Midterm 2 Flashcards
1
Q
What is direct intercellular communication
A
gap junctions, membrane nanotubes, mechanosignals
2
Q
What is indirect intercellular communication
A
chemical messengers (indirect because no contact is required between cells, only synapse)
3
Q
What are types of gap junctions
A
connexons and intercalated discs
4
Q
What are connexons
A
subunits that form a channel (gap junction)
5
Q
What are intercalated discs
A
the gap junction units found in cardiac cells
6
Q
What are nanotubes
A
formed from the plasma membrane
- longer than gap junctions and have larger pore diameter
7
Q
What is mechanosignal transduction
A
direct physical stress to cells that elicits a response
8
Q
What is paracrine signalling
A
cell communication between two nearby cells via indirect signalling
9
Q
What are neurotransmitters
A
signalling molecules between neurons and target cells
10
Q
What are hormones in relation to cell signalling
A
indirect signalling where cell secretes a hormone to the blood stream that targets a specific cell via a receptor
11
Q
In what two ways can an endocrine cell release a hormone
A
exocytosis and diffusion
12
Q
What are hydrophilic messengers in hormone secretion
A
water-loving; secreted via exocytosis
- dissolves in plasma (no hatred to water) so no need for carrier
13
Q
What are hydrophobic messengers in hormone secretion
A
water-hating; secreted via diffusion
- cannot dissolve in plasma (hates water) so carrier is needed
- binds to a carrier lipid in the blood to be carried to target
14
Q
Which of the two (hydrophilic and hydrophobic) hormone messengers are more prevalent in the body
A
hydrophilic (<99%)
- hydrophobic hormones requiring a carrier have limited storage so they are only really made on demand
15
Q
What makes cell-cell signalling specific
A
receptor specificity (cannot bind to a receptor that does not match)
16
Q
What is the function of hydrophobic chemical messengers
A
binds to cytosolic or nuclear receptors and turns genes on to make new proteins
17
Q
What is the function of hydrophilic chemical messengers
A
bind to cell surface to alter the activity of existing enzymes/proteins
18
Q
Where does amplification occur in hydrophobic chemical messenger cell signalling
A
hormone/receptor complexes are formed to amplify the amount of protein synthesized (ie. if mRNA is the target, the complex elicits a response to synthesize mRNA but can cause many mRNA to be formed just with one complex - amplification!)
also many proteins are formed from the amplified amounts of mRNA, so this is another form of amplification!
19
Q
Where does amplification occur in hydrophilic chemical messenger cell signalling
A
one messenger/receptor complex binds numerous G proteins - amplification!
each G protein activates an adenyl cyclase - amplification!
adenyl cyclase synthesizes hundreds of cAMP molecules - amplification!
each cAMP activates a protein kinase A - amplification!
protein kinase A phosphorylates hundreds of proteins - amplification!
*in essentially every step of this process amplification occurs!
20
Q
Since hydrophilic chemical messengers synthesize such amplified amounts of protein, what is an important occurrence
A
signal must be turned off to prevent the overproduction of proteins
21
Q
Which chemical signalling pathway has fast duration of response and which has long duration of response
A
hydrophilic - fast
hydrophobic - slow
22
Q
What two factors play a role in the neuroendocrine signalling system (don’t overcomplicate this)
A
neural signalling and endocrine (hormone) signalling
23
Q
What is the secretory cell in neuroendocrine signalling
A
neuron
24
Q
What is the messenger in neuroendocrine signalling
A
neurotransmitter (neurohormones)
25
What is the pathway in neuroendocrine signalling
bloodstream
26
What are the target cells of the neuroendocrine system
endocrine cells
27
Where is specificity found in the neuroendocrine system?
receptors are specific to given neurohormones
28
Does the neuroendocrine system have immediate or delayed onset of response
delayed - but longer duration once in effect
29
Where do the messengers originate in the neuroendocrine system and where do they travel, what is the final destination
begin in a neuron, neurohormones are released into the bloodstream and travel to target cells that hold the specific receptor
30
What is the time to onset effect in the nervous system independently
immediately, and brief effect
31
What is the time to onset effect in the endocrine system independently
delayed, but duration is long
*neuroendocrine response mimics that of the endocrine system*
32
What are chloride and sodium channels regulated by
protein kinase (and cAMP)
33
What is an example of disease that occurs as a result of signal not being turned off in cell-signalling pathways
cholera - a toxin that causes life-threatening diarrhea
- activates G proteins for prolonged periods so signal does not shut off, causing excess influx of Cl-, Na+ and water
34
What is the relationship between cystic fibrosis and cholera that we learned in relation to cell-signalling pathways
cholera = when signal is not shut off and influx of chloride and sodium occur
cystic fibrosis = less water loss (thicker fluids)
therefore, if someone with cystic fibrosis were infected with cholera, it is likely they would be less impacted due to the combating defects in cell signalling
35
What is a regulated healthcare professional
governed by a regulatory body
- ie. doctor, nurse practitioner, registered dietitian, pharmacist, etc.
36
What is an unregulated healthcare professional
not governed by a regulatory body
- ie. traditional Chinese medicine, acupuncture, herbal medicine, naturopath, etc.
37
What is an example of a public health profession
epidemiologist, infectious disease specialist, public health dietitian, etc.
38
What are other career options related to biological concepts of human health not within the regulated and unregulated professional categories
research, education, industry worker, etc.
39
What are the components of the central nervous system (CNS)
brain and spinal cord
40
What are the components of the peripheral nervous system (PNS)
somatic and autonomic nervous system
41
What are the 4 components of the control and communication network
central nervous system, peripheral nervous system, endocrine system, and local support and defence (immune)
42
What is the pathway of input/output in the central nervous system
sensory input (ie. external stimuli, sensory receptors on the skin, sensory receptors on internal organs, etc.), to central nervous system, leading to motor output either in somatic (voluntary) or autonomic (involuntary) systems
43
What are the 5 major cell types of the CNS
neurons, oligodendrocytes (CNS)/Schwann cells (PNS), astrocytes, microglia, & ependymal cells
44
What are dendrites
branched structure on neuron ends that receive signals from previous neurons and send to rest of neuron to be passed on
45
What is an axon
takes the signal from dendrites and cell body and moves it to axon terminal to be passed on
46
What is the axon terminal
the end of a neuron where the signal is passed on via a synapse
47
What does multiple sclerosis have to do with neurons
destruction of the myelin sheath occurs in this disease, causing slower nerve signalling
48
Do neurons typically release one neurotransmitter type or various at a given pre synaptic neuron
usually only one type
48
What is the myelin sheath
myelination of the axon of a neuron that causes the signal to jump down the axon, increasing the speed of signal transmission
49
What happens when the impulse reaches the end of the axon terminal
synapse is formed
50
What is a synapse
space between the axon terminal of one neuron and the dendrites of the next neuron, or the membrane of the target cell, where neurohormones are released from the axon terminal and travel to the target
51
What is an excitatory response
when release of the neurotransmitter increases a response or function
52
What is an inhibitory response
when release of the neurotransmitter decreases a response or stops it
53
What if the signal does not reach threshold level
action potential cannot occur
54
What is important to know about the occurrence of action potentials in neurons
it is an all-or-none response, meaning if threshold is not met, nothing happens
55
What determines whether threshold is met
the summation of net response of all excitatory and inhibitory effects
56
What occurs in age 10 related to neurons
begin to diverge, converge, and form networks
57
What is the diverging, converging, and network formation called in neurons
networking
58
What is increased during networking
myelination
59
What is the association between impulsivity and teenagers in relation to neuron function
increased myelination in networking, which occurs beginning in early teen years, so quicker signalling could explain impulsivity
60
What system are oligodendrocytes found in
CNS
61
What system are Schwann cells found in
PNS
62
What is the function of oligodendrocytes and Schwann cells
form the myelin on axons
63
What are the nodes of ranvier
the spaces in between myelinated parts of the axon where the signal jumps to
64
What is the difference in the function of oligodendrocytes in the CNS and Schwann cells in the PNS
oligodendrocytes - span and support numerous axons
Schwann cells - only span and support 1 axon
*refer to slide 12 of lecture 9 for visual*
65
What are astrocytes
*star-shaped cells important in communication
- coordination of function of the blood-brain barrier (BBB)
- coordination of function at nodes of ranvier
- coordination of function of brain network
- form tripartite synapses with neurons
- serve as "super-hubs" for neural networks via syncytium formation and calcium signalling
66
What is the blood brain barrier
the barrier of what molecules can flow to the brain and what cannot
67
What are microglia
macrophage-like immune cells
68
What are ependymal cells
lines ventricle to form a barrier, and forms cerebrospinal fluid
69
What neural cell type is important in communication and function of blood brain barrier
astrocytes
70
What neural cell type is important in forming myelin in CNS
oligodendrocytes
71
What neural cell type is important in forming myelin in PNS
Schwann cells
72
What neural cell type is important in forming cerebral spinal fluid
ependymal cells
73
What neural cells are macrophage-like immune cells
microglia
74
What gets through the BBB
mostly very small lipid-soluble compounds (fatty acids), caffeine, alcohol, glucose (with a specific glucose transporter), etc.
75
What is the limitation with pharmaceuticals in relation to the blood brain barrier
issue with producing drugs small enough and capable of crossing the BBB to effectively work
76
Who is an important individual in the understanding of the brain networks (think pole through the brain and change in personality)
Phineas Gage
77
What are brain networks responsible for producing per individual
emergent properties
78
What are examples of emergent properties derived from different brain networks
personality, rational decision making, emotion processing, etc.
79
What does PET scan stand for
positron emission tomography
80
What does a PET scan do
uses gamma rays to track glucose uptake in the brain via a glucose tracer
81
What does fMRI stand for
functional magnetic resonance imaging
82
What does an fMRI scan do
tracks blood flow - when a region of the brain is in high demand for a given activity/occurrence, it is in high demand of oxygenated blood
oxygenated and deoxygenated blood impact the magnetic properties of hemoglobin, so when magnetic properties change the blood can be tracked in varying regions
83
What is norepinephrine responsible for
attention, arousal, sleep-wake
84
What is serotonin responsible for
happiness, mood, sleep-wake
85
What is acetylcholine responsible for
learning, memory, etc
86
What is dopamine responsible for
motor control, reward, pleasure, etc.
87
What network do psychostimulants exert their effects through
norepinephrine networks
88
What network do antidepressants exert their effects on
serotonin networks (increase serotonin to increase happiness)
89
What neurohormone is seen in low levels of Alzheimers patients and why
acetylcholine
- related to memory and learning, so in low levels, memory and learning is impaired (as in Alzheimers)
90
What neurohormone is seen in low levels in Parkinsons disease and why
dopamine
- related to motor control, so in low levels, motor control is impaired (as in Parkinsons)
91
What neurohormone is involved in the "pleasure network"
dopamine
92
What network is typically associated with addiction
pleasure network: dopamine
93
What two things can the dopamine network be increased by
addictive drugs
natural endorphins (ie working out)
94
Is dopamine excitatory or inhibitory
excitatory
95
How does cocaine impact the release of dopamine
dopamine, a neurohormone, is released from the axon terminal but cannot bind to the receptors due to the inhibitor protein GABA, so the dopamine exhibits reuptake back into the axon terminal
96
How do heroine and morphine impact the release of dopamine
block the release of inhibitory protein GABA so more dopamine can be released than normal (reuptake does not occur but a surplus in dopamine release occurs)
97
What is seen in PKU patients who dont eat excess phenylalanine / protein
decreased dopamine and serotonin
98
What are some possible health implications/concerns involving PKU patients
higher levels of depression and anxiety due to decreased dopamine and serotonin
99
What is the role of hormones in the body
growth/development
homeostasis
reproduction
100
Where do hormones come from
endocrine glands
nerves
organs (produce hormones as their secondary function)
adipose tissue
muscle
101
What are the signalling molecules called when nerves release their hormones directly into the bloodstream?
neurohormones
102
What are neurohormones
neurotransmitters with downstream effects on hormone secretion
103
What is the difference between neurotransmitters and neurohormones
neurotransmitters: transmit signals to nearby cells via synapses
neurohormones: transmitted directly into bloodstream by neurons
104
What is the posterior pituitary vs the anterior pituitary
posterior = back of body
anterior = front of body
105
What two hormones are the main release focus of the posterior pituitary
oxytocin (OT) and antidiuretic hormone (ADH)
106
Where are the hormones made that are released by the posterior pituitary
the hypothalamus
107
What is low oxytocin associated with
higher levels of perceived pain as well as stress, depression and anxiety
108
What is the function of oxytocin
social cognition and behaviour
109
What is the function of antidiuretic hormone?
blood pressure regulation
110
When is increased antidiuretic hormone seen
heart failure and severe blood loss (to compensate for the reduced blood flow)
111
What does the anterior pituitary act as
a gland (releases many different types of hormone
112
What is WADA
world anti-doping agency
113
What drug was banned according to WADA up until 2004
caffeine
114
Why are steroids dangerous to the body
the effects are superphysiological, meaning they are beyond the scope of a natural response in the body
115
What does it mean for hormones to be used as ergogenic aids
increase performance, energy, ability, etc.
ie. steroids are examples of hormones used as ergogenic aids
*many are banned due to health risk
116
What levels of defence are non specific
first and second lines of defence
117
What levels of defence are specific
third line of defence
118
What levels of defence does the innate immune system consist of
first and second levels
119
What levels of defence does the adaptive immune response consist of
third level
120
What makes up the first line of defence
physical barriers (ie. skin, tears, saliva, and internal organs unrelated to the immune response
121
What makes up the second line of defence
internal resident cells, proteins, inflammation, and fever response
- remember this is NON SPECIFIC so memory is not formed
122
What are examples of defensive cells in the second line of defence
phagocytic cells: neutrophils and macrophages
eosinophils
natural killer cells
123
What are examples of defensive proteins in the second line of defence
interferons
complement system
124
What is inflammation
widening of blood vessels and increased capillary permeability
- leads to redness, heat, swelling, and pain
125
What is a fever
abnormally high body temperature caused by infection, the body's defence to slow the growth of bacteria and speed up body defences
126
What is cell-based defence
first phagocytes enter to consume bacteria or other invading molecules
eosinophils release signalling molecules for other immune cells
natural killer cells weaken the foreign cells to destroy them using perforin and proteases
127
What is perforin in relation to natural killer cells
released by natural killer cells
- form pores
128
What are proteases in relation to natural killer cells
released by natural killer cells
- cuts peptide bonds
129
What is the protein based response in the second line of defence
lysis of foreign cells via the complement system
130
What are the 4 key signs of inflammation
redness, swelling, heat, pain
131
What does redness mean/do in inflammatory response
blood flows, transporting defensive cells to damaged tissue, to remove toxins
132
What does the heat mean/do in inflammatory response
increases metabolic rate of cells in the injured area
133
What does the swelling mean/do in inflammatory response
fluid containing defensive chemicals, clotting factors, oxygen, nutrients, and defensive cells, seeps into injured area
134
What does the pain mean/do in inflammatory response
restricts movement, allowing injured area to heal
135
What is acute inflammation
bruises and torn tissue
136
What is chronic inflammation
disease states (arthritis, obesity, etc.)
- body is under constant state of inflammation
137
As the body works towards fever, cytokines build up, what is this state called
cytokine storm
138
What is the cytokine storm
cytokines that build up as body builds toward fever
139
What is the name for functional cells in the LSDS
parenchymal cells
140
What is the name for support cells in the LSDS
stromal cells
141
What are some examples of parenchymal cells
organs such as liver, heart, brain, pancreas, as well as skeletal muscle and adipose tissue
142
What are some examples of stromal cells
astrocytes, capillary endothelial cells, cells of lymphoid, cells of myeloid, fibroblasts, stem cells, gap junctions
143
What cells are more prominent; parenchymal or stromal
parenchymal (functional)
144
What do stromal cells look like
branched in nature
145
Is the LSDS always on or turned on and off
always on!
think of it as on and waiting, not always at peak function but is always on and ready for invaders
146
If the LSDS is always on, what is it doing when infection is not occurring
response to damage unrelated to infection
normal tissue turnover (cell death and tissue repair)
looks out for transformed cell appearances (ie. cancer)
147
What does LSDS stand for
local support and defence system,
148
In the third line of defence, what markers are used to identify self and foreign cells
MHC (major histocompatibility complex) markers
149
Do MHC markers display self or non self antigens
both!
150
If a cell presents non-self MHC markers, what occurs
would cause immune cells to attack because they recognize the cell as foreign
151
What are the 7 steps of the third line of defence
step 1: invader enters
step 2: macrophage encounters the invader and digests it
step 3: macrophage presents both self and non-self MHC markers to helper T cells
step 4: alarm to initiate B cell or T cell response
step 5: building specific defences
step 6: defence
step 7: continued surveillance
152
What is the antibody-mediated response
the B cell response
153
What is the cell-mediated response
the T cell response
154
What is the route of cell-based immunity (T cell)
effector T cells activate naive cytotoxic T cells, which divide and induce amplification, forming memory T cells and effector cytotoxic T cells
155
What is the route of antibody-based immunity (B cell)
effector T cells activates naive B cells, which divide and induce amplification, forming cytotoxic B cells that secrete antibodies to target pathogens outside of the cell
156
What memory cells are produced in the entirety of the third line of defence
memory helper T, memory cytotoxic T, and memory B
157
What is the importance of building memory cells
next time body encounters that specific disease, the immune response is much faster and more effective, lowering the effects of infection
158
What turns off the signal in the third line of defence
supressor T cells
159
Why is turning off the signal for third line of defence important
if signal is on too long, cells will start to attack self antigens, leading to autoimmunity
160
What is observed with too little suppressor T cells
autoimmunity
161
What is observed with too much suppressor T cells
increased incidence of infection and potential cancer
162
What are the three main components of the cardiovascular system
heart, blood vessels, blood
163
What other fluids (aside from blood) are affiliated with the cardiovascular system
lymph. cerebrospinal fluid, and extracellular fluid
164
What are the two systems of the circulatory system
cardiovascular and lymphatic
165
What are some examples of cardiovascular disease
coronary artery disease
stroke
heart attack
heart failure
hypertension
diabetes
166
What is hypertension
high blood pressure (hyper = increased)
167
Beginning with deoxygenated blood heading toward the heart, what is the pathway of blood flow in the cardiovascular system
deoxy blood flows into right atrium and right ventricle, leaving the heart via the venae cavae and heading toward the lungs
in the lungs, the blood travels from veins to venules to capillaries where gas exchange occurs and blood oxygenates
the blood leaves the lungs via arteries and travels back to the heart, entering the left atrium and left ventricle, and exiting via the aorta, down to the systemic circuit where the blood is then deoxygenated
the pathway then repeats in a continuous cycle
168
What are the thickest blood vessels and why
arteries - need to handle high pressures
169
What blood vessels have the highest surface area and for what purpose
capillaries - the site at which gas exchange occurs so large surface area is needed for maximum efficiency
170
What blood vessel is the main site of blood pressure regulation
arterioles
171
What blood vessel is the main site of lymphocytes
venules
172
What blood vessels are thin but muscular
veins
173
What is observed in atherosclerosis
build-up of plaque in the blood vessels, restricting blood flow and increasing risk for things such as CVD and stroke
174
Is velocity low or high in capillaries
low velocity but high surface area - optimal for gas exchange because it is a slow process over a large surface area
175
How is cardiac output calculate
heart rate x stroke volume
176
In resting blood flow, how is flow distributed across the body
evenly, no parts are at higher demand than others (at least not significantly)
177
In exercise blood flow, how is blood distributed across the body
blood flows to areas that need it most (ie skeletal muscle)
178
In veins, is blood moved toward or against gravity
against gravity
179
How is blood moved against gravity in veins
via a pressure gradient between left and right side of heart
180
How is the pressure gradient between left and right sides facilitated
expansion of thoracic cavity, contraction of skeletal muscles, and valves
181
What is an example of a valvular disorder
varicose veins
- valves malfunction and blood moves in opposite direction allowing for back flow and pooling
182
What is the longest vein in the body called
great saphenous
183
Where are varicose veins most prevalent
superficial veins in the thigh and calf
184
What makes cardiac muscle different than skeletal muscle
cardiac = involuntary (autonomic)
heart functions as one large unit due to fast gap junction neural conductions (whereas skeletal muscles act independently of one another (ie. arms and legs))
heart is much more resistant to fatigue than skeletal muscle (high oxidative capacity)
185
Why does cardiac muscle have such high oxidative capacity
lots of mitochondria - very fatigue resistant
186
What sound is made when AV valves are closing
LUB
187
What sound is made when semilunar valves are closing
DUB
188
Where in the heart is the lub sound synthesized
closing of AV valves, which are located between the atria and ventricles
189
Where in the heart in the dub sound synthesized
closing of semilunar valves, which are located after ventricles (pulmonary and aortic valves)
190
What is stenosis
narrowing of valves
191
What symptoms does stenosis cause
fatigue, shortness of breath, exercise intolerance, and in serious cases heart failure
192
What is the surgical solution to stenosis
heart valve replacement (very common)
193
What are some issues associated with heart valve replacements
durability
clot formation
can get stuck
resistance to flow
194
In biological valve replacements (ie pig valves) what is required
immunosuppressive drugs
- so the patients immune system doesn't reject the foreign cells
195
What is the relationship between age and CVD
age age increases, risk for CVD increases
196
What is the relationships between HDL and CVD
as HDL increases, risk for CVD decreases
197
What is the relationship between total cholesterol and CVD
as total cholesterol increases, risk for CVD increases
198
What is the relationship between smoking and CVD
if you smoke you are at greater risk for CVD
199
What is the relationship between systolic blood pressure and CVD
as your systolic BP increases (consistent increase over time), risk for CVD increases
200
What is the Framingham risk score (FRS)
a method that investigates health information to apply a score based on risk of CVD in a patient
