Introduction to Physiology: Homeostasis and Cell Structure and Function Flashcards Preview

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Flashcards in Introduction to Physiology: Homeostasis and Cell Structure and Function Deck (33)
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1
Q

What is physiology

A

A foundational sciences for the understanding and practice of medicine.

  • The study of the function the body at the molecular, cellular, organ system and organismal levels.
  • The study of how everything maintains homeostasis
2
Q

Homeostasis

A

The maintenance of steady state in the internal environment despite changes in the external environment

Or maintenance of constant internal environment (Clause Bernard’s Milieu Interieur) despite changes in the external environment

3
Q

Extracellular Fluid (ECF)

A

ECF of multi cellular organisms mimic primordial environment and buffers cell from external environment

4
Q

Before we had multicullular organisms with “internal environments”, there were…

A

unicellular organisms

5
Q

Multicellular organisms have ____ interaction with the outside environment, and require ways to communicate between cells

A

Less direct

6
Q

Proteins comprise ___% of the membrane by mass

A

50%

7
Q

Integral/Intrinsic/transmembrane Proteins

A

Ion channels, transport proteins- span the entire cell membrane or are embedded in the membrane

8
Q

Peripheral/Extrinsic Proteins

A

Are not embedded and are located on one side of the cell membrane either intra- or extracellular side.

9
Q

Can water soluble substances dissolve in lipid bilayer?

A

NO- but some can cross the cell membrane through water-filled channels/pores or may be transported by carrier proteins

10
Q

Examples of water soluble substances that cannot dissolve in lipid bilayer

A

Na+, Cl-, Glucose, H2O

11
Q

How can cell membrane proteins act as?

A

transporters, channels, receptors, enzymes, antigens

12
Q

5 types of membrane transports

A
  1. simple diffusion
  2. facillitated diffusion
  3. primary active transport
  4. secondary active transport
  5. osmosis
13
Q

What does the rate of diffusion depend on in simple diffusion?

A
  • Concentration gradient
  • Permeability of the membrane
  • Surface area
14
Q

In simple diffusion, ___ is directly proportional to the ___

A

Rate of diffusion, concentration difference

15
Q

In facilitated diffusion, why is rate of diffusion faster?

A

Due to the presence of the carrier protein at lower conc.

16
Q

Facilitated diffusion follows all features of a carrier mediated transport- which are…

A

Saturation, Specificity, Competition

17
Q

Facilitated Diffusion rate of diffusion…

A

reaches saturation at high concentration

18
Q

3 features of ALL forms of carrier-mediated transport

A
  1. Chemical specificity/stereospecificity
  2. Competition
  3. Saturation
19
Q

Carrier-mediated transport proteins have a limited number of ___ for the solute

A

binding sites

20
Q

At high solute concentrations, rate of transport reaches a ___, as all the binding sites are saturated (occupied)

A

Plateau

21
Q

Transport Maximum (Tm) definition

A

The maximum rate at which the substance can be reabsorbed

22
Q

Primary active transport

A

Transport of solutes against the concentration gradient- requiring use of energy (ATP) to pump solutes DIRECTLY-ATPASE activity

23
Q

Primary active transport follows all features of a carrier mediated transport, which are…

A

Saturation, Specificity, Competition

24
Q

Secondary Active Transport

A

Transport in which transport of a solute is coupled with sodium transport and is transported against its gradient

  • Active, carrier mediated process
  • Energy is used INDIRECTLY by the carrier
  • Driving force is the sodium concentration gradient, created by primary active transport
25
Q

What makes secondary active transport stop?

A

If there is no sodium gradient

-Inhibiting Na+K+ pump

26
Q

Uniport

A

Transport of a single susbstance

27
Q

Symport

A

Transport of more than one substance in the same direction (AKA Cotransport)

28
Q

Antiport

A

Transport of more than one substance in opposite directions (AKA countertransport or exchange)

29
Q

Symporter

A

Involves more than one type of particle being transported by in the SAME direction at the same time by the same mechanism

30
Q

Counter transport/Antiport/Exchange

A

When solutes move in opposite directions across the cell membrane

31
Q

Osmosis

A

Movement of water across the cell membrane OR selectively permeable membrane due to DIFFERENCE IN CONCENTRATION OF SOLUTES

32
Q

The water concentration of a solution is determined by the….

A

Concentration of solute

33
Q

Difference between Osmosis and Diffusion

A

Osmosis occurs because of a pressure difference

Diffusion occurs because of a concentration difference