Body Cavities, Membranes, and Abdominopelvic Quadrants & Regions

Body Cavities

The human body contains several major and specific cavities that house vital organs and structures. Understanding these cavities is essential for identifying organ locations and their protective environments.

• Major Cavities:

  • Dorsal cavity: Contains the cranial and spinal cavities.

  • Ventral cavity: Includes thoracic and abdominopelvic cavities.

• Specific Cavities:

  • Cranial cavity: Houses the brain.

  • Spinal cavity: Contains the spinal cord.

  • Thoracic cavity: Contains the heart and lungs.

  • Pleural cavity: Surrounds each lung.

  • Pericardial cavity: Surrounds the heart.

  • Mediastinum: Central compartment of the thoracic cavity.

  • Abdominopelvic cavity: Includes abdominal and pelvic cavities.

  • Abdominal cavity: Contains digestive organs.

  • Pelvic cavity: Contains reproductive organs, bladder, and rectum.

Membranes

Membranes line body cavities and cover organs, providing protection and reducing friction.

• Serous membranes (serosa): Double-layered membranes with parietal (lining cavity) and visceral (covering organ) layers. Examples: pleura (lungs), pericardium (heart), peritoneum (abdominal organs).

• Mucous membranes (mucosa): Line cavities open to the exterior (e.g., digestive, respiratory tracts).

• Cutaneous membrane: The skin.

• Synovial membranes: Line joint cavities and produce synovial fluid.

Abdominopelvic Quadrants and Regions

The abdominopelvic area is divided into quadrants and regions to help locate organs and describe pain or injury.

• Quadrants:

  • Right upper quadrant

  • Left upper quadrant

  • Right lower quadrant

  • Left lower quadrant

• Regions:

  • Right hypochondriac

  • Epigastric

  • Left hypochondriac

  • Right lumbar

  • Umbilical

  • Left lumbar

  • Right inguinal (iliac)

  • Hypogastric (pubic)

  • Left inguinal (iliac)

Organ Systems

Organ systems are groups of organs that work together to perform complex functions necessary for life.

• Integumentary

• Skeletal

• Muscular

• Nervous

• Endocrine

• Cardiovascular

• Lymphatic

• Respiratory

• Digestive

• Urinary

• Reproductive

Example: The digestive system includes the stomach, intestines, and liver, and is responsible for nutrient breakdown and absorption.

Microscope Use and Cell Biology

Microscope Structure and Use

Microscopes are essential tools for studying cells and tissues. Understanding their parts and functions is crucial for laboratory work.

• Parts: Base, arm, head, ocular lenses, objective lenses, nosepiece, coarse/fine focus knobs, stage, light source, brightness control, power switch.

• Total Magnification Formula:

Cell Biology

Cells are the basic units of life. Understanding their structure and function is foundational in anatomy and physiology.

• Parts of the Cell: Cell membrane, cytoplasm, chromatin, chromosomes, nuclear envelope, nucleolus, cytoskeleton, lysosome, centrioles, flagellum, cilia, Golgi apparatus, rough/smooth endoplasmic reticulum, ribosome, mitochondria, peroxisome.

Mitosis and Meiosis

Cell division occurs via mitosis (somatic cells) and meiosis (gametes). Each process has distinct phases.

• Mitosis Phases: Prophase, Metaphase, Anaphase, Telophase, Cytokinesis.

• Meiosis: Reduces chromosome number by half, producing gametes.

Cellular Transport

Cells exchange substances with their environment through various transport mechanisms.

• Osmosis: Movement of water across a semipermeable membrane.

• Diffusion: Movement of molecules from high to low concentration.

• Solutions: Isotonic, hypotonic, hypertonic.

Histology: Tissues and Their Features

Four Main Tissue Types

Tissues are groups of similar cells performing specific functions. The four main types are:

• Epithelial tissue: Covers surfaces and lines cavities.

• Connective tissue: Supports, binds, and protects organs.

• Muscle tissue: Produces movement.

• Nervous tissue: Transmits electrical signals.

Epithelial Tissue Types

• Simple squamous: Single layer, flat cells.

• Simple cuboidal: Single layer, cube-shaped cells.

• Simple columnar: Single layer, tall cells.

• Stratified squamous: Multiple layers, flat cells (keratinized/nonkeratinized).

• Stratified cuboidal/columnar: Multiple layers, cube/tall cells.

• Pseudostratified columnar: Appears layered, but all cells touch basement membrane.

• Transitional: Stretches, found in urinary tract.

Epithelial Features

• Apical/basal surface

• Basement membrane

• Microvilli (increase surface area)

Connective Tissue Types

• Adipose tissue

• Dense (fibrous) connective tissue

• Regular/irregular dense c.t.

• Fibrocartilage

• Elastic cartilage

• Bone

• Blood

Connective Tissue Features

• Collagen and elastin fibers

• Extracellular matrix

• Cells: Fibroblasts, adipocytes, chondrocytes

• Lacuna: Small cavity in cartilage/bone

Integumentary System

Layers and Sub-layers of Cutaneous Membrane

The skin consists of multiple layers, each with distinct functions and cell types.

• Epidermis:

  • Stratum corneum

  • Stratum lucidum (thick skin only)

  • Stratum granulosum

  • Stratum spinosum

  • Stratum basale (germinativum)

• Dermis:

  • Papillary layer

  • Reticular layer

• Subcutaneous layer (hypodermis): Contains adipose tissue.

Integumentary Structures

• Dermal papillae

• Hair shaft, root, follicle

• Pore

• Arrector pili muscle

• Sebaceous gland

• Merocrine (eccrine) sweat gland

• Apocrine sweat gland

• Free nerve ending

• Meissner's (tactile) corpuscle

• Pacinian (pressure) corpuscle

• Keratinocyte

• Melanocyte

Skeletal System: Bones, Joints, and Features

Introductory Material

The skeletal system provides structure, protection, and movement. Bones are classified by shape and function.

• Long bone features: Diaphysis, epiphysis, medullary cavity, periosteum.

• Compact vs. spongy bone: Compact bone is dense; spongy bone contains trabeculae.

• Major functions: Support, protection, movement, mineral storage, blood cell formation.

Skull

The skull protects the brain and forms the structure of the face.

• Major bones: Frontal, parietal, temporal, occipital, maxilla, zygomatic, sphenoid, ethmoid, nasal, palatine, vomer, mandible.

• Major sutures: Coronal, sagittal, squamous, lambdoid.

• Other features: Mastoid process, styloid process, external auditory meatus, foramen magnum, cribriform plate, sella turcica, optic canal, zygomatic arch, mandibular condyle.

Vertebral Column and Thoracic Cage

• General features: Body, vertebral canal, transverse processes, spinous process, intervertebral discs.

• Specific vertebrae: Cervical (7), Atlas (C1), Axis (C2), Sacrum, Coccyx, Thoracic (12), Lumbar (5).

• Ribs and sternum: Protect thoracic organs.

Pectoral Girdle and Upper Limb

• Clavicle and scapula: Connect upper limb to trunk.

• Humerus, radius, ulna: Major bones of the arm.

• Hand: Carpals, metacarpals, phalanges.

Pelvic Girdle and Lower Limb

• Pelvic bones: Ilium, ischium, pubis, acetabulum, pubic symphysis, obturator foramen, iliac crest, greater sciatic notch.

• Femur: Head, greater/lesser trochanter, lateral/medial condyles.

• Tibia, fibula: Medial/lateral condyles, malleolus.

• Foot: Tarsals, calcaneus, talus, metatarsals, phalanges.

• Patella: Kneecap.

Joints

Joints connect bones and allow movement. They are classified by structure and function.

• Fibrous joints: Suture, syndesmosis, gomphosis.

• Cartilaginous joints: Synchondrosis, symphysis.

• Synovial joints: Plane (gliding), hinge, pivot, condyloid, saddle, ball and socket.

• Components: Synovial membrane, articular cartilage, joint cavity, articular capsule.

Knee Joint

• Quadriceps tendon, patellar ligament, anterior/posterior cruciate ligaments, tibial/fibular collateral ligaments, medial/lateral meniscus.

Motion Words

• Flexion, extension, hyperextension, abduction, adduction, rotation (medial/lateral), circumduction, pronation, supination, elevation, depression, opposition, protraction, retraction, inversion, eversion, dorsiflexion, plantar flexion.

Example: Flexion decreases the angle between bones, while extension increases it.