Lecture 3 - Chemical Signals in Animals Flashcards
1
Q
- system that conveys high-speed electrical signals along specialized cells called neurons
- these signals regulate other cells
A
nervous system
1
Q
what are the regulatory mechanisms
A
- nervous system
- endocrine system
2
Q
specialized cells in the nervous system
A
neurons
3
Q
secretes hormones that coordinate slower but longer-acting responses including reproduction, development, energy metabolism, growth, and behavior
A
endocrine system
4
Q
example of what the endocrine system coordinates
A
- reproduction
- development
- energy metabolism
- growth
- behavior
5
Q
- chemical signals that are secreted into the circulatory system and communicate regulatory messages within the body
- reach all parts of the body, but only target cells are equiped to respond
A
hormones
6
Q
only cell that respond to hormones
A
target cells
7
Q
example of a process that is regulated by hormones
A
metamorphosis
8
Q
two types of glands
A
- exocrine glands
- endocrine glands
9
Q
secrete chemicals into ducts and the effect is where the duct empties
A
exocrine glands
10
Q
ex. of exocrine glands
A
sweat glands
11
Q
secrete chemical messengers (hormones) into the blood for distribution throughout the animal’s body and bind to specific hormone receptors
A
endocrine glands
12
Q
what regulates the development of humans
A
various signaling pathways
13
Q
activates signaling pathways
A
specific signaling molecules
14
Q
where do hormones and other signaling molecules bind to
A
target receptors
15
Q
Different Intercellular Communication
A
- endocrine signaling
- paracrine signaling
- direct signaling
16
Q
- secreted molecules diffuse into the bloodstream and trigger responses in target cells anywhere in the body
- relatively slow
A
endocrine signaling
17
Q
signaling under endocrine signaling
A
neuroendocrine signaling
18
Q
neurohormones diffuse into the bloodstream and trigger responses
A
neuroendocrine signaling
19
Q
- secreted molecules diffuse locally and trigger a response in neighboring cells
- quick response
A
paracrine signaling
20
Q
signaling under paracrine signaling
A
- autocrine signaling
- synaptic/neuronal signaling
21
Q
secreted molecules diffuse locally and trigger a response in the cells that secrete them
A
autocrine signaling
22
Q
neurotransmitters diffuse across synapses and trigger responses in cells of target tissues
A
synaptic/neuronal signaling
23
Q
- for some signals to be recieved, the cells must be in direct contact
- signals are send either via interacting membrane proteins on two different cells, or through special cell-cell junctions
A
direct signaling
24
signaling under direct signaling
1. Juxtacrine signaling
2. signaling through gap junctions
3. signaling through plasmodesmata
25
involves contact between cells, in which a ligand on one cell surface binds to a receptor on the other.
juxtacrine signaling
26
types of secreted signaling molecules
1. local regulators
2. neurotransmitters
3. neurohormones
4. pheromones
5. hormones
27
- chemical signals that travel over short distances by diffusion
- help regulate blood pressure, nervous system function, and reproduction
local regulators
28
what do local regulators help regulate
- blood pressure
- nervous system function
- reproduction
29
two types of local regulators
1. paracrine signals
2. autocrine signals
30
act on cells near the secreting cell
paracrine signals
31
act on the secreting cell itself
autocrine signals
32
example of local regulators
1. growth factors
2. cytokines
3. nitric oxide (NO)
4. prostaglandins (PGs)
33
proteins and polypeptides that stimulate cell proliferation
growth factors
34
- proteins that bind to receptors on the surface of cells to activate the cells for proliferation and or differentiation
- rapid reproduction of a cell, part, or organism
proliferation
35
- small proteins that are crucial in controlling the growth and activity of other immune system cells and blood cells
- play a role in immune respones
cytokines
36
- 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
nitric oxide (NO)
37
nitric oxide (NO) when secreted by neurons
acts as a neurotransmitter
38
where are neutrotransmitters transmitted
across the synaptic cleft
39
nitric oxide (NO) when secreted by WBCs
kills bacteria and cancer cells
40
nitric oxide (NO) when secreted by endothelial cells
dilates the walls of blood vessels
41
form a single cell layer that lines all blood vessels and regulates exchanges between the bloodstream and the surrounding tissues.
Endothelial cells
42
where is nitric oxide released during erection
corpus cavernosum
43
forms most of the penis and contains blood vessels that fill with blood to help make an erection
corpus cavernosum
44
enhances the effect of nitric oxide
sildenafil (viagra)
45
what does sildenafil (viagra) do
inhibit phosphodiesterase type 5 (PDE5)
46
function of phosphodiesterase type 5 (PDE5)
degradation of cGMP in the corpus cavernosum
47
what is the role of cGMP
1. reduce concentration of Ca++
2. smooth muscle relaxation
3. increased blood flow into penis
4. erection
48
- modified fatty acids
- secreted by the placenta which 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)
prostaglandins (PGs)
49
different functions of prostaglandins (PGs)
1. stimulate uterine contractions
2. promote fever and inflammation
3. intensify sensation of pain
4. regulate aggregation of platelets (for blood clotting)
50
- secreted by neurons at many synapses
- diffuse a very short distance
- bind receptors on target cells
- play a role in sensation, memory, congition, and movement
neurotransmitters
51
example of roles that neurotransmitters play
- sensation
- memory
- cognition
- movement
52
example of a neurotransmitter
acetylcholine (ACh)
53
some examples of the functions of Acetylcholine
- memory
- muscle contraction
54
- secreted by neurosecretory cells
- diffuse from nerve cell endings into the bloodstream
neurohormones
55
secretes neurohormones
neurosecretory cells
56
example of a neurohormone
Vasopressin or antidiuretic hormone (ADH)
57
function of Vasopressin or antidiuretic hormone (ADH)
- increase water permeability of kidney's collecting ducts
- causes vasoconstriction
58
chemical signals that are released from the body and used to communciate with other individuals in the species
pheromones
59
example of function of pheromones
1. mark trails leading to food
2. defining territories
3. warning of predators
4. attracting potential mates
60
- chemicals that transfer information and instructions between cells in animals and plants
- body's chemical messenger
- regulate growth and development
- control the function of various tissues
- support reproductive functions
- regulate metabolism
- slow acting but long lasting
hormones
61
hormones are slow __ but long __
slow acting, long lasting
62
two types of feedback regulation
1. negative feedback
2. positive feedback
63
inhibits a response by reducing the initial stimulus, thus preventing excessive pathway activity
negative feedback
64
reinforces a stimulus to produce an even greater response
positive feedback
65
the same hormone may have __ __ on target cells
different effects
66
how can hormones have different effects on target cells
different
1. receptors
2. signal transduction pathway
3. proteins for carrying out the response
67
effect of epinephrine in liver cell vs skeletal muscle blood vessel (same receptors)
liver cell = glycogen breaks down, glucose released
skeletal muscle blood vessel = dilation
68
effect of epinephrine in skeletal muscle blood vessel vs intestinal blood vessel (different receptors)
skeletal (α receptor) = dilation
intestinal (β receptor) = constriction
69
different signal-transduction pathways in different cells can lead to __ __ to the same signal
different responses
70
example of different response to the same signal due to differences in signal-transduction pathways
acetylcholine
1. skeletal muscle contraction
2. heart muscle relaxation
3. endocrine cell secretion
71
Three major classes of hormones in vertebrates
1. polypeptides
2. amines
3. steroid
72
polypeptide hormone example
- oxytocin
- insulin
73
amine hormone examples
- norepinephrine
- triiodothyronine
74
steroid hormones example
cortisol
75
water-soluble hormones
- polypeptides
- amines
76
lipid-soluble hormones
- steroid hormones
- other largely non-polar hormones
77
secreted by exocytosis, travel freely in the bloodstream, and bind to cell-surface receptors
water-soluble hormones
78
how are water-soluble hormones secreted
exocytosis
79
how do water-soluble hormones travel
freely in the bloodstream
80
how are water-soluble hormones received
bind to cell-surface receptors
81
- diffuse across cell membrane
- travel in the bloodstream bound to transport proteins
- diffuse through the membrane of target cells
lipid-soluble hormones
82
how do lipid-soluble hormones exit cells
diffusion across cell membrane
83
how do lipid-soluble hormones travel
bound to transport proteins in the bloodstream
84
how are lipid-soluble hormones received
diffuse through membrane of target cells
85
where do water-soluble hormones bind
receptors in plasma membrane of target cells
86
where do lipid-soluble hormones bind
receptors in cytoplasm or nucleus of target cells
87
response caused by water-soluble hormones
triggers the release of messenger molecules that activate enzymes
88
response caused by lipid-soluble hormones
- change in gene expression
- transcriptional regulator of specific target genes
89
Four key events in signaling of hormones
1. reception
2. signal transduction
3. amplification
4. response
90
detection of a signal in the environment
reception
91
increase in the intracellular concentration of a secondary messenger molecule
amplification
92
activating a series of proteins inside the cell
signal transduction
93
change in behavior that occurs inside the cell
response
94
refers to the duration of time required to decrease the concentration of a circulating hormone by half
half life of a hormone
95
two factors influencing the hormone concentrations in the blood
rate of hormone secretion and removal in the blood
96
rate of removal of the hormones from the blood
metabolic clearance rate
