Human Anatomy: Skeletal and Muscular Systems

Functions:
- Supports and protects internal organs
- Provides framework for muscles to attach and move
- Produces blood cells
- Stores minerals such as calcium and phosphorus
Components:
- 206 bones in adult human skeleton
- 4 types of bones: long, short, flat, and irregular
- Joints connect bones and allow movement
- Ligaments connect bones to each other
- Tendons connect muscles to bones

Types of Muscle:
- Skeletal (voluntary): attached to bones, enables movement
- Smooth (involuntary): found in internal organs, regulates functions such as digestion
- Cardiac (involuntary): found in heart, regulates heartbeat
Functions:
- Movement and locomotion
- Maintenance of posture
- Regulation of body temperature
- Support of blood circulation

Common Disorders:
- Alzheimer's disease: degeneration of brain cells, memory loss
- Parkinson's disease: degeneration of dopamine-producing neurons, motor dysfunction
- Multiple sclerosis: damage to myelin sheath, motor and sensory dysfunction
- Stroke: interruption of blood flow to brain, brain damage
Causes and Risk Factors:
- Genetic predisposition
- Injury or trauma
- Infection
- Lifestyle factors (e.g. smoking, lack of exercise)

Components:
- White blood cells (leukocytes): defend against infection
- Lymphatic system: network of vessels, organs, and tissues that defend against infection
- Barriers: skin, mucous membranes, and respiratory tract
Functions:
- Recognizes and responds to pathogens
- Activates immune response through inflammation
- Produces antibodies to neutralize pathogens

Mouth:
- Mechanical digestion: chewing breaks down food
- Chemical digestion: salivary amylase breaks down carbohydrates
Stomach:
- Mechanical digestion: churning and mixing of food
- Chemical digestion: gastric acid and pepsin break down proteins
Small Intestine:
- Chemical digestion: enzymes break down carbohydrates, proteins, and fats
- Absorption of nutrients into bloodstream

Endocrine System:
- Produces and regulates hormones
- Hormones: chemical messengers that regulate various bodily functions
Hormone Functions:
- Regulates growth and development
- Regulates metabolism and energy balance
- Regulates reproductive functions
- Regulates stress response

Barrier Function:
- Protects against external damage and infection
- Regulates water loss and temperature
Sensory Function:
- Detects sensations such as touch, pressure, and temperature
Regulation of Body Temperature:
- Sweating and evaporation to cool the body
- Vasoconstriction and vasodilation to conserve or release heat

Skeletal muscles are voluntary and attached to bones, enabling movement
Smooth muscles are involuntary and found in internal organs, regulating functions such as digestion
Cardiac muscles are involuntary and found in the heart, regulating heartbeat
Muscles enable movement and locomotion
Muscles maintain posture
Muscles regulate body temperature
Muscles support blood circulation

Alzheimer's disease is a degenerative disorder that causes memory loss
Parkinson's disease is a degenerative disorder that causes motor dysfunction
Multiple sclerosis is a disorder that causes damage to the myelin sheath, leading to motor and sensory dysfunction
Stroke is a condition that occurs when there is an interruption of blood flow to the brain, causing brain damage
Genetic predisposition, injury or trauma, infection, and lifestyle factors can cause or increase the risk of nervous system disorders

White blood cells (leukocytes) defend against infection
The lymphatic system is a network of vessels, organs, and tissues that defend against infection
Barriers such as skin, mucous membranes, and respiratory tract provide defense against infection
The immune system recognizes and responds to pathogens
The immune system activates immune response through inflammation
The immune system produces antibodies to neutralize pathogens

Mechanical digestion occurs in the mouth through chewing
Chemical digestion occurs in the mouth through salivary amylase breaking down carbohydrates
Mechanical digestion occurs in the stomach through churning and mixing of food
Chemical digestion occurs in the stomach through gastric acid and pepsin breaking down proteins
Chemical digestion occurs in the small intestine through enzymes breaking down carbohydrates, proteins, and fats
Absorption of nutrients into the bloodstream occurs in the small intestine

The skin provides a barrier function, protecting against external damage and infection
The skin regulates water loss and temperature
The skin has sensory functions, detecting sensations such as touch, pressure, and temperature
The skin regulates body temperature through sweating and evaporation, and vasoconstriction and vasodilation