General Physiology BMS114 Quiz

Introduction to General Physiology

• General Physiology is a subject in BMS114.
• Science is magic, that works.

Levels of Structural Organization in the Body

• Cellular Level: The cell is the basic structural and functional unit of the body.
• Tissue Level: A group of similar cells with similar structure and function.
• Organ Level: An organ is a collection of similar tissues that carry out a specific function.
• System Level: A collection of related organs that work together to perform a complex function.

Cell Structures and Functions

• Cell Membrane: A thin membrane that encloses the cell, separating its contents from the surrounding environment.

  • The fluid within the cell is called intracellular fluid (ICF).
  • The fluid outside the cell is called extracellular fluid (ECF).
  • Composed of a phospholipid bilayer with proteins interspersed within it.
  • Phospholipids have hydrophilic heads and hydrophobic tails.
  • The bilayer structure gives flexibility and selective permeability.
  • Proteins in the cell membrane include integral proteins, which pass all the way through the membrane, and peripheral proteins, which are only attached to on surface.
  • Some proteins form complexes with carbohydrates, important for self-recognition.
  • Cholesterol embedded in the bilayer affects membrane permeability.

• Cellular Respiration.

  • ATP source of energy for the body
  • Processing and packaging of substances formed in RER.
  • Secretory vesicle storage.
  • Protein synthesis

• Cellular Subdivisions:

  • Plasma membrane
  • Nucleus
  • Cytoplasm

• Many cells share common features despite different structures and functions.

Functions of Cell Membrane Proteins

• Structural proteins
• Passive Channels: Non-gated and gated channels (voltage & ligand gated).
• Facilitated Diffusion Carriers
• Active Transport Carriers/Pumps
• Receptors

Body Compartments

• The body of a normal adult male is comprised of:
  • 60% water (Total Body Water (TBW))
  • 18% protein
  • 15% fat
  • 7% minerals

Movement of Molecules Across Cell Membrane

• Passive Transport
  • Simple Diffusion: movement of small substances from high to low concentration.
  • Osmosis: Movement of water across a selectively permeable membrane from high to low water concentration.
  • Facilitated Diffusion: needs carrier and concentration gradient but no energy.
• Active Transport
  • Primary Active Transport: energy provided directly by ATP. e.g. Sodium-Potassium Pump.
  • Secondary Active Transport: Energy from electrochemical gradient created by pumps.
• Bulk
  • Endocytosis: movement of molecules into the cell (e.g. Pinocytosis and Phagocytosis)
  • Exocytosis: movement of molecules out of the cell

Homeostasis

• Maintenance of a constant internal environment (extracellular fluid) within the body.
• Body has mechanisms to keep cells in constant environment.
• Example: body temperature regulation.

Components of a Homeostatic System

• Receptors: detect changes in internal environment.
• Integrating Center: processes information and sets a set point.
• Effectors: respond to maintain set point.
• Communication System: links different parts together (e.g., nerves, hormones).

Types of Communication Systems

• Endocrine System: communication via hormones.
• Nervous System: communication via nerve impulses.

Components of Homeostatic Control Systems

• Stimulus
• Receptor
• Integrating Center
• Effector
• Response
• Feedback

Feedback Mechanisms

• Negative Feedback: minimizes the initial change. Example: regulation of body temperature.
• Positive Feedback: aggravates the initial change. Example: blood coagulation , action potential, delivery of the baby.