Systems in Human Body
Skeletal System
- Function: Provides structure, protection, and support to the body. It facilitates movement by serving as points of attachment for muscles. It also produces blood cells and stores minerals.
- Components:
- Bones: 206 bones in the adult human body, including long bones (e.g., femur), short bones (e.g., carpals), flat bones (e.g., skull), and irregular bones (e.g., vertebrae).
- Joints: Where two or more bones meet, allowing for movement and flexibility.
- Cartilage: Provides cushioning between bones.
- Ligaments: Connect bones to other bones.
Muscular System
- Function: Allows movement of the body, maintains posture, and circulates blood throughout the body.
- Components:
- Skeletal Muscles: Voluntary muscles attached to bones, responsible for body movements.
- Smooth Muscles: Involuntary muscles found in the walls of internal organs like the stomach, intestines, and blood vessels.
- Cardiac Muscle: Involuntary muscle that forms the heart and is responsible for pumping blood.
Circulatory System
- Function: Transports nutrients, gases (oxygen and carbon dioxide), hormones, and wastes through the body.
- Components:
- Heart: Pumps blood through the circulatory system.
- Blood Vessels: Includes arteries (carry blood away from the heart), veins (carry blood to the heart), and capillaries (small vessels where exchange of substances occurs).
- Blood: Consists of red blood cells (carry oxygen), white blood cells (fight infection), platelets (assist in clotting), and plasma (liquid component).
Respiratory System
- Function: Facilitates the exchange of oxygen and carbon dioxide between the body and the environment.
- Components:
- Nose/Mouth: Entry points for air.
- Pharynx/Larynx: Pathway for air to reach the lungs.
- Trachea: Windpipe that leads to the bronchi.
- Bronchi/Bronchioles: Branching tubes that lead to the lungs.
- Lungs: Main organs where gas exchange occurs.
- Alveoli: Small air sacs in the lungs where oxygen and carbon dioxide exchange occurs.
Digestive System
- Function: Breaks down food into nutrients that can be absorbed into the bloodstream and eliminates waste.
- Components:
- Mouth: Begins the process of digestion with chewing and saliva.
- Esophagus: Tube that carries food to the stomach.
- Stomach: Secretes acid and enzymes to break down food.
- Small Intestine: Absorbs nutrients from digested food.
- Large Intestine: Absorbs water and forms feces.
- Liver: Produces bile, which helps digest fats.
- Pancreas: Produces digestive enzymes and insulin.
- Gallbladder: Stores bile from the liver.
Nervous System
- Function: Controls and coordinates body activities by transmitting electrical impulses.
- Components:
- Central Nervous System (CNS): Consists of the brain and spinal cord.
- Peripheral Nervous System (PNS): Includes all the nerves outside the CNS.
- Neurons: Nerve cells that transmit impulses.
- Sensory Organs: Eyes, ears, nose, tongue, and skin, which receive stimuli.
Endocrine System
- Function: Regulates body functions through hormones.
- Components:
- Glands: Include the pituitary, thyroid, adrenal, and others.
- Hormones: Chemical messengers released by glands.
Urinary System
- Function: Removes waste products from the blood and regulates fluid balance.
- Components:
- Kidneys: Filter blood and produce urine.
- Ureters: Tubes that carry urine from the kidneys to the bladder.
- Bladder: Stores urine until it is excreted.
- Urethra: Tube through which urine exits the body.
Reproductive System
- Function: Produces offspring and maintains reproductive health.
- Components:
- Male: Testes, vas deferens, prostate, penis.
- Female: Ovaries, fallopian tubes, uterus, vagina.
Lymphatic System
- Function: Defends the body against infection and disease, maintains fluid balance.
- Components:
- Lymph Nodes: Filter lymph and store white blood cells.
- Lymph Vessels: Carry lymph throughout the body.
- Spleen: Filters blood and helps fight infection.
- Thymus: Produces T-cells for immune response.
Integumentary System
- Function: Protects the body from external damage, regulates temperature, and provides sensory information.
- Components:
- Skin: Largest organ of the body.
- Hair: Provides protection and sensory input.
- Nails: Protect the tips of fingers and toes.
- Sweat and Oil Glands: Regulate temperature and keep skin moisturized.