Introduction to the Study of the Human Body **Adapted from BIS 101 Lab Manual Appendix, Triton College** When studying anatomy, it is important that one be able to describe the location of a structure with terms that are descriptive enough so that there is no doubt as to the exact position of that structure. For example, when describing the location of the liver, it is not enough to say “The liver is under the right ribcage.” Does that mean the ribs lie on top of, and cover the liver? Or does that mean the liver is “south” of the ribcage, as in “towards the feet?” In another example, imagine a surgeon operating on a patient. The surgeon has both hands in the abdominal cavity of the patient, and needs the assisting surgeon to tie off a bleeding artery. He can’t let go of what he’s doing to point to the bleeder; he instead can describe the location using words that are standardized, meaning they are used the same way by everyone, leaving no confusion as to the exact location. Use this terminology regularly in order to thoroughly understand anatomy. Study the following relative terms, and use them to complete the questions. Part A: Anatomical Position and Anatomical Planes/Cuts/Crosses When describing the location of a structure, always assume the body is in the standardized anatomical position which is, erect feet slightly apart, toes pointed forward, arms hanging at the sides with palms facing forward, and eyes looking straight ahead. A plane, or section, is a real or imaginary cut through the body, used to reveal internal anatomical structures. The three most common planes/cuts you will encounter in this course are sagittal, frontal (coronal) and cross. A sagittal section is a cut through the body from front to back in a vertical direction that divides the body into right and left portions. Your instructor will show you an example of a midsaggital section. Midsaggital is a saggital cut through the center, or middle, of the body. A frontal or coronal section is a cut through the body from side to side in a vertical direction. This divides the body into anterior and posterior (front and back) portions. A cross section is a horizontal cut that divides the body into superior and inferior (top and bottom) portions. Part B: Major Body Region For purposes of study, the body is divided into two major regions called the axial and appendicular regions, each with many smaller regions. The axial region forms the central axis of the body—that is, everything but the limbs. It consists of the head, neck (cervical region), and trunk. The trunk is further divided into the thoracic region above the diaphragm and the abdominal and pelvic regions below it. The abdomen can be divided into nine regions defined by four lines that intersect like a “tic-tactoe” grid. The three lateral regions of this grid on each side are from upper to lower, the hypochondriac, lumbar, and inguinal (iliac) regions. The three median regions from upper to lower are the epigastric, umbilical, and hypogastric (pubic) regions. The regions are used to identify the locations of specific parts of various abdominal organs. Another way of referring to the locations of abdominopelvic structures is to divide the region into quadrants. Two perpendicular lines intersecting at the umbilicus (navel) divide the area into a right upper quadrant (RUQ), right lower quadrant (RLQ), left upper quadrant (LUQ), and left lower quadrant (LLQ). The quadrant scheme is often used to describe the site of an abdominal pain or abnormality. The appendicular region of the body consists of the upper and lower limbs (also called appendages or extremities). The upper limb includes the arm (brachium), forearm (antebrachium), wrist (carpus), hand (manus), and fingers (digits). The lower limb includes the thigh (femoral region), leg (crus), ankle (tarsus), foot (pes), and toes (digits). Part C: Anatomical Directions In your study of the human body describing the locations of structures, we utilize a set of standard directional terms. You will need to be very familiar with these in order to understand anatomical descriptions later in this book. The table below states some common directional terms, their definitions and examples of them. Note: The terms assume that the body is in anatomical position. Directional Term Lateral Medial Anterior Posterior Superior Inferior Dorsal Ventral Proximal Distal Visceral Parietal Deep Superficial Medullary (Medulla) Cortical (Cortex) Definition Towards the side; away from the middle of the body Towards the middle; away from the side of the body Towards the front of the body Towards the back of the body Towards the top of the body Towards the bottom of the body Along/towards the vertebral surface of the body Along/towards the belly surface of the body Closer to the middle of the body Farther from the middle of the body Towards an internal structure/organ of the body Away from an internal structure/organ of the body Towards the inside of a structure/organ; Away from the body surface Towards the outside of structure/organ; Close to the body surface Refers to the inner region of a structure/organ Refers to the outer region of a structure/organ Example The eyes are lateral to the nose The eyes are medial to the ears The nose is on the anterior portion of the head The heel is posterior to the toes The shoulders are superior to the hips The stomach is inferior To the heart Her scar is along the dorsal surface of the her body The naval is located on the ventral side of the body This joint is proximal to the toe nail The hand is distal to the elbow This organ is covered with a visceral membrane This organ is covered with parietal membrane The thigh muscles are deep to the skin The skin is a superficial to the heart This is the medullary region of the adrenal gland This is the cortical region of the cerebrum Part D: Surface Regions Knowledge of the external anatomy and landmarks of the body is important in performing a physical examination, reporting patient complaints, and many other clinical procedures. The table below states several surface regions and their “common body part or surface location”. Surface Regional Abdominal Common Body Part/Surface Location Belly; Below Chest Axillary Armpit Brachial Upper Arm Buccal Check; Side of Mouth Calf Posterior Lower Leg Cervical Neck Cubital Lower Arm Femoral Thigh, Upper Leg Gluteal Buttocks Lumbar Lower Back Occipital Posterior and Inferior Head Orbital Eye Patellar Anterior Portion of Knee Joint Popliteal Posterior Portion of Knee Joint Scapular Posterior Portion of Shoulder Thoracic Chest Tibial Anterior Lower Leg Part E: Body Cavities The body contains spaces-called cavities- that contain the majority of the human body organs. The two major body cavities are the dorsal (posterior) and ventral (anterior) cavity. Within the dorsal and ventral cavities are smaller cavities. The body contains other smaller cavities including the orbital cavity for the eyes, the oral cavity for the mouth, and middle ear cavity which house the ear bones. The dorsal cavity is composed of superior cavity called the cranial cavity and a posterior cavity called the spinal cavity. The cranial cavity contains the brain while the spinal cavity contains the spinal cord. The ventral cavity is also composed of two smaller cavities, the superior cavity is called the thoracic cavity and the inferior cavity is called the abdominopelvic cavities. The thoracic cavity and abdominopelvic cavity are separated by the diaphragm. In the medial portion of the thoracic cavity is the mediastinum that contains the trachea, esophagus, thymus and the heart located in a pericardial cavity. Laterally to the mediastinum are two pleural cavities; one which contain the left lung and the other right lung. The abdominopelvic cavity is also subdivided. The larger superior portion of the abdominopelvic cavity is simply called the abdominal cavity, while the smaller inferior portion of the abdominopelvic cavity is called pelvic cavity. The abdominal cavity contains primarily digestive system organs. The pelvic cavity contains the urinary system organs and some of the male and female reproductive organs and the rectum. The anterior portion of the abdominopelvic cavity is called the peritoneal cavity. The peritoneal cavity contains the liver, gall bladder, stomach, spleen and the small intestine (jejunum and ileum) and the majority of the large intestine (colon). The posterior portion of the abdominopelvic cavity is called retroperitoneal cavity. The retroperitoneal cavity contains the kidneys, bladder, pancreas, inferior vena cava, and abdominal aorta, the superior portion of the small intestine (duodenum), the rectum, and some of male and female reproductive organs. Part F: Body Membranes Thin sheets of tissues called membranes; fulfill numerous crucial functions in the human body. Membranes 1) line the body cavities, 2) cover the body, surface, 3) separate one organ from another, and some 4) secrete lubricating fluids to reduce friction during movement. There are two major categories of membranes, called epithelial and connective tissue membranes. Epithelial membranes are primarily composed of sheets of epithelial tissue. There are three major types of epithelial membranes. One is called the cutaneous membrane. The cutaneous membrane is commonly referred to as the skin. Second are the mucous membranes. Mucous membranes are epithelial membranes that cover organs that come in direct contact with the external environment. Mucous membranes are associated with the inside of the mouth, anus, nasal regions, vagina, and urethral openings. Mucous membranes also produce and secrete a liquid substance called mucous that lubricates and protects these organs. A third type of epithelial membrane is called serous membranes. Serous membranes are epithelial membranes that cover organs that do not come in contact with the outer environment. The three serous membranes are 1) the pleura membranes that surround each lung, 2) the pericardium membrane that surrounds the heart and 3) the peritoneum cover the abdominal organs. Connective tissue membranes are primarily composed of connective tissue. An example of a connective tissue membrane is synovial membranes. Synovial membranes line the space between adjacent bones. Synovial membranes secrete a fluid to reduce friction during movement. Part G: Body Systems Organ System Integumentary Principle Organs Skin Primary Functions Protection, Temperature Regulation, Sensation Skeletal Bone, Ligaments, Joints Support, Protection, Movement, Mineral/Lipid Storage, Blood Production Muscular Skeletal Muscles, Tendons Movement, Posture, Heat Production Nervous Brain, Spinal Cord, Nerves, Sense Organs: Eyes, Ears Endocrine Pituitary Gland, Adrenal Glands Pancreas Thyroid, Parathyroid Control/Regulation/Coordination of other systems, Sensation, Memory Vision, Hearing Control/Regulation of other systems Cardiovascular Heart, Arteries, Veins, Capillaries, Blood Exchange and Transport of Materials Lymphatic Lymph Nodes, Lymphatic Vessels Spleen, Thymus, Tonsils Immunity, Fluid Balance Respiratory Lungs, Bronchial Tree Trachea, Larynx, Nasal Cavity Gas Exchange, Acid-Base Balance Digestive Mouth, Esophagus, Stomach, Small and Large Intestine Salivary Glands, Pancreas, Liver, Gall Bladder Kidneys, Ureters, Bladder, Urethra Digestion and Absorption of Nutrients Removal of Solid Waste Urinary Reproductive Male Female Testis, Epididymis, Vas Deferens, Prostate Gland, Seminal Vesicle, Cowper’s Gland, Penis Ovaries, Fallopian Tubes, Uterus, Vagina, Vulva, Mammary Glands Excretion of Metabolic Waste Fluid/Electrolyte Balance Acid/Base Balance Blood Volume/Pressure Production of Sperm, Testosterone Production of Eggs, Estrogen/Progesterone Fertilization, Development Birth, Lactation Part A: Anatomical Position and Anatomical Planes/Cuts/Crosses 1. Answer the following question: In your own words, describe the anatomical position of the human body. _____________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ 2. Match each anatomical plane/cut/cross up with it correct definition 1. Sagittal ______ a. is a horizontal cut that divides the body into superior and inferior (top and bottom) portions 2. Frontal ______ b. cut through the body from front to back in a vertical direction that divides the body into right and left portions 3. Cross ______ c. cut through the body from side to side in a vertical direction that divides the body into anterior and posterior (front and back) portions. Part B: Major Body Region 1. Match each area or structure up with the region it is located in Arm _____ A. Axial Abdominal _____ B. Appendicular Hand/Fingers _____ Thoracic ______ Leg ______ Neck _____ Foot/Toes ______ Head _____ Forearm _____ Thigh _____ Pelvic _____ Wrist _____ Ankle _____ 2. Match each general appendicular sub-region up with it technical name. Thigh _____ A. Brachial Wrist _____ B. Pedal Arm _____ C. Carpus Ankle _____ D. Femoral Fingers/Toes _____ E. Manus Foot _____ F. Digits Hand ____ G. Crus Forearm _____ H. Tarsal Leg _____ I. Antibrachium Part C: Anatomical Directions Match each anatomical direction term up with its correct definition Anatomical Directional Term Definition 1. Lateral ______ a. Towards the middle; away from the side of the body 2. Visceral ______ b. Towards the front of the body 3. Dorsal ______ c. Along/towards the vertebral surface of the body 4. Proximal ______ d. Towards an internal structure/organ of the body 5. Inferior ______ e. Towards the side; away from the middle of the body 6. Deep ______ f. Towards the inside of a structure/organ; Away from the body surface 7. Anterior ______ g. Closer to the middle of the body 8. Superior ______ h. Towards the back of the body 9. Superficial ______ i. Towards the top of the body 10. Distal ______ j. Refers to the inner region of a structure/organ 11. Cortical ______ k. Farther from the middle of the body 12. Medullary ______ l. Refers to the outer region of a structure/organ 13. Medial ______ m. Towards the bottom of the body 14. Ventral ______ n. Away from an internal structure/organ of the body 15. Parietal ______ o. Along/towards the belly surface of the body 16. Posterior ______ p. Towards the outside of structure/organ; Close to the body surface Part D: Surface Regions Match each surface region up with its common body part/surface location Surface Region Common Body Part/Surface Location 1. Abdominal ______ a. Armpit 2. Calf ______ b. Neck 3. Femoral ______ c. Shoulder 4. Lumbar ______ d. Belly; Below Chest 5. Scapular ______ e. Buttocks 6. Occipital ______ f. Chest 7. Popliteal ______ g. Check; Side of Mouth 8. Axillary ______ h. Lower Back 9. Cervical ______ i. Thigh, Upper Leg 10. Gluteal ______ j. Posterior Lower Leg 11. Patellar ______ k. Posterior and Inferior Head 12. Cubital ______ l. Anterior Portion of Knee 13. Thoracic ______ m. Upper Arm 14. Brachial ______ n. Anterior Lower Leg 15. Tibial ______ o. Lower Arm 16. Buccal ______ p. Posterior Portion of Knee Part E: Body Cavities Answer the following questions regarding the body cavities. 1. The two major cavities located in the human body are called 1) ____________________ cavity and the ________________________ cavity. 2. State the name of the two major organs located in dorsal cavity. 1) _________________________________ 2) ___________________________________ 3. The superior portion of the ventral cavity is called the ____________________ cavity, and the inferior portion is called the __________________ cavity. The superior and inferior portions of the ventral cavity are separated by the ______________________. 4. The medial portion of the thoracic cavity is called the __________________, which contains the ____________________, _____________________, _____________________, and ________________. 5. Name the organ located in the pleural cavity. ________________________ 6. The abdominal cavity contains primarily the _______________________ system organs, while the pelvic cavity contains the __________________ system and _____________________ system organs. 7. Match the organ up with its location with its location. Organ Location Liver ______ A. Peritoneal Cavity Rectum ______ B. Retroperitoneal Cavity Pancreas ______ Colon ______ Stomach _______ Inferior Vena Cava _______ Spleen _______ Kidney _______ Gall Bladder _______ Abdominal Aorta _______ Bladder _______ Part F: Body Membranes Answer the following questions regarding the body membranes. 1. List 3 functions of body membranes. 1) ______________________________________________________________________ 2) _______________________________________________________________________ 3) ________________________________________________________________________ 2. Name the 3 major types of epithelial membranes and one location for each of them. Name Location 1) ________________________________ ___________________________________ 2) _______________________________ ____________________________________ 3) _________________________________ ___________________________________ 3. Match each serous membrane up with what it surrounds. 1) Pleura _______ A. Heart 2) Pericardium ______ B. Abdominal Organs 3) Peritoneum ______ C. Lungs 4. Name 1 type of synovial membrane and state it general location. Name Location ___________________________________ ____________________________________ Part G: Human Systems 1. Match the organ system with its principle organs. Organ System Principle Organs Nervous ______ A. Heart, Arteries, Veins, Capillaries, Blood Endocrine ______ B. Spleen, Tonsils, Thymus Cardiovascular ______ C. Pituitary Gland, Adrenal Glands, Pancreas, Thyroid Respiratory ______ D. Testis, Epididymis, Vas Deferens, Penis Digestive ______ E. Brain, Spinal Cord, Nerves, Sense Organs Male Reproductive ______ Lymphatic ______ F. Esophagus, Stomach, Small and Large Intestine Salivary Glands, Pancreas, Liver G. Kidneys, Ureters, Bladder, Urethra Urinary ______ H. Lungs, Bronchial Tree, Trachea, Larynx, Nasal Cavity 2. Match the organ system with its primary functions. Organ System Primary Functions Integument ______ A. Production of Eggs, Fertilization, Lactation Skeletal ______ B. Sensation, Memory, Vision, Hearing Muscular ______ C. Protection, Mineral/Lipid Storage, Blood Production Lymphatic ______ D. Fluid/Electrolyte Balance, Acid/Base Balance Urinary ______ E. Digestion and Absorption of Nutrients, Removal of Solid Waste Female Reproductive ______ F. Immunity, Fluid Balance Nervous ______ G. Temperature Regulation, Sensation Digestive ______ H. Movement, Posture, Heat Production 3. Which two systems control and regulate the other systems in the human body? 1) __________________ 3) _________________ Part H: Additional Questions 1. The middle portion of the small intestine is located in the ___________________ abdominal region. 2. The majority of the stomach is located in the ______________________________ quadrant. 3. The heart is located in the ______________ cavity. 4. The lungs are located in the ____________ cavity. 5. The intestines are located in the ___________ region. 6. The urinary bladder is located in the ___________ region. 7. One applies antiperspirant to the ___________ region. 8. The voice box is in the __________ region. 9. The tongue is in the __________ region. 10. The heart is in the _________ region. 11. The wrist is _________ to the elbow. 12. The kneecap is on the ___________ side of the body. 13. The naval is __________ to the ribcage. 14. The spine is _________ to the stomach. 15. The muscles are _________ to the skin.
