Physiofuckology 2 Flashcards
1
Q
what are the 2 ways to regulate a metabolic pathway and what are the features of each
A
Gene regulation - slower, but allows way more product to be formed
End product feedback inhibition - quicker
if first product is not used then it inhibits the first enzyme , slowing down the whole pathway
2
Q
difference between magnetic resonance and diffusion weighted magnetic resonance imaging
A
magnetic resonance - used for diagnosing disease
diffusion weighted magnetic resonance - used for identifying connections
3
Q
What do the CNS and PNS include
A
CNS - spinal cord, brain
PNS - spinal nerves, cranial nerves, ganglia
4
Q
name the myelinating cells of the CNS/PNS and which is only found in the PNS
A
astrocyte oligodendrocyte microglia epyndemal cells only PNS - schwann cells
5
Q
difference between white and gray matter
A
white - axons reside in white matter
gray - cell bodies reside in gray matter
6
Q
what are the 4 brain divisions
A
cerebrum
diencephalon
cerebellum
brain stem
7
Q
what are the divisions of the cerebrum
A
frontal lobe
temporal lobe
parietal lobe
occipital lobe
8
Q
what is a sulci
A
the infoldings of the cerebrum that form valleys between gyri
9
Q
what is a gyri
A
ridges of the unfolded cerebral cortex
10
Q
in the cerebrum, which domain is responsible for what
A
frontal lobe - motor
parietal lobe - sensory
temporal lobe - auditory
occipital lobe - vision
11
Q
what is each hemisphere of the brain dominant in
A
left - language and math skills
right - visual-spatial skills and creativity
12
Q
what is homunculus
A
body is represented in an upside-down fashion in the sensory and motor cortices
13
Q
what is located in the diencephalon and what are their functions
A
thalamus - major relay station for sensory information entering the cortex from the brain stem and spinal cord
hypothalamus - autonomic control centre - homeostasis
14
Q
function of the brain stem
A
attaches spinal cord and cerebellum to the cerebrum
relay impulses between the cerebrum/diencephalon
15
Q
division of the brain stem and their functions
A
midbrain - eye movement, reflexes
pons - major relay area between cerebrum and cerebellum
medulla oblongata - control centre for many involuntary functions
16
Q
what protects the spinal cord
A
bone,meninges and CSF
17
Q
name the protective tissue layers and their features
A
dura - strongest, usually in contact with bone
arachnoid - adhered closely to dura, web-like in appearance
pia - deepest layer, in direct contact with CNS tissue
18
Q
what is CSF and what produces it and where is it located
A
cerebrospinal fluid - clear cell-free fluid
produced by the choroid plexus
located in the subarachnoid space
19
Q
what is the BBB composed of, and what does it allow to pass through it
A
blood-brain barrier is composed of endothelial cells and astrocytes
allows O2, CO2, and lipid soluble molecules (hormones)
prevents free diffusion of molecules larger than 500 daltons
20
Q
what divisions are in the motor system
A
visceral motor division
somatic motor division
21
Q
difference between afferent and efferent
A
afferent - carries info into the CNS
efferent - carries info away from the CNS
22
Q
difference between somatic and visceral
A
somatic - refers to the body wall and limbs
visceral - relates to internal organs
23
Q
what division of the nervous system controls the visceral aspects of the body
A
ANS - autonomous nervous system
24
Q
the visceral motor system can be divided into what?
A
sympathetic and parasympathetic nervous system
25
difference between a myotome and dermatome
myotome - provide sensory motor supply to an adjacent muscle mass
dermatome - cutaneous supply to an area of skin
26
steps of the reflex arc
receptor, sensory neuron, integration centre, motor neuron, effector
27
what does the spinal reflex show
somatic spinal reflex shows information on the integrity of the reflex arc and the level of excitability by the spinal cord
28
what is the resting membrane potential of a neuron
-70mV
29
what is the membrane potential of a neuron at step 1 of a membrane potential wave
-70mV - resting potential
30
what happens in step 2 of an action potential
membrane is passively depolarised
31
step 3 of action potential wave
voltage-gated Na+ channels open
| Na+ depolarises the membrane
32
step 4 of action potential wave
positive feedback loop of more Na+ that enters causing more voltage-gated Na+ channels to open
rapid depolarisation
33
step 5 of action potential wave
peak depolarisation is reached
Na+ channels begin to close
K+ channels begin to open
repolarisation begins
34
step 6 of action potential wave
Na+ channels closed
Ka+ channels open
rapid repolarisation back to resting membrane potential
35
step 7 of action potential wave
repolarisation undershoots the resting value
36
final step of action potential wave
Na+ channels de-inactivate
K+ channels close
returned back to resting potential
37
what is the absolute refractory period
right after the spike of depolarisation, the membrane is not excitable because the Na+ channels are closed
38
why are only a few ions required to activate an action potential
because the lipids in the membrane are a capacitor which store electrical charge
39
what does Na+/K+ ATPase do
pumps out 3 Na+ ions for every 2 K+ ions pumped in
40
function of ouabain
blocks Na+/K+ ATPase
41
why when a neuron is at rest does it have a high energy state
because at rest the Na+ are not at equilibrium
42
resting membrane potential is largely determined by what
the selective permeability of the membrane to K+ ions, mainly
43
what are transposable elements
mobile DNA elements that translocate from one part of the genome to another
44
what are the 2 major classes of transposable elements
```
class I - retrotransposons
class II - DNA transpososns
```
45
what is a titin filament
elastic filaments that run along the core of myosin and anchor it to the Z-line
46
what are the thin/thick filaments
thin - F-actin
| thick - myosin
47
where is mitochondria mainly located and why
I band
| close to the myosin and actin filaments
48
what is the structure of myosin
a dimer of 2 heads with intertwined tails
49
how does Ca2+ allow the myosin head to bind to the actin binding site
Ca2+ binds to the troponin which will cause the tropomyosin to move off the binding site
allows myosin head to bind to it
50
what is the connective tissue in smooth muscle called
endomysium
51
what releases the Ca2+ ions in a smooth muscle cell
calveole
52
function of Ca2+ activated calmodulin
activates myosin light chain kinase (MLCK)
53
how does phosphorylated MLCK allow myosin bind to actin
phosphorylated MLCK activates myosin ATPase
54
what do latch-bridges allow
allow for smooth muscle cell to maintain contraction even when Ca2+ is removed and myosin kinase is inactivated
55
what is a varicosity
varicosities are swollen regions found on an autonomic neuron which lines multiple smooth muscle cells
they contain vesicles containing neurotransmitters which are released when an action potential passes the varicosity
56
visceral muscle is connected by what and why
gap junctions
| the muscle contracts as a single unit
57
what is the stress-relaxation response in visceral muscle
when a hollow organ is filled, the stretching induces a contraction in the visceral tissue
immediately followed by relaxation to prevent all contents from being expelled prematurely
58
what are multi-unit smooth muscle cells and where are they located
don't contain gap junctions, electrical impulses are limited to the originally stimulated cell
large blood vessels
respiratory airways
eyes
59
function of intercalated disks
gap-junctions which allow the spread of excitation
60
what is end-diastolic volume
the amount of blood that fills the ventricles from venous return
approx. 110-120ml
61
what is the ejection fraction
the fraction of end-diastolic volume ejected from the ventricles
approx. 60%
62
what is end-systolic volume normally and for a strong contraction
amount of blood left in the ventricle after systole
normal - 40-50ml
stronger - 10-20ml
63
equation for cardiac output
CO = (EDV - ESV) x HR
64
what are the global controls for heart regulation
autonomous nervous system
| Starling's law
65
what are the local controls for heart regulation
nitric oxide
| tissue pH
66
what causes an increase in K+ efflux and decreased Ca+ influx in the heart
parasympathetic neurones (ACh) signal to the muscarinic receptors on autorhythmic cells
67
what causes increased Na+ and increased Ca+ influx in the heart
sympathetic neurones (NAdr) signal to B1 receptors on autorhythmic cells
68
pressure difference / total peripheral resistance = ?
cardiac output
69
function of a sphincter
guard different sections and control movement through the digestive tract
70
name the 4 layers of the gastrointestinal tract
mucosa
sub mucosa
smooth muscle
serosa
71
what does the mucosa contain in the GI tract
transporting epithelial cells
connective tissue
nerve fibres
blood vessels
72
what does the submucosal contain
the submucosal plexis
73
features of smooth muscle in the gastrointestinal tract
important for lumen contraction
| contains myenteric plexus
74
name the accessory organs of the digestive system
salivary glands
pancreas
liver
gall bladder
75
what are phasal contraction and what cells do they apply to in the digestive system
produce slow wave potentials, cycle of relax-contract
| interstitial cells of cajal
76
what are tonic contractions and what cells do they apply to in the digestive system
long term contractions
| sphincter cells
77
function of the submucosal plexus
contains sensory neurones that receives signals from the lumen and control secretion
78
function of the myenteric plexus
controls motitlity
79
function of smooth muscle in tracheobronchial tree
increase resistance
| reduce dead space
80
function of cartilage in the tracheobronchial tree
increase dead space
| reduce resistance
81
what causes the saline layer in the tracheobronchial tree
pseudostratified mucociliary epithelium
82
what is the Hz that the specialised cilia beat at
20Hz
83
how many alveoli are contained in 2 lungs
300 million
84
what surrounds the lung in the thoracic cavity
pleural fluid
85
how is a negative pressure between the visceral surface of the lung pleura and the parietal pleura of the thoracic cavity achieved
continual transfer of fluid into the lymphatic channels
86
what is pleural pressure
pressure in the intrapleural space
| always slightly negative
87
what is alveolar pressure
pressure inside the alveoli
88
what is transpulmonary pressure
alveolar pressure - pleural pressure = transpulmonary pressure
89
what is the pleural pressure at the beginning of inspiration
-5cm
90
what is the pleural pressure at maximal inspiration
-7.5 cm of water
91
what is pneumothorax
when the lung collapses to its unstretched size
92
what does a lower compliance mean and what diseases cause this
lungs and thorax are harder to expand
pulmonary fibrosis
pulmonary oedama
93
how long does it take for blood to equilibrate with gases in a normal lung
0.2 seconds
94
how does increasing blood flow (perfusion, Q) effect O2 levels in the blood
has no effect
95
what can blood in lungs with oedema/fibrosis not do
reach full O2 saturation
| full CO2 release
96
effects of increasing pulmonary arterial blood pressure
increases blood flow speed through capillaries from 0.8 to 0.25 seconds
opens collapsed vessels in the lung, increasing overall alveolar perfusion
97
what is the pulmonary/systemic capillary pressure
pulmonary capillary pressure - 7mmHg
| systemic capillary pressure - 25mmHg
98
what are the 2 regulatory factors that determine O2/CO2 transfer between alveolus and tissue
rate of alveolar ventilation, V
| blood flow, Q
99
not all alveoli are equally ventilated, where is V and Q higher and lower in the lungs
upper lung - V is higher, Q is lower
| lower lung - V is lower, Q is higher
100
what is the ventilation perfusion ratio trying to achieve
balance between alveolar blood flow and alveolar ventilation
101
what is hypoxic vasoconstriction and why is it useful
when the pO2 drops in alveoli decreases, there is a decrease in blood flow to that alveoli
allows more blood to be directed towards alveoli with higher pO2
102
how does hypoxic vasoconstriction work
results of O2 sensitive K+ channels in the smooth muscle cell membranes in the arterioles
when low pO2, K+ channels close, causes the cell to depolarise and contract
causes arterioles to partially close
103
what does V/Q equal
0.8
104
how does hypoxic vasoconstriction maintain the ventilation perfusion ratio
V/Q < 0.8 in alveoli that has low pO2 but normal blood flow
after decreased blood flow the V/Q rises to about 0.8 again
matches the blood flow to gas exchange ability to minimise dead space
105
what is anatomical dead space
the volume of respiratory tract involved in conducting gas which isn't transferring blood
106
what is physiological dead space
portion of tidal volume not participating in gaseous exchange with pulmonary capillary blood
107
what is Henry's law
concentration of a gas in a liquid is determined by its partial pressure and its solubility coefficient
108
what is the equation to Henry's law
concentration dissolved = PP of gas x solubility
109
when saturated how much O2 does 1 gram of haemoglobin carry
1.3mls
110
what % oxygen is transported in haemoglobin and plasma
haemoglobin - 98.5%
| plasma 1.5%
111
at what partial pressure does the oxy-haemoglobin dissociation curve show that haemoglobin is fully saturated
80mmHg
112
what occurs during prolonged hypoxia (2-3hours)
more anaerobic glycolysis occurs
| 1,3-diphosphoglycerate and hence 2,3-biphosphoglycerate increases in blood and hence in RBC
113
what are the 4 factors that affect haemoglobin affinity for oxygen
H+ concentration (pH)
partial pressure of CO2
temperature
concentration of 2,3-diphosphoglycerate
114
what is the Haldane effect
central peptide of oxyhaemoglobin (lung) is a stronger acid than haemoglobin (tissue)
115
how is CO2 displaced in haemoglobin
H+ ions react at carbamino termini (-NH3) of Hb
116
when H+ ions react with the carbamino termini, what does the increased acidity cause
causes bicarbonate ions to form carbonic acid
| carbonic acid dissociates into H2O and CO2 which is then released into the alveoli
117
function of C anhydrase
aids in the dissociation of carbonic acid into water and carbon dioxide
118
how is CO2 transported and the % each mode contains
bicarbonate ions - 70%
blood proteins - 24%
plasma - 6%
119
how does plasma pH regulate breathing
a drop in plasma pH indirectly causes an increase in respiration rate to drive off CO2
120
what does the respiratory control centre consist of and where is it located
several groups of neurons
| located bilaterally in the medulla oblongata and pons
121
what does the dorsal respiratory group consist of and its function
dorsal medulla
| mainly causes inspiration
122
constituents and function of the ventral respiratory group
ventrolateral medulla
| modifies expiration and inspiration
123
location and function of the pneumotaxic centre
dorsally in the superior pons
| mainly controls rate and depth of breathing
124
what happens when the dorsal respiratory group is separated from the lower and higher inputs
causes the neurons to spontaneously burst
| leads to an intrinsic repetitive potential
125
location and function of the apneustic centre
located in the lower pons
| prevents turn off of the ramp signal
126
what is the apneustic centre regulated by
vagal input - stretching of the lung
| pneumotaxic centre
127
what does the pneumotaxic centre time
times the switch off point of the inspiratory ramp
128
what does a stronger signal from the pneumotaxic centre lead to
shorter inspiration - panting
129
what does the ventral respiratory area contribute to during heavy exercise and where does it send signals to
to both inspiration and expiration
| sends signals to abdominal muscles
130
together what do the respiratory control centres have
basic rhythmic activity - DRC
| regulatory activity - (pneumotaxic and apneustic centres)
131
to regulate lung activity, where from and to do signals reach and via what
several types of receptors in the lungs
peripheral chemoreceptors
transmit sensory signals through the glossophyrangeal nerves into the respiratory centres
132
in terms of respiratory regulation, what are cortical factors
voluntary respiratory control:
speech
swallowing
exercise
133
what stimulates the central chemoreceptors
the low pH in the cerebrospinal fluid
134
where is the chemo-sensitive area that detects H+ ions
in the medulla, lying directly under the pia
135
what is the Herring-Breuer reflex
stretch receptors on the walls of the lungs which send impulses to terminate inspiration
136
why is the Herring-Breuer reflex needed
prevents over expansion of the lung
| co-ordinates the pneumotaxic and apneustic centres
137
when do peripheral chemoreceptors play a role
only when blood oxygen levels fall too low
| pO2<70mmHg or 90% Hb saturation
138
how is dopamine released in response to low oxygen levels
carotid body chemoreceptors cells detect hypoxia
closes K+ channel leads to depolarisation
activated voltage-gated Ca2+ channels
results in exocytosis of dopamine
139
in terms of hypoxia, what is the effect of dopamine
increases the activity of the chemosensory afferent fibre
140
what is anaemic-hypoxia
low Hb content
| CO poisoning - competes for Hb to form HbCO complexes
141
what is stagnant-hypoxia
poor circulation
shock
congestive heart failure
142
what is histotoxic-hypoxia
inhibition of oxidative processes by poisons
| cyanide
143
how does cyanide kill
binds with cytochrome oxidase
| prevents O2 from acting as a final electron acceptor
144
what does the cephalic reflex stimulate
ECL cells
| parietal cells
145
what happens when acid acts on pepsinogen
pepsin is formed
146
what are zymogens
inactive enzymes secreted from the pancreas
147
name the zymogens secreted from the pancreas
```
trypsinogen
chymotrypsinogen
procarboxypeptidase
procolipase
prophospholipase
```
148
what activates trypsin and where is it located
enteropeptidase
| brush border of the intestinal mucosa
149
what enzymes does trypsin activate
chymotrypsin
carboxypeptidase
colipase
phospholipase
150
function of hepatocytes and give an example of a bile acid and bile pigment
produce and secrete bile
bile acid - detergent
bile pigment - bilirubin
151
difference between GLUT2 and GLUT5
GLUT2 - hexose transporter
| GLUT5 - fructose transporter
152
how is glucose transported from the small intestine into the blood
enters the intestinal mucosa from the lumen of the intestine with Na+ on SGLT
glucose then is transported in GLUT2
153
difference between endo and exopeptidase
endopeptidase - digests internal bonds in an amino acid chain
exopeptidase - digests from an amino acid chain from the terminals
154
how are amino acids absorbed into the small intestine
Na+ co-transport
155
how are di/tri-peptides absorbed into the small intestine
H+ cotransport
156
how are small peptides absorbed into the small intestine
endo/exocytosis
157
what is required for lipid emulsion and the product of it
bile
| micelles
158
how is iron transported in and out of cells
in - DMT1
| out - ferroportin
159
what are the ways Na+ can enter a cell
sodium channels
Cl- cotransport
proton pumps
160
where is primary lymphoid tissue found
bone marrow
| thymus
161
where is secondary lymphoid tissue found
spleen
| lymph nodes
162
features of innate immunity
immediate response
targets groups of pathogens
limited diversity of antigen receptors
no memory of pathogens
163
features of adaptive immunity
gradual response - over days
targets specific pathogens
highly diverse antigen receptors
produces immunological memory
164
what is the innate response to a virus
mucus
antigen presenting cells
phagocytes
cytokines
165
name the non-specific defences
```
skin
mucous membrane
temperature
pH
chemical mediators
phagocytic
inflammatory
```
166
name the non-specific chemical mediators
lysosomes
interferons
complement - lyses microbes
toll like receptors (TLRs)
167
what component of inflammation causes redness, swelling and heat
vasodilation
168
what is margination
attraction of blood monocytes and neutrophils into endothelial of venules
169
what is extravasation
emigration from the vessel between the endothelial cells into the tissue
170
what is chemotaxis
migration to the site of injury/invasion
171
what do monocytes differentiate into when they leave the bloodstream
macrphages
172
when is pathogen killing inititated
when the phagocytic vacuole fuses with the lysosome forming a phagolysosome
173
what does a phagolysosome release
oxygen radicals
chlorine products
nitric oxide pathway
174
what is NAHD oxidase and where is it located
a membrane bound enzyme complex
| faces the inner space of phagosomes
175
what are used to destroy lipid membrane and bacterial DNA
```
superoxide
hydrogen peroxide
chlorine
hypochlorite
hydroxyl radical
```
176
what does superoxide dismutase convert super oxide into
hydrogen peroxide
177
what converts hydrogen peroxide into hypochlorite
myeloperoxidase
178
what are pattern recognition receptors
the innate immune system uses these to detect repeating patterns on the surface of the microorganism
179
what are mannose receptors
binds to mannose residues on the pathogen surface
180
what are glycan receptors
binds to polysaccharides on the surface of bacteria and yeast
181
what are scavenger receptors
recognise complex sugars on bacteria and yeast
182
what are toll-like receptors (TLR)
bind to lipopolysaccharides (LPS) on the cell wall of gram negative bacteria
183
what are complement receptors (CR)
recognise complement covered structures on yeast and bacteria
184
function of TLR
signals to immune cells the type of pathogen that has invaded
185
what releases IL-12
macrophages
186
what is IFNy (gamma) stimulated by
IL-12
187
what does IFNy lead to
further macrophage activation
| leads to a feedback loop which amplifies the innate immune response
188
function of IL-1 and TNFalpha and what does this allow
induce endothelial cells to express adhesion molecules
| allows neutrophils and monocytes to leave the bloodstream
189
what is IL-8
a potent neutrophil chemoattractant
| activates macrophages
190
what interleukins increase endothelium permeability
TNFalpha
platelet activating factor (PAF)
PG
191
what is a complement
a group of plasma and cell membrane proteins that lead to the formation of a membrane attack complex and inflammation
bitches cant take em
192
what triggers the acute phase
if the reason for the inflammation is not eliminated, cytokines in the blood rise
causes a systemic acute phase
193
what does IL-1 cause in the brain
fever
sleepiness
anorexia
194
what does IL-6 do in the liver
stimulates hepatocytes to release many acute phase proteins
| these rise by 100-1000x
195
what is opsonisation and when does it occur
C-reactive proteins binds phosphocholine on pathogenic organisms and damaged cells to facilitate uptake
occurs during the acute phase
196
function of phospholipase C
hydrolyses negatively charged bacterial membranes
197
what are the cells of the adaptive immune response
B cells
CD4+T cells
CD8+T cells
198
what cell is active in the humuoral immune response
B cell
199
what cells are active during the cellular immune response
CD4+ T cells
| CD8+ T cells
200
where are T-lymphocytes derived from
thymus
201
where are B lymphocytes derived from
bursa of fabricus in bone marrow
202
what do B-lymphocytes produce
immunoglobulins - Ab antibodies
203
what are antibodies
opsonins that binds proteins, sugars and sometimes lipids
204
in terms of Daltons how heavy are the heavy and light chains of antibodies
heavy chain - 50-75kDa
| light chain - around 25kDa
205
what is the hinge region of an antibody composed of
prolines in an alpha-helical structure
206
what does an antibody bind to
a specific part of the antigen called an epitope
207
how big is the epitope
8-22 amino acids
208
what is avidity
binding of a whole antibody ( 2 or more epitope bindings)
209
difference between a monoclonal and polyclonal antibody
monoclonal - produced by 1 B-cell and recognises only one epitope
polyclonal - produced by multiple B-cells and recognises multiple
210
what are the 5 classes of antibodies
```
IgM
IgG
IgA
IgE
IgD
```
211
what is the most abundant antibody
IgG
| 70%
212
what are the first 3 functions of antibodies
1 - activates B-lymphocytes
2 - acts as opsonins to tag antigens for phagocytosis
3 - causes antigen clumping and neutralises pathogenic toxins
213
what are function 4-6 of antibodies
4 - activate antibody-dependant cellular activity
5 - activate complement
6 - trigger mast cell degranulation
214
specific function of CD4+T cells
immunity against intracellular bacteria and parasites
provides help to CD8+T cells
promotes humoural immune response
215
features of CD8+T cells
when activated they become cytotoxic
kill virally infected cells
kill tumour cells
216
where do all blood-borne immune cells originate from
hematopoietic stem cells (HSC)
217
what is hematopoiesis
formation of erythrocytes (RBC)
218
when and where does hematopoiesis occur
3rd to 7th months of gestation
| from liver to spleen
219
difference between live attenuated vaccines and inactivated vaccines
live attenuated - weakened version of the virus
| inactivated - killed virus
220
what is a recombinant vaccine
targeted towards a specific sub-unit of the virus
221
what is a toxoid vaccines
toxin released by the virus
222
what are the forces during glomerular filtration
capillary blood pressure - 55mmHg
osmotic pressure - 30mmHg
fluid pressure - 15mmHg
223
what is GFR
filtration efficiency
224
what is filtration coefficeint
surface area of glomerular capillaries
| permeability of endothelial cells
225
what happens in terms of arterioles in the kidney if there is high blood pressure
afferent arterioles constrict
| efferent arterioles dilate
226
what is the auto regulatory range for renal blood flow pressure
80mmHg - 180mmHg
227
out of the substances that pass through the kidneys, which one isn't reabsorbed
creatinine
