Human Body Systems Functions of the Skeletal System

Human Body Systems

Functions of the Skeletal System 1. Provides shape & support 2. Helps you move 3. Protects organs 4. Produces blood cells 5. Stores certain minerals

Organs of the Skeletal System • Bones • Cartilage • L i g a m e n t 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 1. Helps the body move 2. Moves food through the digestive system 3. Keeps the heart beating

Muscle Action • Involuntary muscle – 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: Muscle Types • Smooth Muscle – Inside many internal organs – Involuntary – Ex: Stomach

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

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 1. Breaks down food into molecules 2. Rids the body of cansolid use waste the

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

Roles of Organs • Large Intestine – 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

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

Organs of the Circulatory System Heart 1. • -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 1. 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 bronchi pharynx alveoli The diaphragm is the muscle underneath the lungs that aids in the breathing process. trachea

Functions of the Nervous System 1. Receives information about what is happening inside & outside of the body. 2. Directs the body’s response to this information. (Remember stimulus and response? )

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 &

Functions of the Integumentary System (Skin) 1. Covers the body & prevents water loss 2. Protects the body from injury & infection 3. Regulates body temperature 4. Eliminate wastes (perspiration) 5. Gathers information about the environment 6. Produces vitamin D

Layers of the Skin • Epidermis – 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: 1. Filter wastes from blood 2. Eliminate liquid wastes (urine) from the body

– Kidneys. Urinary System: – 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

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