Comprehensive Study Notes on Human Anatomy and Physiology

Fundamental Definitions of Anatomy and Physiology

• Anatomy: The study of structures and the relationship of structures without regard for their functions.

  • Etymology of Anatomy: The term derives from "Ana", meaning upward, and "Tome", meaning to cut.

• Physiology: The study of the functions of the body parts.

Subdivisions of Anatomy

• Macroscopic Subdivisions: These involve structures that can be examined without the use of a microscope. There are two types:

  • Gross Anatomy: The dissection of human cadavers.

  • Surface Anatomy: The study of the form and markings of the surface of the body.

• Microscopic Subdivisions: These involve structures that must be examined with the use of a microscope. There are two types:

  • Histology: The study of the structures of tissues.

  • Cytology: The study of the structure of cells.

• Pathology: The study of structural changes associated with disease.

Diagnostic Techniques for Internal Structures

• Radiographs (X-ray): Radiation produces an image on a photographic film.

• Computerized Axial Tomography (CAT scans): A computer produces a tomography of cross-sectional scans along a single axis of a bodily structure, resulting in a 3D scan of an image.

  • Tomography: A technique used to produce a detailed x-ray of a specific plane or section of a solid object while blurring out images of other planes that are of no particular interest.

• Magnetic Resonance Imaging (MRI’s or NMR’s): Produces electronic images of specific atoms and molecular structures within cells, tissues, and organs.

• Positron Emission Tomography (PET scans): Radioactive isotopes are injected into the body. These isotopes emit positrons, which produce gamma rays to form an image.

• Sonography: Sound waves strike objects and bounce back to form an image. This is used in applications such as cardiac echos and monitoring pregnant mothers (sonogram).

Levels of Structural Organization

• Chemical Level: Includes all chemical substances essential for maintaining life.

  • Atoms include elements such as carbon ($C$), hydrogen ($H$), oxygen ($O$), nitrogen ($N$), calcium ($Ca$), potassium ($K$), and sodium ($Na$).

  • Atoms combine to form molecules. Familiar examples include proteins, CHO (carbohydrates), fats, and vitamins.

  • Molecules combine to form a cell.

• Cellular Level: Cells are the basic structural and functional units of an organism.

  • Organelles: Specialized structures within cells, such as the nucleus and mitochondria, that perform specific functions.

  • Cell types include muscle cells, nerve cells, and blood cells.

• Tissue Level: Groups of similar cells and their intercellular material (material between cells) performing a specific function. There are four types of tissues:

  • Muscle tissue.

  • Nervous tissue.

  • Connective tissue.

  • Epithelial tissue.

• Organ Level: Structures composed of two or more different tissues that have specific functions and usually possess recognizable shapes.

• System Level: Consists of related organs that have a common function. An organ can be part of more than one system; for example, the pancreas belongs to both the digestive and endocrine systems.

• Organism level: The integration of all systems into an individual. This is the largest level of the human body.

Systems of the Human Body

• Integumentary System: Skin and related structures including hair, sweat glands, and oil glands.

• Skeletal System: Bones and associated cartilage and joints.

• Muscular System: Specifically skeletal muscle tissue. (Note: Smooth and cardiac muscle tissues are categorized within other systems).

• Nervous System: Brain, spine, nerves, and sense organs.

• Endocrine System: All glands and tissues that produce hormones.

• Cardiovascular System: Blood, blood vessels, and the heart (composed of cardiac muscle tissue).

• Lymphatic System: Lymph, lymph nodes, spleen, thymus, and tonsils.

• Respiratory System: Trachea, bronchi, lungs, and alveoli.

• Digestive System: Mouth, pharynx, esophagus, stomach, and associated organs such as salivary glands, liver, and gallbladder.

• Urinary System: Kidneys, ureters, bladder, and urethra.

• Reproductive System: Ovaries and testes.

Anatomical Position

• The body is in an upright position (standing erect).

• The person is facing the observer.

• The upper extremities are placed along the sides.

• The palms are turned forward.

• The feet are flat on the ground.

Directional Terms

• Superior (Cranial or Cephalid): Toward the head or the upper part of a structure.

• Inferior (Caudal): Away from the head or the upper part of a structure.

• Anterior (Ventral): Near or at the front of the body.

• Posterior (Dorsal): Near or at the back of the body.

• Medial: Toward the midline of the body.

• Lateral: Away from the midline.

• Intermediate: Located between a medial and a lateral structure.

• Deep: Away from the surface of the body.

• Superficial: Toward or on the surface of the body.

• Ipsilateral: On the same side.

• Contralateral: On the opposite side.

• Distal: Farther from the point of reference (used strictly with extremities).

• Proximal: Nearer to the point of reference (used strictly with extremities).

Planes of the Human Body

• Sagittal Plane: A vertical plane that divides the body into right and left portions.

  • Midsagittal: Passes down the midline of the body, dividing it into equal right and left sides.

  • Parasagittal: ("para" meaning near) divides the body into unequal right and left sides.

• Frontal (Coronal or Cross-Sectional) Plane: Divides the body into anterior and posterior portions.

• Horizontal (Transverse) Plane: Divides the body into superior and inferior portions.

• Oblique Plane: A diagonal cut through the body.

Body Cavities

• Definition: Spaces within the body containing internal organs. Their functions are to separate, protect, and support organs.

• Separation: Each cavity is separated by ligaments, muscles, and bones.

• Dorsal (Posterior) Cavity: Located near the posterior surface of the body.

  • Cranial Cavity: Contains the skull and the brain.

  • Minor cavities within the skull include the oral cavity, nasal cavity, sinus (paranasal) cavities, pulp cavities (inside teeth), orbital cavities (for eyes), and middle ear cavities.

  • Vertebral Canal: Contains the vertebrae of the backbone, the spinal cord, and the roots (beginnings) of the spinal nerves.

• Ventral Cavity: Located on the anterior aspect of the body. Organs within this cavity are termed the viscera.

  • Serous Membrane: A thin, slippery membrane lining the cavity walls and covering the organs.

  • Thoracic Cavity (Superior portion/Chest cavity):

    • Pleural Cavity: ("pleura" meaning rib/side) contains the lungs.

    • Pericardial Cavity: Contains the heart, located within the mediastinum.

    • Mediastinum: The area between the lungs, extending from the sternum to the vertebral column. It includes the heart, thymus gland, esophagus, and trachea, but excludes the lungs themselves.

  • Diaphragm: A respiratory muscle that divides the thoracic cavity from the abdomino-pelvic region.

• Abdomino-Pelvic Cavity:

  • Abdominal (Upper) portion: Contains the stomach, spleen, liver, gallbladder, pancreas, small intestine, and most of the large intestine.

  • Pelvic (Lower) portion: Contains the urinary bladder, portions of the large intestine, and internal reproductive organs.

Abdomino-Pelvic Organization

• Abdomino-pelvic Quadrants: Formed by two perpendicular lines intersecting at the umbilicus. They are used to locate pain, tumors, or cancers.

  1. Right upper quadrant.

  2. Left upper quadrant.

  3. Right lower quadrant.

  4. Left lower quadrant.

• Perpendicular Lines for Nine Regions:

  1. Subcostal: Top horizontal line, inferior to the bottom of the rib cage, across the lower stomach ("sub" = below, "costal" = ribs).

  2. Transtubercular: Bottom horizontal line, inferior to the tops of the hipbones.

  3. Right Midclavicular: Vertical line through the midpoint of the right clavicle, medial to the nipple.

  4. Left Midclavicular: Vertical line through the midpoint of the left clavicle, medial to the nipple.

• Nine Regions of the Human Body:

  1. Right Hypochondriac: ("hypo" = under, "chondro" = cartilage).

  2. Right Lumbar: ("lumbus" = loin).

  3. Right Iliac (Inguinal): ("iliac" refers to the superior part of the hipbone).

  4. Epigastric: ("epi" = above, "gaster" = stomach).

  5. Umbilical: The starting point.

  6. Hypogastric: ("hypo" = under, "gaster" = stomach).

  7. Left Hypochondriac.

  8. Left Iliac (Inguinal).

  9. Left Lumbar.

Combining Forms and Word Roots

• Acou-, Acu-: Hearing (e.g., acoustics).

• Acr-, Acro-: Extremity (e.g., acromion process).

• Aden-, Adeno-: Gland (e.g., adenoid).

• Angi-: Vessel (e.g., angiography).

• Arth-, Arthro-: Joint (e.g., arthritis).

• Bio-: Life, living (e.g., biology).

• Brachi-: Arm (e.g., brachioradialis).

• Bronch-: Trachea, windpipe (e.g., bronchitis).

• Bucc-: Cheek (e.g., buccocervical).

• Carcin-: Cancer (e.g., carcinogenic).

• Capit-: Head (e.g., decapitate).

• Cardi-, cardia-, cardio-: Heart (e.g., cardiology).

• Cephal-: Head (e.g., cephalic).

• Cerebro-: Brain (e.g., cerebrospinal fluid).

• Chondr-, chondri-, chondrio-: Cartilage (e.g., chondrocyte).

• Chrom-, chrommat-, chromato-: Color (e.g., hyperchromic).

• Cor-, coron-: Heart (e.g., coronary).

• Cost-: Rib (e.g., intercostal space).

• Crani-: Skull (e.g., cranial).

• Cut-: Skin (e.g., subcutaneous).

• Cyt-, cyto-, cyte-: Cell (e.g., cytology).

• Derma-, Dermato-: Skin (e.g., epidermis).

• Dura-: Hard/Head (e.g., dura mater).

• Entero-: Intestine.

• Erythro-: Red (e.g., erythrocyte).

• Galacto-: Milk (e.g., galactose).

• Gastr-: Stomach (e.g., gastrointestinal).

• Gloss-, glosso-: Tongue (e.g., hypoglossal).

• Glyco-: Sugar (e.g., glycogen).

• Hem-, hemat-: Blood (e.g., hematoma).

• Hepar-, hepato-: Liver (e.g., hepatitis).

• Hist-, histio-: Tissue (e.g., histology).

• Hydr-: Water (e.g., hydration).

• Ilio-: Ilium (e.g., iliosacral).

• Kines-: Motion (e.g., kinesiology).

• Leuco-, leuko-: White (e.g., leucocyte).

• Lip-, lipo-: Fat (e.g., lipase).

• Lumbo-: Lower back, loin (e.g., lumbar region).

• Malign-: Bad, harmful (e.g., malignant condition).

• Mamm-: Breast (e.g., mammary gland).

• Meningo-: Membrane (e.g., meningitis).

• Myo-: Muscle (e.g., myocardium).

• Necro-: Corpse, dead (e.g., necrosis).

• Nephro-: Kidney (e.g., nephrosis).

• Neuro-: Nerve (e.g., neurology).

• Oculo-: Eye (e.g., binocular).

• Onco-: Mass, tumor (e.g., oncology).

• Patho-: Disease (e.g., pathology).

• Phag-, phago-: To eat (e.g., phagocytosis).

• Philic, philo-: To like, have an affinity for (e.g., hydrophilic).

• Phleb-: Vein (e.g., phlebitis).

• Pneumo-: Lung (e.g., pneumonia).

• Pod-: Foot (e.g., podiatrist).

• Psycho-: Soul (e.g., psychology).

• Pulmon-: Lung (e.g., pulmonary disease).

• Ren-: Kidneys (e.g., renal gland).

• Rhino-: Nose (e.g., rhinitis).

• Scler-, sclero-: Hard (e.g., arteriosclerosis).

• Soma-, somato-: Body (e.g., somatotropic).

• Stasis-, stat-: Stand still (e.g., homeostasis).

• Tegument-: Skin (e.g., integumentary system).

• Thermo-: Heat (e.g., thermometer).

• Thromb-: Clot, lump (e.g., thrombus).

• Vas-: Vessel, duct (e.g., cardiovascular disease).

• Viscer-: Organ (e.g., visceral).