Chapter 1 The Human Body: An Orientation PDF

Chapter 1 The Human Body: An Orientation © 2018 Pearson Education, Ltd.  Anatomy ▪ Anatomy ▪ Study of the structure and shape of the body and its parts ▪ Observation is used to see sizes and relationships of parts © 2018 Pearson E...

Chapter 1 The Human Body: An Orientation © 2018 Pearson Education, Ltd.  Anatomy ▪ Anatomy ▪ Study of the structure and shape of the body and its parts ▪ Observation is used to see sizes and relationships of parts © 2018 Pearson Education, Ltd.  Anatomy ▪ Gross anatomy ▪ Large structures ▪ Easily observable © 2018 Pearson Education, Ltd.  Anatomy ▪ Let’s look at an example of gross anatomy using the digestive system organs © 2018 Pearson Education, Ltd. Figure 1.2i The body’s organ systems. Oral cavity Esophagus Stomach Small intestine Large intestine Rectum (i) Digestive System Breaks food down into absorbable nutrients that enter the blood for distribution to body cells; indigestible foodstuffs are eliminated as feces. © 2018 Pearson Education, Ltd.  Anatomy ▪ Microscopic anatomy ▪ Structures are too small to be seen with the naked eye ▪ Cells and tissues can be viewed only with a microscope © 2018 Pearson Education, Ltd.  Anatomy ▪ Let’s look at an example of microscopic anatomy using a digestive system organ, the stomach © 2018 Pearson Education, Ltd. Figure 14.4c Anatomy of the stomach. Gastric pits Surface Gastric pit epithelium Pyloric sphincter Mucous neck cells Gastric gland Parietal cells Gastric glands Chief cells (c) © 2018 Pearson Education, Ltd. Figure 14.4d Anatomy of the stomach. Pepsinogen Pepsin HCl Parietal cells Chief cells Enteroendocrine (d) cell © 2018 Pearson Education, Ltd.  Physiology ▪ Physiology ▪ Study of how the body and its parts work or function © 2018 Pearson Education, Ltd.  Physiology ▪ Structure determines what functions can occur ▪ For example, the air sacs of the lungs have very thin walls, a feature that enables them to exchange gases and provide oxygen to the body © 2018 Pearson Education, Ltd.  Levels of Structural Organization ▪ Six levels of structural organization 1. Atoms 2. Cells 3. Tissues 4. Organs 5. Organ systems 6. Organisms © 2018 Pearson Education, Ltd. Figure 1.1 Levels of structural organization. Slide 1 Smooth muscle cell Atoms 1 Chemical level Molecules Atoms combine to 2 Cellular level form molecules. Cells are made up of molecules. Smooth muscle tissue 3 Tissue level Blood Tissues consist of vessels similar types of cells. Heart Epithelial tissue Smooth muscle tissue Blood vessel (organ) Cardio– Connective vascular tissue system 4 Organ level Organs are made up of 5 Organ system level 6 Organismal level different types of tissues. Organ systems consist of Human organisms are different organs that work made up of many organ together closely. systems. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Integumentary system ▪ Forms the external body covering (skin) and includes hair and fingernails ▪ Waterproofs the body ▪ Cushions and protects deeper tissue from injury ▪ Produces vitamin D with the help of sunlight ▪ Excretes salts in perspiration ▪ Helps regulate body temperature ▪ Location of cutaneous nerve receptors © 2018 Pearson Education, Ltd. Figure 1.2a The body’s organ systems. Hair Skin Fingernails (a) Integumentary System Forms the external body covering; protects deeper tissue from injury; synthesizes vitamin D; location of sensory receptors (pain, pressure, etc.) and sweat and oil glands. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Skeletal system ▪ Consists of bones, cartilages, ligaments, and joints ▪ Provides muscle attachment for movement ▪ Protects vital organs ▪ Site of blood cell formation ▪ Stores minerals © 2018 Pearson Education, Ltd. Figure 1.2b The body’s organ systems. Cartilages Joint Bones (b) Skeletal System Protects and supports body organs; provides a framework the muscles use to cause movement; blood cells are formed within bones; stores minerals. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Muscular system ▪ Skeletal muscles contract (or shorten) ▪ Produces movement of bones © 2018 Pearson Education, Ltd. Figure 1.2c The body’s organ systems. Skeletal muscles (c) Muscular System Allows manipulation of the environment, locomotion, and facial expression; maintains posture; produces heat. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Nervous system ▪ Fast-acting control system ▪ Consists of brain, spinal cord, nerves, and sensory receptors ▪ Responds to internal and external stimuli ▪ Sensory receptors detect changes ▪ Messages are sent to the central nervous system ▪ Central nervous system assesses information and activates effectors (muscles and glands) © 2018 Pearson Education, Ltd. Figure 1.2d The body’s organ systems. Brain Sensory receptor Spinal cord Nerves (d) Nervous System Fast-acting control system of the body; responds to internal and external changes by activating appropriate muscles and glands. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Endocrine system ▪ Secretes chemical molecules, called hormones, into the blood ▪ Body functions controlled by hormones include: ▪ Growth ▪ Reproduction ▪ Use of nutrients © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Endocrine system (continued) ▪ Endocrine glands include: ▪ Pituitary gland ▪ Thyroid and parathyroids ▪ Adrenal glands ▪ Thymus ▪ Pancreas ▪ Pineal gland ▪ Ovaries (females) and testes (males) © 2018 Pearson Education, Ltd. Figure 1.2e The body’s organ systems. Pineal gland Pituitary gland Thyroid gland (parathyroid glands on posterior aspect) Thymus gland Adrenal glands Pancreas Testis (male) Ovary (female) (e) Endocrine System Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use by body cells. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Cardiovascular system ▪ Includes heart and blood vessels ▪ Heart pumps blood ▪ Vessels transport blood to tissues ▪ Blood transports: ▪ Oxygen and carbon dioxide ▪ Nutrients ▪ Hormones ▪ Blood also contains white blood cells and chemicals that provide protection from foreign invaders © 2018 Pearson Education, Ltd. Figure 1.2f The body’s organ systems. Heart Blood vessels (f) Cardiovascular System Blood vessels transport blood, which carries oxygen, nutrients, hormones, carbon dioxide, wastes, etc.; the heart pumps blood. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Lymphatic system ▪ Includes lymphatic vessels, lymph nodes, and lymphoid organs ▪ Complements the cardiovascular system by returning leaked fluids back to bloodstream ▪ Lymph nodes and other lymphoid organs cleanse the blood ▪ Houses white blood cells, which are involved in immunity © 2018 Pearson Education, Ltd. Figure 1.2g The body’s organ systems. Lymph nodes Lymphatic vessels (g) Lymphatic System Picks up fluid leaked from blood vessels and returns it to blood; disposes of debris in the lymphatic stream; houses white blood cells involved in immunity. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Respiratory system ▪ Includes the nasal passages, pharynx, larynx, trachea, bronchi, and lungs ▪ Gases are exchanged with the blood through air sacs in the lungs ▪ Supplies the body with oxygen ▪ Removes carbon dioxide © 2018 Pearson Education, Ltd. Figure 1.2h The body’s organ systems. Nasal cavity Pharynx Larynx Trachea Bronchi Lungs (h) Respiratory System Keeps blood constantly supplied with oxygen and removes carbon dioxide; the gaseous exchanges occur through the walls of the air sacs of the lungs. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Digestive system ▪ Includes the oral cavity (mouth), esophagus, stomach, small and large intestines, rectum, and accessory organs ▪ Breaks down food ▪ Allows for nutrient absorption into blood ▪ Eliminates indigestible material as feces © 2018 Pearson Education, Ltd. Figure 1.2i The body’s organ systems. Oral cavity Esophagus Stomach Small intestine Large intestine Rectum (i) Digestive System Breaks food down into absorbable nutrients that enter the blood for distribution to body cells; indigestible foodstuffs are eliminated as feces. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Urinary system ▪ Includes the kidneys, ureters, urinary bladder, and urethra ▪ Eliminates nitrogenous wastes ▪ Maintains acid-base balance ▪ Regulates water and electrolyte balance ▪ Helps regulate normal blood pressure © 2018 Pearson Education, Ltd. Figure 1.2j The body’s organ systems. Kidney Ureter Urinary bladder Urethra (j) Urinary System Eliminates nitrogen-containing wastes from the body; regulates water, electrolyte, and acid-base balance of the blood. © 2018 Pearson Education, Ltd.  Organ System Overview ▪ Reproductive system ▪ For males, includes the testes, scrotum, penis, accessory glands, and duct system ▪ Testes produce sperm ▪ Duct system carries sperm to exterior ▪ For females, includes the ovaries, uterine tubes, uterus, and vagina ▪ Ovaries produce eggs ▪ Uterus provides site of development for fetus © 2018 Pearson Education, Ltd. Figure 1.2k-l The body’s organ systems. Mammary glands (in breasts) Prostate Seminal gland Uterine vesicles tube Ovary Uterus Penis Testis Vagina Scrotum (k) Male Reproductive System (l) Female Reproductive System Overall function of the reproductive system is production of offspring. Testes produce sperm and male sex hormone; ducts and glands aid in delivery of viable sperm to the female reproductive tract. Ovaries produce eggs and female sex hormones; remaining structures serve as sites for fertilization and development of the fetus. Mammary glands of female breasts produce milk to nourish the newborn. © 2018 Pearson Education, Ltd.  Maintaining Life: Necessary Life Functions ▪ Maintaining boundaries ▪ Boundaries separate the “inside” from the “outside” ▪ Movement ▪ Locomotion ▪ Movement of substances ▪ Responsiveness (irritability) ▪ Ability to sense changes and react ▪ Digestion ▪ Breakdown and absorption of nutrients © 2018 Pearson Education, Ltd.  Necessary Life Functions ▪ Metabolism—chemical reactions within the body ▪ Breaks down complex molecules into smaller ones ▪ Builds larger molecules from smaller ones ▪ Produces energy (ATP) ▪ Regulated by hormones ▪ Excretion ▪ Eliminates excreta (waste) from metabolic reactions ▪ Wastes may be removed in urine, feces, or sweat © 2018 Pearson Education, Ltd.  Necessary Life Functions ▪ Reproduction ▪ Occurs on cellular level or organismal level ▪ On cellular level—new cells are used for growth and repair ▪ On organismal level—the reproductive system handles the task ▪ Growth ▪ Increases cell size or body size (through increasing the number of cells) ▪ Hormones play a major role © 2018 Pearson Education, Ltd.  Survival Needs ▪ Nutrients ▪ Chemicals used for energy and cell building ▪ Include carbohydrates, proteins, lipids, vitamins, and minerals ▪ Oxygen ▪ Required for chemical reactions ▪ Made available by the cooperation of the respiratory and cardiovascular systems © 2018 Pearson Education, Ltd.  Survival Needs ▪ Water ▪ 60 to 80 percent of body weight ▪ Most abundant chemical in the human body ▪ Provides fluid base for body secretions and excretions ▪ Normal body temperature ▪ 37ºC (98.6ºF) ▪ Below this temperature, chemical reactions slow and stop ▪ Above this temperature, chemical reactions proceed too rapidly © 2018 Pearson Education, Ltd.  Survival Needs ▪ Atmospheric pressure ▪ Must be appropriate for gas exchange © 2018 Pearson Education, Ltd. Figure 1.3 Examples of interrelationships among organ systems that illustrate life functions. Digestive system Respiratory system Takes in nutrients, digests them Takes in oxygen, which is (part of metabolism), and excretes required for metabolism, and unabsorbed matter (feces) excretes carbon dioxide Food O2 CO2 Cardiovascular system Via the blood, distributes oxygen and nutrients to all body cells and delivers wastes and carbon dioxide to disposal organs Blood CO2 O2 Heart Urinary system Nutrients Excretes nitrogen- containing wastes and excess ions Interstitial fluid Nutrients and wastes pass between blood and cells via the interstitial fluid Integumentary system Feces are Protects the body as a whole Urine is excreted from the external environment excreted by maintaining boundaries © 2018 Pearson Education, Ltd.  The Language of Anatomy ▪ Special terminology is used to prevent misunderstanding ▪ Exact terms are used for: ▪ Position ▪ Direction ▪ Regions ▪ Structures © 2018 Pearson Education, Ltd.  The Language of Anatomy ▪ Anatomical position ▪ Standard body position used to avoid confusion ▪ Terminology refers to this position regardless of actual body position ▪ Stand erect, feet parallel, arms hanging at the sides with palms facing forward and thumbs pointing away from the body © 2018 Pearson Education, Ltd. Figure 1.4a The anatomical position and regional terms. © 2018 Pearson Education, Ltd.  Directional Terms ▪ Directional terms ▪ Explain location of one body structure in relation to another © 2018 Pearson Education, Ltd.  Directional Terms ▪ Superior (cranial or cephalic): toward the head or upper part of a structure or the body; above ▪ Inferior (caudal): away from the head or toward the lower part of a structure or the body; below © 2018 Pearson Education, Ltd.  Directional Terms ▪ Anterior (ventral): toward or at the front of the body; in front of ▪ Posterior (dorsal): toward or at the backside of the body; behind ▪ Note: In four-legged animals, the terms ventral (belly) and dorsal (back) correspond to anterior and posterior in humans © 2018 Pearson Education, Ltd. Table 1.1 Orientation and Directional Terms (1 of 3) © 2018 Pearson Education, Ltd.  Directional Terms ▪ Medial: toward or at the midline of the body; on the inner side of ▪ Lateral: away from the midline of the body; on the outer side of ▪ Intermediate: between a more medial and a more lateral structure © 2018 Pearson Education, Ltd.  Directional Terms ▪ Proximal: close to the origin of the body part or point of attachment to a limb to the body trunk ▪ Distal: farther from the origin of a body part or the point of attachment of a limb to the body trunk © 2018 Pearson Education, Ltd. Table 1.1 Orientation and Directional Terms (2 of 3) © 2018 Pearson Education, Ltd.  Directional Terms ▪ Superficial (external): toward or at the body surface ▪ Deep (internal): away from the body surface; more internal © 2018 Pearson Education, Ltd. Table 1.1 Orientation and Directional Terms (3 of 3) © 2018 Pearson Education, Ltd.  Body Regions Upper limbs: upper arm, forearm, wrist, hand Lower limbs: thigh, lower leg, ankle, foot Central region: head, neck, trunk Figure 1.9 ©Eric Wise  Regional Terms ▪ Anterior (ventral) body landmarks © 2018 Pearson Education, Ltd. Figure 1.4a The anatomical position and regional terms. Cephalic Frontal Orbital Upper limb Nasal Acromial Buccal Deltoid Oral Brachial (arm) Mental Antecubital Cervical Olecranal Thoracic Sternal Antebrachial Axillary (forearm) Pectoral Carpal (wrist) Abdominal Manus (hand) Umbilical Digital Pelvic Inguinal (groin) Lower limb Coxal (hip) Pubic (genital) Femoral (thigh) Patellar Crural (leg) KEY: Thorax Fibular Abdomen Pedal (foot) Tarsal (ankle) Digital (a) Anterior/Ventral © 2018 Pearson Education, Ltd.  Regional Terms ▪ Posterior (dorsal) body landmarks © 2018 Pearson Education, Ltd. Figure 1.4b The anatomical position and regional terms. Cephalic Upper limb Occipital (back Acromial of head) Cervical Brachial (arm) Olecranal Back (dorsal) Antebrachial Scapular (forearm) Vertebral Lumbar Manus (hand) Sacral Digital Gluteal Lower limb Femoral (thigh) Popliteal Sural (calf) Fibular KEY: Pedal (foot) Back (Dorsum) Calcaneal Plantar © 2018 Pearson Education, Ltd. (b) Posterior/Dorsal  Body Planes and Sections ▪ Sections are cuts along imaginary lines known as planes ▪ Three types of planes or sections exist as right angles to one another © 2018 Pearson Education, Ltd.  Body Planes and Sections ▪ A sagittal section divides the body (or organ) into left and right parts ▪ A median, or midsagittal, section divides the body (or organ) into equal left and right parts ▪ A frontal, or coronal, section divides the body (or organ) into anterior and posterior parts ▪ A transverse, or cross, section divides the body (or organ) into superior and inferior parts © 2018 Pearson Education, Ltd. Figure 1.5 The planes of the body—median, frontal, and transverse—with corresponding MRI scans. (a) Median (midsagittal) (b) Frontal (coronal) plane (c) Transverse plane Vertebral Right Left column lung Heart lung Liver Aorta Pancreas Spleen Rectum Intestines Liver Stomach Spleen Subcutaneous Spinal fat layer cord © 2018 Pearson Education, Ltd.  Body Cavities ▪ Two internal body cavities ▪ Dorsal ▪ Ventral ▪ Body cavities provide varying degrees of protection to organs within them © 2018 Pearson Education, Ltd. Figure 1.6 Body cavities. Cranial cavity Thoracic cavity Diaphragm Abdominopelvic Abdominal Spinal cavity cavity cavity Pelvic cavity KEY: Dorsal body cavity Ventral body cavity © 2018 Pearson Education, Ltd.  Body Cavities ▪ Dorsal body cavity has two subdivisions 1. Cranial cavity ▪ Houses the brain ▪ Protected by the skull 2. Spinal cavity ▪ Houses the spinal cord ▪ Protected by the vertebrae © 2018 Pearson Education, Ltd.  Body Cavities ▪ Ventral body cavity has two subdivisions separated by the diaphragm 1. Thoracic cavity 2. Abdominopelvic cavity © 2018 Pearson Education, Ltd.  Body Cavities ▪ Thoracic cavity ▪ Cavity superior to the diaphragm ▪ Houses heart, lungs, and other organs ▪ Mediastinum, the central region, houses heart, trachea, and other organs ▪ Protected by the rib cage © 2018 Pearson Education, Ltd.  Body Cavities ▪ Abdominopelvic cavity ▪ Cavity inferior to the diaphragm ▪ Superior abdominal cavity contains the stomach, liver, and other organs ▪ Protected only by trunk muscles ▪ Inferior pelvic cavity contains reproductive organs, bladder, and rectum ▪ Protected somewhat by bony pelvis ▪ No physical structure separates abdominal from pelvic cavities © 2018 Pearson Education, Ltd.  Body Cavities ▪ Abdominopelvic cavity subdivisions ▪ Four quadrants ▪ Nine regions © 2018 Pearson Education, Ltd. Figure 1.7 The four abdominopelvic quadrants. Right upper Left upper quadrant quadrant (RUQ) (LUQ) Right lower Left lower quadrant quadrant (RLQ) (LLQ) © 2018 Pearson Education, Ltd. Figure 1.8 The nine abdominopelvic regions. Diaphragm Liver Stomach Right Left Large hypochondriac Epigastric hypochondriac region region region intestine Large intestine Right Left Small intestine lumbar Umbilical lumbar region region region Appendix Right iliac Hypogastric Left iliac Urinary (inguinal) (pubic) (inguinal) bladder region region region (b) Anterior view of the nine regions (a) Nine regions delineated by four planes showing the superficial organs © 2018 Pearson Education, Ltd.  Body Cavities ▪ Other body cavities include: ▪ Oral and digestive cavities ▪ Nasal cavity ▪ Orbital cavities ▪ Middle ear cavities © 2018 Pearson Education, Ltd. Serous Membranes 1 Line trunk cavities, cover organs Structure: visceral serous membrane covers organs parietal serous membrane is the outer membrane cavity - a flui~d-filled space between the membranes Figure 1.14 Serous Membranes 2 Three sets of serous membranes and cavities: Membrane Cavity Pericardium Pericardial cavity around heart Pleura Pleural cavity around lungs Peritoneum Peritoneal cavity around abdominopelvic cavity and its organs Pericardium and Pericardial Cavity Pericardium visceral pericardium covers heart parietal pericardium thick, fibrous pericardial cavity reduces friction Figure 1.15a Pleura and Pleural Cavity Pleura visceral pleura covers lungs parietal pleura lines inner wall of thorax pleural cavity reduces friction adheres lungs to thoracic wall Figure 1.15b Peritoneum and Peritoneal Cavity Peritoneum visceral peritoneum covers, anchors organs double layers called mesenteries parietal peritoneum lines inner wall of abdominopelvic cavity peritoneal cavity reduces friction Figure 1.15c  Homeostasis ▪ Homeostasis—maintenance of relatively stable internal conditions ▪ A dynamic state of equilibrium, or balance ▪ Necessary for normal body functioning and to sustain life ▪ Main controlling systems ▪ Nervous system ▪ Endocrine system ▪ Homeostatic imbalance ▪ A disturbance in homeostasis results in disease © 2018 Pearson Education, Ltd.  Maintaining Homeostasis ▪ All homeostatic control mechanisms have at least three components: receptor, control center, and effector ▪ Receptor ▪ Responds to changes in the environment (stimuli) ▪ Sends information to control center along an afferent pathway © 2018 Pearson Education, Ltd.  Maintaining Homeostasis ▪ Control center ▪ Determines set point ▪ Analyzes information ▪ Determines appropriate response ▪ Effector ▪ Provides a means for response to the stimulus ▪ Information flows from control center to effector along efferent pathway © 2018 Pearson Education, Ltd.  Feedback Mechanisms ▪ Negative feedback ▪ Includes most homeostatic control mechanisms ▪ Shuts off the original stimulus or reduces its intensity ▪ Works like a household thermostat © 2018 Pearson Education, Ltd. Figure 1.9 The elements of a homeostatic control system. Slide 1 3 Input: Information 4 Output: Information is sent along afferent Control is sent along efferent pathway to control Center pathway to effector. center. Afferent Efferent pathway pathway Receptor Effector 2 Receptor detects change. 5 Response of effector feeds back to reduce 1 Stimulus the effect of produces stimulus and change in returns variable VARIABLE (in homeostasis) to homeostatic variable. level. © 2018 Pearson Education, Ltd. © 2018 Pearson Education, Ltd.  Negative Feedback Control of Body Temperature © 2018 Pearson Education, Ltd.  Feedback Mechanisms ▪ Positive feedback ▪ Rare in the human body ▪ Increases the original stimulus to push the variable farther ▪ Reaction occurs at a faster rate ▪ In the body, positive feedback occurs in blood clotting and during the birth of a baby © 2018 Pearson Education, Ltd.