Anatomical Terminology, Body Organization, and Major Organ Systems: Study Guide for Human Anatomy & Physiology I Laboratory

Anatomical Terminology and Regional Anatomy

Introduction to Anatomical Position and Terminology

Understanding anatomical terminology is essential for accurately describing the locations and relationships of body parts. The anatomical position is the standard reference point in which the body stands upright, facing forward, with arms at the sides and palms facing forward. All directional terms are based on this position.

• Regional terms refer to specific areas of the body, such as cranial (head), facial (face), thoracic (chest), and abdominal (abdomen).

• Directional terms describe the locations of structures relative to other structures or locations in the body (e.g., superior, inferior, anterior, posterior).

• Planes of the body include sagittal (divides left/right), frontal (divides anterior/posterior), and transverse (divides superior/inferior).

Example: The heart is medial to the lungs and superior to the diaphragm.

Key Anatomical Regions and Terms

The following table summarizes important anatomical regions and their corresponding terms:

Anatomical, regional term	Body region or part definition/description	Anatomical, regional term	Body region or part definition/description
Metacarpal	Bones between wrist and fingers	Metatarsal	Bones between ankle and toes
Phalangeal	Fingers or toes	Trunk	The body excluding the head, neck, and limbs
Cranial	Part of skull that houses the brain	Facial	Part of skull that forms the face
Abdomen	Region between chest and pelvis	Thigh	Portion of lower limb between hip and knee
Forearm	Between elbow and wrist	Leg	Between knee and ankle
Additional info:	This table is a partial list; refer to your lab manual for a complete set of regional terms.

Directional Terms

Definitions and Applications

Directional terms are used to describe the locations of structures relative to other structures. Mastery of these terms is crucial for clear communication in anatomy.

Directional term (for humans)	Definition (for humans)
Cephalic or cranial	Toward the head or upper part of a structure (Placement of a structure along the long axis of the body)
Caudal	Away from the head; closer to lower part of the body (Placement of a structure along the long axis of the body)
Ventral	Toward or at the front of the body
Dorsal	Toward or at the back of the body
Medial	Nearer the midline of the body or structure
Lateral	Farther from the midline of the body or structure
Proximal	Nearer to the point of origin or trunk attachment (Primarily for the extremities)
Distal	Farther from the point of origin or trunk attachment (Primarily for the extremities)
Superficial	Toward or on the body surface (Relative closeness to the body surface)
Internal	Away from the body surface (Relative closeness to the body surface)
Median	Lying in the midline (central position)
Intermediate	Between two structures
Parietal	Refers to body cavity structures
Visceral	Pertaining to the outer covering of an organ within a body cavity (refers to body cavity structures)
Ipsilateral	On the same side
Contralateral	On the opposite side
Prone	The body when lying face down
Supine	The body when lying face up

Example: The nose is medial to the eyes, and the thumb is lateral to the little finger.

Body Cavities and Quadrants

Major Body Cavities

The human body contains several major cavities that house organs and protect them from shock and injury. The two main body cavities are the dorsal cavity (containing the cranial and vertebral cavities) and the ventral cavity (containing the thoracic and abdominopelvic cavities).

• Thoracic cavity: Contains the heart and lungs.

• Abdominopelvic cavity: Contains digestive organs, urinary bladder, and reproductive organs.

The abdominopelvic cavity is further divided into quadrants for clinical reference:

Quadrant	Major Organs
Right Upper Quadrant (RUQ)	Liver (right lobe), Gall bladder, Stomach (pylorus), Duodenum, Head of pancreas, Right kidney, Right adrenal gland, Parts of ascending and transverse colon
Left Upper Quadrant (LUQ)	Liver (left lobe), Spleen, Stomach (body and fundus), Jejunum and proximal ileum, Pancreas (body and tail), Left kidney, Left adrenal gland, Parts of transverse and descending colon
Right Lower Quadrant (RLQ)	Cecum, Appendix, Most of ileum, Ascending colon (inferior part), Right ovary and uterine tube (female), Right ureter, Right spermatic cord (male), Urinary bladder (if very full)
Left Lower Quadrant (LLQ)	Part of descending colon, Sigmoid colon, Left ovary and uterine tube (female), Left ureter, Left spermatic cord (male), Urinary bladder (if very full)

Example: Pain in the RLQ may indicate appendicitis.

Levels of Structural Organization

Hierarchy of Body Organization

The human body is organized into several levels, each building upon the previous one:

1. Chemical level: Atoms and molecules essential for life.

2. Cellular level: Cells are the basic structural and functional units of life.

3. Tissue level: Groups of similar cells performing a common function. Four basic tissue types: epithelial, connective, muscle, and nervous tissue.

4. Organ level: Structures composed of two or more tissue types working together (e.g., heart, liver).

5. Organ system level: Groups of organs that perform related functions (e.g., digestive system).

6. Organismal level: The complete living being.

Example: The stomach is an organ composed of muscle, epithelial, and connective tissues.

Overview of Major Organ Systems

Functions and Key Structures

The human body contains several major organ systems, each with specific functions and associated organs. The following table summarizes the main systems and their functions:

System	Some Function(s)	"Organs, Structures and More…"
Integumentary system	Forms the external body covering; protection; temperature regulation; waste elimination; vitamin D synthesis	Skin, hair, nails, sweat glands
Skeletal system	Supports and protects the body; stores minerals; blood cell formation within bone cavities	Bones, joints, cartilage
Muscular system	Movement; thermogenesis; maintains posture	Skeletal muscles, tendons
Nervous system	Regulates body activities through nerve impulses	Brain, spinal cord, nerves
Endocrine system	Regulates body activities through hormones	Pituitary gland, thyroid gland, adrenal glands, pancreas, gonads
Cardiovascular system	Transports O2, CO2, nutrients, wastes, etc.; protects against disease and hemorrhage	Heart, blood vessels
Lymphatic system (Immune system)	Filters body fluids; produces white blood cells; involved in immune responses	Lymph nodes, spleen, thymus
Respiratory system	Gaseous exchange; helps regulate acid/base balance	Lungs, trachea, bronchi
Digestive system	Physical and chemical breakdown of food; absorption of food nutrients; elimination of undigested foodstuffs in feces	Mouth, esophagus, stomach, intestines, liver, pancreas
Urinary system	Elimination of nitrogenous wastes in urine; regulates water, electrolyte, acid/base balance of blood	Kidneys, ureters, bladder, urethra
Reproductive system	Propagation of the species	Ovaries, testes, uterus, penis

Example: The cardiovascular system transports oxygen and nutrients to tissues and removes waste products.

Laboratory Identification: Bones, Muscles, and Organs

Skeletal System: Major Bones to Identify

Students are expected to identify major bones on anatomical models. The following are key bones to locate:

Bone or Structure Identification	SOMSO Torso	Bone or Structure Identification	SOMSO Torso
Frontal bone	x	Cervical vertebra	x
Mandible	x	Thoracic vertebra	x
Maxilla	x	Lumbar vertebra	x
Nasal bone	x	Sacrum	x
Parietal bone	x (x2)	Sternum	x
Occipital bone	x	Rib	x
Temporal bone	x (x2)	Clavicle	x
Zygomatic bone	x	Scapula	x
Pubic symphysis	x	Hyoid bone	x

Additional info: Refer to your laboratory manual for figures and more detailed identification.

Muscular System: Major Muscles to Identify

Key muscles to identify on anatomical models include:

• Deltoid

• Gluteus maximus

• Rectus abdominis

• External abdominal oblique

• Pectoralis major

• Trapezius

• Latissimus dorsi

Example: The deltoid muscle is responsible for abduction of the arm at the shoulder.

Endocrine and Cardiovascular Systems: Organs and Structures

Students should be able to identify the following organs on models:

• Endocrine system: Hypothalamus, pituitary gland, thyroid gland, adrenal glands, pancreas, ovaries, testes

• Cardiovascular system: Heart, aorta, vena cava, pulmonary arteries and veins

Additional info: Some organs may not be present on all models; refer to your lab manual for specific instructions.

Summary and Study Tips

• Master anatomical terminology and directional terms for clear communication.

• Familiarize yourself with the major body regions, cavities, and organ systems.

• Practice identifying bones, muscles, and organs on anatomical models.

• Use tables and diagrams in your lab manual for reference and review.

Additional info: For more detailed study, consult the figures and activities referenced in your laboratory manual and use online resources such as MasteringA&P for interactive learning.