General Physiology Introduction

General Physiology Introduction

• Physiology is the study of biological function, how the body works, from cells to tissues, organs, systems, and how the entire organism performs essential life functions.

Objectives

• Physiology aims to review organ systems.
• It investigates homeostasis and feedback control mechanisms.
• It examines body fluid compartments.
• It introduces cells.

Organ Systems Categories

• Four categories of organ systems, include support, movement, and protection.

Integumentary System

• The integumentary system includes skin, hair, nails, sweat glands, and sebaceous glands.
• It's the largest organ of the body.

Skeletal and Muscular Systems

• These systems provide support and enable movement.
• Skeletal system components include skull, spinal column, ribs, humerus, ulna, radius, carpals, metacarpals, phalanges, femur, patella, tibia, fibula, tarsals, metatarsals, and phalanges among others.
• Muscular system components include various muscles like frontalis, zygomaticus, sternocleidomastoid, trapezius, deltoid, pectoralis major, biceps brachii, rectus abdominus, external oblique, sartorius, gracilis, adductor longus, rectus femoralis, and vastus lateralis, among others.

Integration and Coordination

• Nervous system: Composed of the brain, spinal cord, and nerves. Nerves transmit nerve impulses from sensory organs to the brain and spinal cord, as well as to muscles and glands.
• Sense organs provide information about the environment. The brain processes this information, and the body responds.
• Endocrine system: Consists of hormone glands that release chemical messengers between body parts.

Maintenance of the Body

• Cardiovascular system: The heart and blood vessels circulate blood. Blood carries nutrients and oxygen to cells and removes waste. Lymphatic system produces cells for blood.
• Respiratory system: The lungs and associated tubes bring oxygen into the lungs, and takes carbon dioxide out of the lungs.
• Digestive system: The mouth, esophagus, stomach, intestines, and accessory organs like teeth, tongue, salivary glands, liver, gallbladder and pancreas process food into nutrients.
• Urinary system: The kidneys and urinary bladder eliminate nitrogenous waste and regulate the fluid and chemical balance in the blood.

Reproduction and Development

• Male and female reproductive systems include various organs responsible for reproduction and development from fertilisation until birth.

Homeostasis and Feedback Control

• Homeostasis maintains stable conditions in the internal environment.
• Various organ systems work together to maintain nearly constant conditions, like the lungs providing oxygen and the kidneys maintaining ion balance.

Contribution of Organ Systems to Homeostasis

• Nervous system regulates muscular activity and glandular secretion.
• Endocrine System regulates metabolic processes.
• Muscular system enables body movement and thermoregulation.
• Circulatory system transports substances throughout the body.
• Respiratory system obtains oxygen and eliminates carbon dioxide.
• Gastrointestinal tract digests food to provide nutrients.
• Renal system eliminates body waste and regulates the volume and chemical balance in the blood.

Negative Feedback

• Keeps a variable close to a set point.
• Has three components: sensor, regulatory center, and effector.
• Sensor detects change, regulatory center activates effector, effector reverses change, and sensor stops the process.

Positive Feedback

• Brings greater change in the same direction.
• Some examples are helpful like in blood clotting, digestion, or childbirth.
  • Sometimes, positive feedback loops can be harmful, like fever or death.

Body Fluid Compartments

• Body fluids are in two compartments: intracellular fluid (inside cells); extracellular fluid (outside cells).
• These compartments contain water and different chemical compositions.
  • ICF: 2/3 total body water.
  • ECF: 1/3 total body water.
    • ECF subdivided into interstitial fluid (surrounding cells) and blood plasma.

Cell Structure and Function

• The notes provide a brief overview of cell structures and functions based on the image presented in the slides.
  • Note that all cell components are included but the exact roles of each cell are not detailed.

Cell Membrane

• Gives form and shape to the cell.
• Controls passage of materials into and out of the cell.

Nucleus

• Controls gene expression and mediates DNA replication during cell division.
• Controls hereditary characteristics of an organism.
• Involved in protein synthesis, cell division, growth, and differentiation.
• Stores hereditary material (DNA) in chromatin.

Mitochondria

• Releases energy from food molecules.
• Forms adenosine triphosphate (ATP).

Endoplasmic Reticulum

• Smooth endoplasmic reticulum (SER) metabolizes compounds and stores Ca2+ in muscles.
• Rough endoplasmic reticulum (RER) assists in protein synthesis.

Golgi Apparatus

• Synthesizes carbohydrates, packs molecules, and secretes lipids and glycoproteins.

Lysosome

• Digests foreign molecules, worms, and damaged organisms.
• Occupies space, and holds various organelles of the cell in place.

Explore the fundamentals of physiology, including the study of organ systems and homeostasis. This quiz reviews key concepts like the integumentary, skeletal, and muscular systems. Test your understanding of how these systems function to maintain life.