Topic_1_Orientation

Chapter 1: The Human Body - An Orientation

Introduction

• Lecture presentation by Patty Bostwick-Taylor, Florence-Darlington Technical College © 2018 Pearson Education, Ltd.

Anatomy

Definition

• Study of the structure and shape of the body and its parts.

• Involves observation to understand sizes and relationships of parts.

Types of Anatomy

• Gross Anatomy:

  • Focuses on large structures that are easily observable.

• Microscopic Anatomy:

  • Deals with structures too small to be seen with the naked eye.

  • Cells and tissues must be viewed with a microscope.

Example of Gross Anatomy

• Digestive System:

  • Includes organs such as the oral cavity, esophagus, stomach, small intestine, large intestine, and rectum.

  • Function: To break down food into absorbable nutrients and eliminate indigestible foodstuff as feces.

Example of Microscopic Anatomy

• Stomach Anatomy:

  • Important cells in gastric pits include Parietal cells (produce HCl) and Chief cells (produce pepsinogen).

Physiology

Definition

• Study of how the body and its parts work or function.

Structure-Function Relationship

• Example: The thin walls of air sacs in lungs facilitate efficient gas exchange, providing oxygen to the body.

Six Levels of Organization

1. Atoms

2. Cells

3. Tissues

4. Organs

5. Organ Systems

6. Organisms

Hierarchical Structure

• Chemical Level: Atoms combine to form molecules.

• Cellular Level: Cells are made up of molecules.

• Tissue Level: Tissues consist of similar types of cells.

• Organ Level: Organs are made up of different types of tissues.

• Organ System Level: Organ systems consist of different organs that work closely together.

• Organismal Level: Human organisms are made up of many organ systems.

Organ System Overview

Integumentary System

• Forms external body covering (skin), includes hair and nails.

• Functions:

  • Waterproofs the body.

  • Cushions/protects deeper tissues from injury.

  • Produces vitamin D with sunlight.

  • Excretes salts & regulates body temperature.

Skeletal System

• Composed of bones, cartilages, ligaments, and joints.

• Functions:

  • Provides muscle attachment for movement.

  • Protects vital organs.

  • Site for blood cell formation and mineral storage.

Muscular System

• Includes skeletal muscles.

• Functions:

  • Facilitates movement of bones.

Nervous System

• Fast-acting control system consisting of the brain, spinal cord, and nerves.

• Functions:

  • Responds to stimuli internally and externally, using sensory receptors.

Endocrine System

• Secretes hormones to regulate body functions.

• Glands include pituitary, thyroid, adrenal, pancreas, and reproductive glands.

• Functions: Growth, reproduction, nutrient use.

Cardiovascular System

• Composed of heart and blood vessels.

• Transports oxygen, nutrients, carbon dioxide, and hormones; helps protect against diseases.

Lymphatic System

• Supports the cardiovascular system; returns leaked fluids to the bloodstream and cleanses blood.

• Houses white blood cells for immunity.

Respiratory System

• Involves nasal passages, trachea, and lungs.

• Supplies oxygen and removes carbon dioxide.

Digestive System

• Comprises organs for breaking down food, nutrient absorption, and waste elimination.

Urinary System

• Includes kidneys, ureters, and bladder.

• Eliminates nitrogenous wastes and regulates water and electrolyte balance.

Reproductive System

• Male: testes, duct system for sperm production.

• Female: ovaries, uterus, and accessory structures for egg production and fetal development.

Maintaining Life

Necessary Life Functions

• Maintaining Boundaries: Separates internal from external environments.

• Movement: Locomotion and movement of substances.

• Responsiveness: Ability to sense and respond to changes.

• Digestion: Breakdown and absorption of nutrients.

• Metabolism: Chemical reactions, energy production, and building molecules.

• Excretion: Removal of waste.

• Reproduction: New cells for growth and repair.

• Growth: Increase in cell or body size.

Survival Needs

• Nutrients: Chemicals for energy and cell building.

• Oxygen: Required for metabolic reactions.

• Water: Most abundant chemical in the body (60-80%).

• Normal Body Temperature: About 37ºC (98.6ºF).

• Atmospheric Pressure: Needed for efficient gas exchange.