An Introduction to Studying the Human Body

1. An Introduction to Studying the Human Body Classification of Living Things Humans and many other animals are vertebrates Characterized by a segmented vertebral column Common characteristics suggest the same path in evolution Homeostasis The goal of physiological regulation and the key to survival in a changing environment

2. 1-1 Anatomy and Physiology Directly Affect Your Life • Anatomy • Is the oldest medical science • 1600 B.C. • Physiology • Is the study of function • Biochemistry • Biology • Chemistry • Genetics

3. 1-3 Anatomy and Physiology • Anatomy • Describes the structures of the body • What they are made of • Where they are located • Associated structures • Physiology • Is the study of: • Functions of anatomical structures • Individual and cooperative functions

4. 1-4 Relationships between Anatomy and Physiology • Anatomy • Gross anatomy, or macroscopic anatomy, examines large, visible structures • Surface anatomy: exterior features • Regional anatomy: body areas • Systemic anatomy: organ systems • Developmental anatomy: from conception to death • Clinical anatomy:medical specialties

5. 1-4 Relationships between Anatomy and Physiology • Anatomy • Microscopic anatomy examines cells and molecules • Cytology: study of cells and their structures • cyt- = cell • Histology: study of tissues and their structures

6. 1-4 Relationships between Anatomy and Physiology • Physiology • Cell physiology: processes within and between cells • Organ physiology: functions of specific organs • Systemic physiology: functions of an organ system • Pathological physiology: effects of diseases

7. 1-5 Levels of Organization • The Chemical (or Molecular) Level • Atoms are the smallest chemical units • Molecules are a group of atoms working together • The Cellular Level • Cells are a group of atoms, molecules, and organelles working together • The Tissue Level • A tissue is a group of similar cells working together • The Organ Level • An organ is a group of different tissues working together

8. 1-5 Levels of Organization • The Organ System Level • An organ system isa group of organs working together • Humans have 11 organ systems • The Organism Level • A human is an organism

9. Figure 1-1 Levels of Organization Cellular Level Chemical and Molecular Levels Heart musclecell Protein filaments Complex protein molecule Atoms in combination

10. Figure 1-1 Levels of Organization Organismlevel Organ systemlevel Organ Level Tissue Level The heart Cardiac muscletissue Thecardiovascularsystem

11. 1-5 Levels of Organization The Organ Systems Integumentary Major Organs Skin Hair Sweat glands Nails Functions Protects against environmental hazards Helps regulate body temperature Provides sensory information

12. 1-5 Levels of Organization The Organ Systems Skeletal Major Organs Bones Cartilages Associated ligaments Bone marrow Functions Provides support and protection for other tissues Stores calcium and other minerals Forms blood cells

13. 1-5 Levels of Organization The Organ Systems Muscular Major Organs Skeletal muscles and associated tendons Functions Provides movement Provides protection and support for other tissues Generates heat that maintains body temperature

14. 1-5 Levels of Organization The Organ Systems Nervous Major Organs Brain Spinal cord Peripheral nerves Sense organs Functions Directs immediate responses to stimuli Coordinates or moderates activities of other organ systems Provides and interprets sensory information about external conditions

15. The Organ Systems Endocrine Major Organs Pituitary gland Pancreas Gonads Endocrine tissues in other systems Functions Directs long-term changes in the activities of other organ systems Adjusts metabolic activity and energy use by the body Controls many structural and functional changes during development 1-5 Levels of Organization • Thyroid gland • Adrenal glands

16. 1-5 Levels of Organization The Organ Systems Cardiovascular Major Organs Heart Blood Blood vessels Functions Distributes blood cells, water and dissolved materials including nutrients, waste products, oxygen, and carbon dioxide Distributes heat and assists in control of body temperature

17. 1-5 Levels of Organization The Organ Systems Lymphatic Major Organs Spleen Thymus Lymphatic vessels Lymph nodes Tonsils Functions Defends against infection and disease Returns tissue fluids to the bloodstream

18. 1-5 Levels of Organization The Organ Systems Respiratory Major Organs Nasal cavities Sinuses Larynx Trachea Bronchi Lungs Alveoli

19. 1-5 Levels of Organization The Organ Systems Respiratory Functions Delivers air to alveoli (sites in lungs where gas exchange occurs) Provides oxygen to bloodstream Removes carbon dioxide from bloodstream Produces sounds for communication

20. 1-5 Levels of Organization The Organ Systems Digestive Major Organs Teeth Tongue Pharynx Esophagus Stomach Small intestine Large intestine Liver Gallbladder Pancreas

21. 1-5 Levels of Organization The Organ Systems Digestive Functions Processes and digests food Absorbs and conserves water Absorbs nutrients Stores energy reserves

22. 1-5 Levels of Organization The Organ Systems Urinary Major Organs Kidneys Ureters Urinary bladder Urethra Functions Excretes waste products from the blood Controls water balance by regulating volume of urine produced Stores urine prior to voluntary elimination Regulates blood ion concentrations and pH

23. 1-5 Levels of Organization The Organ Systems Male Reproductive Major Organs Testes Epididymis Ductus deferentia (vas deferens) Seminal vesicles Prostate gland Penis Scrotum

24. 1-5 Levels of Organization The Organ Systems Male Reproductive Functions Produces male sex cells (sperm), suspending fluids, and hormones Sexual intercourse

25. 1-5 Levels of Organization The Organ Systems Female Reproductive Major Organs Ovaries Uterine tubes Uterus Vagina Labia Clitoris Mammary glands

26. 1-5 Levels of Organization The Organ Systems Female Reproductive Functions Produces female sex cells (oocytes) and hormones Supports developing embryo from conception to delivery Provides milk to nourish newborn infant Sexual intercourse

27. 1-6 Homeostasis • Homeostasis • All body systems working together to maintain a stable internal environment • Systems respond to external and internal changes to function within a normal range (body temperature, fluid balance)

28. 1-6 Homeostasis • Mechanisms of Regulation • Autoregulation(intrinsic) • Automatic response in a cell, tissue, or organ to some environmental change • Extrinsic regulation • Responses controlled by nervous and endocrine systems

29. 1-6 Homeostasis • Receptor • Receives the stimulus • Control center • Processes the signal and sends instructions • Effector • Carries out instructions

30. Figure 1-2 The Control of Room Temperature RECEPTOR Informationaffects Normalconditiondisturbed Thermometer STIMULUS:Room temperaturerises CONTROL CENTER(Thermostat) HOMEOSTASIS Airconditionerturns on Airconditionerturns off Normal roomtemperature RESPONSE:Room temperaturedrops 20° 30° 40° Normalrange Room temperature (°C) 22 Normalconditionrestored EFFECTOR Sendscommandsto Air conditionerturns on Time In response to input from a receptor (a thermometer), a thermostat(the control center) triggers an effector response (either an air condi-tioner or a heater) that restores normal temperature. In this case,when room temperature rises above the set point, the thermostatturns on the air conditioner, and the temperature returns to normal. With this regulatory system, roomtemperature fluctuates around theset point.

31. 1-7 Negative and Positive Feedback • The Role of Negative Feedback • The response of the effector negates the stimulus • Body is brought back into homeostasis • Normal range is achieved

32. Figure 1-3 Negative Feedback in the Control of Body Temperature RECEPTORS Informationaffects Temperaturesensors in skinandhypothalamus Normaltemperaturedisturbed CONTROL CENTER STIMULUS:Body temperaturerises HOMEOSTASIS Thermoregulatorycenter in brain Vesselsdilate,sweatingincreases Vesselsconstrict,sweatingdecreases Normal bodytemperature RESPONSE:Increased heat loss,body temperaturedrops 37.2 EFFECTORS Normaltemperaturerestored Normalrange Body temperature (°C) Sendscommandsto 37 • Sweat glands in skin increase secretion• Blood vessels in skin dilate 36.7 Time Events in the regulation of body temperature, which arecomparable to those shown in Figure 12. A control centerin the brain (the hypothalamus) functions as a thermostatwith a set point of 37°C. If body temperature exceeds37.2°C, heat loss is increased through enhanced blood flowto the skin and increased sweating. The thermoregulatory center keepsbody temperature fluctuatingwithin an acceptable range, usuallybetween 36.7 and 37.2°C.

33. 1-7 Negative and Positive Feedback • The Role of Positive Feedback • The response of the effector increases change of the stimulus • Body is moved away from homeostasis • Normal range is lost • Used to speed up processes

34. Figure 1-4 Positive Feedback: Blood Clotting Clottingaccelerates Positivefeedbackloop Blood clot Chemicals Chemicals The chemicals start chainreactions in which cells,cell fragments, andsoluble proteins in the blood begin to form a clot. Damage to cells in theblood vessel wall releaseschemicals that begin theprocess of blood clotting. As clotting continues,each step releaseschemicals that furtheraccelerate the process. This escalating processis a positive feedbackloop that ends with theformation of a blood clot,which patches the vesselwall and stops the bleeding.

35. 1-7 Negative and Positive Feedback • Systems Integration • Systems work together to maintain homeostasis • Homeostasis is a state of equilibrium • Opposing forces are in balance • Dynamic equilibrium —continual adaptation • Physiological systems work to restore balance • Failure results in disease or death

36. Table 1-1 The Roles of Organ Systems in Homeostatic Regulation

37. 1-8 Anatomical Terminology • Superficial Anatomy • Locating structures on or near the body surface • Anatomical Landmarks • Anatomical position: hands at sides, palms forward • Supine: lying down, face up • Prone: lying down, face down

38. 1-8 Anatomical Terminology • Superficial Anatomy • Anatomical Landmarks • References to palpable structures • Anatomical Regions • Body regions • Abdominopelvic quadrants • Abdominopelvic regions • Anatomical Directions • Reference terms based on subject

39. Figure 1-5a Anatomical Landmarks Frontal orforehead Nasal or nose Ocular, orbitalor eye Cranialor skull Otic or ear Cephalic or head Buccal or cheek Facialor face Cervical or neck Oral or mouth Mental or chin Thoracic orthorax, chest Axillary or armpit Mammaryor breast Brachialor arm Trunk Abdominal(abdomen) Antecubitalor front of elbow Umbilicalor navel Anterior view

40. Figure 1-5a Anatomical Landmarks Antebrachialor forearm Pelvic(pelvis) Trunk Carpal or wrist Palmar or palm Manualor hand Pollexor thumb Digits(phalanges)or fingers (digitalor phalangeal) Inguinalor groin Pubic(pubis) Patellar or kneecap Femoralor thigh Cruralor leg Tarsal orankle Digits (phalanges)or toes (digital orphalangeal) Pedalor foot Hallux orgreat toe Anterior view

41. Figure 1-5b Anatomical Landmarks Cephalicor head Acromial orshoulder Cervicalor neck Dorsal orback Olecranalor backof elbow Upperlimb Posterior view

42. Figure 1-5b Anatomical Landmarks Upperlimb Lumbaror loin Glutealor buttock Lower limb Popliteal orback of knee Suralor calf Calcaneal orheel of foot Plantar orsole of foot Posterior view

43. Figure 1-6a Abdominopelvic Quadrants and Regions Left UpperQuadrant(LUQ) Right UpperQuadrant(RUQ) Left LowerQuadrant(LLQ) Right LowerQuadrant(RLQ) Abdominopelvic quadrants. The fourabdominopelvic quadrants are formed by twoperpendicular lines that intersect at the navel. Theterms for these quadrants, or their abbreviations, are most often used in clinical discussions.

44. Figure 1-6b Abdominopelvic Quadrants and Regions Righthypochondriacregion Left hypochondriacregion Epigastricregion Umbilicalregion Left lumbarregion Right lumbarregion Hypogastric(pubic)region Rightinguinalregion Left inguinalregion Abdominopelvic regions. The nine abdominopelvicregions provide more precise regional descriptions.

45. Figure 1-6c Abdominopelvic Quadrants and Regions Liver Stomach Gallbladder Spleen Large intestine Small intestine Appendix Urinarybladder Anatomical relationships. The relationship betweenthe abdominopelvic quadrants and regions and thelocations of the internal organs are shown here.

46. Figure 1-7 Directional References Superior Cranial Right Left Proximal Anterioror ventral Posterioror dorsal Medial Lateral Caudal Proximal Distal Distal Inferior A lateral view. An anterior view. Arrowsindicate important directionalterms used in this text;definitions and descriptionsare given in Table 12.

47. Table 1-2 Directional Terms

48. 1-8 Anatomical Terminology • Sectional Anatomy • Planes and sections • Plane: a three-dimensional axis • Section: a slice parallel to a plane • Used to visualize internal organization and structure • Important in radiological techniques • MRI • PET • CT

49. Figure 1-8 Sectional Planes Frontal plane Sagittal plane Transverse plane

50. Table 1-3 Terms That Indicate Sectional Planes