Human Physiology: Transport Systems

Fill-in-the-blank flashcards reviewing cell transport mechanisms including passive diffusion, osmosis, active transport, vesicular transport, and fluid compartments.

Passive transport requires no energy and solute moves from high concentration to low concentration, which is moving __________ the concentration gradient.

down

Active transport requires energy and moves solute from low concentration to high concentration, which is moving __________ the concentration gradient.

against

__________ transport uses vesicles to move large molecules or several molecules in bulk.

Vesicular

Being within __________ of a capillary reduces diffusion time.

$$100\,\mu m$$

Lipid-soluble or hydrophobic substances such as urea, $O_2$, and __________ cross the membrane via simple diffusion without assistance.

$$CO_2$$

Facilitated diffusion uses membrane proteins that change shape to transport larger molecules such as __________ and amino acids.

glucose

A __________ channel opens when a ligand binds to a receptor on the channel protein.

ligand-gated

A __________ channel opens when the membrane potential reaches a specific value.

voltage-gated

Osmosis is the passive transport of water from an area of __________ solute concentration to an area of high solute concentration.

low

In a __________ solution, there is lower solute concentration outside the cell, causing water to enter and the cell to swell.

hypotonic

In a __________ solution, there is higher solute concentration outside the cell, causing water to leave and the cell to shrink.

hypertonic

Primary active transport directly uses __________ to move solutes against their concentration gradient.

ATP

The Na+/K+ pump moves $3\text{ Na}^+$ out of the cell and __________ into the cell.

$$2\text{ K}^+$$

__________ active transport uses indirect energy by coupling the down-gradient movement of one molecule to move a second molecule against its gradient.

Secondary

A membrane carrier that moves two solute types in the same direction is called a __________.

symport

A membrane carrier that moves two solute types in opposite directions is called an __________.

antiport

During vesicular transport, __________ brings material into the cell while exocytosis sends material out.

endocytosis

Total Body Water (TBW) is divided into ICF, which makes up $\text{67}\%$, and ECF, which makes up __________.

$$\text{33}\%$$

Inside the cell, intracellular fluid (ICF) has a high concentration of __________.

$$K^+$$

Extracellular fluid (ECF) is split into interstitial fluid, which accounts for $\text{80}\%$, and plasma, which accounts for __________.

$$\text{20}\%$$