Anatomical Terminology and Body Organization

Directional Terms

Directional terms are used to describe the locations of structures in relation to other structures or locations in the body.

• Superior/Inferior: Superior means above; inferior means below.

• Anterior/Posterior: Anterior (ventral) refers to the front; posterior (dorsal) refers to the back.

• Medial/Lateral: Medial means toward the midline; lateral means away from the midline.

• Superficial/Deep: Superficial means closer to the surface; deep means further from the surface.

• Proximal/Distal: Proximal means closer to the point of attachment; distal means farther from the point of attachment.

Sectional Planes

Sectional planes are used to divide the body or organs for anatomical study.

• Frontal (coronal) plane: Divides the body into anterior and posterior parts.

• Sagittal plane: Divides the body into right and left parts. The midsagittal plane divides it into equal halves; the parasagittal plane divides it into unequal halves.

• Transverse (horizontal) plane: Divides the body into superior and inferior parts.

Body Cavities

Body cavities protect organs and allow for changes in organ size and shape.

• Dorsal cavity: Includes the cranial and vertebral cavities.

• Ventral cavity: Includes the thoracic (pleural, pericardial, mediastinum) and abdominopelvic cavities.

Serous Membranes and Associated Cavities

Serous membranes line body cavities and cover organs, reducing friction.

• Pleura: Surrounds the lungs.

• Pericardium: Surrounds the heart.

• Peritoneum: Surrounds abdominal organs.

Visceral layers cover organs; parietal layers line cavity walls.

Abdominopelvic Regions and Quadrants

The abdominopelvic cavity is divided for anatomical study and clinical reference.

• Quadrants: Right upper, left upper, right lower, left lower.

• Regions: Right and left hypochondriac, epigastric, right and left lumbar, umbilical, right and left iliac, hypogastric.

Example: The liver is primarily in the right upper quadrant and right hypochondriac region.

Organ Systems Overview

The human body is organized into organ systems, each with specific functions.

• Endocrine: Hormone production and regulation

• Respiratory: Gas exchange

• Digestive: Nutrient breakdown and absorption

• Lymphatic: Immune response and fluid balance

• Cardiovascular: Transport of blood and nutrients

• Reproductive: Production of offspring

• Urinary: Waste elimination and fluid balance

Microscopy and Cell Structure

Parts of a Light Microscope

Understanding microscope parts is essential for laboratory work.

• Arm, base, head: Structural support

• Objective lens, ocular lens: Magnification

• Nosepiece: Rotates objectives

• Coarse/fine focus knob: Focus adjustment

• Stage, mechanical stage control: Slide placement and movement

• Light/brightness control, power switch: Illumination

Cellular Structures

Cells contain specialized structures for various functions.

• Plasma membrane: Selective barrier

• Cytoplasm: Cellular contents outside nucleus

• Chromatin, chromosomes: Genetic material

• Nucleus, nucleolus, nuclear envelope: Genetic control center

• Organelles: Mitochondria (energy), ribosomes (protein synthesis), endoplasmic reticulum (protein/lipid synthesis), Golgi apparatus (modification/packaging), lysosomes (digestion), peroxisomes (detoxification), cytoskeleton (structure/movement), centrioles (cell division), flagella/cilia/microvilli (movement/absorption)

Stages of Mitosis and Meiosis

Cell division occurs via mitosis (somatic cells) and meiosis (gametes).

• Mitosis phases: Prophase, metaphase, anaphase, telophase

• Function: Growth, repair, asexual reproduction

Meiosis: Produces gametes with half the chromosome number.

Osmosis and Tonicity

Osmosis is the movement of water across a semipermeable membrane.

• Isotonic solution: No net water movement

• Hypertonic solution: Water moves out; cell shrinks

• Hypotonic solution: Water moves in; cell swells

Example: Placing elodea leaves in NaCl solution causes water to leave the cells (plasmolysis).

Histology: Tissues of the Human Body

Epithelial Tissues

Epithelial tissues cover surfaces and line cavities.

• Simple squamous: Single flat layer; found in alveoli, capillaries

• Simple cuboidal: Single cube-shaped layer; found in kidney tubules

• Simple columnar: Single tall layer; found in digestive tract lining

• Pseudostratified ciliated columnar: Appears layered, has cilia; found in respiratory tract

• Stratified squamous: Multiple flat layers; found in skin, mouth, esophagus

Connective Tissues

Connective tissues support, bind, and protect organs.

• Areolar: Loose, supports epithelia

• Adipose: Stores fat

• Dense regular/irregular: Tendons/ligaments (regular), dermis (irregular)

• Hyaline cartilage: Ends of bones, nose, trachea

• Fibrocartilage: Intervertebral discs

• Elastic cartilage: Ear, epiglottis

Integumentary System

Skin Structure and Function

The skin consists of three main layers, each with specific functions.

• Epidermis: Outermost layer; protection

• Dermis: Middle layer; contains papillary and reticular layers, provides strength and elasticity

• Hypodermis: Subcutaneous layer; fat storage, insulation

Strata of the epidermis: Stratum basale, spinosum, granulosum, lucidum (thick skin), corneum

Skin Structures and Glands

• Dermal papillae: Increase surface area for exchange

• Eccrine sweat gland: Thermoregulation

• Apocrine sweat gland: Scent, found in axilla/groin

• Sebaceous gland: Secretes sebum (oil)

• Arrector pili muscle: Causes hair to stand (goosebumps)

• Meissner's corpuscle: Touch receptor

• Pacinian corpuscle: Pressure receptor

• Hair follicle, root, shaft: Hair structure

Skeletal System

Bone Structure and Function

Bones provide support, protection, movement, mineral storage, and blood cell formation.

• Osteon: Structural unit of compact bone

• Periosteum, endosteum: Membranes covering bone

• Central canal, perforating canal: Pathways for blood vessels/nerves

• Lacunae, lamellae, osteocyte: Bone cells and their spaces

• Trabeculae: Spongy bone structure

Major Bones of the Human Skeleton

The human skeleton is divided into axial and appendicular components.

• Cranial bones: Frontal, parietal, temporal, occipital

• Facial bones: Maxilla, mandible, zygomatic, sphenoid, ethmoid, lacrimal, nasal, palatine, vomer

• Vertebrae: Cervical, thoracic, lumbar, sacrum, coccyx

• Ribs: True, false, floating

• Pectoral girdle: Clavicle, scapula

• Upper limb: Humerus, ulna, radius, carpals, metacarpals, phalanges

• Pelvic girdle: Ilium, ischium, pubis

• Lower limb: Femur, tibia, fibula, tarsals, metatarsals, phalanges, patella

Bone Features and Landmarks

Bone features serve as attachment points, passageways, or articulations.

• Temporal: Mastoid process, styloid process, external auditory meatus, mandibular fossa, zygomatic process

• Occipital: Condyles, foramen magnum

• Sphenoid: Sella turcica, optic canal

• Ethmoid: Cribriform plate, crista galli, perpendicular plate

• Mandible: Coronoid process, mandibular condyle

• Maxilla: Palatine process

• Vertebrae: Body, vertebral canal, transverse process, spinous process, intervertebral discs

• Sternum: Manubrium, body, xiphoid process

• Scapula: Spine, acromion, coracoid process, glenoid cavity (fossa)

• Humerus: Greater/lesser tubercle, head, deltoid tuberosity, medial/lateral epicondyle, olecranon fossa

• Ulna: Olecranon process, trochlear notch, coronoid process, radial notch, styloid process

• Radius: Head, tuberosity, styloid process

• Pelvis: Acetabulum, pubic symphysis, pubic arch, ischial tuberosity, obturator foramen, iliac crest

• Tibia: Tibial tuberosity, anterior crest, medial malleolus

• Fibula: Head, lateral malleolus

Additional info:

• Some content was expanded for clarity and completeness, such as the functions of organ systems and the purpose of anatomical features.

• Tables were not present in the original, so none were recreated.