Anatomy & Physiology: Foundational Structures and Terminology

Body Cavities and Regional Terms

Body Cavities

The human body contains several major cavities that house vital organs and structures. Understanding these cavities is essential for anatomical orientation and clinical application.

• Cranial cavity: Contains the brain.

• Spinal cavity: Encloses the spinal cord.

• Thoracic cavity: Houses the heart and lungs.

• Abdominal cavity: Contains digestive organs.

• Pelvic cavity: Contains reproductive and excretory organs.

Regional Terms

Regional terms are used to describe specific areas of the body for anatomical reference.

• Cephalic: Head

• Cervical: Neck

• Thoracic: Chest

• Brachial: Arm

• Antebrachial: Forearm

• Carpal: Wrist

• Femoral: Thigh

• Crural: Leg

• Tarsal: Ankle

• Orbital: Eye

• Plantar: Sole of foot

Nine Regions of the Abdomen

Abdominal Regions

The abdomen is divided into nine regions for clinical and anatomical purposes.

• Epigastric

• Umbilical

• Hypogastric

• Right/Left Hypochondriac

• Right/Left Lumbar

• Right/Left Iliac (Inguinal)

Integumentary System

Skin Structure

The integumentary system includes the skin and its associated structures, providing protection and sensory functions.

• Epidermis: Outermost layer

• Dermis: Middle layer containing connective tissue

• Subcutaneous (hypodermis): Deepest layer, mainly fat

• Sebaceous gland: Produces sebum (oil)

• Sudoriferous gland: Sweat gland

• Arrector pili muscle: Causes hair to stand up

Hair and Nails

• Hair: Shaft, bulb, root, follicle

• Nails: Free edge, lunula, nail bed

Cell Structure

Cellular Components

Cells are the basic units of life, containing organelles that perform essential functions.

• Organelles: Specialized structures within cells (e.g., mitochondria, nucleus)

Histology

Tissue Types

Histology is the study of tissues. The body contains four primary tissue types:

• Epithelial tissue: Simple squamous, simple cuboidal, simple columnar, stratified squamous, transitional, pseudostratified ciliated columnar

• Connective tissue: Areolar, adipose, dense regular, dense irregular, hyaline cartilage, elastic cartilage, osseous (bone), blood

• Muscular tissue: Skeletal, cardiac, smooth

• Nervous tissue: Neuron

Skull Anatomy

Major Bones and Landmarks

The skull consists of several bones and features important for protection and function.

• Frontal bone: Supraorbital foramen, glabella

• Parietal bone: Sagittal suture, coronal suture, lambdoid suture

• Temporal bone: Squamous suture, external auditory meatus, styloid process, zygomatic process, mastoid process, mandibular fossa, jugular foramen

• Occipital bone: Lambdoid suture, foramen magnum, occipital condyle, external occipital protuberance (EOP)

• Sphenoid: Greater/lesser wings, sella turcica, optic canal, foramen ovale

• Ethmoid bone: Cribriform plates, olfactory foramina

• Mandible: Body, mandibular condyle, coronoid process, mental foramen, alveoli

• Maxilla(e): Alveoli, intermaxillary suture, zygomatic process

• Other bones: Zygomatic, palatine, lacrimal, nasal, vomer

Vertebral Column

Vertebrae Types and Features

The vertebral column supports the body and protects the spinal cord. It is divided into regions:

• Cervical vertebrae: 7 (including atlas and axis)

• Thoracic vertebrae: 12

• Lumbar vertebrae: 5

• Vertebral body, spinous process, transverse process, vertebral foramen, intervertebral foramen (IVF)

Other Axial Bones

• Hyoid: U-shaped bone in the neck

• Ribs: 7 true pairs, 5 false pairs (2 floating)

• Sternum: Body, manubrium, xiphoid process

• Sacrum and Coccyx: Lower spine

Upper Extremity Anatomy

Major Bones and Landmarks

The upper extremity includes the shoulder girdle and arm bones, each with distinct features.

• Clavicle

• Scapula: Acromion process, coracoid process, glenoid fossa, spine, supraspinous fossa, infraspinous fossa, subscapular fossa

• Humerus: Head, greater/lesser tubercles, capitulum, trochlea, deltoid tuberosity, radial groove, coronoid fossa, olecranon fossa

• Radius: Head, neck, styloid process

• Ulna: Olecranon process, coronoid process, styloid process

Lower Extremity Anatomy

Major Bones and Landmarks

The lower extremity includes the pelvic girdle and leg bones, supporting movement and weight-bearing.

• Pelvis: Ilium (ASIS, iliac crest), ischium (ischial spine, tuberosity), pubis (pubic symphysis), obturator foramen, acetabulum

• Femur: Head, neck, greater/lesser trochanters, medial/lateral condyles, medial/lateral epicondyles

• Patella: Kneecap

• Tibia: Tibial tuberosity, lateral/medial condyles, medial malleolus

• Fibula: Lateral malleolus, head

• Tarsals: 7 bones (talus, calcaneus, etc.)

• Metatarsals: 5 bones

• Phalanges: Distal, middle, proximal

Summary Table: Major Bone Features

Bone	Key Features
Frontal	Supraorbital foramen, glabella
Parietal	Sagittal suture, coronal suture, lambdoid suture
Temporal	Squamous suture, external auditory meatus, styloid process, zygomatic process, mastoid process, mandibular fossa, jugular foramen
Occipital	Lambdoid suture, foramen magnum, occipital condyle, EOP
Mandible	Body, mandibular condyle, coronoid process, mental foramen, alveoli
Scapula	Acromion process, coracoid process, glenoid fossa, spine
Femur	Head, neck, greater/lesser trochanters, condyles, epicondyles
Tibia	Tibial tuberosity, condyles, medial malleolus
Fibula	Lateral malleolus, head

• Abbreviations such as ASIS (anterior superior iliac spine) and EOP (external occipital protuberance) are commonly used in anatomy.