Introduction to Human Anatomy & Physiology 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 di...

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.  1.2: 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 2  Figure 1.2: Function is Determined by Structure © McGraw Hill, LLC 3  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 4  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 5  Figure 1.3: Levels of Organization Access the text alternative for these images © McGraw Hill, LLC 6  BODY SYSTEMS © McGraw Hill, LLC 7  Figure 1.12: Organ Systems Interact for Homeostasis Access the text alternative for these images © McGraw Hill, LLC 8  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 9  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 10  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 11  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 © McGraw Hill, LLC 12  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 C O2 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 13  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 © McGraw Hill, LLC 14  HOMEOSTASIS © McGraw Hill, LLC 15  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 © McGraw Hill, LLC 16  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 17  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 18  Figure 1.5: Components of Homeostatic Mechanisms Access the text alternative for these images © McGraw Hill, LLC 19  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 © McGraw Hill, LLC 20  Figure 1.6: Negative Feedback in Thermoregulation Access the text alternative for these images © McGraw Hill, LLC 21  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 22  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 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 © McGraw Hill, LLC 24  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 25  End of Main Content Because learning changes everything. ® www.mheducation.com © McGraw Hill LLC. 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