Chapter One
Feedback Loop: Stimulus
Any physiological change from the body's set point - Applies to all aspects of the body's condition -intracellular and extracellular Examples: -change in the concentration of certain chemicals -change in blood pressure -change in body position -change in body temp.
Human experiments
Complications that make it difficult to interpret results - Genetic variables - each organism has unique genome, its hard to find two groups who are idential - Placebo effect - A treatment that will work because they BELIEVE it will work -Nocebo effect - A treatment has a negative effect because they BELIEVE it will have a negative effect. -Ethics
Nervous
The endocrine and _________ systems are responsible for communication around the body.
Dependent variable pg 20
the y-axis variable that is dependent on the manipulated or independent variable
Organ Systems (pg.4)
-Integumentary -Musculoskeletal -Respiratory -Digestive -Reproductive -Urinary -Circulatory -Nervous -Endocrine -Immune
The scientific method
-Observation -Research question -Hypothesis -testable -based on previous knowledge -Experiment -variables, controls, and data collection -replication -Theories and models -theories are based on thousands and thousands of different studies
Feedback loops: Effector's action
-The effector is a STRUCTURE -What it does is its ACTION Example: -secretion of sweat -contraction -transport of ions
4 Themes in Physiology
1. Structure & Function Relationship 2. Energy Processing by the Body 3. Information Flow to Coordinate Body Function 4. Homeostasis to Maintain the Internal Environment of the Body
Homeostasis
Environmental balance: whole organism -External -Internal Cellular level - Intracellular fluid (ICF)- Inside cells -Extracellular fluid (ECF)- serves as the transition between an organisms external environment and the intracellular fluid. -When the extracellular fluid composition varies outside its normal range of values, compensatory mechanisms activate and try to return the fluid to the normal state. (figure 1.3 on pg 11) also look at figure 1.4 on page 12 Intra- within Extra- outside of Inter- between -The body monitors its internal state and takes action to correct disruptions that threaten its normal functions.
Living organisms need energy (pg.9)
Growth, reproduction, movement, homeostasis all require energy. The molecule ATP is a critical component in this theme in physiology.
Steady state
In a state of homeostasis, the composition of both body compartments is relatively stable. This condition is called dynamic ___________________. The modifier dynamic indicates that materials are constantly moving back and forth between the two compartments. In a ________________, there is no net movement of materials between the compartments. Figure 1.6 pg 14
Information flow coordinates body functions (pg 9-10)
Information flow in living systems ranges from the transfer of information stored in DNA from generation to generation (genetics) to the flow of information within the body of a single organism. In the human body, information flow between cells takes the form or either chemical signals or electrical signals. Chemical signal molecules can travel from one location to another to deliver information around the body.
Homeostasis maintains internal stability (pg 10-11)
Organisms that survive in challenging habitats cope with external variability by keeping their internal environment relatively stable, an ability known as homeostasis. Homeostasis and the regulation of the internal environment are key principles of physiology and underlying themes in each chapter of the book.
Levels of Organization (pg.2-3)
Physiology includes all levels of organization beginning with molecules and building all the way up to populations of species. -At the simplest level of organization, atoms of elements link together to form molecules. Collections of molecules in living organisms form cells, the smallest unit of structure capable of carrying out all life processes. -The cell is the unit of life -Cells, tissues, organs, organ systems, organisms -Collections of cells that carry out related functions are called tissues. -Tissues form structural and functional units known as organs -Groups of organs integrate their functions to create organ systems
Emergent properties (pg.2)
Properties that cannot be predicted to exist based only on knowledge of the systems individual components. Among the most complex emergent properties in humans are emotion, intelligence and other aspects of brain function. None of these properties can be predicted from knowing the individual properties of nerve cells.
Equilibrium
Steady state is not the same thing as _______________. _______________ implies that the composition of the body compartments is identical.
Figure 1.3 on pg 11
Step 1: External or internal change Step 2: Physiological attempt to correct Step 3: Normal responses/adjustments Alternate step 3: Failure of system to adjust or compensate(correct) -Loss of homeostasis
Physiology (pg.2)
Study of the functions and processes of living organisms. -Literally means "knowledge of nature"
Function (pg.5)
The __________ of a physiological system or event is the "why" of the system or event. -The teleological approach- thinking about a physiological event in terms of its adaptive significance
Independent variable pg 20
The altered variable
Feedback loop: Response
The outcome of the effectors action. If you know the stimulus, you can immediately identify the response.
Feedback loops
The process of maintaining homeostasis -This is the basis of the study of physiology Steps: 1. Stimulus 2. Sensor (Afferent pathway) - sensory neuron 3. Integrating Center (Efferent pathway) 4. Effector (Effector's action) 5. Response
Negative feedback loop
The response is the exact opposite of the stimulus -99% processes in the body involve negative feedback loop figure 1.11 on page 17
Positive feedback loop
The response pushes the stimulus even further from set point figure 1.12 on page 18
Feedback loop: Effector
The structure that can act to remove you from the stimulus Examples: - Individual proteins - Organelles - Cells -Organs
Feedback Loop: Sensor
The structure that detects the change from set point (stimulus) Examples: -Chemoreceptors (detect change in chemicals ex-carbon dioxide) -Thermoreceptors(detect change in temp) -Noiceceptors (pain) -Osmoreceptors -Proprioceptors -Baroreceptors (detect pressure ex-blood pressure)
Feedback Loop: Integrating Center
The structure where the information from the sensor is processed and interpreted. Examples: -Individual proteins -Individual cells - Regions of the central nervous system - Endocrine cells
Structure and function are closely related (pg.8-9)
This theme includes the integration of structure and function that extends across all levels of organization, from the molecular level to the intact body. This theme subdivides into two major ideas: molecular interactions and compartmentation. -Molecular interactions- The ability of individual molecules to bind or react with other molecules is essential for biological function. A molecules function depends on its structure and shape. -Compartmentation- the division of space into separate compartments. Compartments allow a cell, a tissue or an organ to specialize and isolate functions. It is the binding of individual molecules that must perfectly fit together in order to perform an essential job in the body.
Concept mapping
Ways of organizing information in logical formats -Structure & function map (fig 1.2 pg 5) -Integration across all levels -Look at lecture notes -Flowcharts or process maps -Follow process in sequence -The movement from the top to the bottom indicates the passage of time (must be in correct order)
Mechanism (pg.7)
___________(or process) describes the "how". -Mechanistic approach- examines process.
