Introduction to Physiology

Introduction to Physiology

• Physiology is the study of how living organisms function.
• It encompasses the study of all aspects of life processes.

Cells and Tissues

• Cells are the basic units of life, possessing specialized functions.
• Numerous types of cells exist, including muscle, nerve, and epithelial cells.
• Tissues are groups of similar cells working together to perform a specific function.
• Major tissue types include: epithelial, connective, muscle, and nervous.

Organ Systems

• Organ systems are groups of organs working together to carry out complex functions like respiration, digestion, reproduction, etc.
• Key bodily organ systems include:
  • Integumentary system (skin): Provides protection, regulates body temperature.
  • Skeletal system (bones): Supports and protects body structures.
  • Muscular system (muscles): Enables movement.
  • Nervous system (brain, spinal cord, nerves): Controls and coordinates body functions.
  • Endocrine system (glands): Produces hormones regulating various processes.
  • Cardiovascular system (heart, blood vessels): Transports blood, nutrients, and oxygen.
  • Lymphatic system (lymph nodes, vessels): Maintains fluid balance, and defends against infection.
  • Respiratory system (lungs): Facilitates gas exchange (oxygen and carbon dioxide).
  • Digestive system (esophagus, stomach, intestines, liver): Processes food for absorption.
  • Urinary system (kidneys, bladder): Removes waste products from the blood.
  • Reproductive system (testes, ovaries): Enables reproduction.

Homeostasis

• Homeostasis is the maintenance of a stable internal environment despite external fluctuations.
• This is essential for optimal function of cells and organs.
• Mechanisms like negative feedback loops help maintain homeostasis.

Cellular Processes

• Metabolism encompasses all chemical reactions in cells.
• Catabolism breaks down molecules, while anabolism builds them.
• Cellular respiration produces energy (ATP) from glucose.
• Protein synthesis involves the translation of genetic code into proteins.
• Cell division ensures growth and repair of tissues.

Nervous System

• The nervous system transmits signals throughout the body.
• Neurons are specialized cells that transmit electrical impulses.
• Sensory receptors detect stimuli, transmitting information to the brain through nerve pathways.
• The nervous system controls voluntary and involuntary actions.

Endocrine System

• The endocrine system regulates functions via hormones.
• Hormones are chemical messengers transported in the blood.
• The endocrine system influences metabolism, growth, and reproduction among other functions.

Cardiovascular System

• The cardiovascular system circulates blood throughout the body.
• The heart pumps blood, and blood vessels transport it.
• Blood carries oxygen, nutrients, hormones, and waste products.

Respiratory System

• The respiratory system facilitates gas exchange.
• Lungs exchange oxygen and carbon dioxide with the environment.
• Oxygen is essential for cellular respiration.

Muscular System

• Muscles enable movement and perform various functions throughout the body.
• Different types of muscle are involved in all aspects of bodily movement.

Digestive System

• The digestive system processes food for absorption and utilization.
• Enzymes break down food into absorbable nutrients.
• Absorption of nutrients occurs in various sections of the digestive tract.

Urinary System

• The urinary system removes waste products from the blood.
• Kidneys filter waste, and urine is excreted.
• Regulation of fluid balance and electrolyte balance is crucial.

Immune System

• The immune system protects the body from harmful invaders (bacteria, viruses, etc.).
• White blood cells defend against infection.
• The immune system responds to various stimuli.

Reproduction

• The reproductive systems enable propagation of species.
• Systems in both sexes involve various processes, structures, and organs.

Sensory Systems

• Sensory systems provide the body with information about the external environment.
• Vision, hearing, taste, smell, and touch are crucial senses.
• Specialized sensory receptors detect specific stimuli.

Temperature Regulation

• Mechanisms maintain body temperature despite variations in the external environment.

Fluid Balance

• Maintaining proper fluid balance is critical for all physiological processes.
• Water is essential for cell function, transport of substances, and chemical reactions.

Energy Metabolism

• The process of converting food into energy and using it to power bodily functions.
• Includes pathways like cellular respiration.

Growth and Development

• Physiological processes that lead to an increase in size and complexity of an organism.
• Includes genetic and hormonal factors.

Aging Processes

• Physiological changes associated with the aging process.
• These changes may impact various organ systems.

Environmental Influences on Physiology

• External factors like temperature, altitude, and diet can significantly impact physiological processes.