water)

• Red Blood Cell:– Transports oxygen to body cells and

removes carbon dioxide• Hemoglobin:

– Iron-rich protein that helps transport oxygen and carbon dioxide

• White Blood Cell:– Attacks, surrounds, and destroys pathogens

• Pathogen:– Germ that causes disease

• Platelet:– Particle that helps blood clot

Blood Vessels• Artery:– Carries blood away from heart

• Vein:– Returns blood to heart

• Capillary:– Tiny vessel that connects arteries

and veins– Have thin walls that allow for

transfer of nutrients, oxygen, carbon dioxide, and cellular waste to and from blood and body cells

Atrium: upper two chambersVentricle: lower two chambers

Immune System• Removes harmful organisms

from the blood and combats pathogens

• Main parts:– Lymph:

• Clear liquid that surrounds body cells• Carries harmful pathogens to nodes

– Lymph Node:• Structure that filters and destroys

pathogens– Spleen:

• Organ on left side of abdomen that filters foreign matter from blood and lymph

– Lymph vessels– Tonsils– thymus

Respiratory System• Provides body cells with oxygen

and removes carbon dioxide that cells produce as waste

• Main Parts:– Pharynx: throat– Trachea: tube air moves to lungs– Cilia: hair-like structures that

remove dust from air– Bronchi: 2 tubes through which air

moves to lungs– Lungs: main organs– Bronchioles: smaller tubes divided

into alveoli– Alveoli: Tiny air sacs

Skeletal System• Serves as a support framework,

protects vital organs, works with muscles to produce movement, and produces blood cells

• 206 bones in adults• Cartilage: – soft, connective tissue on end of

some bones– Acts as cushion where bones meet

• Ligament: – Tough fibers that connect bones

together• Joint: – point where 2 bones meet

Muscular System• Consists of muscles that provide

motion and maintain posture• More than 600 in body• Types:– Voluntary (can control)– Involuntary (without thought)

• Muscle Tissue Types:– Smooth (internal organs)– Skeletal (attached to bone)– Cardiac (in heart)

• Tendon: Attaches muscles to bone

Endocrine System

• Consists of glands that control many of the body’s activities by producing hormones

• Hormone:– Chemical messenger that is

released directly into bloodstream

Digestive System• Breaks down food into nutrients

that can be used by the body• Main Parts:– Mouth (break food into small pieces)– Esophagus (connects mouth to

stomach)– Stomach (releases acid and juices that

mix with food and make chyme)– Small Intestine (greatest amount of

digestion and absorption)– Liver (releases bile to break down fats,

maintain blood sugar level, and filter waste

– Pancreas (produces digestive enzymes and insulin)

– Large Intestine (undigested food prepared for elimination)

Urinary System• Removes liquid waste from the

body and maintains body’s water balance

• Main organs:– Kidneys (filters blood and excretes

waste and excess water in urine)– Ureters (connects kidneys to bladder)– Bladder (muscular sac that stores

urine)– Urethra (connects bladder to outside

of body)

Integumentary System

• Covers and protects the body• Main parts:– Skin– Glands associated with skin, hair,

and nails