Human Skeletal System

Functions:
- Supports the body
- Protects internal organs
- Provides movement through joint articulation
- Produces blood cells
- Stores minerals (e.g. calcium, phosphorus)
Components:
- Bones (206 in adult human skeleton)
- Joints (connect bones)
- Ligaments (connect bones to each other)
- Tendons (connect muscles to bones)
Types of bones:
- Long bones (e.g. femur, humerus)
- Short bones (e.g. carpals, tarsals)
- Flat bones (e.g. ribs, sternum)
- Irregular bones (e.g. vertebrae, pelvis)

Functions:
- Controls and coordinates body functions
- Interprets and responds to sensory information
- Regulates body temperature, hunger, and thirst
Components:
- Central nervous system (CNS): brain and spinal cord
- Peripheral nervous system (PNS): nerves
- Somatic nervous system: controls voluntary movements
- Autonomic nervous system: controls involuntary movements
Types of neurons:
- Sensory neurons: transmit sensory information
- Motor neurons: transmit motor signals
- Interneurons: integrate and process information

Functions:
- Brings oxygen into the body
- Removes carbon dioxide from the body
Components:
- Upper respiratory tract: nose, mouth, pharynx, larynx
- Lower respiratory tract: trachea, bronchi, lungs
- Diaphragm: muscle that separates chest and abdominal cavities
Process of breathing:
- Inhalation: diaphragm contracts, air enters lungs
- Exhalation: diaphragm relaxes, air leaves lungs

Functions:
- Moves body parts
- Maintains posture
- Regulates body temperature
- Supports movement of other systems (e.g. circulatory, respiratory)
Types of muscles:
- Skeletal muscles: voluntary movement
- Smooth muscles: involuntary movement (e.g. digestive tract)
- Cardiac muscles: involuntary movement (e.g. heart)
Muscle structure:
- Muscle fibers: contractile units
- Muscle cells: contain multiple fibers

Functions:
- Transports oxygen and nutrients to cells
- Removes waste products from cells
- Regulates body temperature
Components:
- Heart: pumps blood
- Arteries: carry oxygenated blood away from heart
- Veins: carry deoxygenated blood back to heart
- Blood vessels: capillaries, arterioles, venules
Blood components:
- Plasma: liquid portion
- Red blood cells: carry oxygen
- White blood cells: immune function
- Platelets: clotting function

Provides support, protection, and movement for the body
Produces blood cells and stores minerals like calcium and phosphorus
Consists of 206 bones, joints, ligaments, and tendons in an adult human skeleton
Bones are categorized into long bones (e.g. femur, humerus), short bones (e.g. carpals, tarsals), flat bones (e.g. ribs, sternum), and irregular bones (e.g. vertebrae, pelvis)

Controls and coordinates body functions, interprets sensory information, and regulates body temperature, hunger, and thirst
Comprises the central nervous system (brain and spinal cord), peripheral nervous system (nerves), somatic nervous system (voluntary movements), and autonomic nervous system (involuntary movements)
Neurons are categorized into sensory neurons (transmit sensory information), motor neurons (transmit motor signals), and interneurons (integrate and process information)

Brings oxygen into the body and removes carbon dioxide
Consists of the upper respiratory tract (nose, mouth, pharynx, larynx), lower respiratory tract (trachea, bronchi, lungs), and diaphragm (separates chest and abdominal cavities)
The process of breathing involves inhalation (diaphragm contracts, air enters lungs) and exhalation (diaphragm relaxes, air leaves lungs)

Enables movement, maintains posture, regulates body temperature, and supports movement of other systems
Comprises skeletal muscles (voluntary movement), smooth muscles (involuntary movement, e.g. digestive tract), and cardiac muscles (involuntary movement, e.g. heart)
Muscles are composed of muscle fibers (contractile units) and muscle cells (contain multiple fibers)

Transports oxygen and nutrients to cells, removes waste products, and regulates body temperature
Consists of the heart (pumps blood), arteries (carry oxygenated blood away from heart), veins (carry deoxygenated blood back to heart), and blood vessels (capillaries, arterioles, venules)
Blood components include plasma (liquid portion), red blood cells (carry oxygen), white blood cells (immune function), and platelets (clotting function)