The Body in Health and Disease

1. 2 The Body in Health and Disease

2. The Body in Health Seven different approaches for studying the body: Body planes and body directions approach Body cavities approach Quadrants and regions approach Anatomy and physiology approach Microscopic-to-macroscopic approach Body systems approach Medical specialties approach

3. Figure 2-1 Human body in anatomical position

4. The Coronal Plane and Body Directions The coronal plane (or frontal plane) is a vertical plane that divides the body into front and back sections. The coronal plane is named for the coronal suture in the cranium.

5. Figure 2-2 Coronal plane

6. Figure 2-3 Coronal and sagittal sutures of the cranium

7. The Coronal Plane and Body Directions (cont’d) The front of the body is the anterior or ventral section. The back of the body is the posterior or dorsal section. Lying with the anterior section of the body down is being in the prone position. Lying with the posterior section of the body down is being in the dorsal or supine position.

8. Figure 2-4 Anterior and posterior directions

9. Figure 2-5 Posteroanterior direction

10. The Sagittal Plane and Body Directions A vertical plane that divides the body into right and left sections. Named for the sagittal suture in the cranium. If this plane divides the body at the midline into equal right and left sections, then it is a midsagittal plane.

11. The Sagittal Plane and Body Directions (cont'd) If this plane divides the body anywhere to the left or right of the midline, it is a parasagittal plane.

12. The Sagittal Plane and Body Directions (cont’d) Moving from the side of the body toward the midline is moving in a medial direction, or medially. Moving from the midline toward the side of the body is moving in a lateral direction, or laterally.

13. Figure 2-6 Sagittal plane

14. Figure 2-7Midsagittal view of the head on an MRI scan (DR Unique/Custom Medical Stock Photo, Inc.)

15. Figure 2-8 Medial and lateral are directional opposites

16. The Transverse Plane and Body Directions Horizontal plane that divides the body into top and bottom sections. The upper half of the body is the superior section, and the lower half is the inferior section.

17. Figure 2-9 Transverse plane

18. The Transverse Plane and Body Directions (cont’d) Moving toward the head is moving in a superior direction, or superiorly. This is also the cephalad direction. Moving toward the tailbone is moving in an inferior direction, or inferiorly. This is also the caudaddirection.

19. Other Body Directions and Positions Moving from the body toward the end of a limb (arm or leg) is moving in a distal direction, or distally. Moving from the end of a limb toward where it is attached to the body is moving in a proximal direction, or proximally.

20. Figure 2-10 Superior and inferior parts

21. Figure 2-11 Cephalad and caudad directions

22. Figure 2-12 Distal and proximal directions

23. Other Body Directions and Positions (cont’d) Structures on the surface of the body are superficial or external structures. Structures below the surface and inside the body are deep or internal structures.

24. Figure 2-13 External and internal positions

25. Body Cavities Approach The human body can be studied according to its body cavities and their internal organs. A cavity is a hollow space that is surrounded by bones or muscles. The cranial cavity lies within and is protected by the cranium.

26. Body Cavities Approach (cont’d) The spinal cavity or spinal canal is a continuation of the cranial cavity as it travels down the midline of the back. The spinal cavity lies within and is protected by the bones (vertebrae) of the spinal column. The spinal cavity contains the spinal cord, the spinal nerves, and spinal fluid.

27. Body Cavities Approach (cont’d) The thoracic cavity lies within the chest and is protected by the breastbone (sternum) anteriorly, the ribs laterally, and the spinal column posteriorly. The inferior border of the thoracic cavity is the large, muscular diaphragm that functions during respiration. The thoracic cavity contains the lungs.

28. Body Cavities Approach (cont’d) The abdominal cavity lies within the abdomen and is protected by the bones of the spinal column posteriorly. The pelvic cavity is a continuation of the abdominal cavity and lies within and is protected by the pelvic bones anteriorly and laterally. These two cavities are often referred to as the abdominopelvic cavity.

29. Figure 2-14 Body cavities

30. Quadrants and Regions Approach The human body can be studied according to its quadrants and regions. The anterior surface of the abdominopelvic area can be divided into four quadrants or nine regions.

31. Quadrants and Regions Approach (cont’d) The four quadrants include: Right upper quadrant (RUQ). Left upper quadrant (LUQ). Left lower quadrant (LLQ). Right lower quadrant (RLQ).

32. Figure 2-15 Quadrants of the abdominopelvic area

33. Quadrants and Regions Approach (cont’d) The nine regions include the: Right and left hypochondriac regions. Epigastric region. Right and left lumbar regions. Umbilical region. Right and left inguinal or iliac regions. Hypogastric region.

34. Figure 2-16 Regions of the abdominopelvic area

35. Anatomy and Physiology Approach Anatomy is the study of the structures of the human body. Physiology is the study of the function of those structures.

36. Microscopic-to-Macroscopic Approach Most cells and cellular structures are microscopic in size and can be seen only through a microscope. Some cells, such as a female ovum, are large enough to be seen with the naked eye. Cells combine to form tissues, and tissues combine to form organs.

37. Figure 2-17 Using a microscope to study the human body (microscope: Custom Medical Stock Photo, Inc.; heart muscle: Michael Abbey/Photo Researchers, Inc.

38. Microscopic-to-Macroscopic Approach (cont’d) Tissues and organs are macroscopic, that is, they can be seen with the naked eye. Organs combine to form a body system. The human body contains several different body systems.

39. Body Systems Approach The human body can be studied according to its various organs and how they function together in a body system. Gastrointestinal (Gl) system Respiratory system Cardiovascular (CV) system Blood Lymphatic system Integumentary system

40. Body Systems Approach (cont’d) The human body can be studied according to its various organs and how they function together in a body system. Skeletal system Muscular system Nervous system Urinary system Male genital and reproductive system Female genital and reproductive system

41. Body Systems Approach (cont’d) The human body can be studied according to its various organs and how they function together in a body system. Endocrine system Eyes Ears, nose, and throat (ENT) system

42. Medical Specialties Approach The human body can be studied according to the medical specialties that make up the practice of medicine. Each medical specialty includes the anatomy, physiology, diseases, diagnostic tests, medical and surgical procedures, and drugs for that body system.

43. Other Medical Specialties Other medical specialties that are not directly related to a body system include the following:

44. Other Medical Specialties (cont’d)