Hole's Essentials of Human Anatomy & Physiology - Chapter 01 PDF

Because learning changes everything.® Chapter 01 Introduction to Human Anatomy and Physiology HOLE’S ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY Fifteenth Edition Charles J. Welsh and Cynthia Prentice-Craver © McGraw Hill LLC. All rights reserved. No reproduction or distribution without...

Because learning changes everything.® Chapter 01 Introduction to Human Anatomy and Physiology HOLE’S ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY Fifteenth Edition Charles J. Welsh and Cynthia Prentice-Craver © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.  1.1: Introduction: History of the Study of the Human Body The early students of anatomy and physiology were most likely concerned with treating illnesses and injuries. Early healers relied on superstitions and magic. Later, herbs and natural chemicals were used to treat certain ailments. Early study involved dissection of cadavers Techniques for accurate observations and performing experiments were developed. Greek and Latin words are still the basis of the language of anatomy and physiology. Scientific method has been used to gather information about the natural world, including the workings of the body. © McGraw Hill, LLC 2  Figure 1.1: 1543 Illustration by Andreas Vesalius Access the text alternative for these images © McGraw Hill, LLC 3  1.2: Anatomy and Physiology Anatomy is the study of the structure (morphology) of the body and its parts (form and organization) Physiology is the study of the functions of these parts and how they work and interact The two disciplines are closely interrelated, because the functional role of a part depends on how it is constructed. Anatomists rely on observation and dissection, while physiologists employ experimentation. It is more common to discover new information about physiology, but anatomical discoveries are also being made. © McGraw Hill, LLC 4  Figure 1.2: Function is Determined by Structure © McGraw Hill, LLC 5  1.3: Levels of Organization 1 All materials, non-living and living, are composed of chemicals. The human body is the sum of its parts, and these parts can be studied at a variety of levels of organization. Chemicals: Atoms are the smallest unit of a chemical Molecules consist of two or more atoms Macromolecules are larger particles composed of small molecules bound together © McGraw Hill, LLC 6  Levels of Organization 2 The smallest unit to display all of the characteristics of living organisms is the cell. Some living organisms consist only of one cell, but the human body consists of trillions of cells. Cells are the basic units of structure and function in all living things. Tissues are groups of cells that function together. Organs are groups of tissues that perform specialized functions. Organ systems are groups of organs that function together. Organisms are composed of organ systems functioning together. © McGraw Hill, LLC 7  Figure 1.3: Levels of Organization Access the text alternative for these images © McGraw Hill, LLC 8  1.4: Characteristics of Life 1 Characteristics, or qualities, of life are traits shared by all organisms: Growth – increase in body size, and size and number of cells Reproduction – production of new organisms or cells Responsiveness – reaction to internal or external change Movement – change in position of the body or a body part; motion of an internal organ © McGraw Hill, LLC 9  Characteristics of Life 2 Metabolism (nutrient cycling): The sum of all chemical reactions going on in the cells of an organism as it ingests food, breaks down and synthesizes chemicals, and removes wastes: Respiration – release of energy from food, by using oxygen and giving off of carbon dioxide Digestion – breakdown of food into usable forms, which are them absorbed into the blood Circulation – movement of cells and chemicals in body fluids Excretion – removal of metabolic wastes from the body © McGraw Hill, LLC 10  1.5: Maintenance of Life Requirements of organisms to maintain life: Environmental factors needed by all organisms to remain alive Water Most abundant chemical in the body Required for many metabolic processes Provides environment for internal processes Transport medium Regulates body temperature Makes up intracellular and extracellular fluids Other Chemicals Oxygen and carbon dioxide are exchanged with the environment Oxygen is used to release the energy from food Carbon dioxide is a waste product of food breakdown Food (nutrients) enter the body to supply energy for body processes Wastes are excreted from the body © McGraw Hill, LLC 11  Figure 1.4: Water: Intracellular and Extracellular Fluids Access the text alternative for these images © McGraw Hill, LLC 12  Requirements for Maintenance of Life Requirements of organisms to maintain life, continued: Heat Form of energy produced in metabolic reactions Temperature controls reaction rates in the body Pressure Force applied to something Atmospheric pressure is needed for breathing Hydrostatic (fluid) pressure is needed to move blood through blood vessels, to deliver oxygen and nutrients to the cells © McGraw Hill, LLC 13  Homeostasis 1 When factors in the external environment (the outside world) change, conditions in the internal environment (the fluid around the body cells) must remain stable. Maintenance of a stable internal environment is called homeostasis. Homeostasis is regulated through control systems called homeostatic mechanisms, which consist of the following components: Receptors detect and monitor specific types of changes The set point is the normal value or range of values Effectors are muscles or glands that respond to the changes, to return the internal environment to stability © McGraw Hill, LLC 14  Homeostasis 2 Homeostatic mechanisms: Self-regulating control systems that the body uses to maintain homeostasis The body functions properly only when heat, pressure, and the concentrations of water, nutrients, oxygen, etc., remain within narrow specific ranges Example: Regulation of body temperature occurs in a manner similar to the functioning of a thermostat in a home Example: Regulation of blood pressure occurs via pressure- sensitive receptors and muscle cells in the blood vessels © McGraw Hill, LLC 15  Components of Homeostatic Mechanisms 1 Homeostatic Mechanisms consist of 3 components: Receptors: Structures that monitor deviations from a set point, and provide information about changes in specific conditions (stimuli) in the internal environment Set Point: The normal value for a particular variable, which the body tries to maintain (for example, the set point for body temperature is 98.6°F or 37°C) Effectors: Muscle cells or glands that bring about the changes necessary to bring a variable back to its set point or normal range © McGraw Hill, LLC 16  Figure 1.5: Components of Homeostatic Mechanisms Access the text alternative for these images © McGraw Hill, LLC 17  Negative Feedback A mechanism by which a deviation in a variable from its set point is corrected Used in most homeostatic mechanisms When receptors detect that a variable has deviated from its set point, effectors return conditions toward normal As the variable returns toward its set point, the activity of the effectors gradually lessens; this prevents the correction from progressing too far Example: A thermostat is similar to a homeostatic control mechanism in the body; it contains receptors, a set point, and effectors, and maintains normal room temperature © McGraw Hill, LLC 18  Figure 1.6: Negative Feedback in Thermoregulation Access the text alternative for these images © McGraw Hill, LLC 19  Temperature Regulation in the Body 1 Responses to Cold Environmental Temperature: Thermoreceptors detect drop in body temperature Thermoreceptors send nerve signals to control center in brain Blood vessels in skin constrict, to prevent heat loss through the skin and conserve heat Certain muscles are caused to contract involuntarily (shivering) to produce body heat Sweat glands remain inactive Body is warmed, and body temperature returns toward normal © McGraw Hill, LLC 20  Temperature Regulation in the Body 2 Responses to Warm Environmental Temperature: Thermoreceptors detect rise in body temperature Thermoreceptors send nerve signals to control center in brain Sweat glands are activated to secrete sweat, which cools the skin Heart rate is increased, to send more blood to surface blood vessels Surface blood vessels (in the skin) dilate to lose heat to the environment Breathing rate is increased, to allow expiration of more heat- containing air © McGraw Hill, LLC 21  Contributions by Organ Systems to Homeostasis Organ systems contribute to homeostasis in various ways: Digestive system brings nutrients into the body Respiratory system brings in oxygen and gets rid of carbon dioxide Cardiovascular system distributes oxygen and nutrients to the body cells, and transports wastes away from them Urinary and respiratory systems remove wastes from the body © McGraw Hill, LLC 22  Figure 1.7: Contributions by Organ Systems to Homeostasis Access the text alternative for these images © McGraw Hill, LLC 23  Positive Feedback Mechanisms A mechanism by which a deviation in a variable from its set point moves conditions farther away from the normal range Change from the set point increases Many positive feedback mechanisms produce unstable conditions in the body, but they are short-lived, and eventually bring about homeostasis Not a common type of homeostatic mechanism in the body Examples associated with normal health: Blood clotting leads to more blood clotting, which stops bleeding During childbirth, uterine contractions stimulate more uterine contractions, which lead to birth of baby © McGraw Hill, LLC 24  1.6: Organization of the Human Body Body Cavities: The body can be divided into an axial portion (head, neck, and trunk) and an appendicular portion (upper and lower limbs) The axial portion contains several cavities that house body organs: Cranial cavity – brain Vertebral canal – spinal cord Thoracic cavity – heart, lungs, mediastinum Abdominopelvic cavity: Abdominal cavity – stomach, liver, spleen, gallbladder, kidneys, most of intestines Pelvic cavity – end of large intestine, urinary bladder, and internal reproductive organs A broad, thin muscle called the diaphragm separates the thoracic and abdominopelvic cavities © McGraw Hill, LLC 25  Figure 1.8: Major Body Cavities: Lateral and Anterior Views Access the text alternative for these images © McGraw Hill, LLC 26  Small Cavities in the Head Small cavities within the head include: Oral cavity: Mouth area; contains tongue and teeth Nasal cavity: Inside nose; divided into left and right portions by nasal septum, and contains sinuses Orbital cavities: Contain eyes along with their nerves and skeletal muscles Middle ear cavities: Contain middle ear bones © McGraw Hill, LLC 27  Figure 1.9: Small Cavities in the Head Access the text alternative for these images © McGraw Hill, LLC 28  Thoracic and Abdominopelvic Membranes Double-layered membranes that surround organs and line cavities The parietal portion lines the wall of the cavity, and the visceral portion covers each internal organ Examples of membranes: Pleural Membranes: Line the thoracic cavity; the parietal pleura lines the inner wall of thoracic cavity, while the visceral pleura covers the lungs; a thin layer of serous fluid separates the two layers; potential space between layers is pleural cavity Pericardial membranes: Surround heart; the parietal pericardium is the outer layer, and the visceral pericardium covers the heart; serous fluid separates the two layers; potential space between layers is pericardial cavity Peritoneal membranes: Line the abdominopelvic cavity; the parietal peritoneum lines the wall, while the visceral peritoneum covers each of the organs; potential space between layers is the peritoneal cavity © McGraw Hill, LLC 29  Figure 1.10: Transverse Section Through the Thorax Access the text alternative for these images © McGraw Hill, LLC 30  Figure 1.11: Transverse Section Through the Abdomen Access the text alternative for these images © McGraw Hill, LLC 31  Organ Systems Body consists of several organ systems Each system contains a group of organs that work together to accomplish a specific function Each system contributes to homeostasis through the specific functions that it performs © McGraw Hill, LLC 32  Organ Systems: Body Covering System that provides the body covering: Integumentary system: Includes skin, hair, nails, sweat and sebaceous glands Protects underlying tissues, helps regulate body temperature, senses changes via a variety of sensory receptors, and synthesizes certain products © McGraw Hill, LLC 33  Organ Systems: Support and Movement Body systems that provide support and movement: Skeletal system: Consists of bones, ligaments and cartilages Supports and protects soft tissues, provides frameworks, stores inorganic salts, and houses tissues that produce blood cells Muscular system: Consists of the muscles Provides body movement and posture, and is major source of body heat © McGraw Hill, LLC 34  Organ Systems: Integration & Coordination Body systems that provide integration and coordination: Nervous system: Consists of the brain, spinal cord, nerves, and sense organs Cells communicate with each other and with muscles and glands via neurotransmitters Nerve cells function in either sensory reception, integration of incoming information, or stimulation of muscles and glands Endocrine system: Consists of all glands that secrete chemical messengers called hormones Includes the hypothalamus, pituitary, thyroid, parathyroid, pineal, and thymus glands, pancreas, ovaries, and testes, along with other organs that secrete hormones Hormones alter metabolism of specific target cells Hormones are slower to respond than neurotransmitters, but effects last longer © McGraw Hill, LLC 35  Organ Systems: Transport Body systems that provide transport of substances throughout the body: Cardiovascular system: Consists of the heart, blood vessels, and the blood Distributes oxygen, carbon dioxide, nutrients, and hormones throughout the body, while removing wastes from the cells Lymphatic system: Consists of lymphatic vessels, lymph nodes, thymus, spleen, and lymph (fluid that flows through the lymphatic system) Drains excess tissue fluid and returns it to the bloodstream Lymphocytes are a type of white blood cells used extensively in immunity; defend body against infection © McGraw Hill, LLC 36  Organ Systems: Absorption and Excretion Body systems that provide absorption and excretion: Digestive system: Consists of the mouth, tongue, teeth, pharynx, esophagus, stomach, intestines, and accessory organs Receives, breaks down, and absorbs nutrients, and excretes wastes Respiratory system: Moves air into and out of lungs, and exchanges O2 and CO2 between the blood and air Consists of the lungs and air passageways (nasal cavity, pharynx, larynx, trachea, bronchi) Urinary system: Consists of the kidneys, ureters, bladder, and urethra Removes wastes from the blood and helps to maintain water and electrolyte balance Produces, stores, and eliminates urine © McGraw Hill, LLC 37  Organ Systems: Reproduction Body systems that provide reproduction of new offspring: The reproductive systems of the male and female produce new organisms together Male reproductive system: Consists of the testes, scrotum, epididymides, ductus deferentia, seminal vesicles, prostate gland, bulbourethral glands, penis, and urethra Produces and maintains sperm, and conduct them to the female reproductive tract Female reproductive system: Consists of ovaries, uterine tubes, uterus, vagina, clitoris, vulva Produces female sex cells (egg cells or oocytes) Receives male sex cells for fertilization Houses the developing offspring and functions in childbirth © McGraw Hill, LLC 38  Figure 1.12: Organ Systems Interact for Homeostasis Access the text alternative for these images © McGraw Hill, LLC 39  1.7: Anatomical Terminology Anatomical position: Body erect, face forward, upper limbs at sides with palms forward Terminology assumes that body is in anatomical position Terms of relative position: Terms that describe location of one body part with respect to another Superior – above another part Inferior – below another part Anterior (ventral) – toward the front Posterior (dorsal) – toward the back Medial – closer to the midline (when body is divided into left and right halves) Lateral – toward the side, away from midline © McGraw Hill, LLC 40  Terms of Relative Position Bilateral – paired structures with one on each side Ipsilateral – structures on the same side of body Contralateral – structures on the opposite sides of body Proximal – closer to point of attachment to trunk or another referenced body part Distal – further from the point of attachment to trunk or another referenced body part Superficial or peripheral – near the surface or outward Deep – more internal than other structure © McGraw Hill, LLC 41  Figure 1.13: Terms of Relative Position Aaron Roeth Photography Access the text alternative for these images © McGraw Hill, LLC 42  Terminology of Body Sections Study of body organization and relative locations of body parts requires cutting the body along specific planes or sections: Sagittal section: Longitudinal section that divides the body into right and left portions If the section passes along the midline and divides the body into equal parts, it is a median or midsagittal section A section lateral to the midline is parasagittal Transverse (horizontal) section: Section that divides the body into superior and inferior portions Frontal (coronal) section: Section that divides the body into anterior and posterior portions © McGraw Hill, LLC 43  Figure 1.14: Body Sections (top left, right): Karl Rubin/McGraw Hill; (bottom left): Living Art Enterprises/Science Source; (center): Eric Wise/McGraw Hill Access the text alternative for these images © McGraw Hill, LLC 44  Sections in Cylindrical Organs 1 Cylindrical organs, such as blood vessels or long bones, have their own set of sectional terms: Cross section – A cut across the structure Oblique section – An angular cut through the structure Longitudinal section – A lengthwise cut through the structure © McGraw Hill, LLC 45  Figure 1.15: Sections in Cylindrical Organs Access the text alternative for these images © McGraw Hill, LLC 46  Body Regions of the Abdominal Area The abdominal area can be subdivided into nine regions: Epigastric – Upper middle part Right and left hypochondriac – To the sides of epigastric region Umbilical – Middle part Right and left lateral (lumbar) – To the sides of umbilical region Pubic (hypogastric) – lower middle part Right and left inguinal (iliac) – To the sides of pubic region The abdominal area can also be subdivided into four quadrants: Right upper quadrant Right lower quadrant Left upper quadrant Left lower quadrant © McGraw Hill, LLC 47  Figure 1.16a: Body Regions of the Abdominal Area Juice Images/ILI/Alamy Stock Photo Access the text alternative for these images © McGraw Hill, LLC 48  Figure 1.16b: Quadrants of the Abdominal Area Juice Images/ILI/Alamy Stock Photo Access the text alternative for these images © McGraw Hill, LLC 49  Figure 1.17: Terms for Various Body Regions Access the text alternative for these images © McGraw Hill, LLC 50  Because learning changes everything. ® www.mheducation.com © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.