phys chapter 1-4

describe a general stimulus pathway

stimulus- sensor/receptor- afferent pathway-integrating center-efferent pathway-effector-response

a stimulus triggers a receptor which activates effector which produces a response.

general negative feedback pathway

stimulus-receptor/sensor-afferent pathway- integrating center-effernet pathway-receptor-NFL (self regulating process)

describe a positive feedback pathway

stimulus-receptor-afferent pathway-integrating center-efferent pathway effector-response-

PFL (reinforces stimulus)

describe a general feedforward pathway

a reflex that evolves to start the response loop in anticipation of a change.

compare general patterns of stimulus-response, negative feedback, positive feedback, and feedforward control.

stimulus-responce : any response direction

negative feedback : opposes change

positive feedback : amplifies change

feedforward : preemptive (anticipates change)

define physiology

the study of the normal function of living organisms and their component parts, encompassing all chemical and physical processes that sustain life

define pathophysiology

the study of body functions in a disease state

compare teleological and mechanistic approaches to physiology

teleology is describing a physiological process by their purpose

mechanistic approach is the ability to explain the mechanisms that underlie physiological events

explain levels of scientific confidence

the levels of certainty and trust the researches have in their findings

hypothesis- educated guesses

evidence-based medicine- literature

observation and experimentation- explain physiological processes

explain how a physiologist would use scientific inquiry to approach a scientific problem.

start by noticing something unusual or interesting

review scientific literature, studies, to understand what is already known

create a testable explanation

perform a controlled experiment to test the hypothesis

gather date

conclude if hypothesis is supported, rejected, or needs revision

publish findings in journals, and conferences to allow others to evaluate and replicate results

how does medical knowledge change over time?

because of scientific discovery, testing, and revision.

what are some issues a physiologist might encounter when interpreting physiological data.

variability: genetic and environmental

psychological factors: placebo and nocebo effect

ethical considerations

different forms of studies: longitudinal, cross-sectional, retrospective

how do you make a figure in a lab?

how do you interpert and analyze a figure in a lab?

define homeostasis

the ability of the body to maintain a relatively constant internal environment despite external changes.

what happens when homeostasis fails?

normal function is disrupted and a disease state, or pathological condition may result.

extracellular fluid compartments

interstitial fluid, and plasma

what are the intracellular fluid compartments of the body?

cytosol, inclusions, insoluble protein fibers, organelles,

what is the significance of compartmentalization?

the internal division of the body or cell into compartments so that functions can be isolated from one another

what is the concept of internal and external environments?

internal environment is essential for survival and proper cell function, external environment changes all the time, but the body maintains a constant internal environment through homeostasis.

how does water move among compartments?

explain in words- mass balance

if the amount of a substance in the body is to remain constant, any gain must be offset by an equal loss.

mass balance= intake+production-excertion-metabolism

explain mathematically- mass balance

explain the concept of chemical disequilibrium

hat the concentrations of solutes (ions, molecules) are not the same across different compartments of the body.

explain the concept of electrical disequilibrium

there is a difference in electrical charge between two compartments, usually inside vs. outside the cell (charged particles)

concept of osmotic equilibrium

exists when the total concentration of solutes (osmolarity) is the same across two compartments, so there is no net movement of water by osmosis.

homeostasis compared to equilibrium compared to disequilibrium

homeostasis- maintain a stable internal environment

equilibrium- a state where there is no net change, forces are balanced

disequilibrium- differences across compartments exist

define clearance

the rate at which a substance disappears from the blood.

define solvent

the substance in a solution that dissolves other substances (water)

describe the ways we can express solute concentration

molarity- # of moles per solute per liter of solution

osmolarity- total concentration of all solute particles in a solution

tonicity- the effect a solution has on a cell volume based on solute (whether water moves into, out of, or not at all from cells.

define pH

a measure of the concentration of H+ ions

define pH mathematically

pH=-log10(H+)

compare acids, bases, and buffers

acids - pH below 7 (molecules that release H+ when they dissolve in water

basses - pH above 7

7 is neutral

buffer- moderates change in pH

compare the structure of ions, polar molecules, and nonpolar molecules

ions- atoms or molecules that have lost or gained an electron

polar molecules- have regions of partial positive and negative charges due to uneven sharing of electrons in covalent bonds

non polar molecules- evenly shared electrons, so no regions of partial change.

compare the solubility of ions, polar molecules, and nonpolar molecules

ions- highly soluble (break easy)

polar molecules- dissolve well in water because of partial charges

nonpolar molecules- don’t dissolve well

how is molecular shape related to molecular function?

determines interaction, chemical properties, enables specific functions, and can alter functions

what are the general functions of a plasma membrane?

physical isolation, regulation of exchange, communication, structure and support.

define energy

the capacity to do workk

compare kinetic and potential energy

kinetic energy is energy of motion, potential is stored energy

what is the cellular function of ATP?

energy transfer, metabolic reactions, active transport, and protein synthesis

aerobic pathway of ATP production

atp production requires oxygen

anaerobic pathway of ATP production

atp production without oxygen, primarily involves glycolysis

define metabolism

all the chemical reactions in the body

enzyme regulation, compartmentalization, pathway regulation, and hormonal influence.

how is metabolism controlled?

what is the relationship between enzyme structure and function?

its shape determines its specificity and how well it can catalyze a reaction.

define work

chemical- making and breaking chemical bonds

transport work - moving ions and molecules across cell membranes

mechanical work- involves movement, like muscle contraction

define chemical work

making and breaking chemical bonds

define transport work

moving ions and molecules across cell membranes

define mechanical work

involves movement, like muscle contraction

ions are

highly soluble (break easy)

emergent properties

properties that cannot be predicted to exist based only on knowledge of the systems individual components.

independent variable

not relying on or influenced by others

dependent variable

relying on or determined by another

controls

a constant factor that is deliberately kept the same

plasma membrane

separates the intracellular fluid inside the cell from the surrounding extracellular fluid

plasma membrane regulates the exchange with the environment

entry of ions, nutrients, eliminates cellular waste, and releases products from cell

plasma membrane communication

protiens in the membrane enable the cell to recognizee and respond to molecules or to changes in its external env.

plasma membrane provides structural support

cytoskeleton protiens maintain cell shape, also create specialized junctions between adjacent cells and extracellular matrix.

The maintenance of a stable internal environment compatible for life is called

homeostasis

What is the primary mechanism for maintaining homeostasis?

negative feedback

Changes in the external environment alter a ________ of the internal environment, which is detected by a ________.

If you were to take the temperature of everyone in class, assuming no one is sick, you would find that not everyone has a temperature of 37°C. Which statement below best explains your findings?

Most regulated variables, such as temperature, fluctuate continuously and oscillate about the set point due to negative feedback control

"Glucose is transported from blood into cells because cells require glucose to meet their energy needs." This type of explanation is

teleological

Which of the following is one of Cannon's "internal secretions"?

hormones

intensity of exercise

You conduct an experiment on twenty 18-year-old male subjects to see how various intensities of exercise influence heart rate. Which of the following is/are considered an independent variable?

You want to display data on the finish times of the 10 fastest race horses in a single race at the Kentucky Derby.
Which type of graph would be best to display this information?

bar

what compartments are part of or entirely the internal environment?

plasma, interstitial fluid, extracellular fluid

Which of the following best describes intracellular fluid?

rich in proteins and potassium

describe the ions in extracellular fluid

lots of Na+(sodium), a lot of Cl-(Chloride) and a little K+(potassium)

describe the ions in intracellular fluid

a little Chloride, a little more Sodium and a lot of potassium

covalent

Hydrogen gas forms when two atoms of hydrogen come together and share their electrons. This type of bond is a ________ bond.

covalent

which is stronger hydrogen or covalent bonds?

Ions in aqueous solutions are known as electrolytes

Which of the following is true regarding ions and ionic bonds?

aqueous

containing water

Which of the following is true regarding carbohydrates?

the simplest form of carbohydrate is the monosaccharide

Plants produce a carb that is used for structural support

In most living organisms, carbohydrates are used as a source of energy

Carbohydrates are made up of carbon, oxygen and hydrogen

glucose

Which is a monosaccharide that is a very important source of energy for cells?

The most important physical characteristic of lipids is that they:

are relatively insoluble in water

what are composed of long chains of amino acids covalently bonded to one another

polypeptides

Which of the following molecules is stored in adipose tissue and serves as an important source of energy for the human body?

triglycerides

what is a function of a protein?

forms part of the cell membrane

aids in muscle contraction

acts as a catalyst

polar covalent bonds

In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by _____.

Which of the following effects can occur because of the high surface tension of water?

Bruising when jumping into water from 10 m

plasma intersticial fluid

The extracellular fluid compartment is composed of ________

Where is most of our body water located?

inside cells

The lumen of a hollow organ such as the stomach is considered to be part of the ________ environment.

external

Cell membranes are said to be

selectively permeable barrier

Most of the ATP required to power cellular operations is produced in the

mitochondria

The term secretion refers to

the process by which a cell releases a substance into the extracellular space

true

Every substance that enters or leaves the internal environment of the body must cross an epithelium.

Energy

the capacity to do work

The general term that describes energy stored in chemical bonds is

potential energy

When an enzyme is working as fast as it can because its active site is continually refilled with substrate, the condition is referred to as

saturation

Compartmentation can refer to

grouping related enzymes into specific organelles

mass flow

describes the rate of transport of a substance (x) as it moves through body fluids and out of the body.