Human Anatomy and Physiology: Organisation of the Human Body & Homeostasis (Weeks 1-7 Study Guide)

Organisation of the Human Body

Introduction to Anatomy and Physiology

Anatomy and physiology are foundational sciences in understanding the structure and function of the human body. Anatomy focuses on the physical structures, while physiology explores how these structures operate and interact.

• Anatomy: The study of body structures, their composition, location, and associated features.

• Physiology: The study of the functions of anatomical structures, both individually and collectively.

Types of Anatomy

• Gross (Macroscopic) Anatomy: Examines large, visible structures.

• Surface Anatomy: Studies exterior features.

• Regional Anatomy: Focuses on specific body areas.

• Sectional Anatomy: Investigates cross sections of the body.

• Systemic Anatomy: Studies organ systems.

• Clinical Anatomy: Applies anatomical knowledge to medical specialties.

• Developmental Anatomy: Examines changes from conception to adulthood, including embryology.

• Microscopic Anatomy: Studies cells (cytology) and tissues (histology).

Types of Physiology

• Cell Physiology: Functions of cells.

• Organ Physiology: Functions of specific organs.

• Systemic Physiology: Functions of organ systems.

• Pathological Physiology: Effects of diseases on organs or systems.

Levels of Organisation in the Human Body

The human body is organised into hierarchical levels, each building upon the previous.

1. Chemical Level: Atoms and molecules are the smallest units of matter.

2. Cellular Level: Cells are the smallest living units in the body.

3. Tissue Level: Groups of cells working together to perform specific functions.

4. Organ Level: Organs are made of two or more tissues working together.

5. Organ System Level: Groups of interacting organs (humans have 11 organ systems).

6. Organism Level: The individual life form.

Major Organ Systems of the Human Body

The human body consists of 11 major organ systems, each with distinct functions essential for survival and health.

• Integumentary System

• Skeletal System

• Muscular System

• Nervous System

• Endocrine System

• Cardiovascular System

• Lymphatic System

• Respiratory System

• Digestive System

• Urinary System

• Reproductive System

Additional info: Each system contributes to homeostasis and overall human performance, health, and fitness.

Anatomical Terminology

Body Regions, Positions, and Directions

Precise anatomical terms are used to describe locations, positions, and directions in the body, aiding communication in clinical and academic settings.

• Anatomical Position: The standard reference position: body upright, hands at sides, palms facing forward, feet together.

• Supine: Lying face up.

• Prone: Lying face down.

Anatomical Landmarks and Regions

• Landmarks: Structures that can be felt or palpated.

• Regions: Used to describe general areas of interest or injury.

• Quadrants: Clinicians divide the abdomen into four quadrants (RUQ, LUQ, RLQ, LLQ).

• Abdominopelvic Regions: Anatomists use nine regions for more precise mapping.

Directional Terms

• Superior/Inferior: Above/below.

• Anterior/Posterior: Front/back.

• Medial/Lateral: Toward the midline/away from the midline.

• Proximal/Distal: Closer to/farther from the point of attachment.

• Superficial/Deep: Toward/away from the body surface.

Sectional (Anatomy) Planes

• Frontal (Coronal) Plane: Divides body into anterior and posterior portions.

• Sagittal Plane: Divides body into left and right portions.

  • Midsagittal: Directly in the middle.

  • Parasagittal: Offset from the middle.

• Transverse Plane: Divides body into superior and inferior portions.

Body Cavities of the Trunk

Major Body Cavities

Body cavities are closed, fluid-filled spaces lined by serous membranes, housing and protecting internal organs (viscera).

• Functions: Protect organs from shocks and impacts; allow changes in size and shape of organs.

• Serous Membrane: Lines cavity walls and covers organs, secreting serous fluid to reduce friction.

• Visceral Serosa: Covers organs directly.

• Parietal Serosa: Lines the cavity wall.

Ventral Body Cavity (Coelom)

• Subdivided by the diaphragm into:

  • Thoracic Cavity: Contains right and left pleural cavities (lungs) and pericardial cavity (heart).

  • Abdominopelvic Cavity: Contains:

    • Peritoneal Cavity: Surrounds abdominal organs.

    • Abdominal Cavity: Contains digestive organs.

    • Pelvic Cavity: Contains reproductive organs, rectum, and bladder.

Homeostasis in the Human Body

Definition and Importance

Homeostasis refers to the maintenance of a stable internal environment, essential for survival. It is a dynamic equilibrium, with continual adaptation to internal and external changes.

• Prevents harmful changes in body fluids and cellular environments.

• Failure to maintain homeostasis leads to illness or death.

Mechanisms of Homeostatic Regulation

• Autoregulation: Automatic response in a cell, tissue, or organ.

• Extrinsic Regulation: Responses controlled by nervous and endocrine systems.

Components of Homeostatic Regulation

• Receptor: Receives the stimulus.

• Control Center: Processes the signal and sends instructions.

• Effector: Carries out instructions.

Feedback Loops

• Negative Feedback: The effector's response negates the stimulus, restoring homeostasis and maintaining a normal range. Example: Regulation of body temperature.

• Positive Feedback: The response amplifies the original change, moving the body away from homeostasis to complete a process quickly. Example: Blood clotting after injury.

Equations and Diagrams

General Feedback Loop Equation:

$\text{Stimulus} \rightarrow \text{Receptor} \rightarrow \text{Control Center} \rightarrow \text{Effector} \rightarrow \text{Response}$

Negative Feedback Example (Body Temperature):

$\text{Increase in body temperature} \rightarrow \text{Thermoreceptors} \rightarrow \text{Hypothalamus} \rightarrow \text{Sweat glands} \rightarrow \text{Sweating}$

Intended Learning Outcomes

• Describe the organisation of the human body systems.

• Identify and label major structures of each organ system.

• List major functions of each organ system.

• Demonstrate and explain joint movements using anatomical terminology.

• Identify muscles involved in sport/exercise movements.

• Provide examples of sport/exercise movements and types of muscle contraction.

• Articulate the role of each organ system in human performance, health, and fitness.

Course Schedule Overview

Week	Lecture Topic	Lab Activity
1	Organisation of the human body	Lab Activity
2	Skeletal System and joints	Lab Activity
3	Introduction to the skeletal muscle system	Lab Activity
4	Skeletal muscle system: upper extremities	Lab Activity
5	Skeletal muscle system: lower extremities (E-learning)	E-learning
6	Skeletal muscle system: trunk and spinal column; Group Presentation	Lab Activity
7	Revision: Weeks 1-6	Revision

Additional info: This schedule provides a logical progression from basic organisation to specific systems and their relevance to movement and health.

----------------------------------------