the human body: an orientation

1. 26/09/2011 Ahmad ata 1 The Human Body: An Orientation

2. 26/09/2011 Ahmad ata 2 Survival Needs Nutrients – chemical substances used for energy and cell building Proteins Carbohydrates Lipids Micronutrients Vitamins and minerals Oxygen – needed for metabolic reactions Water – provides the necessary environment for chemical reactions

3. 26/09/2011 Ahmad ata 3 Survival Needs Maintaining normal body temperature – necessary for chemical reactions to occur at life-sustaining rates Atmospheric pressure – required for proper breathing and gas exchange in the lungs

4. 26/09/2011 Ahmad ata 4 Anatomical Position Reference position Body erect with arms at sides and palms forward. Head & feet pointing forward. Bilateral symmetry: is a term meaning that right & left sides of body are mirror images. 1) Ipsilateral structures: are on the same side of the body in anatomical position. 2) Contralateral structures: are on opposite sides of the body in anatomical position.

5. 26/09/2011 Ahmad ata 5 Body cavities There are two major cavities are called :

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8. 26/09/2011 Ahmad ata 8 Body cavities

9. 26/09/2011 Ahmad ata 9 Protect the organs Permit the organs to change in size and shape Heart contraction Stomach distend with food Two major cavities Dorsal Ventral

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11. 26/09/2011 Ahmad ata 11 Smaller cavities within the head Sinus – air filled cavities in cranial bones Orbital cavity - eyeball Nasal cavity – air and mucus Oral cavity – teeth and tongue Middle ear cavity – connects ear with atmospheric pressure via pharynx

12. 26/09/2011 Ahmad ata 12 Thoracic and Abdominopelvic Membranes: 1. The thoracic cavity is lined with pleura; the parietal pleura lines the cavities while the visceral pleura covers the lungs. A thin layer of serous fluid separates the two layers. 2. The heart is surrounded by pericardium. The visceral pericardium covers the heart and the parietal pericardium makes up an outer sac. Serous fluid separates the two layers. 3. Peritoneum lines the abdominopelvic cavity; a parietal peritoneum lines the wall while visceral peritoneum covers the organs.

13. 26/09/2011 Ahmad ata 13 Thoracic and pericardium

14. 26/09/2011 Ahmad ata 14 Body regions The body as a whole can be subdivided into major coponant: Axial : consist of head, kneck torso or trunk. Appendicular: consist of the lower and upper extremities and their connection of axial portion

15. 26/09/2011 Ahmad ata 15 Abdominal region

16. 26/09/2011 Ahmad ata 16 Right hypochondriac (gallbladder& liver) Epigastric region ( large portion of stomach& right and left lobe of liver) left hypochondriac (small portion of the stomach and large intestine) Right lumbar ( large and small intestine) left lumbar (small intestine) Right iliac ( cecum and parts of small intestine) left iliac ( portion of colon and small intestine) Umbilical ( transverse colon and small intestine) Hypogastric ( urinary bladder and appendix)

17. 26/09/2011 Ahmad ata 17 Division of the abdomen into four quadrants

18. 26/09/2011 Ahmad ata 18 Homeostasis It comes from two greek words (homoios) the same and stasis (standing) Homeostasis is the ability to maintain a relatively stable internal environment in an ever-changing outside world

19. 26/09/2011 Ahmad ata 19 Homeostatic Control Mechanisms The variable produces a change in the body The four interdependent components of control mechanisms are: Receptor Control center Effector Feedback

20. 26/09/2011 Ahmad ata 20 Nervous and Endocrine system Nervous system Electrical signals - impulses Endocrine system Hormones transported in blood to target cells Receptor Monitors the environment Detects changes Stimuli – changes in the environment

21. 26/09/2011 Ahmad ata 21 Homeostatic Control Mechanisms Control Center Integration center Determines the set point within the range Analyzes the information Determines the response Effector Provides the response Muscles contract or relax Glands secrete or stop secreting

22. 26/09/2011 Ahmad ata 22 Feedback Homeostasis maintained through either: Negative feedback mechanisms opposes response to stimulus and reverse a change Most homeostatic mechanisms in the body involved negative feedback Example: Regulation of blood glucose levels Positive feedback mechanisms enhances and amplify response to stimulus. Blood clotting

23. 26/09/2011 Ahmad ata 23 Negative Feedback

24. 26/09/2011 Ahmad ata 24 Positive Feedback In positive feedback systems, the output enhances or exaggerates the original stimulus. Rarely used to promote homeostasis Example: Regulation of blood clotting

25. 26/09/2011 Ahmad ata 25 Homeostatic imbalance Most diseases and/or disorders result from homeostatic imbalance With aging: body organs and control systems become less efficient internal environment becomes less and less stable greater risk of illness/injury

26. 26/09/2011 Ahmad ata 26 Anatomical direction They are Terms used in describing body structure are used to describe the location of a part relative to another part. Assume anatomical position Superior (cranial): means “toward the head” Inferior (caudal): toward the feet Anterior (ventral): in front of Posterior (dorsal): in back of Medial: toward the midline of the body

27. 26/09/2011 Ahmad ata 27 Lateral: toward the side of the body Proximal: nearest the trunk of the body Distal: away from the trunk Superficial: nearer the surface Deep: farther away from the body surface

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29. 26/09/2011 Ahmad ata 29 Planes and Sections Plane – imaginary line separating body parts Section – cut along the plane (named for the plane) Body Sections: 1. A sagittal section divides the body into right and left portions. 2. A transverse section divides the body into superior and inferior portions. It is often called a “cross section”. 3. A coronal section divides the body into anterior and posterior sections.

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31. 26/09/2011 Ahmad ata 31 Any Question????