Transcript Human Body Systems Notes for Coloring

Human Body
Systems
Science 8th Grade
Mrs. Roberts
Body Organization
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Cell  Tissue  Organ  System
Cell—basic building block of living things; smallest unit of
organization in a living thing
Types of Tissue
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Nervous—carries messages back and forth between brain and
the rest of the body (Ex. optic nerve)
Muscle—helps move body parts such as arms and legs (Ex.
Bicep)
Epithelial—covers and protects body surfaces (inside and
outside) (Ex. Skin or the lining of the stomach)
Connective—supports the body and hold it together (ex. Bone)
Homeostasis
Homeostasis—the process by which an
organism’s internal environment is kept
stable in spite of changes in the external
environment.
 To maintain homeostasis, the Nervous
System delivers message between the
brain and various body systems (ex.
hunger, thirst, sweating).
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Skeletal System
Functions
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Shape & Support – skull,backbone (spine)
Movement – fingers, legs, arms
Protects organs – skull, ribs
Produces red blood cells
Storage – minerals & other
Major Organ(s): Bones (newborns 275, adults 206)
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Compact bone
Spongy bone
Joints
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Immovable – skull, ribs
Moveable – arms, legs
Ligaments – connect bones
Cartilage
The Human Skeleton
Muscular System
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Major Organ(s): Muscles
Three Types of Muscles
Skeletal-attached to bones; allows movement; voluntary;
2. Smooth-inside organs (stomach, intestines); involuntary-can’t control
3. Cardiac-only in heart; involuntary; never get tired
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Functions
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Enables movement of the body and internal organs
Skeletal muscles work in pairs to move bones; one muscle
contracts as the other muscle relaxes.
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Example: triceps & biceps (in the arms)
Tendons attach muscles to bones
Voluntary Muscles – Under conscious control – You make them
move
Involuntary Muscles – Not under conscious control – work
automatically.
The Human Muscles
Digestive System
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Major Organs: stomach and intestines
Three Main Functions
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Digestion – breaking down food into nutrient molecules
Absorption – Nutrients are absorbed into blood
Elimination – getting rid of undigested food
Digestive Tract/Path of food: mouth→ esophagus→
stomach→ small intestine→ large intestine→ rectum
Villi – Line the small intestine; increases surface area
so more nutrients can be absorbed from food.
Intestines are named based on their diameter (how
big around) not their length.
Other/Helper Organs (that produce or secrete digestive
enzymes)
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Liver –Gallbladder –Pancreas
The Digestive System
Circulatory (Cardiovascular)
System
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Functions
1. Delivers needed substances to cells through blood
2. Removes waste products from cells, carries it to
lungs, kidneys, intestines to be removed from the
body
3. Fights disease – white blood cells & T cells
Major Organ: Heart
Blood – carries needed materials (oxygen and
glucose) to body cells and carries wastes away
from body cells.
Arteries – (aorta) – carry blood away from heart
Veins – (vena cava & jugular) – carry blood to heart
Capillaries – connect arteries & veins – where
needed substances are dropped off to cells and
waste products are picked up.
Circulatory System
Respiratory System
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Major Organ: Lungs
Functions
 Takes in oxygen through the lungs
 Removes carbon dioxide and water from the body
through the lungs
Diaphragm-large, dome-shaped muscle involved in
breathing
 Diaphragm moves up – exhale
 Diaphragm moves downward – inhale
Alveoli – Grapelike structures in the lungs where
oxygen is taken out of the air and put in the blood
and carbon dioxide is taken out of the blood and put
into the air.
Breathing Passageway aka Path of Air
 Nose →pharynx (throat) →trachea (windpipe lined
with cilia and mucus) →bronchi →lungs into alveoli
(where gas exchange takes place)
Respiratory System
Excretory System
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Function—Collects wastes (water, urea, other)
produced by cells and removes the wastes from the
body
Major Organ(s): Kidneys (2) – remove urea & wastes
from blood (urine-watery fluid which contains urea)
Excretion & Homeostasis—keeps internal environment
stable and free of harmful chemicals
Other Organs involved in getting rid of wastes
 Lungs – removes carbon dioxide & some water
 Skin – removes water & urea
 Liver – filters blood & breaks down chemicals and
blood cells into usable substances (recycling facility)
Excretory System
Nervous System
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Major Organ(s): Brain & Spinal Cord
Central Nervous System—the control center of the body
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Brain-cerebrum, cerebellum, brain stem
 Spinal Cord-link from brain to other nerves
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Peripheral Nervous System—network of nerves
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Voluntary-move muscles
Involuntary -reflexes
Functions
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Receives information from inside and outside the body—carries
messages back and forth between the brain and other parts of the
body
 Directs body responses/Responds to information
 Helps maintain homeostasis—makes you feel hungry, thirsty, or
sweat when needed to maintain stable internal conditions
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Reflex – an automatic response that occurs rapidly and without
conscious control (ex. blinking)
The Nervous System
Immune System
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Function: reacts to pathogens with a defense to fight disease
Lympohocytes (white blood cells)
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T cells – recognize antigens
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Destroy viruses
Activate B cells
B cells – produce antibodies
Three Lines of Defense against Pathogens
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Barrier – skin, nose, throat, mouth stomach
Inflammation – phagocytes (white blood cells), inflammation, fever
Immune Response
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Lymphocytes – T cells and B cells