CHAPTER 1a THE HUMAN BODY AN ORIENTATION Copyright

CHAPTER # 1(a) THE HUMAN BODY: AN ORIENTATION Copyright © 2010 Pearson Education, Inc.

Overview of Anatomy and Physiology • Anatomy: The study of structure • Subdivisions: • Gross or macroscopic (e. g. , regional, surface, and systemic anatomy) • Microscopic (e. g. , cytology and histology) • Developmental (e. g. , embryology) Copyright © 2010 Pearson Education, Inc.

Overview of Anatomy and Physiology • Essential tools for the study of anatomy: • Mastery of anatomical terminology • Observation • Manipulation • Palpation • Auscultation Copyright © 2010 Pearson Education, Inc.

Overview of Anatomy and Physiology • Physiology: The study of function at many levels • Subdivisions are based on organ systems (e. g. , renal or cardiovascular physiology) Copyright © 2010 Pearson Education, Inc.

Overview of Anatomy and Physiology • Essential tools for the study of physiology: • Ability to focus at many levels (from systemic to cellular and molecular) • Basic physical principles (e. g. , electrical currents, pressure, and movement) • Basic chemical principles Copyright © 2010 Pearson Education, Inc.

Principle of Complementarity • Anatomy and physiology are inseparable. • Function always reflects structure • What a structure can do depends on its specific form Copyright © 2010 Pearson Education, Inc.

Levels of Structural Organization • Chemical: atoms and molecules (Chapter 2) • Cellular: cells and their organelles (Chapter 3) • Tissue: groups of similar cells (Chapter 4) • Organ: contains two or more types of tissues • Organ system: organs that work closely together • Organismal: all organ systems Copyright © 2010 Pearson Education, Inc.

Atoms Organelle Smooth muscle cell Molecule 1 Chemical level Atoms combine to form molecules. Cardiovascular system Heart Blood vessels 2 Cellular level Cells are made up of molecules. Smooth muscle tissue 3 Tissue level Tissues consist of similar types of cells. Blood vessel (organ) Smooth muscle tissue Connective tissue Epithelial tissue 4 Organ level Organs are made up of different types of tissues. 6 Organismal level The human organism is made up of many organ systems. Copyright © 2010 Pearson Education, Inc. 5 Organ system level Organ systems consist of different organs that work together closely. Figure 1. 1

Atoms Molecule 1 Chemical level Atoms combine to form molecules. Copyright © 2010 Pearson Education, Inc. Figure 1. 1, step 1

Atoms Molecule 1 Chemical level Atoms combine to form molecules. Copyright © 2010 Pearson Education, Inc. Organelle Smooth muscle cell 2 Cellular level Cells are made up of molecules. Figure 1. 1, step 2

Atoms Molecule 1 Chemical level Atoms combine to form molecules. Organelle Smooth muscle cell 2 Cellular level Cells are made up of molecules. Smooth muscle tissue 3 Tissue level Tissues consist of similar types of cells. Copyright © 2010 Pearson Education, Inc. Figure 1. 1, step 3

Atoms Molecule 1 Chemical level Atoms combine to form molecules. Organelle Smooth muscle cell 2 Cellular level Cells are made up of molecules. Smooth muscle tissue 3 Tissue level Tissues consist of similar types of cells. Blood vessel (organ) Smooth muscle tissue Connective tissue Epithelial tissue 4 Organ level Organs are made up of different types of tissues. Copyright © 2010 Pearson Education, Inc. Figure 1. 1, step 4

Atoms Organelle Smooth muscle cell Molecule 1 Chemical level Atoms combine to form molecules. Cardiovascular system Heart Blood vessels 2 Cellular level Cells are made up of molecules. Smooth muscle tissue 3 Tissue level Tissues consist of similar types of cells. Blood vessel (organ) Smooth muscle tissue Connective tissue Epithelial tissue 4 Organ level Organs are made up of different types of tissues. 5 Organ system level Organ systems consist of different organs that work together closely. Copyright © 2010 Pearson Education, Inc. Figure 1. 1, step 5

Atoms Organelle Smooth muscle cell Molecule 1 Chemical level Atoms combine to form molecules. Cardiovascular system Heart Blood vessels 2 Cellular level Cells are made up of molecules. Smooth muscle tissue 3 Tissue level Tissues consist of similar types of cells. Blood vessel (organ) Smooth muscle tissue Connective tissue Epithelial tissue 4 Organ level Organs are made up of different types of tissues. 6 Organismal level The human organism is made up of many organ systems. Copyright © 2010 Pearson Education, Inc. 5 Organ system level Organ systems consist of different organs that work together closely. Figure 1. 1, step 6

Overview of Organ Systems • Note major organs and functions of the 11 organ systems (Fig. 1. 3) Copyright © 2010 Pearson Education, Inc.

Hair Skin Nails (a) Integumentary System Forms the external body covering, and protects deeper tissues from injury. Synthesizes vitamin D, and houses cutaneous (pain, pressure, etc. ) receptors and sweat and oil glands. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 a

Bones Joint (b) Skeletal System Protects and supports body organs, and provides a framework the muscles use to cause movement. Blood cells are formed within bones. Bones store minerals. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 b

Skeletal muscles (c) Muscular System Allows manipulation of the environment, locomotion, and facial expression. Maintains posture, and produces heat. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 c

Brain Spinal cord Nerves (d) Nervous System As the fast-acting control system of the body, it responds to internal and external changes by activating appropriate muscles and glands. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 d

Pineal gland Pituitary gland Thyroid gland Thymus Adrenal gland Pancreas Testis Ovary (e) Endocrine System Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 e

Heart Blood vessels (f) Cardiovascular System Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes, etc. The heart pumps blood. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 f

Red bone marrow Thymus Lymphatic vessels Thoracic duct Spleen Lymph nodes (g) Lymphatic System/Immunity Picks up fluid leaked from blood vessels and returns it to blood. Disposes of debris in the lymphatic stream. Houses white blood cells (lymphocytes) involved in immunity. The immune response mounts the attack against foreign substances within the body. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 g

Nasal cavity Pharynx Larynx Trachea Bronchus Lung (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. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 h

Oral cavity Esophagus Liver Stomach Small intestine Large intestine Rectum Anus (i) Digestive System Breaks down food into absorbable units that enter the blood for distribution to body cells. Indigestible foodstuffs are eliminated as feces. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 i

Kidney Ureter Urinary bladder Urethra (j) Urinary System Eliminates nitrogenous wastes from the body. Regulates water, electrolyte and acid-base balance of the blood. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 j

Mammary glands (in breasts) Prostate gland Ovary Penis Testis Scrotum Ductus deferens Uterus Vagina Uterine tube (l) Female Reproductive System (k) Male Reproductive System Overall function is production of offspring. Testes produce sperm and male sex hormone, and male ducts and glands aid in delivery of sperm to the female reproductive tract. Ovaries produce eggs and female sex hormones. The remaining female structures serve as sites for fertilization and development of the fetus. Mammary glands of female breasts produce milk to nourish the newborn. Copyright © 2010 Pearson Education, Inc. Figure 1. 3 k-l

Organ Systems Interrelationships • All cells depend on organ systems to meet their survival needs • Organ systems work cooperatively to perform necessary life functions Copyright © 2010 Pearson Education, Inc.

Digestive system Takes in nutrients, breaks them down, and eliminates unabsorbed matter (feces) Respiratory system Takes in oxygen and eliminates carbon dioxide Food O 2 Cardiovascular system Via the blood, distributes oxygen and nutrients to all body cells and delivers wastes and carbon dioxide to disposal organs Blood CO 2 Heart Nutrients Interstitial fluid Urinary system Eliminates nitrogenous wastes and excess ions Nutrients and wastes pass between blood and cells via the interstitial fluid Integumentary system Feces Protects the body as a whole Urine from the external environment Copyright © 2010 Pearson Education, Inc. Figure 1. 2

Necessary Life Functions 1. Maintaining boundaries between internal and external environments • Plasma membranes • Skin 2. Movement (contractility) • Of body parts (skeletal muscle) • Of substances (cardiac and smooth muscle) Copyright © 2010 Pearson Education, Inc.

Necessary Life Functions 3. Responsiveness: The ability to sense and respond to stimuli • Withdrawal reflex • Control of breathing rate 4. Digestion • Breakdown of ingested foodstuffs • Absorption of simple molecules into blood Copyright © 2010 Pearson Education, Inc.

Necessary Life Functions 5. Metabolism: All chemical reactions that occur in body cells • Catabolism and anabolism 6. Excretion: The removal of wastes from metabolism and digestion • Urea, carbon dioxide, feces Copyright © 2010 Pearson Education, Inc.

Necessary Life Functions 7. Reproduction • Cellular division for growth or repair • Production of offspring 8. Growth: Increase in size of a body part or of organism Copyright © 2010 Pearson Education, Inc.

Survival Needs 1. Nutrients • Chemicals for energy and cell building • Carbohydrates, fats, proteins, minerals, vitamins 2. Oxygen • Essential for energy release (ATP production) Copyright © 2010 Pearson Education, Inc.

Survival Needs 3. Water • Most abundant chemical in the body • Site of chemical reactions 4. Normal body temperature • Affects rate of chemical reactions 5. Appropriate atmospheric pressure • For adequate breathing and gas exchange in the lungs Copyright © 2010 Pearson Education, Inc.

Homeostasis • Maintenance of a relatively stable internal environment despite continuous outside changes • A dynamic state of equilibrium Copyright © 2010 Pearson Education, Inc.

Homeostatic Control Mechanisms • Involve continuous monitoring and regulation of many factors (variables) • Nervous and endocrine systems accomplish the communication via nerve impulses and hormones Copyright © 2010 Pearson Education, Inc.

Components of a Control Mechanism 1. Receptor (sensor) • Monitors the environment • Responds to stimuli (changes in controlled variables) 2. Control center • Determines the set point at which the variable is maintained • Receives input from receptor • Determines appropriate response Copyright © 2010 Pearson Education, Inc.

Components of a Control Mechanism 3. Effector • Receives output from control center • Provides the means to respond • Response acts to reduce or enhance the stimulus (feedback) Copyright © 2010 Pearson Education, Inc.

3 Input: Information sent along afferent pathway to control center. 2 Receptor detects change. Receptor 1 Stimulus produces change in variable. 4 Output: Information sent along efferent pathway to effector. Control Center Afferent Efferent pathway Effector IMB AL AN CE BALANCE IMB AL Copyright © 2010 Pearson Education, Inc. AN 5 Response of effector feeds back to reduce the effect of stimulus and returns variable to homeostatic level. CE Figure 1. 4

1 Stimulus produces change in variable. IMB AL AN CE BALANCE IMB AL Copyright © 2010 Pearson Education, Inc. AN CE Figure 1. 4, step 1

2 Receptor detects change. Receptor 1 Stimulus produces change in variable. IMB AL AN CE BALANCE IMB AL Copyright © 2010 Pearson Education, Inc. AN CE Figure 1. 4, step 2

3 Input: Information sent along afferent pathway to control center. 2 Receptor detects change. Receptor 1 Stimulus produces change in variable. Control Center Afferent pathway IMB AL AN CE BALANCE IMB AL Copyright © 2010 Pearson Education, Inc. AN CE Figure 1. 4, step 3

3 Input: Information sent along afferent pathway to control center. 2 Receptor detects change. Receptor 1 Stimulus produces change in variable. 4 Output: Information sent along efferent pathway to effector. Control Center Afferent Efferent pathway Effector IMB AL AN CE BALANCE IMB AL Copyright © 2010 Pearson Education, Inc. AN CE Figure 1. 4, step 4

3 Input: Information sent along afferent pathway to control center. 2 Receptor detects change. Receptor 1 Stimulus produces change in variable. 4 Output: Information sent along efferent pathway to effector. Control Center Afferent Efferent pathway Effector IMB AL AN CE BALANCE IMB AL Copyright © 2010 Pearson Education, Inc. AN 5 Response of effector feeds back to reduce the effect of stimulus and returns variable to homeostatic level. CE Figure 1. 4, step 5

Negative Feedback • The response reduces or shuts off the original stimulus • Examples: • Regulation of body temperature (a nervous mechanism) • Regulation of blood volume by ADH (an endocrine mechanism) Copyright © 2010 Pearson Education, Inc.

Control Center (thermoregulatory center in brain) Information sent along the afferent pathway to control center Afferent pathway Information sent along the efferent pathway to effectors Efferent pathway Receptors Temperature-sensitive cells in skin and brain Effectors Sweat glands activated Response Evaporation of sweat Body temperature falls; stimulus ends Stimulus Body temperature rises BALANCE Stimulus Response Body temperature rises; stimulus ends Body temperature falls Receptors Temperature-sensitive cells in skin and brain Effectors Skeletal muscles Shivering begins Copyright © 2010 Pearson Education, Inc. Information sent along the efferent pathway to effectors Efferent pathway Afferent pathway Control Center (thermoregulatory center in brain) Information sent along the afferent pathway to control center Figure 1. 5

Negative Feedback: Regulation of Blood Volume by ADH • Receptors sense decreased blood volume • Control center in hypothalamus stimulates pituitary gland to release antidiuretic hormone (ADH) • ADH causes the kidneys (effectors) to return more water to the blood Copyright © 2010 Pearson Education, Inc.

Positive Feedback • The response enhances or exaggerates the original stimulus • May exhibit a cascade or amplifying effect • Usually controls infrequent events e. g. : • Enhancement of labor contractions by oxytocin (Chapter 28) • Platelet plug formation and blood clotting Copyright © 2010 Pearson Education, Inc.

1 Break or tear occurs in blood vessel wall. Positive feedback cycle is initiated. 3 Released chemicals attract more platelets. 2 Platelets Positive feedback loop adhere to site and release chemicals. Feedback cycle ends when plug is formed. 4 Platelet plug forms. Copyright © 2010 Pearson Education, Inc. Figure 1. 6

1 Break or tear occurs in blood vessel wall. Positive feedback cycle is initiated. Copyright © 2010 Pearson Education, Inc. Figure 1. 6, step 1

1 Break or tear occurs in blood vessel wall. Positive feedback cycle is initiated. 2 Platelets adhere to site and release chemicals. Copyright © 2010 Pearson Education, Inc. Figure 1. 6, step 2

1 Break or tear occurs in blood vessel wall. Positive feedback cycle is initiated. 3 Released chemicals attract more platelets. Copyright © 2010 Pearson Education, Inc. Positive feedback loop 2 Platelets adhere to site and release chemicals. Figure 1. 6, step 3

1 Break or tear occurs in blood vessel wall. Positive feedback cycle is initiated. 3 Released chemicals attract more platelets. 2 Platelets Positive feedback loop adhere to site and release chemicals. Feedback cycle ends when plug is formed. 4 Platelet plug forms. Copyright © 2010 Pearson Education, Inc. Figure 1. 6, step 4

Homeostatic Imbalance • Disturbance of homeostasis • Increases risk of disease • Contributes to changes associated with aging • May allow destructive positive feedback mechanisms to take over (e. g. , heart failure) Copyright © 2010 Pearson Education, Inc.