Body Control and Regulation

Question 1

What are the two types of stimuli that can initiate a response in the body?

Answer 1

Stimuli can be intrinsic (such as blood glucose and blood pressure) or extrinsic (such as temperature, touch, and pain).

Question 2

What internal effects are triggered by stimuli?

Answer 2

Stimuli drive internal effects that initiate a response, typically activating the nervous system, the endocrine system, or both, which signal other systems to respond to changes.

Question 3

What key parameters need to be controlled in the body?

Answer 3

The key parameters that need to be controlled include blood pressure, fluid volume, acid/base balance, temperature, and blood glucose levels.

Question 4

What are the two main types of receptors mentioned?

Answer 4

The two main types of receptors are physical receptors (like baroreceptors and thermoreceptors) and chemical receptors (such as those detecting nutrients, pH levels, and olfactory senses).

Question 5

What type of signal do baroreceptors detect?

Answer 5

Baroreceptors detect pressure.

Question 6

What is mechanosensation?

Answer 6

Mechanosensation refers to the detection of mechanical forces, which can be sensed through specific receptors like baroreceptors and hair cells.

Question 7

How is a signal transmitted after being detected?

Answer 7

Once detected, a signal can be relayed to have an effect through intracellular signalling, intercellular signalling, neural transmission, or through paracrine and endocrine signalling.

Question 8

What are the major targets for drug action in the signalling process?

Answer 8

Major targets for drug action include receptors (like ligand-gated and G protein-coupled receptors), ion channels, transporters, and enzymes.

Question 9

What types of ion channels are there?

Answer 9

There are voltage-gated ion channels, ligand-gated ion channels, mechanically gated ion channels, and always-open ion channels.

Question 10

What is the role of enzymes like cyclase in signal transduction?

Answer 10

Enzymes like cyclase form cyclic compounds, such as adenylate cyclase forming cyclic AMP from ATP, which play critical roles in intracellular signalling pathways.

Question 11

What is signal transduction, and how does it typically work?

Answer 11

Signal transduction is the process by which an external signal is converted into an internal effect within a cell, often involving activated signalling pathways and cascades, such as enzyme cascades.

Question 12

Can the same signalling molecule activate multiple receptors?

Answer 12

Yes, a signalling molecule can activate more than one type of receptor, and the effects may vary depending on the specific cell type involved.

Question 13

What are the two main categories of chemical signalling?

Answer 13

The two main categories of chemical signalling are paracrine signalling (local signalling to nearby cells) and endocrine signalling (long-distance signalling via hormones).

Question 14

What types of ion channels are classified as cationic and anionic?

Answer 14

Cationic ion channels allow the entry of cations such as potassium, calcium, and protons, while anionic ion channels permit the entry of anions, such as chloride.

Question 15

What is the role of transporters in cellular signalling?

Answer 15

Transporters facilitate the movement of substances across cell membranes and can be classified as exchangers, symporters, or antiporters, depending on their function.

Question 16

How do ligand-gated receptors operate?

Answer 16

Ligand-gated receptors open or close in response to the binding of a specific ligand (signal molecule), allowing ions to flow into or out of the cell, thereby triggering a cellular response.

Question 17

What effect do kinases have in signalling pathways?

Answer 17

Kinases are enzymes that add phosphate groups to other proteins (phosphorylation), which can activate or deactivate the target proteins and thus modulate cellular activities.

Question 18

What is an enzyme cascade in the context of signal transduction?

Answer 18

An enzyme cascade is a series of enzymatic reactions where the product of one reaction serves as the substrate for the next, amplifying the original signal and leading to a significant cellular response.

Question 19

What are nuclear receptors, and how do they function?

Answer 19

Nuclear receptors are a class of receptors that, upon binding to their ligands (such as hormones), translocate to the cell nucleus and regulate gene expression, influencing cellular functions.

Question 20

How do mechanical forces affect cellular signalling?

Answer 20

Mechanical forces, detected by mechanosensitive receptors, can initiate signalling pathways that influence cellular responses such as growth, differentiation, and migration.

Question 21

What is the significance of homeostasis in relation to the controlled parameters?

Answer 21

Homeostasis is the maintenance of stable internal conditions (like blood pressure, fluid volume, and temperature) despite external changes, ensuring the body functions optimally.

Question 22

Can the effects of a signal vary between different cell types?

Answer 22

Yes, the effects of a signal can be different in various cell types due to the presence of different receptors and signalling pathways activated within those cells.

Question 23

What is the primary function of thermoreceptors?

Answer 23

Thermoreceptors detect changes in temperature and help the body respond appropriately to maintain thermal balance.