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Chapter 1: Introduction to Anatomy and Physiology. For the first lecture test, I should be able to…. A. Define anatomy and physiology . 1. Explain how they are related. 2. Describe major specialties of each. B. Define homeostasis and explain its importance for survival.
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For the first lecture test, I should be able to… • A. Define anatomy and physiology. • 1. Explain how they are related. • 2. Describe major specialties of each. • B. Define homeostasis and explain its importance for survival. • 1.Compare/contrast intrinsic and extrinsic regulation and provide an example of each. • 2.Compare/contrast negative and positive feedback and provide an example of each. • 3.Discuss the relationship between homeostasis and disease.
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 • Biochemistry, Biology, Chemistry, Genetics
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 • Developmental anatomy: from conception to death • Clinical anatomy:medical specialties
Relationships between Anatomy and Physiology • Microscopic anatomyexamines cells and molecules • Cytology: study of cells and their structures • cyt- = cell • Histology: study of tissues and their structures
1-4 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
1-5 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
1-5 Levels of Organization • The Organ System Level • An organ system isa group of organs working together • Humans have 11 organ systems • The Organism Level • A human is an organism
Figure 1-1 Levels of Organization Cellular Level Chemical and Molecular Levels Heart musclecell Protein filaments Complex protein molecule Atoms in combination
Figure 1-1 Levels of Organization Organismlevel Organ systemlevel Organ Level Tissue Level The heart Cardiac muscletissue Thecardiovascularsystem
KEY CONCEPT • The body is divided into 11 organ systems • All organ systems work together • Many organs work in more than 1 organ system
1-6 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)
1-6 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
1-6 Homeostasis • Receptor • Receives the stimulus • Control center • Processes the signal and sends instructions • Effector • Carries out instructions CONTROL CENTER
Figure 1-2 The Control of Room Temperature RECEPTOR Informationaffects Normalconditiondisturbed Thermometer STIMULUS:Room temperaturerises CONTROL CENTER(Thermostat) HOMEOSTASIS Airconditionerturns on Airconditionerturns off Normal roomtemperature RESPONSE:Room temperaturedrops 20° 30° 40° Normalrange Room temperature (°C) 22 Normalconditionrestored EFFECTOR Sendscommandsto Air conditionerturns on Time In response to input from a receptor (a thermometer), a thermostat(the control center) triggers an effector response (either an air condi-tioner or a heater) that restores normal temperature. In this case,when room temperature rises above the set point, the thermostatturns on the air conditioner, and the temperature returns to normal. With this regulatory system, roomtemperature fluctuates around theset point.
1-7 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
Figure 1-3 Negative Feedback in the Control of Body Temperature RECEPTORS Informationaffects Temperaturesensors in skinandhypothalamus Normaltemperaturedisturbed CONTROL CENTER STIMULUS:Body temperaturerises HOMEOSTASIS Thermoregulatorycenter in brain Vesselsdilate,sweatingincreases Vesselsconstrict,sweatingdecreases Normal bodytemperature RESPONSE:Increased heat loss,body temperaturedrops 37.2 EFFECTORS Normaltemperaturerestored Normalrange Body temperature (°C) Sendscommandsto 37 • Sweat glands in skin increase secretion• Blood vessels in skin dilate 36.7 Time Events in the regulation of body temperature, which arecomparable to those shown in Figure 12. A control centerin the brain (the hypothalamus) functions as a thermostatwith a set point of 37°C. If body temperature exceeds37.2°C, heat loss is increased through enhanced blood flowto the skin and increased sweating. The thermoregulatory center keepsbody temperature fluctuatingwithin an acceptable range, usuallybetween 36.7 and 37.2°C.
1-7 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 Wouldn’t you want to speed this up? Clottingaccelerates Positivefeedbackloop Blood clot Chemicals Chemicals The chemicals start chainreactions in which cells,cell fragments, andsoluble proteins in the blood begin to form a clot. Damage to cells in theblood vessel wall releaseschemicals that begin theprocess of blood clotting. As clotting continues,each step releaseschemicals that furtheraccelerate the process. This escalating processis a positive feedbackloop that ends with theformation of a blood clot,which patches the vesselwall and stops the bleeding.
1-7 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