Human Body Systems

Functions of the Skeletal System Provides shape & support Helps you move Protects organs Produces blood cells Stores certain minerals

Organs of the Skeletal System Bones Cartilage L i g a m e n t B o n e B o n e

Bone Marrow Marrow – soft connective tissue found in spaces in bone Red marrow Produces the body’s blood cells Yellow marrow Stores fat (energy reserve)

Functions of the Muscular System Helps the body move Moves food through the digestive system Keeps the heart beating

Muscle Action Involuntary muscle Voluntary muscles Muscles not under your conscious control Ex: muscles used for breathing & digesting food Voluntary muscles Muscles that are under your conscious control Ex: Smiling, turning the pages in a book, walking to class

Organs of the Muscular System: Muscles Types Skeletal Muscle Attached to bones & move bones using tendons Connective tissue attaching muscles to bones Striated, or banded Voluntary Organs of the Muscular System: Muscles Types

Organs of the Muscular System: Muscle Types Smooth Muscle Inside many internal organs Involuntary Ex: Stomach Organs of the Muscular System: Muscle Types

Organs of the Muscular System: Muscle Types Cardiac Muscle Found only in the heart Involuntary Never gets tired (unlike skeletal muscles) T e n d o n M u s c l e Organs of the Muscular System: Muscle Types

How do muscles work? Muscles move by contracting, or becoming shorter Must work in pairs One contracts, the other returns to its original length

Functions of the Digestive System Breaks down food into molecules the body can use 2. Rids the body of solid waste

Roles of Organs Mouth – mechanical & chemical digestion starts here Mechanical – physically breaking down food (teeth) Chemical – breakdown of molecules of food (saliva) Esophagus – muscular tube connecting the mouth to the stomach Peristalsis (muscle contraction) moves the food

Roles of Organs Epiglottis- flap that keeps food from entering the trachea Stomach Most mechanical digestion takes place Some chemical with the help of digestive juices (enzymes & acids) Small Intestine Most of the chemical digestion takes place Absorption of nutrients from digested food into the bloodstream

Roles of Organs Large Intestine Rectum & Anus Water is absorbed into the bloodstream Remaining material is readied for elimination from the body Rectum & Anus Waste material is compressed into solid form Opening where waste exits the body

Roles of Accessory/Secondary Organs: Liver Produces bile used in the digestion of fat Gallbladder Stores bile until it is needed in the small intestine Pancreas Produces other digestive juices that are sent to the small intestine for digestion

Carries needed substances to cells and carries wastes away from cells. Functions of the Circulatory System Carries needed substances to cells and carries wastes away from cells.

Organs of the Circulatory System 1. Heart -4 chambers: Right & left atria Right & left ventricle 2. Blood vessels -veins -arteries -capillaries 3. Blood -plasma -platelets -red blood cells -white blood cells

Functions of the Respiratory System Moves oxygen from the outside environment into the body. 2. It also removes carbon dioxide and water from the body.

Organs of the Respiratory System Path of air into the body: nose pharynx trachea bronchi alveoli The diaphragm is the muscle underneath the lungs that aids in the breathing process.

Functions of the Nervous System Receives information about what is happening inside & outside of the body. Directs the body’s response to this information. (Remember stimulus and response?) 3. Helps maintain homeostasis.

Organs of the Nervous System Brain Nerves (neurons – nerve cells) Spinal Cord

Central Nervous System Brain - controls most functions in the body Cerebrum Interprets input from the senses Controls movement of skeletal muscles Complex mental processes (learning) Cerebellum Coordinates muscle actions & balance Brainstem (medulla) Controls involuntary actions (ex: breathing) Spinal cord - link between brain & the rest of the body

Functions of the Integumentary System (Skin) Covers the body & prevents water loss Protects the body from injury & infection Regulates body temperature Eliminate wastes (perspiration) Gathers information about the environment Produces vitamin D

Layers of the Skin Epidermis Dermis Outermost layer No nerves or blood vessels Surface is made of dead cells (provide protection) Dermis Lower layer of the skin Contains nerves, blood vessels, sweat glands, hairs & oil glands

The Skin

Function of the Urinary System: Filter wastes from blood Eliminate liquid wastes (urine) from the body

Urinary System: Kidneys Eliminate urea, excess water, & some other waste materials Filter wastes from the blood Produce urine Ureters Tubes that transport urine to the bladder from the kidneys Urinary Bladder Stores urine until it can be released from the body Urethra Tube that carries urine out of the body

Function of the Excretory Systems: All of the organs/systems collect and remove wastes from the body.

Excretory Systems/Organs: Urinary System The kidneys filter wastes from the blood & and removes urine (liquid waste) from the body Digestive System The lg. intestine, rectum, & anus help remove solid wastes from the body Respiratory System The lungs remove carbon dioxide produced during cellular respiration Integumentary System (Skin) Removes perspiration (dissolved waste materials)