Chemical Signals in Animals

Question 1

conveys high-speed electrical signals along specialized cells called neurons; these signals regulate other cells

Answer 1

Nervous System

Question 2

secretes hormones that coordinate slower but longer-acting
responses including reproduction, development, energy metabolism, growth, and behavior

Answer 2

Endocrine System

Question 3

are chemical signals that are secreted into the circulatory system and communicate regulatory messages within the body

Answer 3

Hormones

Question 4

reach all parts of the body, but only target cells are equipped to respond

Answer 4

Hormones

Question 5

secrete chemicals into ducts and the effect is where the duct empties; sweat glands

Answer 5

Exocrine glands

Question 6

secrete chemical messengers (hormones) into the blood for distribution throughout the animal’s body and bind to specific hormone receptors.

Answer 6

Endocrine glands

Question 7

In humans, our development is regulated by various ____

Answer 7

signaling pathways

Question 8

These signaling pathways are activated by _____.

Answer 8

specific chemical signaling molecules

Question 9

Hormones and other signaling molecules bind to ____, triggering specific response pathways

Answer 9

target receptors

Question 10

___ bind to receptor proteins on target cells

Answer 10

Chemical signals

Question 11

Only ____ respond to the signal

Answer 11

target cells

Question 12

Intercellular Communication

Answer 12

Endocrine Signaling
Paracrine Signaling
Direct Signaling

Question 13

Endocrine Signaling

Answer 13

Neuroendocrine Signaling

Question 14

Paracrine Signaling

Answer 14

1.Autocrine Signaling
2.Synaptic Signaling

Question 15

secreted molecules diffuse into the bloodstream and trigger responses in target cells anywhere in the body. Relatively slow.

Answer 15

Endocrine Signaling

Question 16

neurohormones diffuse into the bloodstream and trigger responses

Answer 16

Neuroendocrine signaling

Question 17

secreted molecules diffuse locally and trigger a response in neighboring cells. Quick response.

Answer 17

Paracrine Signaling

Question 18

secreted molecules diffuse locally and trigger a response in the cells that secrete them

Answer 18

Autocrine Signling

Question 19

neurotransmitters diffuse across synapses and trigger responses in cells of target tissues

Answer 19

Synaptic /Neuronal Signaling

Question 20

for some signals to be received, the cells must be in direct contact. Either via interacting membrane proteins on two different cells, or through special cell-cell junctions.

Answer 20

Direct Signaling

Question 21

Types of Secreted Signaling Molecules

Answer 21

Local Regulators
Nerotransmitters
Neurohormones
Pheromones
Hormones

Question 22

chemical signals that travel over short distances by diffusion

Answer 22

Local Regulators

Question 23

help regulate blood pressure, nervous system function, and reproduction

Answer 23

Local Regulators

Question 24

Local Regulators divided in two types

Answer 24

Paracrine
Autocrine

Question 25

signals act on cells near the secreting cell

Answer 25

Paracrine

Question 26

signals act on the secreting cell itself

Answer 26

Autocrine

Question 27

proteins and polypeptides that stimulate cell proliferation

Answer 27

Growth Factors

Question 28

play a role in immune responses

Answer 28

Cytokines

Question 29

Nitric oxide (NO)

Answer 29

-acts as a neurotransmitter when secreted by neurons -kills bacteria and cancer cells when secreted by WBCs -dilates the walls of blood vessels when secreted by endothelial cells

Question 30

enhances the effect of NO by inhibiting phosphodiesterase type 5 (PDE5), which is responsible for the degradation of cGMP in the corpus cavernosum

Answer 30

Sildenafil (Viagra)

Question 31

Prostaglandins (PGs)

Answer 31

-modified fatty acids -secreted by the placenta stimulate uterine contractions during childbirth -promote fever and inflammation and intensify the sensation of pain -regulate aggregation of platelets (early step in blood clot formation)

Question 32

Signaling Molecules: Neurotransmitters

Answer 32

-secreted by neurons at many synapses -diffuse a very short distance -bind receptors on target cells -play a role in sensation, memory, cognition, and movement - Acetylcholine (ACh) – muscle contraction

Question 33

Signaling Molecules: Neurohormones

Answer 33

-secreted by neurosecretory cells -diffuse from nerve cell endings into the bloodstream -ADH (vasopressin) – increases water permeability of kidney’s collecting ducts and causes vasoconstriction (ADH)

Question 34

secreted by neurons at many synapses

Answer 34

Signaling Molecules: Neurotransmitters

Question 35

secreted by neurosecretory cells

Answer 35

Signaling Molecules: Neurohormones

Question 36

chemical signals that are released from the body and used to communicate with other individuals in the species

Answer 36

Signaling Molecules: Pheromones

Question 37

Pheromones

Answer 37

o mark trails leading to food o defining territories o warning of predators o attracting potential mates

Question 38

chemicals that transfer information and instructions between cells in animals and plants

Answer 38

Signaling Molecules: Hormones

Question 39

Hormones

Answer 39

o body’s chemical messengers o regulate growth and development o control the function of various tissues o support reproductive functions o regulate metabolism o slow acting but long lasting

Question 40

loop inhibits a response by reducing the initial stimulus, thus preventing excessive pathway activity

Answer 40

Negative Feedback

Question 41

reinforces a stimulus to produce an even greater response

Answer 41

Positive Feedback

Question 42

The same hormone may have different effects on target cells that have

Answer 42

o Different receptors for the hormone o Different signal transduction pathways o Different proteins for carrying out the response

Question 43

A hormone can also have ______ in different species

Answer 43

different effects

Question 44

Different ______ in different cells can lead to different responses to the same signal

Answer 44

signal-transduction pathways

Question 45

Three major classes of molecules function as hormones in vertebrates:

Answer 45

o Polypeptides (proteins and peptides) o Amines derived from amino acids o Steroid hormones

Question 46

water-soluble

Answer 46

polypeptides and amines

Question 47

lipid-soluble

Answer 47

steroid hormones and other largely non-polar hormones

Question 48

_____ hormones are secreted by exocytosis, travel freely in the bloodstream, and bind to cell-surface receptors

Answer 48

Water-soluble

Question 49

They bind to receptors in the plasma membranes of the target cells

Answer 49

Water-soluble

Question 50

has multiple effects in mediating the body’s response to short-term stress

Answer 50

epinephrine

Question 51

binds to receptors on the plasma membrane of liver cells

Answer 51

epinephrine

Question 52

triggers the release of messenger molecules that activate enzymes and result in the release of glucose into the bloodstream

Answer 52

epinephrine

Question 53

____ hormones diffuse across cell membranes, travel in the bloodstream bound to transport proteins, and diffuse through the membrane of target cells

Answer 53

Lipid-soluble

Question 54

They bind to receptors in the cytoplasm or nucleus of the target cells

Answer 54

Lipid-soluble

Question 55

response is usually a change in gene expression

Answer 55

Steroid Hormones

Question 56

_____ binds to its cytosolic receptor, a hormone-receptor complex forms that moves into the nucleus

Answer 56

steroid hormone

Question 57

receptor part of the complex acts as a ____ of specific target genes

Answer 57

transcriptional regulator

Question 58

Signaling by any of these hormones involves three key events:

Answer 58

oReception oSignal transduction oResponse

Question 59

detection of a signal in the environment

Answer 59

reception

Question 60

activating a series of proteins inside the cell

Answer 60

Signal Transduction

Question 61

change in behavior that occurs inside the cell

Answer 61

Response

Question 62

It is the multiplication of enzymes after signal tranduction

Answer 62

Amplification

Question 63

Chemical Messengers

Answer 63

Hormones

Question 64

Two factors influencing the hormone concentrations in the blood:

Answer 64

1. rate of hormone secretion into the blood 2.Rate of removal of the hormone from the blood.

Question 65

Clearance of hormones from the plasma include:

Answer 65

1. Metabolic Reaction 2. Binding with the tissues 3.excretion by the liver into the bile. 4.Excretion by the kidney into the urine