Homeostasis

Question 1

Maintenance of relatively stable internal conditions

Answer 1

Homeostasis

Question 2

“homeo” means

Answer 2

same

Question 3

Regulates and maintains balance through hormonal signals

Answer 3

endocrine system

Question 3

“stasis” means

Answer 3

standard scale

Question 4

Responsible for analyzing and
responding to information.

Answer 4

Nervous system (brain)

Question 5

→ A disturbance in homeostasis results
in disease
→ Maintaining balance is vital for
normal physiological functions.
→ Disruptions can lead to conditions
like diabetes, where blood sugar levels are not properly regulated, or affect heart rate and blood pressure.

Answer 5

Homeostatic imbalance

Question 6

receptors send information to control center using what kind of pathway

Answer 6

afferent pathway

Question 6

→ Sensory neurons in the body that
detect or responds to changes in the
environment (stimuli)

Answer 6

Receptor

Question 7

→ Determines set point
→ Analyzes the information
→ Usually the brain, which processes
the information received and determines on the appropriate response to the stimulus

Answer 7

Control center

Question 8

Provides a means of response to the
stimulus

Answer 8

effector

Question 9

Includes most homeostatic control
mechanisms
→ Shuts off the original stimulus or reduces its intensity
→ This is the body’s way of reducing the intensity of a stimulus to restore balance. It works like a thermostat in a household.

Answer 9

Negative feedback

Question 9

information flows from control center to effector along what kind of pathway

Answer 9

efferent pathway

Question 9

This produces change in variable

Answer 9

Stimulus

Question 10

→ Rare in the human body
→ Increases the original stimulus to
push the variable farther
→ Reaction occurs at a fasterr ate

Answer 10

Positive feedback

Question 11

Homogenous mixture of two or more components

Answer 11

Solution

Question 12

Dissolving medium present in the larger quantity; the body’s main solvent is water

Answer 12

Solvent

Question 12

Solution inside the plasma membrane
Nucleoplasm and cytosol
→ Solution containing gases, nutrients
and salts dissolved in water

Answer 12

intracellular fluid

Question 13

components in smaller quantities within a solution

Answer 13

solutes

Question 14

→ Is a selectively permeable barrier
→ Controls what substances can pass
through it, allowing certain materials
in and keeping others out.

Answer 14

Plasma membrane

Question 14

→ Substances are transported across
the membrane without any input from the cell
→ Movement of molecules across the cell membrane without requiring energy (ATP).
→ Molecules move from areas of higher concentration to areas of lower concentration.

Answer 14

Passive transport

Question 14

→ Fluid on the exterior of the cell
→ Contains thousand of ingredients
such as nitrogen, hormones neurotransmitters, salts, waste products

Answer 14

extracellular fluid

Question 15

2 types of passive transport

Answer 15

Diffusion and osmosis

Question 16

→ The cell provides the metabolic
energy (ATP) to drive the transport
process
→ Molecules move from areas of lower
concentration to areas of higher concentration.

Answer 16

Active transport

Question 16

2 types of active transport

Answer 16

exocytosis and endocytosis

Question 17

Movement of small, soluble
molecules through the plasma membrane without energy.

Answer 17

diffusion

Question 18

Have the same solute and water concentrations as cells and cause no visible changes in the cell

Answer 18

Isotonic

Question 19

→ An unassisted process
→ Solutes are lipid soluble or small
enough to pass through membrane pores without the need for energy (ATP).

Answer 19

Simple diffusion

Question 19

highly polar water molecules easily cross the plasma membrane through _____

Answer 19

aquaporins

Question 20

→ Simple diffusion of water across a
selectively permeable membrane

Answer 20

osmosis

Question 21

Contain more solutes than the cells do; the cells will begin to shrink
→ There is greater concentration outside the cell; molecules always tend to a higher concentration

Answer 21

Hypertonic solutions

Question 21

in hypotonic solutions, water moves into the cell, causing it to swell. This is known as ______.

Answer 21

cytolysis

Question 21

In hypertonic solutions, water moves out of the cell causing it to shrink. This is called

Answer 21

plasmolysis

Question 22

molecules pass through the cell membrane via protein channels or carriers without the need for energy (ATP).

Answer 22

facilitated diffusion

Question 22

→ Water and solutes are forced through a membrane by fluid, or hydrostatic, pressure
→ A pressure gradient must exist that pushes solute-containing fluid (filtrate) from a high-pressure area to a lower-pressure area
→ This is critical for the kidneys to work properly

Answer 22

filtration

Question 22

→ Contain fewer solutes (more
water) than thee cells do; cells
will plump
→ Lower concentration of solutes
outside the cell

Answer 22

hypotonic

Question 23

Movement of molecules across the
membrane against their concentration gradient, which requires energy (ATP).

Answer 23

Active transport

Question 23

→ Necessary for nerve impulses
→ It uses ATP to transport sodium out of
the cell and potassium into the cell.
→ ATP phosphorylates the pump protein, causing a change in shape that moves sodium out of the cell. When the phosphate group is released, the protein returns to its original shape, allowing potassium to enter the cell.

Answer 23

sodium-potassium pump

Question 23

The _______ binds to the molecule, changes shape, and transports it across the membrane.

Answer 23

protein carrier

Question 24

→ substances are moved across the
membrane “in bulk” without actually
crossing the plasma membrane

Answer 24

Vesicular transport

Question 25

→ Mechanism cells use to actively secrete hormones, mucus, and other products
→ Material is carried in a membranous
sac called a vesicle that migrates to and combines with the plasma membrane
→ Contents of vesicle are emptied to the outside
→ The vesicle, containing proteins or other substances, moves to the plasma membrane. DOcking proteins on both the vesicle and the membrane ensure proper fusion, and the vesicle releases its contents outside the cell

Answer 25

Exocytosis

Question 26

→ The process by which the cell engulfs
external substances, forming a vesicle that detaches from the membrane and enters the cell.
→ Extracellular substances are enclosed (engulfed) in a membranous vesicle
→ Vesicle detaches from the plasma membrane and moves into the cell
→ Once in the cell, the vesicle typically fuses with a lysosome
→ Contents are digested by lysosomal enzymes
→ In some cases, the vesicle is released by exocytosis on the opposite side of the cell

Answer 26

endocytosis

Question 27

→ “Cell eating”
→ A form of endocytosis where pseudopods (extensions of the cell membrane) engulf large particles, such as bacteria, forming a vesicle inside the cell. This is a key mechanism for the immune system to remove invaders.

Answer 27

Phagocytosis

Question 28

The cell engulfs droplets of extracellular fluid, including dissolved
substances.

Answer 28

Pinocytosis

Question 29

→ A highly selective form of endocytosis
where specific molecules, such as hormones or nutrients, bind to receptors on the cell surface and are brought into the cell.
→ Method for taking up specific target molecules

Answer 29

Receptor-mediated endocytosis