Anatomy and Physiology Notes

Anatomy and Physiology

Definitions

  • Anatomy: Describes the structures of the body.
    • What they are made of.
    • Where they are located.
    • Associated structures.
  • Physiology: Study of.
    • Functions of anatomical structures.
    • Individual and cooperative functions.

Human Anatomy

  • Gross Anatomy (Macroscopic Anatomy): Examines large, visible structures.
    • Surface Anatomy: Exterior features.
    • Regional Anatomy: Body areas.
    • Sectional Anatomy: Cross sections.
    • Systemic Anatomy: Organ systems.
    • Clinical Anatomy: Medical specialties.
    • Developmental Anatomy: From conception to adulthood, including embryology.
  • Microscopic Anatomy: Examines cells and molecules.
    • Cytology: Study of cells.
    • Histology: Study of tissues.

Human 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.

Clinical Observations & Diagnosis

  • Signs: Objective indications of a disease (e.g., fever).
  • Symptoms: Subjective experiences of a disease (e.g., tiredness).
  • Scientific Method in Diagnosis
    • Form a hypothesis.
    • Test the hypothesis by collecting and analyzing data.

Levels of Organization

  • Chemical Level
    • Atoms: Smallest stable units of matter.
    • Molecules: Groups of atoms.
  • Cellular Level
    • Cells: Smallest living units in the body.
  • Tissue Level
    • Tissue: A group of cells working together.
  • Organ Level
    • Organs: Made of two or more tissues working together.
  • Organ System Level
    • Organ System: A group of interacting organs.
    • Humans have 11 organ systems.
  • Organism Level
    • Organism: An individual life form.

Organ Systems

  • Integumentary System
    • Major Organs: Skin, hair, sweat glands, nails.
    • Functions: Protects against environmental hazards, regulates body temperature, provides sensory information.
  • Skeletal System
    • Major Organs: Bones, cartilages, associated ligaments, bone marrow.
    • Functions: Provides support and protection, stores calcium and other minerals, forms blood cells.
  • Muscular System
    • Major Organs: Skeletal muscles and associated tendons.
    • Functions: Provides movement, protection, and support; generates heat.
  • Nervous System
    • Major Organs: Brain, spinal cord, peripheral nerves, sense organs.
    • Functions: Directs immediate responses to stimuli, coordinates organ systems, provides and interprets sensory information.
  • Endocrine System
    • Major Organs: Pituitary, thyroid, and adrenal glands; pancreas and gonads; endocrine tissues in other systems.
    • Functions: Directs long-term changes, adjusts metabolic activity and energy use, controls structural and functional changes during development.
  • Cardiovascular System
    • Major Organs: Heart, blood, blood vessels.
    • Functions: Distributes blood cells, water, nutrients, waste products, oxygen, and carbon dioxide; distributes heat to control body temperature.
  • Lymphatic System
    • Major Organs: Spleen, thymus, lymphatic vessels, lymph nodes, tonsils.
    • Functions: Defends against infection and disease; returns tissue fluids to the bloodstream.
  • Respiratory System
    • Major Organs: Nasal cavities, sinuses, larynx, trachea, bronchi, lungs, alveoli.
    • Functions: Delivers air to alveoli, provides oxygen to bloodstream, removes carbon dioxide from bloodstream, produces sounds for communication.
  • Digestive System
    • Major Organs: Teeth, tongue, pharynx, esophagus, stomach, small intestine, large intestine, liver, gallbladder, pancreas.
    • Functions: Processes and digests food, absorbs water and nutrients, stores energy reserves.
  • Urinary System
    • Major Organs: Kidneys, ureters, urinary bladder, urethra.
    • Functions: Excretes waste products, controls water balance, stores urine, regulates blood ion concentrations and pH.
  • Male Reproductive System
    • Major Organs: Testes, epididymides, ductus deferentia, seminal vesicles, prostate gland, penis, scrotum.
    • Functions: Produces sperm, seminal fluids, and hormones; sexual intercourse.
  • Female Reproductive System
    • Major Organs: Ovaries, uterine tubes, uterus, vagina, labia, clitoris, mammary glands.
    • Functions: Produces oocytes and hormones, supports developing embryo, provides milk, sexual intercourse.

Medical Terminology

  • Terms related to the body in health and disease.
  • Most commemorative names or eponyms have been replaced by precise terms.

Anatomical Terminology

  • Surface Anatomy: Locating structures on or near the body surface.
  • Anatomical Landmarks
    • Anatomical Position: Hands at sides, palms forward.
    • Supine: Lying down, face up.
    • Prone: Lying down, face down.
  • Anatomical Regions
    • Abdominopelvic Quadrants
    • Abdominopelvic Regions
  • Anatomical Directions: Reference terms based on subject.
    • Superior: Above; at a higher level (toward the head).
    • Inferior: Below; at a lower level; toward the feet.
    • Anterior (Ventral): The front surface (belly side).
    • Posterior (Dorsal): The back surface (the back).
    • Medial: Toward the midline.
    • Lateral: Away from the midline.
    • Proximal: Toward the point of attachment of a limb to the trunk.
    • Distal: Away from the point of attachment of a limb to the trunk.
    • Cranial (Cephalic): Toward the head.
    • Caudal: Toward the tail (coccyx in humans).
    • Superficial: At, near, or relatively close to the body surface.
    • Deep: Toward the interior of the body; farther from the surface.

Body Cavities

  • Essential Functions
    • Protect organs from shocks and impacts.
    • Permit significant changes in size and shape of internal organs.
  • Ventral Body Cavity (Coelom): Divided by the diaphragm.
    • Thoracic cavity
    • Abdominopelvic cavity
  • Body cavities contain viscera (internal organs).

Serous Membrane (Serosa)

  • Lines body cavities and covers organs.
  • Consists of parietal and visceral layers.
    • Parietal serosa lines cavity.
    • Visceral serosa covers organ.

Thoracic Cavity

  • Right and left pleural cavities: Contain right and left lungs.
  • Mediastinum
    • Upper portion filled with blood vessels, trachea, esophagus, and thymus.
    • Lower portion contains pericardial cavity.
    • The heart is located within the pericardial cavity.

Abdominopelvic Cavity

  • Abdominal Cavity: Superior portion.
    • Diaphragm to top of pelvic bones.
    • Contains digestive organs.
    • Retroperitoneal space: Area posterior to peritoneum and anterior to muscular body wall; contains pancreas, kidneys, ureters, and parts of the digestive tract.
  • Pelvic Cavity: Inferior portion.
    • Medial to pelvic bones.
    • Contains reproductive organs, rectum, and bladder.

Sectional Anatomy

  • A section is a slice through a three-dimensional object.
    • Used to visualize internal organization.
    • Important in radiological techniques (MRI, PET, CT).
  • Sectional Plane: A single view along a two-dimensional flat surface.
    • Frontal (Coronal) Plane: Vertical plane that divides body into anterior and posterior portions. A cut in this plane is a frontal section (coronal section).
    • Sagittal Plane: Vertical plane dividing body into left and right portions. A cut in this plane is a sagittal section. Midsagittal plane lies in the middle. Parasagittal plane is offset from the middle.
    • Transverse Plane: Divides body into superior and inferior portions. A cut in this plane is called a transverse section (cross section).
    • Oblique: divides body at an angle (non-90○)

Homeostasis

  • All body systems work together to maintain a stable internal environment.
  • Systems respond to external and internal changes to keep variables within normal ranges (body temperature, fluid balance).

Homeostatic Regulation

  • Autoregulation: Automatic response in a cell, tissue, or organ to an environmental change.
  • Extrinsic Regulation: Responses controlled by nervous and endocrine systems.

Homeostatic Regulatory Mechanism

  • Receptor: Receives the stimulus.
  • Control Center: Processes the signal and sends instructions.
  • Effector: Carries out instructions.
  • Limits fluctuations of internal conditions to keep them close to a set point, or desired value.

Negative Feedback

  • The response of the effector negates the stimulus.
  • Body is brought back into homeostasis.
  • Normal range is maintained.

Positive Feedback

  • Initial stimulus produces a response that amplifies the original change in conditions.
  • Body is moved away from homeostasis.
  • Normal range is not maintained.
  • A positive feedback loop completes a dangerous process quickly to reestablish homeostasis.

Systems Integration & Equilibrium

  • Systems work together to maintain homeostasis.
  • Homeostasis is a state of equilibrium.
    • Opposing forces are in balance.
    • Dynamic equilibrium—continual adaptation.
  • Physiological systems work to maintain balance.
  • Failure results in disease.