Chapter 1

Physiology

the study of the normal functioning of a living organism and its component parts, including all its chemical and physical process; the study of physiology is closely related to anatomy

genome

the collective term for all the genetic information contained in the DNA of a species or genectic material of an organism

emergent properties

properties that cannot be predicted to exist based only on knowledge of the system's individual components

proteomics

the study of proteins in living organisms

integration of the function of many organizations; organization of life

Physiology focal point; the cell is the smallest unit of structure capable of carrying out all life processes

integrate

to bring varied elements together to create a unified whole

Levels of Organization in Physiology

Molecules > Cells > Tissues > Organs > Organ systems > Organisms > Populations of one Species

ome

a collection of items that make up a whole, such as a genome

biome

all organisms living in a major ecological region

physiome

the organism's coordinated molecular, cellular, and physiological functioning

cells

the basic functional unit of most living organisms

cell membrane

(also called the plasma membrane) the cell membrane that serves as both a gateway and a barrier for substances moving into and out of the cell or lipid and protein barriers that separates cells from their external environment

simple organisms

composed of one cell

complex organisms

have many cells with different structural and functional specializations

tissue

a collection of cells, usually held together by cell junctions, that works together to achieve a common purpose

organs

group of tissues that carries out related functions

integumentary system

composed of the skin, forms a protective boundary that separates the body's internal environment from the external environment (include nails and hair)

musculoskeletal system

support and body movement (muscle and bone)

respiratory (pulmonary) system

exchanges gases like oxygen and carbon dioxide between the internal and external environments

digestive (gastrointestinal) system

takes up nutrients (by conversion of food into particles that can be transported into the body) and water as well as eliminates waste material

reproductive system

produces sex cell in female it's eggs and in male it's sperm

urinary (renal) system

removes excess water and waste material (kidneys included)

circulatory (cardiovascular) system

extend throughout the body; (includes the heart, blood vessels, and blood) that transports materials between all cells of the body (like oxygen and gets rid of carbon dioxide) or distributes materials by pumping blood through vessels

nervous system

extended throughout the body; includes the brain and spinal cored that coordinates the body function through electrical signals and release of regulatory molecules (recognize external and internal changes with senses and electrical pulses)

endocrine system

extended throughout the body; includes the thyroid gland and adrenal gland that coordinates the body function through synthesis and releases of regulatory molecules (release hormones, that regulate your body, how thirsty, how much sleep, and how much you urate)

immune/lymphatic system

extends throughout the body, which is it also includes the lymphatic system as well as the thymus, spleen, and the lymph nodes; it defends the body from foreign invaders (immune tissues are closely associated with the circulatory system)

maps used in physiology

simplified and integrated information used by visual representation also called flow-charts/process-maps, structure/function maps; help you organize information (in nonlinear way) that make sense to you; connecting arrow to describe the type of linkage between the terms (structure/function, cause/effect) or with explanatory phrases; or show steps taken in an experiment; guides in diagnosing and treating patients

function

"why" of the system or events not "how" Example: Why does a certain response help an animal survive in a particular situation? In other word, what is the adaptive significance of this event for this animal? (also see the teleological approach - the purpose rather then mechanism)

teleological approach

describing physiological processes by their purpose rather than their mechanism; answers "why" and not "how"

mechanisms

"how" of the system of events not "why" Example: How do red blood cells transport oxygen? Oxygen binds to hemoglobin molecules in the red blood cells. (also see the mechanistic approach - the mechanism not the purpose)

mechanistic approach

the ability to explain the mechanisms that underlie physiological events; answers "how" not "why"

translational research

applies basic biomedical research findings to treatment and prevention of human diseases

Amylin (chemical)

chemicals from the pancreas; treatment for diabetes mellitus

Physiology philosophy in the chapter

Physiologist pride themselves on relating the mechanisms they study to the functioning of the organisms as a whole; "Physiology is not a science or a profession but a point of view" - R. W. Gerard in Mirror to Physiology: A Self-Survey of Physiological Science, 1958

four themes in physiology

structure-function relationships, biological energy use, information flow within an organism, and homeostasis and the control systems that maintain it (as seen in Ch 1.3)

proteins

biological molecules that include enzymes that speed up chemical reactions, signal molecules, and the receptor proteins that bind signal molecules and specialized proteins that function as biological pumps, filters, motors, or transporters (also in Ch 2)

three mechanical properties of cell and tissues (structure and function)

'compliance' (ability to stretch), 'Elastance' (stiffness or ability to return to the unstretched state), strength, flexibility, and fluidity ('Viscosity') by the interaction of proteins, water and other molecules (also in Ch 2)

compartmentation

the internal division of the body or cell into compartments so that functions can be isolated from one another (also in Ch 3)

energy in the body or living organisms

used to build and brake down molecules; transport molecules and create movement; the process in organism growth, reproduction, movement, and homeostasis depend on energy input (also in Ch 4)

information flow in living systems (or inside an organism)

coordinates function; transfer of information stored in DNA from generation to generation (genetics) to the flow of information within the body of single organism; organismal level - translation of DNA's genectic code into proteins responsible for cell structure and function also called cell-to-cell communication (also in Ch 5, 6)

cell-to-cell communication

chemical signals, electrical signals, or a combination of both in the information flow between cells also called coordinates function (also in Ch 5, 6)

homeostasis

the ability of the body to maintain a relatively constant (stable) internal environment (also in Ch 1.4, 5); regulated within a range of values, not a single value (balance in our body, we don't want to much fluid or to little, we don't want our blood sugar to be to low or to high, we don't want our body temperature to go to high or to low or you get hypothermia, keep things in range)

homeodynamics instead

some physiologist contend that a literal interpretation of stasis in the word homeostasis implies a static, unchanging state; which means that dynamics would reflect the small changes constantly taking place in our internal environment; the body monitors its internal state and takes action to correct disruptions that threaten its normal function

pathological condition

disease state (suffering) occurs when normal functions are disrupted; internal failure of some normal physiological process or those that originate from some outside source; failure to maintain homeostasis

pathophysiology

the study of body functions in a disease state; Example: diabetes mellitus - abnormally high blood glucose

diabetes mellitus

disease characterized by lack of or abnormal action of insulin

extracellular fluid (ECF)

the watery internal fluid (environment) that surrounds the cells; serves as a buffer zone between outside world and ICF; needs to be kept relatively stable (through action of kidneys)

intracellular fluid (ICF)

fluid within the cells (most fluid in your body is ICF)

law of mass balance

if the amount of a substance in the body remains constant, any gain must be offset by an equal loss: Input-intake through intestine, lungs, skin (metabolic production) > existing Body Load > Output- excretion by kidneys, liver, lungs, skin (metabolism to a new substance) = mass balance (total amount of substance X in the body)

excretion

the elimination of material from the body, usually through the urine, feces, lungs, or skin

metabolite

general term for any production created in a metabolic pathway, converting the original nutrient to something different then creates a new mass balance disturbance by adding more of the new substance to the body

mass flow

mass flow equals concentration times volume flow (flow of blood, air, urine, and the like)

clearance

a measurement of the disappearance of a substance from the blood, expressed as milliliters of plasma cleared of solute per unit time

internal environment

stability of the extracellular fluid compartment (ECF); ECF is usually easy to monitor just by taking a blood sample (in the state of homeostasis)

centrifuge blood

spinning it into two parts by a narrow capillary tube, where plasma and heavier blood cells separate (in state of homeostasis)

plasma

the fluid portion of the blood; it can be easy to analyzed by centrifuging blood (in the state of homeostasis)

Steady state

no net movement of materials between the compartments in homeostasis (not the same as equilibrium though); the composition of both body compartments is relatively stable and conditions are dynamic meaning they are constantly moving back and forth between compartments

IONs Concentration of Body Fluid Compartments

IONs is also known as Electrolytes (because they have electric charge in them). In ECF the outer cells, there is alot of Na+ (140 mmol/L) and Cl' (100 mmol/L) and little K+ (less then 10 mmol/L), but in ICF the inner cell, there is alot of K+ (140 mmol/L) and little Na+ and Cl' (less then 10 mmol/L). (Na+ is Sodium, Cl' is Chloride, and K+ is Potassium)

equilibrium

the composition of the body compartments are identical unlike the steady state (ECF and ICF are in a state of relatively stable disequilibrium)

disequilibrium

when the composition of the body compartments are not identical (ECF and ICF exist in a state of relatively stable disequilibrium)

homeostatic control systems of three components

1. input signal = stimulus 2. controller or integrating center that integrates incoming information and initiates an appropriate response (usually the brain) 3. an output signal that creates a response (to effector; response) (has to be balanced like a scale)

local control in cardiovascular system

homeostatic control that takes place strictly at the tissue or cell by using paracrine or autocrine signals; cells in the vicinity of the change initiate the response > then there is a local response > brain evaluates the change and initiates the response > then there is systematic change and reflex response

reflex control in physiology

to maintain homeostasis; a complex control system that require any long-distance pathway that uses the nervous system, endocrine system or both to communicate and coordinate using response loop or feedback loop

Response loop three primary components

1. input signal 2. integrating center to integrate the signal 3. output signal

Expanded sequence in reflex pathway:

stimulus > sensor > input signal > integrating center > output signal > target > response

Stimulus

the change that occurs when the regulated variable moves out of its desirable range (Part of response loop known as reflex pathway:

Sensor

monitors variables that moves out of its desirable range and sends a input signal to the integrating center (Part of response loop known as reflex pathway:

Integrating center

evaluates the information coming from the sensor and initiates an output signal (Part of response loop known as reflex pathway:

output signal

directs a target to carry out a response (Part of response loop known as reflex pathway:

response

brings the regulated variable back into the desired range (Part of response loop known as reflex pathway:

antagonistic control

(work in opposition) the type of response is based on the setpoint of the regulated variable then respond in different response loops from the same stimulus (or setpoint/normal value); example: when two branches of the nervous system or two different hormones have opposing effects on a single target

feedback loop

information about a homeostatic response that sent back to the integrating center

negative feedback

a homeostatic feedback loop designed to keep the system at or near a setpoint; stabilize the regulated variable and thus aid the system in maintaining homeostasis (shuts off the response loop); the response counteracts the stimulus, shutting off the response loop (most body processes are regulated via Negative Feedback; Example: like thermal receptors in our skin that regulate temperature, the sweat glands will help the body cool down; shivering helps body heat up)

positive feedback loop

a feedback loop in which the response reinforces the stimulus, triggering a vicious cycle of ever-increasing response; reinforces the stimulus rather than decreasing or removing it; the response reinforces the stimulus, sending the variable farther from the setpoint (Positive Feedback is rare: platelets build up… cause blood clotting and oxytocin… labor contractions)

feedforward control

anticipatory responses that start a response loop in anticipation of a change that is about to occur

circadian rhythm

biological rhythm based on a 24-hour cycle; includes blood pressure, body temperature, and metabolic processes

acclimatization

the adaptation of physiological processes to a given set of environmental conditions

acclimation

physiological adjustment to environmental change in a laboratory setting

hypotheses

logical guesses, about how events take place

scientific evidence or inquiry

also known as evidence-based medicine; testing hypotheses by designing experiments to collect evidence that supports or disproves their hypotheses; observation and experimentation

independent variable

altered variable or the manipulated element

dependent variable

the outcome factor; the variable that may change in response to manipulations of the independent variable.

control

part of an experiment designed to ensure that any observed changes are due to the experimental manipulation and not to an outside factor

data

information or facts gathered during an experiment

replication

an experiment repeated to ensure that the results were not an unusual one-time event

model

when the data supports a hypothesis in multiple experiments

scientific theory

a model with substantial evidence from multiple investigators supporting it

variability

in a set of numbers, how widely dispersed the values are from each other and from the mean

crossover study

experimental design in which the subjects spend half the time on the experimental treatment and half the time on placebo

placebo

an inactive substance used in medical treatment

placebo effect

the phenomenon in which the expectations of the participants in a study can influence their behavior and do exactly what is expected

nocebo effect

the phenomenon in which the expectations of the participants in a study can influence their behavior and they report of higher side effects when warned then those who wasn't warned