Term
| With the exception of the thumb (pollux), abduction and adduction occur in which plane? |
|
Definition
|
|
Term
| With the exception of the pollux, what movements usually occur in the sagittal plane? |
|
Definition
|
|
Term
| What is the difference between the horizontal plane and the transverse plane? |
|
Definition
| Horizontal only has to be parallel to the ground, however, transverse is at a right angle to the longitudinal axis of the structure considered. |
|
|
Term
| What is the median nerve formed by? |
|
Definition
| chords of the brachial plexus |
|
|
Term
| Where does the median nerve run? |
|
Definition
| superficially within the axilla where it can be stimulated |
|
|
Term
|
Definition
| the armpit (directly under the joint where the arm connects to the shoulder) |
|
|
Term
| Where does the medial nerve originate? |
|
Definition
|
|
Term
| Does the median nerve innervate the muscles of the brachium? |
|
Definition
|
|
Term
| Where does the median nerve descend? |
|
Definition
| down the upper arm, running in a groove deep to the biceps brachii muscle before entering the cubital fossa. |
|
|
Term
| Where is the cubital fossa? |
|
Definition
|
|
Term
| When descending down the arm, what does the median nerve lie laterally to? |
|
Definition
|
|
Term
| What are two stimulation sites? |
|
Definition
within the axilla
bicipital aponeurosis |
|
|
Term
| What happens half way down the arm? |
|
Definition
the nerve crosses over the brachial artery, and becomes situated medially.
GOES DEEP |
|
|
Term
| How does the median nerve enters the anterior compartment of the forearm? |
|
Definition
|
|
Term
| What compartment does the median nerve descend into past half way and what muscles does it contain? |
|
Definition
| the anterior flexor compartment that contains the superficial flexor muscles |
|
|
Term
| What do the muscles in the anterior flexor compartment do? |
|
Definition
| either flex the wrist, flex the digits or both |
|
|
Term
| What does the median nerve give off as it descends? |
|
Definition
| innervating motor branches to all of the anterior compartment muscles with the exception of the medial heads of a deep flexor muscle flexing digits 4 and 5 and a medial wrist flexor |
|
|
Term
| Where does the median nerve run at the wrist? |
|
Definition
| through the carpal tunnel with the superficial flexor tendons |
|
|
Term
| What does the median nerve run laterally to at the wrist? (some people dont have it) |
|
Definition
|
|
Term
| What happens to the median nerve when it enters the hand? |
|
Definition
| divides into several branches |
|
|
Term
| In the hand, what does the median nerve provide sensory innervation to? |
|
Definition
| the palmar surface of the hand and other sensory branches descend 1, 2, 3 and the lateral aspect of the 4th digit. |
|
|
Term
| What does the terminal motor branch of the median nerve do? what is this called? |
|
Definition
| turns back on itself and ascends from the palm to the muscles of the thenar eminence that function specifically at the thumb. This is called the recurrent branch of the median nerve. |
|
|
Term
| Name the Thenar Eminence muscles |
|
Definition
| abductor pollicis brevis, opponens pollicis and flexor pollicis brevis muscles and their names inform us of what function they have on the pollux. |
|
|
Term
| How can activity from contracting fibres of the thenar eminence muscles be recorded? |
|
Definition
| following stimulation of the MEDIAN nerve in the axilla or cubital fossae |
|
|
Term
| Where does the short head of the biceps tendon originate? |
|
Definition
|
|
Term
| Where does the long head of the biceps brachii originate? |
|
Definition
|
|
Term
| Where is your medial epicondyle? |
|
Definition
| bony bit of your elbow closest to your body |
|
|
Term
| Where does the biceps tendon attach? |
|
Definition
| to the proximal aspect of the radius just distal to the apex of the cubital fossae |
|
|
Term
| If the median nerve was to become damaged at the elbow joint, wrist flexion would be... |
|
Definition
| some very weak wrist flexion would persist from the 2 medial heads of a deep flexor muscle of a muscle flexing digits 4 and 5 and a medial wrist flexor |
|
|
Term
| If the median nerve was to become damaged at the elbow joint, flexion of digits 1, 2 and 3 would be... |
|
Definition
| the flexor muscles of digits 1, 2 and 3 are solely innervated by the median nerve so no flexion would be possible if the median nerve was damaged at the elbow joint. Digits 4 and 5 would be able to flex due to their alternative nervous innervation. |
|
|
Term
| If the median nerve was to become damaged at the wrist joint, wrist flexion would be... |
|
Definition
| all the muscles flexing the wrist and digits originate in the forearm and their nervous innervation would have branched from their respective nerves proximal to the wrist. Therefore all wrist flexors would function normally (if a little painfully due to wrist trauma). |
|
|
Term
| If the median nerve was to become damaged at the wrist joint, flexion of digit 1 (the pollux) would be... |
|
Definition
| flexor pollicis brevis would not function due to damage of the recurrent branch of the median nerve at the wrist. However, as its name suggests, there is a flexor pollicis longus muscle that originates in the forearm and is innervated by the median nerve proximal to the wrist joint. This muscle would still function and as it is the larger of the two flexor pollicis muscles, flexion of the pollux would be slightly impaired. This is considering flexion only. With Carpal Tunnel Syndrome the functioning of the thumb is seriously impaired due to no innervation to openens pollicis or abductor pollicis brevis and reduced flexion. |
|
|
Term
|
Definition
|
|
Term
| How can conduction velocity be determined? |
|
Definition
| by stimulating the median nerve at the elbow and at the armpit and determining the difference in the latency of the EMG responses evoked from the flexor muscles of the thumb. |
|
|
Term
| What time are you measuring? |
|
Definition
| the time is takes for action potentials in the motor neurones supplying the flexor pollicis muscle to propagate over a known distance. |
|
|
Term
| How is conduction velocity of the motor neurones involved be calculated? |
|
Definition
1. measure the latency of the EMG response following stimulation of each point
2. measure distance between the two stimulation sites and the flexor muscles and the thumb muscles |
|
|
Term
| Why should this experiment by repeated 3 times? |
|
Definition
Improves reliability
good scientific practice.
Allows for mean values to be calculated.
Outliers can be recognised easier. |
|
|
Term
| Give two factors that determine nerve conduction velocity: |
|
Definition
a) Nerve Diameter
b) Degree of myelination |
|
|
Term
| Give the physiological range of conduction velocities |
|
Definition
| from 0.5 m.s-1 (small non-myelinated fibres) to 100 m.s-1 (large myelinated fibres) |
|
|
Term
| What does the term ‘synaptic delay’ mean? |
|
Definition
| Time for neurotransmitter to be released from pre-synaptic membrane, cross the synaptic cleft and bind with receptor on post-synaptic membrane |
|
|
Term
| What is the neurotransmitter at the neuromuscular junction? |
|
Definition
|
|
Term
| Does botulinum cause muscle relaxation or contraction? How? |
|
Definition
Relaxation. Botulinum is a neurotoxin- consists of 2 polypeptide chains, heavy and light. The light chain processes protease activity and prevents the fusion of vesicles containing the neurotranmitter acetylcholine with the pre-synaptic membrane, thus preventing nerve transmission
In short: Botulinum prevents release of ACh at pre-synaptic terminal. Botox! |
|
|
Term
| Does neostigmine cause muscle relaxation or contraction? How? |
|
Definition
| Contraction. Neostigmine is a reversible acetylcholinesterase inhibitor. This drug blocks the active site of the enzyme acetylcholineesterase- this enzyme normally breaks down acetylcholine bound to receptors on post-synaptic membrane, with acetylcholinesterase inactive nerve transmission continues |
|
|
Term
| Does myasthenia gravis cause muscle relaxation or contraction? How? |
|
Definition
| Relaxation. Myasthenia gravis is an autoimmune disorder whereby circulating antibodies block acetylcholine receptors (on post-synaptic membrane) leading to a reduction in nerve transmission. |
|
|
Term
| How does neostigmine treat myasthenia? |
|
Definition
| inhibiting acetylcholinesterase allows the action of acetylcholinesterase to be prolonged by increase Ach concentration in synaptic cleft. |
|
|
Term
| Define crus (and give its pleural) |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
| big toe down little toe up |
|
|
Term
|
Definition
| lifting toes up but heel remains down |
|
|
Term
|
Definition
|
|
Term
| The tibial nerve is a branch of the ... |
|
Definition
|
|
Term
| What else is a branch of the sciatic nerve? |
|
Definition
| common fibular (or common peroneal) |
|
|
Term
| Together, the common fibular and tibial nerve innervate... |
|
Definition
| 4 of the 6 muscle compartments of the lower limb and foot |
|
|
Term
| What do tibial branches provide motor supply to? |
|
Definition
| the posterior compartments of the lower limb |
|
|
Term
| What do tibial branches carry sensory information from? |
|
Definition
| information from touch receptors on the lateral side of the lower leg and the plantar surface (sole) of the foot, back to the spinal cord |
|
|
Term
| Where does the sciatic nerve exit the pelvis through? |
|
Definition
| the greater sciatic foramen |
|
|
Term
| Where does the sciatic nerve run in regards to the femur? |
|
Definition
| posterior to the femur, deep to the lateral hamstring muscle (biceps femoris) |
|
|
Term
| Where does the sciatic nerve run in regards to the knee joint? |
|
Definition
| runs from the femur to the popliteal fossae on the posterior aspect of the knee joint |
|
|
Term
| When does the tibial branch innervate the hamstring muscle group? |
|
Definition
| as it descends the posterior thigh |
|
|
Term
| When does the sciatic nerve divide into its 2 components? |
|
Definition
| At the most proximal aspect of the popliteal fossa |
|
|
Term
| Describe the descent of the common fibular |
|
Definition
(infero)laterally (obliquely)
superficially wraps around the fibular head
then divides |
|
|
Term
| Describe the division of the common fibular |
|
Definition
| forms superficial and deep branches which provide motor supply to the lateral and anterior compartment muscles of the lower leg respectively (ankle everters and dorsiflexors) |
|
|
Term
| How can the tibial nerve be artificially stimulated? |
|
Definition
| within the popliteal fossae due to its superficial course |
|
|
Term
| Describe the descent of the tibial nerve in the upper leg |
|
Definition
| The tibial nerve descends the popliteal fossa in the midline MEDIAL to the common fibular nerve and then enters the lower leg (crura) department. |
|
|
Term
| Describe the descent of the tibial nerve in the lower leg |
|
Definition
| It begins its descent of the lower leg in the midline before slightly coursing medially to enter to foot and ankle around the medial aspect of the ankle joint. |
|
|
Term
| What does the tibial nerve give of as it descends? |
|
Definition
| innervating motor branches to all the muscles of the posterior compartment of the lower leg (plantarflexors / knee flexors). |
|
|
Term
| What is the popliteal fossa? |
|
Definition
| a shallow depression located at the back of the knee joint |
|
|
Term
| What makes up the proximal medial border of the popliteal fossa? |
|
Definition
|
|
Term
| What makes up the proximal lateral border of the popliteal fossa? |
|
Definition
| semimembranosus and semiteninosus (medial hamstrings) |
|
|
Term
| What makes up the two lower borders of the popliteal fossa? |
|
Definition
| heads of the gastrocnemius |
|
|
Term
| Describe the gastrocnemius muscle |
|
Definition
superficial posterior muscle
2 heads (medial and lateral) |
|
|
Term
| Where does the gastrocnemius muscle attach to the femur? |
|
Definition
| on the medial and lateral condyles |
|
|
Term
| Where does the gastrocnemius muscle insert and how? |
|
Definition
| onto the calcaneal bone via the calcaneal tendon |
|
|
Term
| Where does the soleus muscle originate? |
|
Definition
| proximal ends of the tibia and fibula |
|
|
Term
| Where does the soleus muscle insert? |
|
Definition
| onto the calcaneal bone via the calcaneal tendon |
|
|
Term
| Why cant the soleus muscle flex the knee? therefore what is its primary function |
|
Definition
doesn't originate on the femur
plantarflexion |
|
|
Term
| Describe the distribution of the tibial nerve |
|
Definition
runs deep
1. laterally in the thigh deep to biceps femoris
2. superficially through the popliteal fossae in the midline
3. in between the superficial and deep muscular compartments of the crura coursing medially to enter the foot (medial to calcaneal tendon) |
|
|
Term
| If the tibial nerve was to become damaged within the popliteal fossae, which of the following movements would not occur at the ankle joint? |
|
Definition
Plantarflexion
the tibial nerve provides motor innervation to the muscles of the posterior compartment which all function to plantarflex the ankle joint |
|
|
Term
| If the muscles of the lateral compartment lost their innervation from the (superficial) fibular nerve, which of the following movements would not occur at the ankle joint? |
|
Definition
Eversion
the muscles of the lateral compartment of the leg function on the lateral aspect of the ankle joint thus eversion occurs upon their contraction |
|
|
Term
| If the muscles of the anterior compartment lost their innervation from the (deep) fibular nerve, which of the following movements would not occur at the ankle joint? |
|
Definition
Dorsiflexion
the muscles of the anterior compartment of the leg function on the anterior aspect of the ankle joint thus dorsiflexion occurs upon their contraction |
|
|
Term
| posterior compartment muscles all ........... the ankle joint |
|
Definition
|
|
Term
| only one posterior compartment muscle ....... |
|
Definition
| one flexes the knee (gastrocnemius) |
|
|
Term
| Lateral compartment muscles ......... the foot at the enkle joint |
|
Definition
|
|
Term
| anterior compartment muscles .......... the ankle joint |
|
Definition
|
|
Term
| How can a reflex contraction of the gastrocnemius muscle be produced? |
|
Definition
| by imposing a rapid increase in the length of the muscle |
|
|
Term
| How may the gastrocnemius be stretched? |
|
Definition
| by briskly tapping the Achilles tendon with a patella hammer |
|
|
Term
| How can the latency of the response be measured? |
|
Definition
| if the hammer is set up to trigger the oscilloscope |
|
|
Term
| Does varying the strength of the tendon tap have a significant effect on the latency of the evoked EMG response? Explain your answer |
|
Definition
| No. The latency is unaffected by the strength of the tendon tap. The tap produces a brief stretch of the sensory endings, firing the Ia afferent fibre, which depolarizes the motoneurone producing action potentials that travel along the motor axon (efferent fibres) activating the muscle via the neuromuscular junction. So, the signal travels the same distance along the afferent and efferent nerve fibres, at similar velocities, regardless of the strength of tap. |
|
|
Term
| Does varying the strength of the tendon tap have a significant effect on the amplitude of the evoked response? Explain your answer. |
|
Definition
| Yes. The amplitude increases with the strength of tap. A greater degree of stretch of the muscle spindle increases the firing rate of the sensory neurone which in turn increases the number of motor units recruited to oppose the stretch. Therefore the EMG trace or compound action potential’s amplitude will increase proportionally. |
|
|
Term
| What is the effect of the subject contracting the gastrocnemius muscle just before the tendon is tapped, on the latency and amplitude of the evoked response? |
|
Definition
| The latency is unchanged but the amplitude is decreased for any given strength of tap |
|
|
Term
| Why does the amplitude decrease is the gastrocnemius is contracted? |
|
Definition
| When the muscle is contracted the muscle spindles are slackened and become ‘unloaded’ or ‘off air’. This means that any given degree of stretch applied to the muscle stretches the muscle spindles to a lesser degree. This leads to a decrease in the frequency of action potentials in the sensory neurones and therefore a decrease in the reflex response. |
|
|
Term
| Is there any correlation between the distance from the site of stimulation to the hip of a subject and the latency of the elicited reflex response? |
|
Definition
Slight.
the conduction velocity and the distance for travel of the stimulus and the return of activity is fairly similar across subjects. Under normal conditions only if the distance of travel is significantly larger is the latency affected. However, with peripheral or descending injury the latency is increased. |
|
|
Term
| What innervates intrafusal fibres? |
|
Definition
|
|
Term
| What innervates extrafusal fibres? |
|
Definition
|
|
Term
| What are the 2 longitudinal axis of the brain? |
|
Definition
longitudinal axis of the forebrain
longitudinal axis of the brainstem and spinal cord |
|
|
Term
| Define caudal and rostral |
|
Definition
caudal = posterior and down
rostral = anterior |
|
|
Term
| Which part of the brain is ventral? |
|
Definition
|
|
Term
| which part of the brain is dorsal? |
|
Definition
|
|
Term
| What can the brain be divided into? |
|
Definition
| cerebral hemispheres; cerebellum; midbrain and brainstem |
|
|
Term
| What does the cerebral hemispheres divide into and what are they divided by? |
|
Definition
4 lobes
several major sulci (grooves0 |
|
|
Term
| which lobe is the most rostral? |
|
Definition
|
|
Term
| What separates the frontal lobe from the parietal lobe? |
|
Definition
|
|
Term
| What separates the frontal lobe from the temporal lobe? |
|
Definition
|
|
Term
| What lobe is the most caudal? |
|
Definition
(posterior)
occipital lobe |
|
|
Term
| What separates the occipital lobe from the parietal lobe? |
|
Definition
| the parieto-occipital sulcus |
|
|
Term
| What can be found on the top edge of the temporal lobe? and what is this the location of? |
|
Definition
the superior temporal gyrus
primary auditory cortex |
|
|
Term
| What is found in front of the central sulcus? and what is this the location of? |
|
Definition
The pre-central gyrus
primary motor cortex |
|
|
Term
| What is found behind the central sulcus? and what is this the location of? |
|
Definition
|
|
Term
| What other structures can be found on the medial surface? |
|
Definition
1. corpus callosum
2. lateral ventricles
3. thalamus
4. hypothalamus |
|
|
Term
| What can be found on the ventral surface of the brain? |
|
Definition
1. Olfactory bulb and olfactory tract
2. Optic nerves/tract/chiasm
3. Mammillary bodies
4. Cranial nerves
5. Pons
6. Medulla (oblongata) |
|
|
Term
| What does the Olfactory bulb and olfactory tract form? where are they found? |
|
Definition
| the 1st cranial nerve, which carries information relating to the sense of smell. These are found towards the front of the brain, below the frontal lobe. |
|
|
Term
| Where do the optic nerves lie? |
|
Definition
| Behind and slightly more lateral to the olfactory tracts |
|
|
Term
| What do the optic nerves do? |
|
Definition
| they come together in the midline to form the optic chiasm, where some of the fibre cross. |
|
|
Term
| Describe the mammillary bodies |
|
Definition
| these two “bumps” lie in the midline of the ventral surface, just behind the optic chiasm. These are often classed as being part of the hypothalamus, however rather than a role in hormone control we now believe they are important for memory function and processing sensory information. |
|
|
Term
| What does the pons look like? |
|
Definition
| the pons (meaning “bridge”) is the “bulge” in the brainstem structures present between the midbrain and the medulla. This can be clearly seen on the ventral surface of an intact specimen. |
|
|
Term
| What passes through the pons? |
|
Definition
| Many fibres carrying information from the cerebral hemispheres to either the cerebellum or to the spinal cord |
|
|
Term
| What does the pons also contain? |
|
Definition
| part of the reticular formation – collections of neurons contained within the pons and medulla which are responsible for the control of basic systems such as respiration and heart rate. |
|
|
Term
| Where and what is the medulla? |
|
Definition
| the brain stem region between the pons and the spinal cord. Contains ascending and descending fibre tracts, as well as cranial nerve nuclei and parts of the reticular formation |
|
|
Term
| Where would you find the longitudinal fissure? |
|
Definition
| Separating the 2 hemispheres, running from rostral pole (frontal lobe) to caudal pole (occipital lobe). |
|
|
Term
| If you look deep into the longitudinal fissure you find the corpus callosum. What is this, and what is its functional significance? |
|
Definition
| Sometimes known as the great cerebral commissure, this is a white matter tract (i.e. axons) connecting the cortex of the 2 hemispheres together. |
|
|
Term
| What is the role of the cerebellum? |
|
Definition
| It is an important movement control centre, in particular in the fine calibration of movement (i.e. not the initiation of movements). |
|
|
Term
| What is meant by the term ‘stroke’? |
|
Definition
| Also known as a cerebrovascular insult (CVI), this is an interruption/break in the blood supply to areas of the brain resulting in cell death. Symptoms/any lasting damage or whether a CVI is fatal depends on the areas of the brain affected. |
|
|
Term
| Which two pairs of blood vessels provide the arterial supply to the brain? |
|
Definition
| Vertebral arteries and internal carotid arteries. |
|
|
Term
| List the posterior system of vessels |
|
Definition
Vertebral
Basilar
Spinal branches
Cerebellar branches
Posterior cerebral |
|
|
Term
| List the anterior system of vessels |
|
Definition
Posterior communicating
Internal carotid
Anterior cerebral
Anterior communicating
Middle cerebral |
|
|
Term
| Which of the vessels contribute to the arterial circle (of Willis) which surrounds the diencephalon on the base of the brain? |
|
Definition
| Posterior cerebral, posterior communicating, internal carotid, anterior communicating, anterior cerebral, basilar. Middle cerebral are NOT considered part. |
|
|
Term
| What is the functional significance of this circle? |
|
Definition
| This is a circulatory anastomosis surrounding the diencephalon, meaning that if there is a blockage/break in one of the arteries within the circle, blood can be “re-routed” to limit the break in supply to tissues. |
|
|
Term
| Which cerebral artery supplied the frontal lobes? |
|
Definition
|
|
Term
| Which cerebral artery supplied broca's area? |
|
Definition
|
|
Term
| What is the collective name for the dura, arachnoid and pia mater? |
|
Definition
|
|
Term
| Which are generally afferent nerves – those in the ventral or dorsal roots? |
|
Definition
|
|
Term
| Which are generally efferent nerves – those in the ventral or dorsal roots? |
|
Definition
|
|
Term
|
Definition
| the tough outer meningeal covering of the spinal cord (and brain) |
|
|
Term
| Where is the arachnoid mater? |
|
Definition
| a thinner membrane between the DURA MATER and the PIA MATER |
|
|
Term
|
Definition
| the thinnest membrane, adjacent to the spinal cord |
|
|
Term
| What are the cauda equina? |
|
Definition
| the bundle of nerves running down from the end of the spinal cord to innervate the lower regions of the body |
|
|
Term
| Where can the ventral and dorsal roots be seen entering and exiting the spinal column through? |
|
Definition
| through spaces between the vertebrae, the bony protective covering and surrounding the spinal cord. |
|
|
Term
| At which spinal level are lumbar punctures preformed, and why? |
|
Definition
| Below L1-L2 level – generally at around L4-L5. Need “empty” sub-arachnoid space – i.e. no spinal cord – cauda equine region – can then safely remove CSF without damaging spinal cord as the nerves at this level “move” out the way of the needle. |
|
|
Term
| In the body what is the role of acetylcholinesterase? |
|
Definition
| to break down acetylcholine in the synaptic cleft, thus terminating neurotransmission |
|
|
Term
| Describe an experiment to monitor the activity of AChE |
|
Definition
AChE breaks down acetyl thiocholine.
Thiocholine ion is coupled chemically to a reagent (Ellman's) to yeild a bright yellow product (TNB)
measured using a spectrophotometer |
|
|
Term
| What is the amount of TNB produced directly proportionally to? |
|
Definition
|
|
Term
| What factors influence the kinetics of the AChE reaction? |
|
Definition
| temperature, and the concentrations of substrate, enzyme and inhibitor |
|
|
Term
| Describe the inhibitor you will use |
|
Definition
| neostigmine – this is a prescription drug used in the treatment of myasthenia gravis (an autoimmune disease in which the number of postsynaptic ACh receptors is decreased). |
|
|
Term
| Why are patients with myasthenia gravis given neostigmine? |
|
Definition
| Myasthenia gravis is an autoimmune disease due to presence of antibodies to the Ach receptor resulting in muscle weakness/paralysis. It can be treated with neostigmine because it is an acetylcholinesterase inhibitor, therefore increasing the concentration of Ach in the synaptic cleft. |
|
|
Term
| In enzyme catalysed reactions, why does the rate of reaction decrease as time progresses? |
|
Definition
velocity of back reaction increases
product may inhibit the enzyme
enzyme may be labile |
|
|
Term
| Describe the Michaelis-Menten equation |
|
Definition
v = Vmax [S]/([S] + Km)
Mathematically it is possible to show v is related to [S] |
|
|
Term
|
Definition
| Vmax represents the maximum velocity achieved by the system, at maximum (saturating) substrate concentrations. |
|
|
Term
|
Definition
the Michaelis constant
is the substrate concentration at which the reaction velocity is 50% of the Vmax. |
|
|
Term
| What achieves a Lineweaver-Burk plot? |
|
Definition
Taking the reciprocal of the Michaelis-Menten equation results in the following expression
1/v = [S]/Vmax[S] + Km/Vmax[S] |
|
|
Term
| Name 5 allosteric inhibitors |
|
Definition
ATP
AMP
Fructose-2,6-bisphosphate
Citrate
H+ |
|
|
Term
| Which of these inhibit PFK1 activity? |
|
Definition
|
|
Term
| Which of these activate PFK1 activity? |
|
Definition
AMP
Fructose-2,6-bisphosphate |
|
|
Term
|
Definition
| Phosphofructokinase-1 (PFK-1) is one of the most important regulatory enzymes of glycolysis. |
|
|
Term
| What effect does ATP have on glycolysis? |
|
Definition
| ATP is both a substrate and allosteric regulator of PFK1 activity – it helps to tune the rate of glycolysis to energy status of cells |
|
|
Term
| What effect does AMP have on glycolysis? |
|
Definition
| ATP levels fall and AMP concentrations rise in ischaemia/hypoxia. The latter stimulates PFK1 and hence the rate of glycolysis, to increase anaerobic ATP synthesis. |
|
|
Term
| What effect does Fructose-2,6-bisphosphate have on glycolysis? |
|
Definition
| Counters inhibition of PFK1 by ATP – a component of the fight or flight response. Adrenaline through activation of β-adrenoceptors increases the formation of F-2,6-BP in skeletal muscle, helping to stimulate glycolysis when ATP concentrations are likely to be high. |
|
|
Term
| What effect does citrate have on glycolysis? |
|
Definition
| Inhibition provides a mechanism to conserve glucose in situations such as heavy exercise and starvation where there is a switch to oxidation of fatty acids and generation of ketone bodies for ATP synthesis. In these circumstances citrate levels rise to inhibit glycolysis. |
|
|
Term
| What effect does H+ have on glycolysis? |
|
Definition
| Slows down glycolysis and thereby inhibits lactic acid production – helps to prevent intracellular acidosis and accumulation of lactate |
|
|
Term
| List the mechanisms used to control enzyme activity |
|
Definition
1) Feedback inhibition by a product of a pathway
2) Gene expression alters the amount of enzyme
3) Phosphorylation/dephosphorylation
4) Proteolysis - irreversible acitvation & altering life-span through changes in rate of enzyme degradation |
|
|
Term
| Describe competitive inhibition of an enzyme |
|
Definition
| The inhibitor has a similar shape to the usual substrate for the enzyme, and competes with it for the active site. However, once it is attached to the active site, nothing happens to it. It doesn't react - essentially, it just gets in the way. |
|
|
Term
| Describe non-competitive inhibition of an enzyme |
|
Definition
Non-competitive inhibitors
A non-competitive inhibitor doesn't attach itself to the active site, but attaches somewhere else on the enzyme. By attaching somewhere else it affects the structure of the enzyme and so the way the enzyme works. Because there isn't any competition involved between the inhibitor and the substrate, increasing the substrate concentration won't help. |
|
|
Term
| Describe the drug captopril |
|
Definition
ACE inhibitor
that targets the angiotensin-converting inhibitor
Reversible inhibitor |
|
|
Term
| What are the main therapeutic uses of captopril? |
|
Definition
Antihypertensive agent
Chronic heart failure |
|
|
Term
| Describe the drug simvastatin |
|
Definition
Statin
Targets HMG CoA reductase
Reversible inhibitor |
|
|
Term
| What are the main therapeutic uses of simvastatin? |
|
Definition
Antihyperlipidaemic agent
lipid-lowering drug |
|
|
Term
| Describe the drug ibuprofen |
|
Definition
NSAIDs
targets COX
Reversible inhibitor |
|
|
Term
| What are the main therapeutic uses of ibuprofen? |
|
Definition
Anti-inflammatory
Analgesic
Antipyretic |
|
|
Term
| Describe the drug letrozole |
|
Definition
Aromatase inhibitor
Targets aromatase
Reversible inhibitor |
|
|
Term
| What are the main therapeutic uses of letrozole? |
|
Definition
| Anticancer drug – breast cancer in post menopausal women |
|
|
Term
| Describe the drug amoxicillin |
|
Definition
Pencillin
Targets bacterial cell wall transpeptidases
Irreversible inhibitor |
|
|
Term
| What are the main therapeutic uses of amoxicillin? |
|
Definition
Broad spectrum
antibacterial |
|
|
Term
| What do organophosphates target? |
|
Definition
|
|
Term
| What are oganophosphates used as? |
|
Definition
| Insecticides/ chemical warfare |
|
|
Term
| What are the physiological effects of organophosphates? |
|
Definition
| Nerve agents, produce a cholinergic toxidrome as a result of excessive activation of the parasympathetic nervous system |
|
|
Term
| What are the DUMBBELS effects caused by organophosphates? |
|
Definition
| diarrhoea, urination, miosis, bronchorrhoea, bronchospasm, emesis, lacrimation and salivation |
|
|
Term
| What do you think a graph of initial velocity versus substrate concentration would look like for an enzyme which binds its substrate co-operatively? |
|
Definition
| Should be an S-shaped plot |
|
|
Term
| What is Parkinson's disease? |
|
Definition
| Degenerative disorder of the central nervous system that primarily impairs the sufferer's motor skills and speech. |
|
|
Term
| What is the relevance of the substantia nigra in Parkinson's disease? |
|
Definition
concentrated area of dopaminergic neurones
Dopamine is a chemical that relays messages between the substantia nigra and other parts of the brain to control movements of the human body. |
|
|
Term
| Where does Parkinsons begin? |
|
Definition
|
|
Term
|
Definition
| starts spreading and starts to move into the cortexes |
|
|
Term
| Name a pathological hallmark of Parkinsons |
|
Definition
|
|
Term
| Where and what are Lewy bodies? |
|
Definition
| deposits found within substantia nigra neurones |
|
|
Term
| Describe the structure of Lewy bodies |
|
Definition
| FIlaments and contain granular material |
|
|
Term
| What neurofilament proteins are involved in Lewy bodies? |
|
Definition
alpha-synuclein and ubiquitin
many others also present |
|
|
Term
| What are some of the main genes involved in Parkinsons disease? |
|
Definition
|
|
Term
| When do Parkinson's symptoms appear? |
|
Definition
| when over 50% of the dopamine containing neurones are lsot |
|
|
Term
| What are the 3 factors that enrich the substantia nigra (oxidative damage)? |
|
Definition
iron
dopamine
alpha-synuclein |
|
|
Term
| Why is it important to have iron regulated in neurones in PD? |
|
Definition
- involved in enzymatic reactions
- mitochondria (respiration)
- DNA replication |
|
|
Term
| How is iron regulated and controlled? |
|
Definition
1. import
2. storage
3. export |
|
|
Term
| What happens to loose/labile iron? |
|
Definition
| causes oxidative stress for redox reactions |
|
|
Term
|
Definition
| proteins/cages called ferritin or neuromelanin |
|
|
Term
| What happens to neuormelanin levels in PD? |
|
Definition
| increased levels due to increased iron levels (tries to rescue it) |
|
|
Term
| What happens when there is too much iron inside the cell? |
|
Definition
| shut down import and increases export |
|
|
Term
| What is the role of Amyloid precursor protein? |
|
Definition
| sits on the membrane and is involved in iron export |
|
|
Term
| What happens to it when it is chopped up? |
|
Definition
| produces a protein called amyloid beta which is associated with neurodegeneration because it produces amyloid plaques |
|
|
Term
| What else is dysregulated iron (via APP) associated with? |
|
Definition
| leads to hydroxyl radical production commonly associated with other neurological diseases |
|
|
Term
| What happens when you remove the APP in mice? |
|
Definition
similar effects to Parkinsons disease
- iron accumulated in the cell
- substantia nigra neurone deficiency
- motor deficit |
|
|
Term
| What is iron chelation therapy? |
|
Definition
| removal of excess iron to reduce oxidative stress and minimise the effects of PD |
|
|
Term
|
Definition
toxin injected into substantia nigra that induces neuronal death (specifically dopaminergic)
used to correlate iron deficiency and impairment of motor skills in mice |
|
|
Term
| What is deferiprone (DFP)? |
|
Definition
|
|
Term
| What happens when DFP in introduced to MPTP treated mice? |
|
Definition
DFP reduces brain iron
substania nigra increases
DFP raises dopamine levels |
|
|
Term
| What were the results of the pilot clinical trial for treating PD patients? |
|
Definition
-DFP displayed favourable consequences on dopamine metabolites and dopamine auto-oxidation
-systematic iron losses were largely avoided and hematological parameters were minimally affected |
|
|
Term
| What are the dangers of this treatment? |
|
Definition
its chelating the whole body
could cause anaemia |
|
|
Term
| Define regenerative medicine |
|
Definition
| the development of biological substitutes for implantation into the body and/or the fostering of tissue regeneration and remodelling, with the prupose being to replace, repair, maintain or enhance function |
|
|
Term
| Human body parts fail due to... |
|
Definition
| ...illness, age or injury |
|
|
Term
| What are the therapeutic strategies in tissue engineering? |
|
Definition
1. implantation of tissues which have been grown in vitro
2. implantation of cells
3. in situ tissue regeneration using cell free scaffolds |
|
|
Term
In their simplest form, scaffolds for tissue engineering and
regenerative medicine should provide: |
|
Definition
• Mechanical support
• Shape
• Cell-scale architecture for neo-tissue construction in vitro or in vivo
• |
|
|
Term
|
Definition
• Acellular human (cadaveric) biological scaffolds
• Acellular animal (xenogeneic) biological scaffolds
• Biomaterial Scaffolds |
|
|
Term
| Biomaterial scaffolds include: |
|
Definition
• Scaffolds fabricated from naturally occurring biomaterials
• Scaffolds fabricated from synthetic polymers
• Composites of synthetic and natural polymers |
|
|
Term
| Define an autologous cell |
|
Definition
| (of cells or tissues) obtained from the same individual. |
|
|
Term
| Define an allogeneic cell |
|
Definition
| relating to or denoting tissues or cells which are genetically dissimilar and hence immunologically incompatible, although from individuals of the same species. |
|
|
Term
|
Definition
| cell from a different species |
|
|
Term
| What are the autologous cell sources for tissue engineering? |
|
Definition
• Patients own cells
• Immunologically acceptable
• The ideal cell type
• Not easily commercially exploitable or translatable |
|
|
Term
| What are the allogeneic cell sources for tissue engineering? |
|
Definition
• Cells from another human
• Available off the shelf; commercially exploitable
• Will be subject to immune rejection over time |
|
|
Term
| What are the xenogeneic cell sources for tissue engineering? |
|
Definition
• Cells from another species: unsuitable for human application
• Immunological/ disease transmission/ patient perception |
|
|
Term
| What are the different types for use in tissue engineering? |
|
Definition
1. primary cells
2. embryonic stem cells
3. induced pluripotent stem cells
4. adult stem cells (haematopoietic stem cells and mesenchymal) |
|
|
Term
|
Definition
| Differentiated cells from relevant adult tissue |
|
|
Term
| What types of embryonic stem cells are there? |
|
Definition
| pluripotent and allogeneic |
|
|
Term
| Define haematopoietic stem cells |
|
Definition
Multipotent stem cells which give rise to all the cell types found in
blood |
|
|
Term
| Define mesenchymal stem cells |
|
Definition
| Multipotent stem cells which give rise to bone, cartilage, fat, fibrous connective tissues and cells which support the formation of blood |
|
|
Term
| Name some cardiovascular disease |
|
Definition
• Coronary artery disease
• Peripheral artery disease
• Cerebrovascular disease
• Hypertension |
|
|
Term
| What is atherosclerosis characterised by? |
|
Definition
| fibrosis, lipid deposition and chronic inflammation |
|
|
Term
| What do patients with atherosclerosis experience and why? |
|
Definition
The build up of atherosclerotic plaques reduces the blood flow.
Patients experience ischaemic pain when the demand for oxygen
and nutrients is not met. |
|
|
Term
| How is cardiovascular disease managed? |
|
Definition
Lifestyle counselling - dietary & smoking advice
Medication - including introduction of a statin
Endarterectomy - surgical removal of an atherosclerotic plaque
Angioplasty
Vascular stenting
Bypass surgery |
|
|
Term
| What is a vascular bypass graft? |
|
Definition
Surgically placing a graft to bypass a blocked artery and
revascualrise
Current therapeutic grafts include:
Sthynetic bypass graft;
Autografts such as the saphenous vein.;
Allografts |
|
|
Term
| What do small diameter synthetic bypasses show? |
|
Definition
poor patency rates
(not open) |
|
|
Term
| What is the ideal solution for new vascular bypass grafts? |
|
Definition
• Early intervention in the disease process;
• Replacement vessel restores normal function;
• Replacement regenerates with the patient`s cells;
• Life long treatment. |
|
|
Term
|
Definition
a process to remove native cells whilst maintaining the structural integrity of native ECM
(to isolate ECM) |
|
|
Term
| What are the benefits of decellurisation? |
|
Definition
• Acellular scaffolds closely match the tissue being replaced;
• Maintain the attributes of the original tissue including
biomechanical properties and biochemical composition;
• Composed of native ECM therefore retaining cell attachment
motifs and provide a natural environment for cell proliferation
and differentiation;
• Reduced immunological response - removal of major
xenogeneic or allogeneic antigens;
• Following implantation may become populated with patients
cells and undergo remodeling;
• Cost effective - Life long treatment. |
|
|
Term
| What is the main hope and dream of decellurisation? |
|
Definition
Acellular scaffolds derived from natural tissues have
the potential to deliver life-long treatment due to an
ability to regenerate with a patient’s own cells |
|
|
Term
|
Definition
NO
DUH
(they cannot produce an immune response, only cells can) |
|
|
Term
| What are the advantages of allogeneic acellular scaffolds? |
|
Definition
• Ideal solution for numerous applications such as blood vessels and
cardiac valves
• Retain the three dimensional ECM |
|
|
Term
| What are the disadvantages of allogeneic acellular scaffolds? |
|
Definition
• Same limited availability as tissues for transplantation
Donor shortage
• Major ethical limitations to commercial exploitation
In the United Kingdom cannot sell human donor tissue for profit! |
|
|
Term
| What are the advantages of xenogeneic acellular scaffolds? |
|
Definition
• Provided the decellularisation process is 100% effective, ideal
solution for numerous applications eg cardiac valves
• Retain the three dimensional ECM
• Unlimited supply. |
|
|
Term
| What are the disadvantages of xenogeneic acellular scaffolds? |
|
Definition
• Potential for residual immunogenicity
• Potential presence of infectious agents eg. prions, retroviruses
• Variability between preparations
• Inability to totally specify the materials bioactive components. |
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|
