Human Physiology: Organization of the Body

Human Physiology

Organization of the Human Body

• The human body is composed of:
  • Cells: Basic structural and functional units
  • Tissues: Groups of similar cells performing specific functions
  • Organs: Structures composed of two or more types of tissues
  • Organ Systems: Groups of organs working together to perform specific functions

Organization of the Human Body (continued)

• 11 major organ systems:
  1. Nervous System
  2. Circulatory System
  3. Respiratory System
  4. Digestive System
  5. Endocrine System
  6. Immune System
  7. Integumentary System
  8. Muscular System
  9. Skeletal System
  10. Urinary System
  11. Reproductive System

Homeostasis

• The ability of the body to maintain a stable internal environment despite external changes
• Maintained through negative feedback mechanisms
• Examples:
  • Thermoregulation (body temperature)
  • Blood sugar regulation
  • Blood pH regulation

Cellular Physiology

• Cellular membrane: Semi-permeable, allowing selective transport of molecules
• Cellular transport mechanisms:
  • Passive transport (diffusion, osmosis)
  • Active transport (carrier proteins)
• Cellular metabolism:
  • Cellular respiration (aerobic, anaerobic)
  • Photosynthesis (in plant cells)

Nervous System Physiology

• Central Nervous System (CNS): Brain and spinal cord
• Peripheral Nervous System (PNS): Somatic and autonomic nervous systems
• Neurons: Basic functional units of the nervous system
• Neurotransmission: Chemical transmission of signals between neurons

Muscle Physiology

• Types of muscle tissue:
  • Skeletal muscle (voluntary, striated)
  • Smooth muscle (involuntary, non-striated)
  • Cardiac muscle (involuntary, striated)
• Muscle contraction: Sliding filament theory

Cardiovascular Physiology

• Heart structure and function:
  • Atria and ventricles
  • Valves and blood flow
• Blood vessels:
  • Arteries (elastic and muscular)
  • Veins (low pressure, one-way valves)
• Blood pressure regulation: Short-term and long-term mechanisms

Organization of the Human Body

• The human body is composed of cells, tissues, organs, and organ systems
• Cells are the basic structural and functional units of the body
• Tissues are groups of similar cells performing specific functions
• Organs are structures composed of two or more types of tissues
• Organ systems are groups of organs working together to perform specific functions
• There are 11 major organ systems in the human body

The 11 Major Organ Systems

• Nervous System
• Circulatory System
• Respiratory System
• Digestive System
• Endocrine System
• Immune System
• Integumentary System
• Muscular System
• Skeletal System
• Urinary System
• Reproductive System

Homeostasis

• The ability of the body to maintain a stable internal environment despite external changes
• Maintained through negative feedback mechanisms
• Examples of homeostasis include thermoregulation, blood sugar regulation, and blood pH regulation

Cellular Physiology

• Cellular membrane is semi-permeable, allowing selective transport of molecules
• Cellular transport mechanisms include passive transport (diffusion and osmosis) and active transport (carrier proteins)
• Cellular metabolism includes cellular respiration (aerobic and anaerobic) and photosynthesis (in plant cells)

Nervous System Physiology

• Central Nervous System (CNS) consists of the brain and spinal cord
• Peripheral Nervous System (PNS) consists of the somatic and autonomic nervous systems
• Neurons are the basic functional units of the nervous system
• Neurotransmission occurs through chemical transmission of signals between neurons

Muscle Physiology

• There are three types of muscle tissue: skeletal, smooth, and cardiac
• Skeletal muscle is voluntary and striated
• Smooth muscle is involuntary and non-striated
• Cardiac muscle is involuntary and striated
• Muscle contraction occurs through the sliding filament theory

Cardiovascular Physiology

• The heart has four chambers: right and left atria, and right and left ventricles
• Heart valves ensure one-way blood flow
• Blood vessels include arteries (elastic and muscular) and veins (low pressure, one-way valves)
• Blood pressure regulation occurs through short-term and long-term mechanisms

Learn about the structure and organization of the human body, from cells to organ systems. Discover the 11 major organ systems and their functions.