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2 Chapter 1 The Human Body

3 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 Basic reference systems –Directions, planes, cavities, structural units

4 Terms of Direction

5 Terms of Direction (cont’d.) 5

6 Planes

7 Planes (cont’d.)

8 Cavities

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

10 Cavities (cont’d.)

11 Structural Units

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

13 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

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

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

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

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

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

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

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

21 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

22 Structural Units (cont’d.) Respiratory system –Organs Nasal cavities, pharynx, larynx, trachea, bronchi, lungs –Function O 2 > CO 2 exchange in the blood

23 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

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

25 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

26 Homeostasis

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

28 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

29 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

30 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 Organ systems help control internal environment

31 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) Discussed homeostasis and mechanisms for maintaining it