Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology > General principles > Flashcards

General principles Flashcards

1
Q

Define: homeostasis

A

Maintaining nearly constant conditions in the internal environment (i.e. a steady state)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the difference between equilibrium and steady state?

A

Equilibrium does not require energetic input. Steady state does.
Additionally, in equilibrium, parameters are constant in time. In a steady state, they are nearly constant.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Define: Organ, Organ system

A

Organ: composed of 2 or more kinds of CT
System: A collection of organs that perform a general function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define: Mass balance for a system at steady state

A

Any substance taken in is nearly equal to the amount leaving the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define: Basal Metabolic Rate

A

Energy expenditure at rest in kcal/hr/sq meter surface area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What accounts for most (20-30%) of basal metabolic rate?

A

Skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are some factors that influence metabolic rate?

A

Age, gender, activity level, hormones, climate, nutrition status

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why is positive feedback rarely used?

A

It accelerates a process and can be unstable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Define: gain

A

The capacity of a system to restore a controlled variable to its set point after perturbation.
Mathematically, it is correction/remaining error

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Give some examples of positive feedback in the body

A

Contractions in childbirth, blood clotting, estrogen effects on pituitary-hypothalamus before ovulation, action potential, bleeding out after excessive blood loss

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the goal of negative feedback?

A

To bring a variable back to a set point, opposite the change that has occurred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Define: active transport

A

Moving a solute from a region of low electrochemical potential to a region of high potential. Up the gradient. Requires energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Define: passive transport

A

Moving a solute down its electrochemical potential gradient (from high to low). Does not require energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Define: thermodynamic equilibrium

A

When chemical and electric driving forces on a solute are equal and opposite in direction so the net driving force is zero

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What type of transport is a pump?

A

Primary active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Give two examples of secondary active transport

A

Symporter carrier proteins and antiporter/exchanger carrier proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What type of transport is an ion channel?

A

Passive transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Is simple diffusion mediated or unmediated?

A

Unmediated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which is faster, facilitated diffusion through a carrier protein (uniporter) or through an ion channel?

A

Ion channel, by many orders of magnitude

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Protein-mediated transport can be _____ at high concentrations of solute

A

Saturated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the difference between competitive and noncompetitive transport inhibition?

A

Competitive inhibition can be overcome by an increase in solute concentration. Noncompetitive can not.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Define: electrogenic

A

When the charge transfer from one side of the membrane to the other is unequal, producing a net charge (i.e. Na+/K+ antiporter produces a net positive charge outside of the cell)

23
Q

Define: endotherm

A

An animal that generates its own body heat. Ex. a human.

24
Q

Define: homeotherm

A

An animal that maintains a core body temperature in a narrow range. Ex. a human.

25
Q

Does thermoregulation have a high or a low gain?

A

High gain. It is a very powerful system

26
Q

Define: radiation

A

Transfer of heat as electromagnetic waves between objects that are not in contact

27
Q

Define: conduction

A

Intermolecular heat transfer between solid objects in direct contact

28
Q

Define: convection

A

Loss or gain of heat by movement of air or water over the body

29
Q

Define: evaporation

A

Loss of heat due to transformation of water from liquid to gas on the skin or in the respiratory tract

30
Q

How does a normal person at rest in a normal environment lose most of their heat?

A

Radiation

31
Q

How does an exercising person in a normal environment lose most of their heat?

A

Evaporation- sweating

32
Q

In a hot environment, how does a normal person let off heat?

A

Evaporation- sweating. Radiation and convection do not apply

33
Q

The skin has more (cold/warm) receptors

A

Cold, by about 10-fold

34
Q

The hypothalamus has more (cold/warm) receptors

A

Warm

35
Q

Is thermoregulation a positive or negative feedback response?

A

Negative

36
Q

What happens when a pyrogen is present in the body?

A

The hypothalamus raises the set point of body temperature, creating a fever state. Consequently, the hypothalamus thinks the body is too cold and a person gets chills with vasoconstriction, shivering, piloerection and epinephrine secretion to attempt to warm up the body.

37
Q

Define: heat exhaustion

A

A failure of cardiovascular homeostasis to dissipate heat in a hot environment. Decreased blood volume due to vasodilation and sweating can lead to syncope

38
Q

Define: heat stroke

A

Elevated core temperature in conjunction with severe neuro distrubances (loss of consciousness, convulsions). Accelerated by exercise and humidity

39
Q

Define: hypothermia

A

Heat loss is greater than heat production (i.e. immersal in cold water). Drowsiness, slow speech, bradycardia, hypoventilation and decreased metabolic rate

40
Q

Define: frostbite

A

Exposure to low temperatures causes freezing of surface areas and necrosis. Vasoconstriction with sudden-cold induced vasodilation as a protective response.

41
Q

What gives rise to a membrane potential?

A

A separation of charges (a gradient)

42
Q

What does the Nernst equation tell you?

A

The equilibrium potential for an ion across a membrane that is only permeable to that one ion

43
Q

What does the Goldman equation tell you?

A

Membrane potential for a membrane permeable to more than one ion

44
Q

Positive current is defined as the net flow of (positive/negative) ions (into/out of) a cell

A

Positive ions into a cell

45
Q

Total body water is what percentage of body weight?

A

60%

46
Q

Intracellular fluid is what percentage of total body water? Of total body weight?

A

ICF is 67% of total body water. 40% of total body weight. For a 70 kg standardized patient, ICF volume would be 28L

47
Q

Extracellular fluid is what percentage of total body water? Of total body weight?

A

ECF is 33% of total body water and thus 20% of total body weight. For a 70 kg standardized patient, ICF volume would be 14L

48
Q

Define: osmolality

A

The sum total of all solute concentrations in a compartment

49
Q

What is the normal osmolality of plasma?

A

300 mOsm/L

50
Q

Define: osmotic pressure

A

The amount of pressure needed to force water back into its original chamber once it has moved down its concentration gradient into a chamber of higher osmolality

51
Q

What two ion transporters are activated by cell shrinkage due to an increase in extracellular osmolality?

A

A H+/Na+ antiporter and a HCO3-/CL- antiporter. Outside of the cell, H+ and HCO3- form H2O and CO2 which enter the cell to increase volume and lower osmolality to normal

52
Q

What three mediated transporter proteins are activated by cell swelling due to an decrease in extracellular osmolality?

A

K+ channels, Cl- channels, and a K+/Cl- cotransporter out of the cell. These lower the cell osmolality and thus water moves out of the cell

53
Q

Edema is a shift in fluid from which compartment to which other compartment?

A

Intravascular to interstitial

Physiology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions