Chapter 1 Outline - An Introduction to the Human Body PDF

CHAPTER ONE An Introduction to the Human Body 1.1 An Overview of Anatomy and Physiology A. Anatomy and Physiology courses are branches of biology that help us to understand life. 1. Anatomy is the study of the STRUCTU...

CHAPTER ONE An Introduction to the Human Body 1.1 An Overview of Anatomy and Physiology A. Anatomy and Physiology courses are branches of biology that help us to understand life. 1. Anatomy is the study of the STRUCTURES and FORM of living things. a. Gross anatomy=science of macroscopic anatomy; studying large body structures visible with the naked eye. i. Surface anatomy=the study of internal structures as they relate to the overlying skin surface. ii. Regional anatomy=considers the regions of the body such as head and the extremities and all the systems in the particular region. iii. Systemic anatomy=gives attention to all the structures of a particular system in the body regardless of location. b. Microscopic anatomy=concerned with structures too small to be seen with the naked eye. i. Cytology=study of cells, their components, and their functions. ii. Histology=study of tissues and their functions. 2. Physiology is the study of the FUNCTION of the parts that make up living things. B. Complementarity of Form and Function 1. Physiology and anatomy are closely interrelated both theoretically and practically, for anatomical details are significant only because each has an effect on function, and physiological mechanisms can be fully understood only in terms of the underlying structural relationships. 2. Although our knowledge is incomplete, it is quite clear that living systems are subject to the same laws of physics and chemistry as are buildings, oceans, and mountain ranges. 3. Many advances in our understanding of the human body only came after advances in one of the physical or applied sciences. 1.2 Structural Organization of the Human Body A. Chemical level – the least complex level; composed of atoms, the smallest stable units of matter arranged to form molecules and compounds that possess specific functional properties and unique three-dimensional shapes. Examples: water molecules, glucose, proteins, etc. B. Cellular level – Interactions between molecules and compounds form the organelles of cells. Cells are the structural building block of all plants and animals, can be produced only from pre-existing cells, and are the smallest units capable of performing all vital life functions. Examples of cells: muscle cells, blood cells, nerve cells, etc. C. Tissue level – specialized groups of cells and cell products that work together to perform one or more specific functions. Examples: muscle tissue, nerve tissue, connective tissue, and epithelial tissues. D. Organ level – consists of two or more tissues working in combination to perform several functions. The type of tissues that compose the organ dictates the function of the organ. Examples: heart, lungs, stomach, etc. E. Organ System level – organs interact to form organ systems. Organs and the organ systems they compose perform vital life functions of the body. You need to be able to name the 11 organ systems, identify the basic organs that form each organ system, and give major functions of each organ system. 1. Integumentary system=composed of skin, hair, and nails; external support and protection of the body and temperature regulation. 2. Skeletal system=composed of bones; internal support and flexible framework for body movement, forms blood cells, and stores minerals. 3. Muscular system=composed of muscles attached to the skeleton; locomotion, support, and body heat production.  4. Respiratory system=composed of the lungs, trachea, larynx and nasal passages; exchange of respiratory gases, such as oxygen and carbon dioxide, between the air and circulating blood. 5. Nervous system=composed of the brain, spinal cord, and peripheral nerves; directs immediate response to stimuli, usually by coordinating the activities of other organ systems. 6. Circulatory system=composed of heart and blood vessels; internal transport of nutrients and oxygen to body cells while wastes and carbon dioxide are transported away from body cells. 7. Lymphatic/Immune system=composed of the lymph nodes, spleen, thymus gland, bone marrow, and tonsils; houses the immune system cells of the body, provides protection against infection and disease, transports tissue fluid (called lymph) and absorbs fats. 8. Endocrine system=composed of hormone secreting glands such as the thyroid, pituitary, adrenal gland, pancreas, pineal, etc.; secretion of hormones that direct long-term changes in the activities of other organ systems. 9. Urinary system=composed of the kidneys, ureters, urinary bladder, and urethra; filters the blood to remove nitrogenous wastes, eliminates excess water, salts, and waste products, and controls pH and electrolyte balance. 10. Digestive system=composed of the salivary glands, esophagus, stomach, small intestine, large intestine, liver, and gallbladder. Intake, breakdown, and absorption of food in order to acquire nutrients, minerals, vitamins and water and the elimination of feces. 11. Reproductive system=composed of ovaries, uterus, vagina, and mammary glands in females AND the testes, scrotum, prostate gland, seminal vesicles and penis in the male; production of sperm and egg as well as secretion of sex hormones and copulation. F. Organism= a living being that has a cellular structure and that can independently perform all physiologic functions necessary for life. In multicellular organisms, including humans, all cells, tissues, organs, and organ systems of the body work together to maintain the life and health of the organism. The organism level is the most complex level of organization. 1.3 Functions of Human Life A. Biology is the study of life. 1. Despite tremendous diversity, all living things perform the same basic functions and exhibit the same basic characteristics. 2. Characteristics of life include: a. Organization – Separation of one area from another; organism, cell, organ, etc. Ability to control what enters and exits each area. b. Metabolism - All chemical reactions in a cell/organism (both anabolism and catabolism). Generally, can be: i. Anabolic – Smaller, simpler molecules are combined to create a larger, more complex substance. Will require an input of energy – endergonic. ii. Catabolic – Larger, more complex substances are broken down into smaller, simpler, molecules. Will release energy – exergonic. iii. Adenosine triphosphate (ATP) – A key chemical compound used to store and release energy. Conversion of ADP to ATP is anabolic. Conversion of ATP to ADP is catabolic. c. Responsiveness – The ability of an organism to adjust to changes in its internal and external environments. Examples: Moving toward food and water, or internal homeostasis of body temperature. d. Movement - Coordinated, intentional change in location or position, including internal movement of organs, substances. e. Development, growth and reproduction – Changes in an organism over the life cycle. i. Development – All of the changes the body goes through in life. Including growth and repair, and differentiation – Unspecialized cells become specialized in structure and function to perform specific tasks.  ii. Growth - An increase in body size through an increase in the number of existing cells, non-cellular material around those cells, and rarely, the size of existing cells. iii. Reproduction – The formation of a new organism from parent organisms. For humans, from the interaction between male and female reproductive systems. 1.4 Requirements for Human Life A. Oxygen 1. Our primary atmospheric gas essential for human survival 2. Brain cells require lots of energy and therefore require lots of oxygen to perform 3. Without oxygen brain damage can occur within 5 minutes and death will follow within 10 minutes of oxygen deprivation. B. Nutrients 1. Essential nutrients for humans consist of: a. organic compounds (carbohydrates, lipids, proteins, nucleotides, vitamins) b. inorganic compounds (water and minerals). 2. Nutrients the human body needs a large supply of are called macronutrients, in contrast to micronutrients that the body needs very small amounts of. C. Narrow Range of Temperature 1. Hyperthermia – if body is overheated for prolonged period of time it can lead to heat stroke and death. Sweating helps cool the body down using evaporation. 2. Hypothermia – if the body is to cold it can lead to shock and death. Shivering helps generate heat within the body. D. Atmospheric Pressure Pressure – the force exerted by a substance in contact with another substance. We can withstand a certain range in pressures exerted on the human body via the gasses in the atmosphere or the diving in the ocean. 1.5 Homeostasis A. Homeostasis is a state of equilibrium or balance. 1. Maintaining a “steady state”; constancy within narrow limits; balance or equilibrium; a dynamic state in which internal conditions remain relatively constant despite changes in the external conditions. 2. Vital to an organism’s survival; failure to maintain homeostasis results in illness, disease, or even death. 3. Homeostatic control is not precise-it maintains a normal range rather than an absolute value, or set point. For example: blood pH ranges between 7.35 and 7.45 but the set point is 7.40. 4. Homeostatic regulation involves feedback mechanisms that consist of three components: a. Receptor=detects changes in either the internal or external environment, or stimulus. b. Control center=receives and process the information supplies by the receptor and sends out commands. c. Effector=responds to the commands by opposing the stimulus B. Negative feedback mechanisms provide stability. 1. Shuts off or reduces the original stimulus. 2. Helps to stabilize situation; essential for maintaining homeostasis. 3. Examples: body temperature, heart rate, breathing rate and depth, and blood-glucose levels. C. Positive feedback mechanisms accelerate a process to completion. 1. Intensify or enhance of original stimuli. 2. Amplify and reinforce a change brought on by the stimulus; not typically used for homeostasis. 3. Examples: blood clotting and labor contractions. 1.6 Anatomical Terminology A. Word roots, prefixes, and suffixes are the basis for the language of anatomy 1. arter- = artery 2. a- = without 3. aer- = air 4. –algia = pain 5. artho- = joint 6. auto- = self 7. bio- = life 8. –blast = germ; immature 9. bronch- = windpipe; airway 10. cardi-, cardio-, -cardia = heart 11. cerebr- = brain 12. cervic- = neck 13. chondro- = cartilage 14. cranio- = skull 15. cyt-, cyto- = a hollow cell 16. derm- = skin 17. –ectomy = excision 18. end-, endo- = within 19. epi- = on 20. ex- = out of, away from 21. gastro- = stomach 22. hemo- = blood 23. hemi- = one-half 24. histo- = tissue 25. homo- = same 26. hetero- = different 27. hyper- = above; more than 28. hypo- = under; less than 29. inter- = between 30. iso- = equal 31. leuk-, leuko- = white 32. lyso-, -lysis, -lyze = to burst; to loosen 33. meso- = middle 34. micr- = small 35. morph-, morpho- = form or shape 36. myo- = muscle 37. nephr- = kidney 38. neur-, neuri-, neuro- = nerve 39. –ology = the study of 40. –osis = state 41. ost-, oste-, osteo- = bone 42. oto- = ear 43. path-, -pathy, patho- = disease 44. peri- = around 45. phago- = to eat 46. –phil, -philia = love 47. –phot, photo- = light 48. physio- = nature 49. pre- = before 50. pulmo- = lung  51. retro- = backward 52. sarco- = flesh 53. scler-, sclera- = hard 54. –scope = to view 55. sub- = below 56. super- = above 57. –trophy = nourishment 58. vas- = vessel B. Superficial anatomy and regional anatomy indicate locations on or in the body. 1. Abdominal=anterior torso below diaphragm 2. Acromial=point of shoulder 3. Antebrachial=forearm 4. Antecubital=front of elbow 5. Axillary=armpit 6. Brachial=arm 7. Buccal=cheek 8. Calcaneal=heel 9. Carpal=wrist 10. Cephalic=head 11. Cervical=neck 12. Costal=rib 13. Coxal=hip 14. Cranial=skull 15. Crural=leg 16. Cubital=or olecranal; back of elbow 17. Cutaneous=skin 18. Digital=fingers or toes 19. Dorsum or dorsal=back 20. Epigastric=upper middle area of abdomen 21. Facial=face 22. Femoral=thigh 23. Fibular=side of leg 24. Gluteal=buttock 25. Hallux=great toe 26. Inguinal=groin 27. Lumbar=or loin; lower back 28. Mammary=breast 29. Manus=hand 30. Mastoid=below and behind ear 31. Mental=chin 32. Nasal=nose 33. Occipital=back of lower skull 34. Olecranal=back of elbow 35. Oral=mouth 36. Orbital=or ocular; eye 37. Otic=or auris; ear 38. Palmar=palm of hand 39. Patellar=knee cap 40. Pectoral=chest  41. Pedal=or pes, foot 42. Pelvic=lower torso 43. Perineal=area between anus and genitals 44. Phalangeal=fingers or toes 45. Plantar=sole of foot 46. Pollex=thumb 47. Popliteal=behind knee 48. Pubis=pubic region 49. Sacral=between hips 50. Scapular=shoulder blade 51. Sternal=breastbone 52. Sural=calf 53. Supraclavicular=above collar bone 54. Tarsal=ankle 55. Temporal=side of skull 56. Thoracic=chest 57. Umbilical=area around umbilicus 58. Vertebral=spinal column 59. Volar-palm or sole C. Abdominopelvic quadrants and regions 1. Abdominopelvic quadrants a. Right upper quadrant=contains liver b. Left upper quadrant=contains the stomach and spleen c. Left lower quadrant=contains descending colon d. Right lower quadrant=contains the cecum and ascending colon. 2. Abdominopelvic regions a. Umbilical=centermost region deep to and surrounding the navel. b. Epigastric=superior to the umbilical region c. Hypogastric=located inferior to the umbilical region d. Right and left hypochondriac=flanks the epigastric region laterally. e. Right and left lumbar=lies lateral to the umbilical region f. Right and left iliac (inguinal)=lateral to the hypogastric region D. Directional and sectional terms describe specific points of reference. 1. Directional terms a. Superior (cranial) =above; toward the head end or upper part of the structure or body. b. Inferior (caudal) =below; away from the head end or toward the lower part of the structure or body. c. Anterior (ventral) =toward or at the front of the body. d. Posterior (dorsal) =toward or at the back of the body. e. Medial=toward or at the longitudinal axis of the body. f. Lateral=away from the longitudinal axis of the body. g. Intermediate=between a more medial and a more lateral structure. h. Proximal=closer to the origin of the body part or the point of attachment of a limb to the body trunk. i. Distal=farther from the origin of a body part or the point of attachment. j. Superficial (external) =toward or at the body surface. k. Deep (internal) away from the body surface; more internal. 2. Sectional terms or planes a. Sagittal=a vertical plane that divides the body into right and left parts.  i. Midsagittal (median) =the plane dividing the body exactly in the midline. ii. Parasagittal=all other sagittal planes offset from the midline b. Frontal (coronal) =any plane dividing the body into anterior and posterior portions. c. Transverse (horizontal) =a plane dividing the body into superior and inferior portions. d. Oblique=cuts made diagonally between the horizontal and vertical planes. E. Body cavities protect internal organs from shock or impacts and allow them to change shape. 1. Dorsal body cavity=composed of two smaller cavities: a. Cranial cavity=contains the brain b. Vertebral cavity=contains the spinal cord 2. Ventral body cavity=also known as the coelom; houses internal organs of the body collectively called the viscera or “guts”. Divided into two smaller cavities: a. Thoracic cavity i. Pleural cavity=right and left; contains the lungs ii. Mediastinum=space between the pleural cavities; containing the thymus, lymph vessels, esophagus, trachea, and nerves. Embedded within the mediastinum is the pericardial cavity, which houses the heart. b. Abdominopelvic cavity i. Abdominal cavity=contains digestive organs ii. Pelvic cavity=contains bladder, reproductive organs, and rectum 3. The dorsal and ventral body cavities are lined with serous membranes which secrete a watery, lubricating fluid. a. Meninges line the dorsal body cavity. b. Pleura line the pleural cavity. c. Pericardium lines the pericardial cavity. d. Peritoneum lines the abdominal cavity; some organs are retroperitoneal such as the urinary and reproductive organs. 4. Other less significant cavities of the body a. Nasal cavity=for the passage of air into the respiratory tract b. Orbital cavity=area of the skull that houses the eye c. Middle ear cavity=contains the ossicles d. Synovial cavity=are joint cavities filled with synovial fluid 1.7 Medical Imaging A. X-Ray machine projects high energy electromagnetic radiation against an area of the body with a metal plate behind it. The X-rays are slightly blocked by the soft tissue and fully blocked by bone or teeth resulting in a white “shadow“. B. Computed Tomography (CT) The patient lies on a platform while the Computerized Axial Tomography (CAT) machine generates multiple X-rays as it rotates around the patient. These X-rays or “slices” are then assemble to create a very detailed image. Soft tissue masses can now be measured to the millimeter with the drawback of large radiation exposure. C. Magnetic Resonance Image (MRI) uses electromagnets and radio waves to scan patients. The scan does not expose patients to large doses of radiation like a CT however it is very loud and the tube might trigger claustrophobia. D. Positron Emission Tomography (PET) uses a short-lived radioactive contrast that will travel to areas with high metabolic activity such as cancer. The isotope will break down causing photons to be released and detected by the scanners resulting in an image. PET scans show us activity within our bodies (physiology) while CT and MRIs show us structures (anatomy). E. Ultrasonography uses high frequency sound waves to generate an image. It is the least invasive imaging technique and commonly used to monitor pregnancy.