1 An Introduction to Anatomy and Physiology

An Introduction to Studying the Human Body Learning Outcomes 1-1 Explain the importance of studying anatomy and physiology. 1-2 Identify basic study skill strategies to use in this course. 1-3 Define anatomy and physiology, describe the origins of anatomical and physiological terms, and explain the significance of Terminologia Anatomica (International Anatomical Terminology).

An Introduction to Studying the Human Body Learning Outcomes 1-4 Explain the relationship between anatomy and physiology, and describe various specialties of each discipline. 1-5 Identify the major levels of organization in organisms, from the simplest to the most complex, and identify major components of each organ system. 1-6 Explain the concept of homeostasis.

An Introduction to Studying the Human Body Learning Outcomes 1-7 Describe how negative feedback and positive feedback are involved in homeostatic regulation, and explain the significance of homeostasis. 1-8 Use anatomical terms to describe body sections, body regions, and relative positions. 1-9 Identify the major body cavities and their subdivisions, and describe the functions of each.

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

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

1-2 Good Study Strategies Crucial for Success Attend all lectures, labs, and study sessions Read your lecture and laboratory assignments before going to class or lab Devote a block of time each day to your A&P course Set up a study schedule and stick to it Do not procrastinate Approach the information in different ways Develop the skill of memorization, and practice it regularly As soon as you experience difficulty with the course, seek assistance

1-2 Good Study Strategies Crucial for Success Important Features of the Textbook End-of-Chapter Study and Review Materials Systems Integrators Colored Tabs End-of-Book Reference Sections Learning Outcomes Illustrations, Tables, and Photos Pronunciation Guides Checkpoint Questions Tips & Tricks Clinical Notes Arrow Icons

1-2 Good Study Strategies Crucial for Success Supplements Practice Anatomy Lab™ (PAL™) 3.0 DVD MasteringA&P™ Study Area Interactive Physiology® 10-System Suite (IP-10) CD-ROM Martini’s Atlas of the Human Body Get Ready for A&P! A&P Applications Manual Study Guide Full descriptions in preface of textbook

1-3 Anatomy and Physiology 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

1-4 Relationships between Anatomy and Physiology 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

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

1-4 Relationships between Anatomy and 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

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

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

Figure 1-1 Levels of Organization Cellular Level Chemical and Molecular Levels Heart muscle cell Protein filaments Complex protein molecule Atoms in combination 16

Figure 1-1 Levels of Organization Organism level Organ system level Organ Level Tissue Level Cardiac muscle tissue The heart The cardiovascular system 17

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

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

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

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

1-5 Levels of Organization 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 Thyroid gland Adrenal glands

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

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

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

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

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

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

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

1-5 Levels of Organization The Organ Systems Male Reproductive Major Organs Testes Epididymides Ductus deferentia Seminal vesicles Prostate gland Penis Scrotum

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

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

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

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)

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

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

Figure 1-2 The Control of Room Temperature RECEPTOR Information affects Normal condition disturbed Thermometer STIMULUS: Room temperature rises HOMEOSTASIS CONTROL CENTER (Thermostat) Air conditioner turns on Air conditioner turns off Normal room temperature RESPONSE: Room temperature drops 20° 30° 40° Room temperature (°C) Normal range 22 Normal condition restored EFFECTOR Sends commands to Air conditioner turns 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 thermostat turns on the air conditioner, and the temperature returns to normal. With this regulatory system, room temperature fluctuates around the set point. 37

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

Figure 1-3 Negative Feedback in the Control of Body Temperature RECEPTORS Temperature sensors in skin and hypothalamus Information affects Normal temperature disturbed CONTROL CENTER STIMULUS: Body temperature rises HOMEOSTASIS Thermoregulatory center in brain Normal body temperature Vessels dilate, sweating increases Vessels constrict, sweating decreases RESPONSE: Increased heat loss, body temperature drops 37.2 Normal temperature restored EFFECTORS Sends commands to Body temperature (°C) Normal range 37 • Sweat glands in skin increase secretion • Blood vessels in skin dilate 36.7 Time Events in the regulation of body temperature, which are comparable to those shown in Figure 12. A control center in the brain (the hypothalamus) functions as a thermostat with a set point of 37°C. If body temperature exceeds 37.2°C, heat loss is increased through enhanced blood flow to the skin and increased sweating. The thermoregulatory center keeps body temperature fluctuating within an acceptable range, usually between 36.7 and 37.2°C. 39

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

Figure 1-4 Positive Feedback: Blood Clotting Clotting accelerates Positive feedback loop Chemicals Chemicals Blood clot Damage to cells in the blood vessel wall releases chemicals that begin the process of blood clotting. The chemicals start chain reactions in which cells, cell fragments, and soluble proteins in the blood begin to form a clot. As clotting continues, each step releases chemicals that further accelerate the process. This escalating process is a positive feedback loop that ends with the formation of a blood clot, which patches the vessel wall and stops the bleeding. 41

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

Table 1-1 The Roles of Organ Systems in Homeostatic Regulation 43

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

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

Figure 1-5a Anatomical Landmarks Frontal or forehead Nasal or nose Ocular, orbital or eye Cranial or skull Otic or ear Cephalic or head Buccal or cheek Facial or face Cervical or neck Oral or mouth Mental or chin Thoracic or thorax, chest Axillary or armpit Mammary or breast Brachial or arm Abdominal (abdomen) Trunk Antecubital or front of elbow Umbilical or navel Anterior view 46

Figure 1-5a Anatomical Landmarks Antebrachial or forearm Pelvic (pelvis) Trunk Carpal or wrist Palmar or palm Manual or hand Pollex or thumb Digits (phalanges) or fingers (digital or phalangeal) Inguinal or groin Pubic (pubis) Patellar or kneecap Femoral or thigh Crural or leg Tarsal or ankle Digits (phalanges) or toes (digital or phalangeal) Pedal or foot Hallux or great toe Anterior view 47

Figure 1-5b Anatomical Landmarks Cephalic or head Acromial or shoulder Cervical or neck Dorsal or back Olecranal or back of elbow Upper limb Posterior view 48

Figure 1-5b Anatomical Landmarks Upper limb Lumbar or loin Gluteal or buttock Lower limb Popliteal or back of knee Sural or calf Calcaneal or heel of foot Plantar or sole of foot Posterior view 49

Figure 1-6a Abdominopelvic Quadrants and Regions Right Upper Quadrant (RUQ) Left Upper Quadrant (LUQ) Right Lower Quadrant (RLQ) Left Lower Quadrant (LLQ) Abdominopelvic quadrants. The four abdominopelvic quadrants are formed by two perpendicular lines that intersect at the navel. The terms for these quadrants, or their abbreviations, are most often used in clinical discussions. 50

Figure 1-6b Abdominopelvic Quadrants and Regions Right hypochondriac region Left hypochondriac region Epigastric region Right lumbar region Umbilical region Left lumbar region Hypogastric (pubic) region Right inguinal region Left inguinal region Abdominopelvic regions. The nine abdominopelvic regions provide more precise regional descriptions. 51

Figure 1-6c Abdominopelvic Quadrants and Regions Liver Stomach Gallbladder Spleen Large intestine Small intestine Appendix Urinary bladder Anatomical relationships. The relationship between the abdominopelvic quadrants and regions and the locations of the internal organs are shown here. 52

Figure 1-7 Directional References Cranial Superior Right Left Proximal Posterior or dorsal Anterior or ventral Lateral Medial Caudal Proximal Distal Distal Inferior A lateral view. An anterior view. Arrows indicate important directional terms used in this text; definitions and descriptions are given in Table 12. 53

Table 1-2 Directional Terms 54

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

Figure 1-8 Sectional Planes Frontal plane Sagittal plane Transverse plane 56

Table 1-3 Terms That Indicate Sectional Planes 57

1-9 Body Cavities Essential Functions of Body Cavities Protect organs from accidental shocks Permit changes in size and shape of internal organs Ventral body cavity (coelom) Divided by the diaphragm Thoracic cavity Abdominopelvic cavity

Abdominopelvic Cavity Figure 1-9 Relationships among the Subdivisions of the Ventral Body Cavity Ventral Body Cavity • Provides protection • Allows organ movement • Linings prevent friction Subdivides during development into Thoracic Cavity Abdominopelvic Cavity Surrounded by chest wall and diaphragm Peritoneal Cavity Extends throughout abdominal cavity and into superior portion of pelvic cavity Right Pleural Cavity Mediastinum Left Pleural Cavity Surrounds right lung Contains the trachea, esophagus, and major vessels Surrounds left lung Abdominal Cavity Pelvic Cavity Contains many digestive glands and organs Contains urinary bladder, reproductive organs, last portion of digestive tract Pericardial Cavity Surrounds heart 59

1-9 Body Cavities Serous Membranes Line body cavities and cover organs Consist of parietal layer and visceral layer Parietal layer — lines cavity Visceral layer — covers organ

1-9 Body Cavities The Thoracic Cavity Right and left pleural cavities Contain right and left lungs Mediastinum Upper portion filled with blood vessels, trachea, esophagus, and thymus Lower portion contains pericardial cavity The heart is located within the pericardial cavity

Figure 1-10a The Ventral Body Cavity and Its Subdivisions POSTERIOR ANTERIOR Pleural cavity Thoracic cavity Pericardial cavity Diaphragm Peritoneal cavity Abdominopelvic cavity Abdominal cavity Pelvic cavity 62

Figure 1-10b The Ventral Body Cavity and Its Subdivisions Visceral pericardium Heart Air space Pericardial cavity Balloon Parietal pericardium 63

Figure 1-10c The Ventral Body Cavity and Its Subdivisions ANTERIOR Pericardial cavity Pleural cavity Right lung Left lung Parietal pleura Mediastinum Spinal cord POSTERIOR 64

1-9 Body Cavities The Abdominopelvic Cavity Peritoneal cavity: chamber within abdominopelvic cavity Parietal peritoneum: lines the internal body wall Visceral peritoneum: covers the organs

1-9 Body Cavities The Abdominopelvic Cavity Abdominal cavity — superior portion Diaphragm to top of pelvic bones Contains digestive organs Retroperitoneal space Area posterior to peritoneum and anterior to muscular body wall Contains pancreas, kidneys, ureters, and parts of the digestive tract

1-9 Body Cavities The Abdominopelvic Cavity Pelvic cavity — inferior portion Within pelvic bones Contains reproductive organs, rectum, and bladder