BIO4008M Anatomy & Physiology

BIO4008M – Anatomy and Physiology

Overview of Homeostasis

  • Homeostasis defined: The mechanisms involved in maintaining a relatively stable internal environment, which includes a normal range for various physiological parameters such as pH and temperature.
    • Etymology: Homeo = ‘same or unchanging’; Stasis = ‘to stand still, stay, or stop’.
    • Importance: Essential for growth and survival of the organism.

Course Information

Become a Course Rep

  • Opportunity: Improve the academic experience and work with lecturers to gather feedback and develop solutions.
  • Benefits:
    • Course Rep of the month recognition with vouchers for local venues.
    • Development sessions to enhance employability skills.
    • Discount at Archie's Bar and The Lounge.
  • Eligibility: Nominations for Course Reps to be submitted by a specified date with a cap of three representatives per course per year group.

Frequently Asked Questions for Course Reps

  • Time Commitment: Approximately one hour a week, though this may fluctuate based on specific weeks when more engagement is needed.
  • Role Responsibilities:
    • Gather feedback from classmates on course strengths and areas for improvement.
    • Communicate feedback to lecturers and collaborate on solutions.
    • Report back to class on changes implemented.
  • Training Provided: Training at the start of the year with optional monthly development sessions throughout the year.

Objectives of the Course

  • Understanding: How the human body maintains balance (homeostasis) for survival and growth.
  • Recognizing: The human body consists of approximately 10 body systems contributing to homeostasis.
  • Coordinated Responses: Homeostasis is managed by the Nervous and Endocrine systems predominantly.
  • Control Mechanisms: Distinction between intrinsic (local) and extrinsic (systemic) controls; examples include feedback loops.

Feedback Mechanisms

  • General Pathway for Feedback:
    • Sensor: A receptor detects changes.
    • Relay System: Transmits signals back to the integration center.
    • Control Center: Decodes inputs and initiates responses.
    • Efferent Signals: Signals carrying the response message.
    • Effectors: Target cells or organs where change occurs to restore homeostasis.

Units and Modules

  • Unit 4: Homeostasis
    • Module 8: Homeostasis and Feedback Loops
    • Module 9: Homeostatic Maintenance
    • Module 10: Homeostasis Integration of Systems
  • Related Units (2 and 3): Introduction to Anatomy and Physiology and Levels of Organization.

Hierarchical Structure of Biological Organization

  • Atoms form Molecules.
  • Molecules form Cells.
  • Cells form Tissues: Types include epithelial, connective, muscular, and nervous tissues.
  • Tissues form Organs.
  • Organs form Organ Systems.
  • Systems form the Human Body.
    • Essential elements for life: Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), Sulfur (S).

Control of Body Systems and Imbalances

  • Homeostasis failures often lead to pathology or disease.
  • Homeostatic Imbalances: Increase disease susceptibility and are associated with aging.

Critical Characteristics of Life

  • Movement: Ability to change position.
  • Responsiveness: Capability to respond to changes and maintain homeostasis.
  • Growth: Increase in body size with limited shape change.
  • Reproduction: Production of new cells and organisms.
  • Respiration: Exchange of O2 for CO2; energy production via metabolism.
  • Digestion: Breakdown of food.
  • Absorption: Movement of substances across membranes.
  • Circulation: Transport of substances in body fluids.
  • Assimilation: Alteration of absorbed substances.
  • Excretion: Removal of wastes (e.g., urea).

Factors Under Homeostatic Regulation

  1. Levels of Nutrients
  2. Blood and Tissue Gas Concentrations (CO2, O2)
  3. Concentration of Waste Products (e.g., NH4+)
  4. Maintenance of pH (normal range = 7.35 - 7.45)
  5. Maintenance of Water Content (blood volume)
  6. Concentration of Electrolytes (Osmolarity)
  7. Temperature Regulation
  8. Blood Pressure Stability

Body Systems Contributing to Homeostasis

  • Primarily the Nervous and Endocrine Systems, with contributions from:
    • Cardiovascular
    • Renal (Urinary)
    • Respiratory
    • Digestive
    • Musculoskeletal
    • Integumentary
    • Immune

Overview of Control Systems

  • Intrinsic Control Systems: Local controls inherent to tissue or organ responses.
  • Extrinsic Control Systems: Responses driven largely by nervous and endocrine systems.
  • Feedback Mechanisms: Mostly negative, sometimes positive, rarely feedforward.

Types of Feedback Mechanisms

Negative Feedback

  • A mechanism by which a change in a physiological parameter triggers processes that counteract that change.
    • Example: Body temperature regulation. When temperature exceeds the normal range, mechanisms (like sweating) are activated to lower it back down.

Positive Feedback

  • A mechanism that amplifies responses and processes to move a variable further in the same direction as the initial change.
    • Example: During childbirth, the hormone oxytocin is released to increase uterine contractions, which leads to more oxytocin release until delivery occurs.

Specific Feedback Examples

Body Temperature Regulation (Negative Feedback)

  1. Sensor: Temperature receptors detect elevated body temperature.
  2. Control Center: Hypothalamus processes information.
  3. Effectors: Skin blood vessels dilate, sweat glands increase output.
  4. Outcome: Body heat is lost, lowering temperature back to normal range.

Blood Glucose Homeostasis

  • Normal Levels: Euglycaemia (4-8 mM).
  • Increase in glucose triggers insulin release, while a decrease triggers glucagon release, showing the negative feedback mechanism.

Blood Pressure Regulation

  • Decrease in Blood Pressure: Detected by baroreceptors, resulting in sympathetic response to increase heart rate and vascular resistance, thus raising blood pressure.
  • Increase in Blood Pressure: Detected and responds to decrease heart output and vasodilate.

Resources for Further Information

  • Library Resources: Hard copies, e-books, journals.
  • Online Resources and Apps: Websites such as Anatomy TV, Brain Tutor, and various educational platforms like Khan Academy and Study.com.
  • YouTube Channels: For visual learning about anatomy and physiology.

Additional Resources

  • Recommended Websites: Physiology.org, OpenStax, and educational YouTube videos for visual aid.

Tasks and Activities for Class

  • Group discussions on homeostasis topics, completing diagrams of feedback loops, and exploration of hormone functions in the endocrine system.
  • Study materials with links to practice questions and review exercises for refreshers.