The Human Body

1. Chapter 1 The Human Body

2. Introduction • Anatomy: the study of the structure of the body • Physiology: the study of the function of the body parts • Pathology: the study of the disease of the body

3. Introduction (cont’d.) • Basic reference systems • Directions, planes, cavities, structural units

4. Terms of Direction

5. Terms of Direction (cont’d.) • Superior: uppermost or above • Inferior: lowermost or below • Anterior (or ventral): toward the front • Posterior (or posterior): toward the back • Cephalad (or cranial): toward the head

6. Terms of Direction (cont’d.) • Medial: nearest the midline of the body • Lateral: toward the side or away from the midline of the body • Proximal: nearest the point of attachment or origin • Distal: away from the point of attachment or origin

7. Terms of Direction (cont’d.)

8. Planes

9. Planes (cont’d.) • Midsagittal plane: divides the body through the midline into two equal left and right portions • Sagittal plane: any plane parallel to the midsagittal or median plan vertically dividing the body into unequal right and left portions

10. Planes (cont’d.) • Horizontal (or transverse) plane: any plane dividing the body into superior and inferior portions • Frontal (or coronal) plane: divides the anterior and posterior portions of the body at right angles to the sagittal plane

11. Planes (cont’d.)

12. Animation – Body Planes Click Here to Play Body Planes Animation

13. Cavities

14. Cavities (cont’d.) • Dorsal • Cranial, spinal • Ventral • Thoracic, abdominopelvic • Parietal: walls of a cavity • Visceral: covering on an organ

15. Cavities (cont’d.)

16. Structural Units

17. Structural Units (cont’d.) • Cells • Smallest units of life • Perform all activities necessary to maintain life • Metabolism, assimilation, digestion, excretion, reproduction

18. Structural Units (cont’d.) • Tissues • Made up of different types of cells • Epithelial: covers and protects • Connective: binds and supports other tissues • Muscle: movement • Nervous: connects sensory structures to motor structures

19. Structural Units (cont’d.) • Organs • Cells integrated into tissues • Serve a common function • Examples • Liver • Stomach • System is a group of organs

20. Structural Units (cont’d.) • Integumentary system • Organs • Skin, hair, nails, sweat glands, sebaceous glands • Functions • Protection, insulation, regulation of water and temperature

21. Structural Units (cont’d.) • Skeletal system • Organs • Bones, cartilage, membranous structures • Functions • Movement, blood production, fat and mineral storage, protection

22. Structural Units (cont’d.) • Muscular system • Organs • Muscles, fasciae, tendon sheaths, and bursae • Functions • Movement, pushing food and blood, contracting heart

23. Structural Units (cont’d.) • Nervous system • Organs • Brain, spinal cord, cranial and peripheral nerves, sensory and motor structures • Function • Control and regulation, interpreting stimuli

24. Structural Units (cont’d.) • Endocrine system • Organs • Endocrine glands • Function • Works with nervous system to regulate chemical aspects of the body

25. Structural Units (cont’d.) • Cardiovascular system • Organs • Heart, arteries, veins, capillaries • Function • Transport substances to and from cells

26. Structural Units (cont’d.) • Lymphatic/immune system • Organs • Lymph nodes, lymph vessels, thymus gland, spleen • Functions • Drains tissues of excess fluids, transports fats, develops immunities

27. Structural Units (cont’d.) • Respiratory system • Organs • Nasal cavities, pharynx, larynx, trachea, bronchi, lungs • Function • O2 > CO2 exchange in the blood

28. Structural Units (cont’d.) • Digestive system • Organs • Alimentary canal: mouth, esophagus, stomach, small and large intestines, rectum and anus • Associated glands: salivary, liver, pancreas • Functions • Convert food into absorbable substances, eliminates wastes

29. Structural Units (cont’d.) • Urinary system • Organs • Kidneys, ureters, bladder, urethra • Functions • Chemical regulation of blood • Formation and elimination of urine • Maintenance of homeostasis

30. Structural Units (cont’d.) • Reproductive system • Organs • Women: ovaries, uterine tubes, uterus, vagina • Men: testes, seminal vesicles, prostate gland, penis, urethra • Functions • Maintains sexual characteristics and perpetuates the species

31. Homeostasis

32. Homeostasis (cont’d.) • Maintenance of the body’s internal environment • Within varying narrow limits • Negative feedback loop • Examples • Blood sugar levels • Body temperature

33. Homeostasis (cont’d.) • Blood glucose • Levels rise dramatically after meal • Cells take in glucose • Pancreas secretes insulin • Moves glucose into liver for storage as glycogen • Between meals, pancreas secretes glucagon • Turns glycogen into glucose and returns it to blood • Thus, glucose levels remain nearly constant

34. Homeostasis (cont’d.) • Body temperature • Hypothalamus detects increase in body temperature • Causes sweating • Water evaporates and body is cooled • Blood vessels dilate to bring blood near body surface

35. Homeostasis (cont’d.) • Body monitors deviations in homeostasis • Negative feedback loop • Responses that revise disturbances to body’s condition • Positive feedback • Increase in function in response to stimulus • Uterine contractions during labor

36. Homeostasis (cont’d.) • Organ systems help control internal environment

37. Summary • Discussed the four basic reference systems of body organization (directions, planes, cavities, and structural units) • Discussed organization of the body into different structural levels (cells, tissues, organs, systems, human organism)

38. Summary (cont’d.) • Discussed homeostasis and mechanisms for maintaining it