Chapter 1 An Introduction to Anatomy and Physiology Lecture Presentation by Lee Ann Frederick University of Texas at Arlington
An Introduction to Studying the Human Body Learning Outcomes 1-1 Explain the importance of studying anatomy and physiology. 1-2 Define anatomy and physiology, describe the origins of anatomical and physiological terms, and explain the significance of Terminologia Anatomica (International Anatomical Terminology). 1-3 Explain the relationship between anatomy and physiology, and describe various specialties of each discipline.
An Introduction to Studying the Human Body Learning Outcomes 1-4 Identify the major levels of organization in organisms, from the simplest to the most complex, and identify major components of each organ system. 1-5 Explain the concept of homeostasis. 1-6 Describe how negative feedback and positive feedback are involved in homeostatic regulation, and explain the significance of homeostasis.
An Introduction to Studying the Human Body Learning Outcomes 1-7 Use anatomical terms to describe body regions, body sections, and relative positions. 1-8 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 Anatomy Is the study of body structures Oldest medical science: 1600 BCE Physiology Is the study of function Biochemistry Biology Chemistry Genetics
1-2 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
1-3 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 Clinical anatomy: medical specialties Developmental anatomy: from conception to death
1-3 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
1-3 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
1-4 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
1-4 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 (Part 1 of 4). Cellular Level Chemical Level Protein filaments Heart muscle cell Atoms in combination Complex protein molecule
Figure 1-1 Levels of Organization (Part 2 of 4). Tissue Level Organ Level Organ system level Organism level Cardiac muscle tissue The heart The cardiovascular system
1-4 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
1-4 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
1-4 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
1-4 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
1-4 Levels of Organization The Organ Systems Endocrine Major Organs Pituitary gland Pancreas Gonads Thyroid gland Adrenal glands 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
1-4 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
1-4 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
1-4 Levels of Organization The Organ Systems Respiratory Major Organs Nasal cavities Sinuses Larynx Trachea Bronchi Lungs Alveoli
1-4 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
1-4 Levels of Organization The Organ Systems Digestive Major Organs Teeth Tongue Pharynx Esophagus Stomach Small intestine Large intestine Liver Gallbladder Pancreas
1-4 Levels of Organization The Organ Systems Digestive Functions Processes and digests food Absorbs and conserves water Absorbs nutrients Stores energy reserves
1-4 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
1-4 Levels of Organization The Organ Systems Male Reproductive Major Organs Testes Epididymides Ductus deferentia Seminal vesicles Prostate gland Penis Scrotum
1-4 Levels of Organization The Organ Systems Male Reproductive Functions Produces male sex cells (sperm), seminal fluids, and hormones Sexual intercourse
1-4 Levels of Organization The Organ Systems Female Reproductive Major Organs Ovaries Uterine tubes Uterus Vagina Labia Clitoris Mammary glands
1-4 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
1-5 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)
1-5 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
1-5 Homeostasis Receptor Receives the stimulus Control Center Processes the signal and sends instructions Effector Carries out instructions
Room temperature ( C) Figure 1-2 The Control of Room Temperature. Normal condition disturbed STIMULUS: Room temperature rises RECEPTOR Thermometer Information affects HOMEOSTASIS CONTROL CENTER (Thermostat) Normal room temperature Air conditioner turns on Air conditioner turns off a Normal condition restored RESPONSE: Room temperature drops EFFECTOR Air conditioner turns on Sends commands to 20 30 40 In response to input from a receptor (a thermometer), a thermostat (the control center) triggers an effector response (either an air conditioner 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. 22 Set point b Time With this regulatory system, room temperature fluctuates around the set point, 22 C. Normal range
1-6 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
Body temperature ( C) Figure 1-3 Negative Feedback: Control of Body Temperature. RECEPTORS Normal temperature disturbed STIMULUS: Body temperature rises Temperature sensors in skin and hypothalamus Information affects CONTROL CENTER HOMEOSTASIS Normal body temperature RESPONSE: Increased heat loss, body temperature drops Thermoregulatory center in brain Vessels dilate, sweating increases Vessels constrict, sweating decreases a Normal temperature restored EFFECTORS Sweat glands in skin increase secretion Blood vessels in skin dilate Sends commands to 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. 37.2 Set point 37 36.7 b Time Normal range The thermoregulatory center keeps body temperature fluctuating within an acceptable range, usually between 36.7 C and 37.2 C.
1-6 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 Damaged cells in the blood vessel wall release chemicals that begin the clotting process. 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.
1-6 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.
1-7 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
1-7 Anatomical Terminology Superficial Anatomy Anatomical landmarks References to palpable structures Anatomical regions Abdominopelvic quadrants Abdominopelvic regions Anatomical directions Reference terms based on subject
Figure 1-5a Anatomical Landmarks (Part 1 of 2). Frontal or forehead Nasal or nose Ocular, orbital or eye Cephalic or head Oral or mouth Mental or chin Axillary or armpit Brachial or arm Antecubital or front of elbow Cranial or skull Facial or face Otic or ear Buccal or cheek Cervical or neck Thoracic or thorax, chest Mammary or breast Abdominal (abdomen) Umbilical or navel Trunk a Anterior view
Figure 1-5a Anatomical Landmarks (Part 2 of 2). Antebrachial or forearm Carpal or wrist Palmar or palm Pelvic (pelvis) Trunk Manual or hand Pollex or thumb Digits (phalanges) or fingers (digital or phalangeal) Patellar or kneecap Crural or leg Tarsal or ankle Inguinal or groin Pubic (pubis) Femoral or thigh Digits (phalanges) or toes (digital or phalangeal) Hallux or great toe a Anterior view Pedal or foot
Figure 1-5b Anatomical Landmarks (Part 1 of 2). Cephalic or head Acromial or shoulder Dorsal or back Cervical or neck Olecranal or back of elbow Upper limb b Posterior view
Figure 1-5b Anatomical Landmarks (Part 2 of 2). Lumbar or loin Upper limb Gluteal or buttock Popliteal or back of knee Lower limb Sural or calf Calcaneal or heal of foot Plantar or sole of foot b Posterior view
Figure 1-6a Abdominopelvic Quadrants and Regions. Right Upper Quadrant (RUQ) Right Lower Quadrant (RLQ) Left Upper Quadrant (LUQ) Left Lower Quadrant (LLQ) a 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.
Figure 1-6b Abdominopelvic Quadrants and Regions. Right hypochondriac region Epigastric region Left hypochondriac region Right lumbar region b Right inguinal region Umbilical region Hypogastric (pubic) region Left lumbar region Left inguinal region Abdominopelvic regions. The nine abdominopelvic regions provide more precise regional descriptions.
Figure 1-6c Abdominopelvic Quadrants and Regions. Liver Gallbladder Stomach Spleen Large intestine Small intestine c Appendix Urinary bladder Anatomical relationships. The relationship between the abdominopelvic quadrants and regions and the locations of the internal organs are shown here.
Figure 1-7 Directional References. Superior: Above; at a higher level (in the human body, toward the head) The head is superior to the knee. Superior Right Left Cranial or Cephalic Toward the head The cranial, or cephalic, border of the pelvis is superior to the thigh. Proximal Toward an attached base The shoulder is proximal to the wrist. Posterior or Dorsal Anterior or Ventral Lateral Away from the midline Medial Toward the midline Posterior: The back surface Dorsal: The back. (equivalent to posterior when referring to the human body) The scapula (shoulder blade) is located posterior to the rib cage. Anterior: The front surface Ventral: The belly side. (equivalent to anterior when referring to the human body) The umbilicus (navel) is on the anterior (or ventral) surface of the trunk. Proximal Distal Away from an attached base The fingers are distal to the wrist. Caudal Toward the tail; (coccyx in humans) The hips are caudal to the waist. OTHER DIRECTIONAL TERMS Superficial Distal At, near, or relatively close to the body surface The skin is superficial to underlying structures. Deep Toward the interior of the body; farther from the surface a Anterior view The bone of the thigh is deep to the surrounding skeletal muscles. b Lateral view Inferior: Below; at a lower level; toward the feet The knee is inferior to the hip. Inferior
1-7 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 or coronal plane Plane is oriented parallel to long axis A frontal, or coronal, section separates anterior and posterior portions of the body. Coronal usually refers to sections passing through the skull. Directional term: frontally or coronally Midsagittal plane Sagittal plane Plane is oriented parallel to long axis A sagittal section separates right and left portions. You examine a sagittal section, but you section sagittally. In a midsagittal section, the plane passes through the midline. It separates the body into equal right and left sides. A parasagittal section misses the midline. It separates the body into unequal right and left sides. Directional term: sagittally Transverse, or horizontal, plane Frontal plane Plane is oriented perpendicular to long axis Transverse plane (inferior view) A transverse, or cross, section separates superior and inferior portions of the body. Directional term: transversely or horizontally
1-8 Body Cavities Essential Functions of Body Cavities 1. Protect organs from accidental shocks 2. Permit changes in size and shape of internal organs Ventral Body Cavity (Coelom) Divided by the diaphragm Thoracic cavity Abdominopelvic cavity
1-8 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
1-8 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 1-9a Relationships among the Subdivisions of the Body Cavities of the Trunk. POSTERIOR ANTERIOR Thoracic cavity Pleural cavity Pericardial cavity Diaphragm Abdominopelvic cavity Peritoneal cavity Abdominal cavity Pelvic cavity a A lateral view showing the body cavities of the trunk. The muscular diaphragm subdivides them into a superior thoracic cavity and an inferior abdominopelvic cavity. Three of the four adult true body cavities are shown and outlined in red; only one of the two pleural cavities can be shown in a sagittal section.
Figure 1-9b Relationships among the Subdivisions of the Body Cavities of the Trunk. b Heart Visceral pericardium Pericardial cavity Parietal pericardium Air space Balloon The heart projects into the pericardial cavity like a fist pushed into a balloon. The attachment site, corresponding to the wrist of the hand, lies at the connection between the heart and major blood vessels. The width of the pericardial cavity is exaggerated here; normally the visceral and parietal layers are separated only by a thin layer of pericardial fluid.
Figure 1-9c Relationships among the Subdivisions of the Body Cavities of the Trunk. ANTERIOR Pericardial cavity Pleural cavity Parietal pleura Right lung Heart Left lung Mediastinum Spinal cord POSTERIOR c A transverse section through the thoracic cavity, showing the central location of the pericardial cavity. The mediastinum and pericardial cavity lie between the two pleural cavities. Note that this transverse or crosssectional view is oriented as though the observer were standing at the subject s feet and looking toward the subject s head. This inferior view of a transverse section is the standard presentation for clinical images. Unless otherwise noted, transverse or cross-sectional views in this text use this same orientation (see Spotlight Figure 1-10).
1-8 Body Cavities The Abdominopelvic Cavity Peritoneal cavity: chamber within abdominopelvic cavity Parietal peritoneum: lines the internal body wall Visceral peritoneum: covers the organs
1-8 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
1-8 Body Cavities The Abdominopelvic Cavity Pelvic cavity inferior portion Within pelvic bones Contains reproductive organs, rectum, and bladder