Homeostasis and Signaling

Question 1

What are the key themes in physiology?

Answer 1

1. Homeostasis
2. Communication and movement across the cell.

Question 2

The tendency of organisms to regulate and
maintain relative internal stability.

Answer 2

Homeostasis

Question 3

Who are the 2 important scientists?

Answer 3

Claude Bernard (1872)
Walter B. Cannon (1871-1945)

Question 4

Maintaining stability/constant
conditions despite changes in the
environme

Answer 4

Homeostasis

Question 5

What are the 2 important systems of the body that maintains homeostasis

Answer 5

1. Nervous System
2. Endocrine System

Question 6

Signaling molecules (ligand) are released by ______________.

Answer 6

Signaling Cells

Question 7

The ligand binds to its specific ___________ on a ____________ inducing a conformational change in the receptor

Answer 7

receptor
target cell

Question 8

The study of the functions of living
organisms and how they are regulated and
integrated

Answer 8

Physiology

Question 9

Give some Basis of Physiological Regulation

Answer 9

1. A stable internal environment.
2. Homeostasis
3. Negative and Positive Feedback
4. Steady State and Equilibrium
5. Cellular Communication
6. Different modes of cell communication differ in terms of distance and speed.
7. Chemical signaling molecules (first messengers)
8. Receptors are the receivers and transmitters of signaling molecules.
9. Second messengers
10. Steroid and thyroid hormone receptors
11. Physiology

Question 10

A condition that does not change over
time,

Answer 10

Steady State

Question 11

Represents a balance between opposing
forces.

Answer 11

Equilibrium

Question 12

Feedback and Feed-Forward Control

➢ Negative feedback: promotes stability
➢ Feed-forward: _______________
➢ ________________: promotes a change
in one direction, often leading to
instability, disease, and sometimes death

Answer 12

anticipates change

Positive feedback

Question 13

The initiation of responses that counter deviations of a controlled variable from its
normal range and is

➢the major control process used to maintain a stable internal
environment.

Answer 13

Negative Feedback

Question 14

A flow of information along a closed loop

Answer 14

Feedback

Question 15

What are the three stages in the process of cell signaling or communication?

Answer 15

Reception
Transduction
Response

Question 16

What are the 3 Modes of Intercellular
Communication?

Answer 16

Nervous Signaling
Endocrine Signaling
Neuroendocrine Signaling

Question 17

What are the forms of Intracellular Signaling

Answer 17

1. Contact-dependent
2. Paracrine
3. Synapic
4. Endocrine

Question 18

The conduction of information along nerves occurs via action
potentials, and signal transmission between nerves or between
nerves and effector structures takes place at a ______________.

______________________is almost always mediated by the release of specific chemicals or neurotransmitters from the nerve terminal.

Answer 18

synapse

Synaptic transmission

Question 19

What are the concepts of Cell Communication?

Answer 19

1. Gap Junctions Provide a Pathway for Direct Communication Between Adjacent Cells
2. Cells May Communicate Locally by Paracrine and Autocrine Signaling
3. The Nervous System Provides for Rapid and Targeted Communication
4. The Endocrine System Provides for Slower and More Diffuse Communication
5. The Nervous and Endocrine Control Systems Overlap

Question 20

Give some growth factors that influence cell division, differentiation, and cell survival.

Answer 20

NGF - Nerve growth factor
EGF - Epidermal growth factor
PDGF - Platelet Derived Growth Factor
IGF - Insulin Like Growth factor

Question 21

In the molecular basis of cellular signaling, the pathway may include additional intracellular messengers, called __________________[.

Answer 21

second messengers.

Question 22

________ and _________ are involved in conversion of the signal into a physiological response.

Answer 22

transducers and effectors

Question 23

Signaling systems consist of receptors that reside either in the plasma membrane or within cells and are activated by a variety of extracellular signals or_____________.

Answer 23

first messenger

Question 24

What are the common second messengers?

Answer 24

1. Cyclic nucleotides such as
   cyclic adenosine mono phosphate (cAMP) and Cyclic guanosine monophosphate
   (cGMP)
2. inositol1,4,5-trisphosphate (IP3)
3. diacylglycerol (DAG)
4. Calcium

Question 25

Cellular receptors are divided into two general types. These are?

Answer 25

➢ cell-surface receptors ➢intracellular receptors

Question 26

A receptor that may work both fast and slow ; Always use “second messengers”

Answer 26

Cell-surface receptor

Question 27

In Intracellular receptors ➢Fast – alters _________ functions ➢Slow – alters ___________ expression

Answer 27

protein gene

Question 28

What are the 3 general classes of cell-surface receptors that have been identified?

Answer 28

➢G-protein-coupled receptors ➢ion channel linked receptors ➢enzyme-linked receptors.

Question 29

Intracellular receptors includes what?

Answer 29

➢steroid ➢thyroid hormone receptors

Question 30

What are the 4 Features of Signal transducing systems

Answer 30

1. Specificity 2. Amplication 3. Adaption/Desensitization 4. Integration

Question 31

What are the 2 types of intracellular signaling proteins that act as molecular switches

Answer 31

1. Signaling by phosphorylation 2. Signaling by GTP-binding protein

Question 32

What are the 5 ways in which target cells can become desensitized to a signal molecule?

Answer 32

1. G Protein Coupled Receptors 2. Ion Channel-Linked Receptors 3. Tyrosine Kinase Receptors 4. Calcium 5.

Question 33

What are the 5 ways in which target cells can become desensitized to a signal molecule?

Answer 33

1. G Protein Coupled Receptors 2. Ion Channel-Linked Receptors 3. Tyrosine Kinase Receptors 4. Calcium 5.

Question 34

____________ is necessary for normal cell function and survival of the organism.

Answer 34

A stable internal environment

Question 35

These are used to modulate the body’s responses to changes in the environment.

Answer 35

Positive and negative feedback

Question 36

___________ is essential to integrate and coordinate the systems of the body so they can participate in different functions.

Answer 36

Cellular communication

Question 37

they provide the major means of intercellular communication

Answer 37

Chemical signaling molecules (first messengers)

Question 38

________________ are important for amplification of the signal received by plasma membrane receptors.

Answer 38

Second messengers

Question 39

___________ and __________ are intracellular receptors that participate in the regulation of gene expression.

Answer 39

Steroid and thyroid hormone receptors

Question 40

For optimal cell, tissue, and organ to function in animals, several conditions in the internal environment must be maintained within narrow limits. What are these? ➢These include but are not limited to:

Answer 40

1. oxygen and carbon dioxide tensions 2. concentrations of glucose and other metabolites 3. osmotic pressure 4. concentrations of hydrogen, potassium, calcium, and magnesium ions 5. temperature

Question 41

With __________ and ________ signaling, a chemical messenger diffuses a short distance through the extracellular fluid and binds to a receptor on the same cell or a nearby cell.

Answer 41

autocrine and paracrine signaling

Question 42

Determined what type of signaling. 1. the release of a neurotransmitter at a synapse. 2. the transport of the hormone by the blood to a distant target cell. 3. the binding of the hormone to specific target cell receptors.

Answer 42

1. Neuron Signaling 2. Neuroendocrine Signaling 3. Endocrine Signaling

Question 43

Determined what type of nerve factor is mentioned. 1. enhances nerve cell development and stimulates the growth of axo 2. stimulate the proliferation of a wide variety of cells and mediate many of the effects of growth hormone 3. stimulates the proliferation of vascular smooth muscle and endothelial cells 4. enhances nerve cell development and stimulates the growth of axons

Answer 43

1. NGF 2. IGF 3. PDGF ;. EGF