Neuroscience Flashcards
Briefly explain the neuromuscular junction
- Action potential arrives at the axon terminal
- Calcium influx
- Vesicles of Ach exocytose
- ACh is released into the junction
- ACh diffuses across , and binds, causing sodium to influx to the muscle cell
- Ach is broken down by acetylcholinesterase
What ion is responsible for muscle contraction?
Ca2+
What are olgiodendrocytes?
The myelinating cells of the CNS. They are surrounded by myelin sheath.
What are Schwann cells?
the myelinating cells of the PNS. They envelop PNS cell axons
What are Anti-AChR antibodies associated with?
Myasthenia Gravis
What are Anti-MuSK antibodies associated with?
Myasthenia Gravis
What are Microglia?
The resident immune cells of the CNS, and they proliferate at sites of injury
What are Astrocytes?
“Star-like” cells which are the most numerous glial cells in the CNS. They provide many functions including enveloping synapses, homeostatic function, metabolic support etc.
Which cells are the “resident immune cells of the CNS”? A) Olgiodendrocytes B) Schwann cells C) Microglia D) Astrocytes E) Glia
C
Which of the following is NOT a part of the blood brain barrier?
A) Astrocyte end feet
B) Fenestrated capillaries
C) Endothelial tight junctions
D) Pericytes
E) Specific transporters for glucose, water, essential ions etc.
B
What is temporal summation?
A) Lots of axons firing simultaneously
B) A new action potential cannot occur
C) When the membrane becomes more negatively polarised than its resting potential
D) A new action potential can only occur if the depolarisation is more significant than the previous one
E) One axon firing multiple times
E
Which of the following is a fast neurotransmitter? A) GABA B) Dopamine C) Noradrenaline D) Serotonin
A
A patient prevents with double vision. She has noticed that when she brushes her hair, her arms seem to get very tired and she has to rest before she’s managed to brush her whole head. You notice that she has ptosis and seems short of breath. Her speech seems to be getting gradually more slurred as she speaks. What is it likely to be?
Myasthenia Gravis
What tests can you do to check for MG?
- Ice pack test: Ptosis improves with ice
- Cogan’s lid twitch: Patient follows your finger up then down, then middle and the patients lid will twitch up
Which component of the eye controls the shape of the lens? A) Sclera B) Cornea C) Choroid D) Ciliary body E) Retina
D
What is a defective outer/middle ear known as? A) Sensorineural hearing loss B) Tympanic hearing loss C) Vestibular hearing loss D) Transmissural hearing loss E) Conductive hearing loss
E
What are the three components of the cochlea?
scala tympani, scala media, scala vestibuli
What is the cerebrum embryonically derived from?
cerebrum derived from the telencephalon of prosencephalon
What are the thalamus, hypothalamus and epithalamus embryonically derived from?
the diencephalon of prosencephalon
What is myasthenia gravis?
An autoimmune disease against nicotinic acetyl choline receptors in the neuromuscular junction
What is the midbrain embryonically derived from?
Mesencephalon
What are the pons and cerebellum embryonically derived from?
metencephalon of rhombencephalon
What is the medulla embryonically derived from?
Myelencephalon of the rhombencephalon
Which of the following is not an element of the human stress response? A) Environmental B) Biochemical C) Emotional D) Cognitive E) Physiological
A
Which extrapyramidal tract is responsible for head/eye movements in response to visual stimuli? A) Corticobulbar B) Tectospinal C) Rubrospinal D) Vestibulospinal E) Reticulospinal
B
Which extrapyramidal tract is responsible for the musculature of the head and neck? A) Corticobulbar B) Tectospinal C) Rubrospinal D) Vestibulospinal E) Reticulospinal
A
What malignancy is associated with myasthenia gravis?
Thymoma
What is a myasthenic crisis?
A medical emergency of respiratory failure, impaired swallow and/or severe limb weakness due to myasthenia gravis
How would you treat a myasthenic crisis?
Plasmapheresis and IV immunoglobulins
Which extrapyramidal tract originates in the red nucleus? A) Corticobulbar B) Tectospinal C) Rubrospinal D) Vestibulospinal E) Reticulospinal
C
Which extrapyramidal tract originates in the superior colliculus? A) Corticobulbar B) Tectospinal C) Rubrospinal D) Vestibulospinal E) Reticulospinal
B
Which extrapyramidal tract is responsible for posture and balance? A) Corticobulbar B) Tectospinal C) Rubrospinal D) Vestibulospinal E) Reticulospinal
D
Which of the following is a characteristic feature of a LMN lesion? A) Hyperreflexia B) Absent fasciculation C) Atrophy D) Hypertonia E) Paralysis of group of muscles
C
What are the classic features of an UMN lesion?
No wasting, hypertonia, paralysis of a group of muscles, hyperreflexia, absent fasiculation, present Babinski sign and clasp-knife reflex
What component of the brain produces dopamine? A) Amygdala B) Globus pallidus C) Subthalamic nucleus D) Hypothalamus E) Substantia Nigra
E
A patient’s blood tests show positive anti-AcR antibodies, and is positive in the ice pack test. How would you treat this patient?
Ach-esterase inhibitors= Pyridostigmine
Steroids= Prednisolone
Steroid sparing agents= Azathioprine
Through which foramen does V1 exit the skull? A) Foramen Ovale B) Superior orbital fissure C) Foramen spinosum D) Foramen magnum E) Foremen rotundum
B
What sensation does the anterior spinothalamic tract carry? A) Pain and temperature B) Deep/ chronic pain C) Fine touch D) Vibration E) Crude touch and pressure
E
What sensation does the DCML pathway carry? A) Pain and temperature B) Deep/ chronic pain C) Fine touch and vibration E) Crude touch and pressure
C
What sensation does the lateral spinothalamic tract carry? A) Pain and temperature B) Deep/ chronic pain C) Fine touch and vibration E) Crude touch and pressure
A
What sensation does the spinoreticular tract carry? A) Pain and temperature B) Deep/ chronic pain C) Fine touch and vibration E) Crude touch and pressure
B
A 35 year old woman comes to her GP complaining of pain that comes and goes, but worsens in the shower. What is it likely to be? A) Myasthenia gravis B) Motor neuron disease C) Multiple sclerosis D) Parkinson’s disease E) ALS
C
What is a transient loss of consciousness?
Spontaneous loss of consciousness with complete recovery
What are the types of syncope?
Vasovagal
Situational
Orthostatic hypotension
Cardiac
What are the different types of TLOC?
Syncope
Seizure
Non-epileptic attack disorder
What is meant by “prodrome”?
Any symptoms that happened before a TLOC (e.g. aura, nausea)
What is a cardiac syncope?
Temporary but sudden reduction in blood supply and hence oxygen to the brain as a result of cardiovascular conditions
A patient has a seizure that lasts for 60 seconds. He first goes stiff and then has myoclonic jerking. Afterwards, he is confused for a few hours. What is it likely to be?
Generalised tonic-clonic epilepsy
What is the different between a generalised and focal seizure?
Focal generates in a circuit localised to one hemisphere (But may spread) whereas generalised is not localised
A patient presents after she has had a loss of consicousness. Her husband says that she was moving randomly, with her head side to side, and it lasted “about 4 minutes”. Afterwards she was very upset. This was her third attack in two weeks. What is it likely to be?
Non-epileptic attack disorder (long seizure, head moving side to side, crying afterwards, frequent attacks)
What is the sagittal plane?
Slicing the body through the midline leaving a left and right side
What is the coronal plane?
Slicing the body to leave a front and a rear section
What is the transverse plane?
Slicing the body to leave an upper and a lower section
How many pairs of spinal nerves are there?
32
What do autonomic motor fibres supply?
Smooth muscle and glands (upper abdomen)
What is a block of muscle supplied by a single nerve referred to as?
Myotome
What is a block of skin sensation supplied by a single nerve referred to as?
Dermatome
Which cranial nerves have parasympathetic control?
10, 9, 7, 3
What dermatome supplies the heart?
T1
Why does heart pain radiate down the arm?
The heart and the arm are supplied by T1 dermatome, so pain is felt all along here
Where do the sympathetic nerves come out of the spinal cord?
T1-L2
What is the nervous supply of the foregut?
Greater splanchnic nerve (T5-T9)
What is the nervous supply of the midgut?
Lesser splanchnic nerve (T10-T11)
What is the nervous supply of the hindgut?
Least splanchnic nerve (T12)
What are the typical presentation of brown-Sequard syndrome?
- Total loss of sensation at the lesion
- Loss of normal sensation, and paralysis from the injury downwards, on the same side
- Loss of pain and temperature on the opposite side from two levels below the lesion
What are the layers of the meninges?
PAD out
- Pia Mata
- Arachnoid mata
- Dura Mata
Where does the spinal cord finish?
L1
What is the difference between a lumbar puncture and an epidural?
A lumbar puncture goes through the meninges, so uses a different needle, whereas epidurals don’t go through the dura.