Study Notes for Anatomy and Physiology: Chapter 1

Chapter 1: Introduction to Anatomy and Physiology

Introduction to Human Anatomy and Physiology

  • Human Anatomy

    • Derived from Greek: ana (up) + tomy (process of cutting)
    • Defined as the science that studies the structure of the human body and the relationship of body parts.

  • Human Physiology

    • Defined as the science that studies the function of the human body.
    • Key concept: The structure of a body part often reflects its function.

Selected Branches of Anatomy and Physiology

Table 1.1 Branches of Anatomy
  • Embryology: Study of the first eight weeks of development after fertilization.
  • Developmental Biology: Complete development from fertilization to death.
  • Cell Biology: Study of cellular structures and functions.
  • Histology: Microscopic structure of tissues.
  • Gross Anatomy: Structures that can be examined without a microscope.
  • Systemic Anatomy: Structure of specific systems (e.g., nervous, respiratory).
  • Regional Anatomy: Specific regions of the body (e.g., head, chest).
  • Surface Anatomy: Surface markings of the body for understanding internal anatomy.
  • Imaging Anatomy: Body structures visualized with techniques (e.g., x-rays, MRI).
  • Pathological Anatomy: Structural changes associated with diseases.
Branches of Physiology
  • Neurophysiology: Functional properties of nerve cells.
  • Endocrinology: Hormones and their control of body functions.
  • Cardiovascular Physiology: Functions of heart and blood vessels.
  • Immunology: Body's defenses against disease-causing agents.
  • Respiratory Physiology: Functions of the lungs and airways.
  • Renal Physiology: Functions of the kidneys.
  • Exercise Physiology: Changes due to muscular activity.
  • Pathophysiology: Functional changes associated with disease and aging.

Levels of Structural Organization

  • Chemical Level: Includes all atoms (e.g., C, H, O, N) and molecules (e.g., carbohydrates, proteins, lipids, nucleic acids).
  • Cell Level: Basic structural and functional unit of living organisms; approximately 100 trillion cells in the human body (e.g., epithelial, nerve, muscle cells).
  • Tissue Level: Groups of cells working together (e.g., epithelial, nervous, muscle, connective tissues).
  • Organ Level: Two or more tissues joined together (e.g., lungs, heart, liver, stomach).
  • System Level: Several related organs with a common function (e.g., digestive system, endocrine system).
  • Organism Level: A single living individual with all body parts functioning together.

Human Body Systems

  • Objective: Understand the general function and components of each body system.
Controlling Systems
  • Monitor and Detect Changes in Body Components
  • Regulate Homeostasis
  • Types:
    • Nervous System
    • Endocrine System
Nervous System
  • Components:
    • Brain, spinal cord, nerves, and special sense organs (e.g., eye, ear).
  • Functions:
    • Regulates body activity through nerve impulses.
    • Detects changes in internal and external environments.
    • Activates (excites) muscles and glands.
Endocrine System
  • Components:
    • All glands producing hormones (e.g., thyroid, adrenal glands, pancreas).
  • Function:
    • Regulates body activity by releasing hormones into the blood.
Vegetative Systems
  • Provide nutrition for cells and removal of wastes.
  • Types:
    • Digestive System
    • Respiratory System
    • Urinary System
    • Circulatory System
Digestive System
  • Components:
    • GI tract: Mouth, pharynx, stomach, small intestine, large intestine, anus;
    • Accessory organs: Salivary glands, liver, gallbladder, pancreas.
  • Functions:
    • Breakdown of food mechanically and chemically.
    • Absorption of nutrients.
    • Eliminates solid waste.
Respiratory System
  • Components:
    • Lungs and air passages.
  • Function:
    • Supplies O₂, eliminates CO₂, regulates acid-base balance, and produces sound.
Urinary System
  • Components:
    • Kidneys, ureters, urinary bladder, urethra.
  • Function:
    • Produces, stores, and eliminates urine; regulates water and mineral balance; maintains blood volume and composition; regulates acid-base balance; regulates red blood cell formation.
Cardiovascular System
  • Components:
    • Heart, blood vessels, and blood.
  • Function:
    • Transportation, distribution of nutrients, delivery of O₂ to cells, elimination of wastes including CO₂, protection against disease, regulation of temperature, acid-base balance, and water content.

Protective Systems

  • Provide protection against foreign invaders and injury.
  • Types:
    • Integumentary System
    • Circulatory System
    • Lymphatic and Immune System
Integumentary System
  • Components:
    • Skin and associated derivatives (hair, nails, sweat glands, oil glands).
  • Function:
    • Provides mechanical protection, regulates temperature, eliminates wastes, vitamin D production, sensation, and fat storage.
Lymphatic System and Immunity
  • Components:
    • Lymph, lymphatic vessels, lymph nodes, spleen, thymus, tonsils.
    • Contains lymphocytes (white blood cells).
  • Function:
    • Protects body by filtering blood, produces antibodies and immune cells, returns lost proteins, transports lipids.
Skeletal System
  • Components:
    • Bones and joints of the body.
  • Function:
    • Protects and supports the body, provides sites for muscle attachment, aids body movements, stores minerals and lipids, and involved in blood cell formation.
Muscular System
  • Components:
    • Primarily skeletal muscle tissue, including smooth and cardiac muscle.
  • Function:
    • Powers body movements, stabilizes body positions, generates heat.
Reproductive System
Female Reproductive System
  • Components:
    • Ovaries, uterine tubes, uterus, vagina, mammary glands.
  • Function:
    • Produces oocytes (eggs), releases hormones that regulate reproduction and body processes, transports and stores gametes, houses developing embryo/fetus, and produces milk.
Male Reproductive System
  • Components:
    • Testes, epididymis, ductus deferens, seminal vesicles, prostate, penis.
  • Function:
    • Produces sperm, releases hormones that regulate reproduction and body processes, transports and stores gametes.

Characteristics of the Living Human Organism

Basic Life Processes
  • Metabolism: Sum total of all chemical reactions in the body.
    • Anabolism: Metabolic processes that build up complex molecules; requires energy.
    • Example: Building muscle tissue through strength training.
    • Catabolism: Breaks down complex molecules into simpler ones; yields energy.
    • Example: Digesting food for energy.
  • Responsiveness: Ability to respond to changes in the environment.
  • Movement: Includes movement of organelles, cells, organs, and the body.
  • Growth: Increase in size; includes cellular enlargement and cell division.
  • Differentiation: Development of specialized cells from stem cells.
  • Reproduction: Formation of new cells and production of new individuals.

Homeostasis

  • Definition: Maintenance of an optimal state or steady state.
    • Example: Maintaining body temperature.
  • Homeostatic imbalance can lead to disease or death.
  • Constant adjustments are necessary to maintain homeostasis.
    • Recognizing cues from the body (e.g., hunger, heat) indicates homeostatic attempts.
Homeostatic Feedback Loop
  1. Stimulus: Disruption in homeostasis.
  2. Control Center: Receives input and processes the information.
  3. Effectors: Produce response to correct the condition.
  4. Response: Alters the controlled condition to restore homeostasis.
Homeostasis of Body Fluids
  • Importance of maintaining volume and composition of body fluids:
    • Intracellular Fluid: Fluid within cells.
    • Extracellular Fluid: Fluid outside cells:
    • Interstitial fluid, blood plasma, lymph, cerebrospinal fluid, synovial fluid, aqueous humor, vitreous humor.
Feedback Systems
  • Definition: Mechanism to maintain homeostasis involving a cycle of monitoring and responding.
  • Components:
    • Stimulus: A change in the environment.
    • Receptors: Sense changes and send information.
    • Control Center: Processes inputs.
    • Effectors: Produce responses to restore homeostasis.
Positive vs Negative Feedback Systems
  • Positive Feedback: Reinforces a change (e.g., contractions during childbirth).
  • Negative Feedback: Negates changes returning to the original state (e.g., blood pressure regulation).

Anatomical Position

  • Defined as the body standing erect, facing the observer, with:
    • Head level, head and eyes forward.
    • Arms at the sides, palms facing forward.
    • Feet together and flat on the floor.

Directional Terms

  • Used to precisely locate parts of the body relative to others.
  • Superior (Cranial): Toward the head; above.
    • Example: The head is superior to the abdomen.
  • Inferior (Caudal): Away from the head; below.
    • Example: The navel is inferior to the chin.
  • Anterior (Ventral): Toward the front; in front of.
    • Example: The breastbone is anterior to the spine.
  • Posterior (Dorsal): Toward the back; behind.
    • Example: The heart is posterior to the breastbone.
More Directional Terms
  • Medial: Toward the midline; on the inner side.
    • Example: The heart is medial to the arm.
  • Lateral: Away from the midline; on the outer side.
    • Example: The arms are lateral to the chest.
  • Intermediate: Between medial and lateral structures.
    • Example: The collarbone is intermediate between the breastbone and shoulder.
  • Proximal: Closer to the body's origin or attachment point.
    • Example: The elbow is proximal to the wrist.
  • Distal: Farther from the origin or body attachment point.
    • Example: The knee is distal to the thigh.
  • Superficial (External): Towards the body's surface.
    • Example: The skin is superficial to skeletal muscles.
  • Deep (Internal): Away from the surface; more internal.
    • Example: The lungs are deep to the skin.

Planes and Sections

  • Definition: Imaginary flat surfaces dividing the body.
  • Types:
    • Transverse (Horizontal): Divides body into superior and inferior parts.
    • Sagittal (Vertical): Divides body into right and left parts.
    • Midsagittal (Median): Equal halves.
    • Parasagittal: Unequal halves.
    • Coronal (Frontal): Divides body into anterior and posterior sections.
Practice Identifying Planes & Sections
  • Review illustrations for identifying planes:
    • (A) Midsagittal Plane
    • (B) Frontal Plane
    • (C) Transverse Plane

Body Cavities

  • Cranial Cavity: Formed by cranial bones; contains the brain.
  • Vertebral Canal: Formed by vertebral column; contains the spinal cord.
  • Thoracic Cavity: Chest cavity; contains pleural and pericardial cavities and mediastinum.
  • Pleural Cavity: Surrounds each lung.
  • Pericardial Cavity: Surrounds the heart.
  • Abdominopelvic Cavity: Subdivided into abdominal and pelvic cavities, containing various organs.

Serous Membranes

  • Definition: Double-layered membranes associated with body cavities.
  • Components:
    • Parietal Layer: Lines cavity walls.
    • Visceral Layer: Covers and adheres to organs.
  • Types:
    • Pleura: Associated with lungs.
    • Pericardium: Associated with the heart.
    • Peritoneum: Associated with the abdominal cavity.

Abdominopelvic Regions

  • Nine regions used to locate pain, tumors, or abnormalities, defined by horizontal and vertical lines.
    • Horizontal Lines:
    • Subcostal Line: Below 10th costal cartilage.
    • Transtubercular Line: Across superior iliac crest.
    • Vertical Lines:
    • Left and Right Midclavicular Lines: Just medial to nipples.
Abdominopelvic Regions
  • Right hypochondriac
  • Epigastric
  • Left hypochondriac
  • Right lateral
  • Umbilical
  • Left lateral
  • Right inguinal
  • Hypogastric
  • Left inguinal
Abdominopelvic Quadrants
  • Divides abdominal cavity into 4 quadrants:
    • Right Upper Quadrant (RUQ)
    • Left Upper Quadrant (LUQ)
    • Right Lower Quadrant (RLQ)
    • Left Lower Quadrant (LLQ)

Preparation for Topic #1 Quiz

  • Review lecture notes and focus on questions outlined in material.