Spina Bifida Flashcards
What is the function of sensory neurones
carry information from the brain to the other parts of the body.
What is the neurotransmitter for the somatic nervous system
• Acetylcholine is the neurotransmitter, and is released from the terminal bouton
Give 2 functions of the parasympathetic division
- constricts pupils
- saliva production
- constricts bronchi
- slows heart rate
- stimulates GI function
- stimulates urination
- increases sexual arousal
Do each relax or contract?
B1 Heart
B2 Bronchi and Bladder
B3 Bladder
A1 Smooth Muscle Sphincter
B1 Heart Relaxes
B2 Bronchi and Bladder Relaxes
B3 Bladder Relaxes
A1 Smooth Muscle Sphincter Contracts
common symptoms of spina bifida
urinary/faecal incontinence
muscle weakness
How do anticholinergics affect incontinence
Block the action of Ach so over-reactive bladder contractions do not occur
What are spinal nerves linked to
specific muscles
Example receptors for Gs
B adrenoreceptors e.g. β1, 2 and 3
For urination, which nerves does the sympathetic signal travel down
Nerves T11- L2
What is a dermatome chart
maps areas of skin that relate to particular spinal nerves
What does the front horn contain
Motor nerve cells
What neurotransmitter is released from the post-ganglionic terminal bouton (PNS)
Ach
Give 3 ideal characteristics of a biomarker
o Fluctuate with the disease/intervention o Easily obtainable and endogenous o Cost effective to obtain o Quick and easy to test o Reproducible o Sensitive o Specific o Consistent across population o Concentration correlates with diseases
What is the function of motor neurones
carry commands from the brain and spinal cord to other parts of the body, particularly to skeletal muscle.
Example receptors for Gi
Muscarinic AchR
M2 and α2
How is CSF formed
the filtration and secretion from networks of capillaries and ependymal cells in the ventricles and central canal
Describe sensory nerves/neurones
deliver information from muscles/joints to spinal cord about body position
transmit sensations such as temperature, pressure, pain and touch from skin’s surface
information enters spinal cord via grey posterior horn
What are the three section of the spinal cord
grey matter
front horn
back horn
What type of preganglionic neuron does the PNS have
1 long from CNS
2 types of spinal nerves
sensory
motor
How does the G protein ensure the signal can be controlled, and does not continually fire
the G-protein contains an intrinsic GTPase enzyme, which converts the GTP product back into GDP
Which section of the sarcomere contains both actin and myosin
A band
What is the subunit of Go
βγ
Explain the steps in skeletal muscle excitation-contraction coupling
- Action potentials travel through the axon terminal and eventually reaches the synaptic terminal
- The depolarization of the synaptic terminal from the action potential induces opening of the Ca2+ voltage gated channels
- Exocytosis of synaptic vesicles containing acetylcholine (ACh) and Ach binds with ligand gated ion channel coupled receptors
- This allows the opening of the channel which in turn cause the flux of Na+ ions inside the muscle fibre
- Accumulation of Na+ within the cell = depolarization of the membrane = End plate potential
- The action potential spreads throughout the T tubules of the muscle fibre
- Depolarization promotes activation of the Ca2+ voltage gated channels located on the plasma membrane and in the T tubules
- Opening of the Ca2+ channels causes influx of Ca2+ ions inside the cell
- Increases in the intracellular Ca2+ concentration open Ca2+ voltage gated channels of the SR near the T tubules allowing even greater increase of intracellular Ca2
What neurotransmitter is released from the post-ganglionic terminal bouton (sympathetic NS)
noradrenaline
What type of neuron does the somatic NS have
1 efferent neuron from the CNS to the target organ
Define myotome
a group of muscles a single nerve innervates
True or false:
Sympathetic nervous system has
• 1 short preganglionic neuron from the CNS
• Ach released from the pre-g terminal bouton
• Post ganglionic neuron has a nicotinic receptor
True
How does the sympathetic pathway effect micturition
causes the upper portion (detrusor muscle) relax and bladder neck to contract, to store urine
What does the back horn contain
Sensory nerve cells
What is the function of Gq
Activates PLC which ↑IP3. DAG + Ca2+=PKC activation
What is the receptor on the target organ for the somatic NS
• A nicotinic/ionotropic Ach receptor is found on the target organ
The external sphincter is under voluntary control from which NS
Somatic
What do the lumbar and sacral spinal nerves control
supply hip, leg, foot muscles
sacral nerves supply anal/urethral sphincters
What are the functions of CSF
protects the brain and CNS from injury by acting as a shock absorber, and buoys the brain in the cranial cavity.
It also has a circulatory function where it delivers nutritive substances filtered from blood to the brain and spinal cord, and removes waste and toxic substances produced by the brain and spinal cord cells.
What type of enzyme inhibits kinases
phosphatases
What is the function of Gi
↓CAMP via adenylate cyclase
Example receptors for Go
Opioids
What is the function of Go
Activates K+ channels and Inhibits Ca2+ channels
In the sarcomere, the A band is light/dark
dark
What do the thoracic spinal nerves control
supply truck muscles and muscles involved with breathing
intercostal and abdominal muscles
Which the the key muscle for micturition
Detrusor muscle
when does spina bifida occur
when the neural tube fails to close during the first month of embryonic development
spinal cord and meningeal membranes protrude
In the sarcomere, the I band is light/dark
light
Which diagnostic procedure analyses CSF
Lumbar puncture
Are M2 Gαi or Gαq
Gαi
For urination, which nerves does the parasympathetic signal travel down
Nerves S2, 3 and 4
Describe motor nerves/neurones
pass info from brain to skeletal muscles through spinal tracts
direct precise voluntary movements
Explain the steps in the actin and myosin complex- leading to powerstroke
- ADP + Pi bound to myosin head
- Ca2+ binds to TnC
- Conformational change in thin filament
- TnI inhibitory region released from actin and Tm moves, so filament switched on
- Myosin cross bridges form (bind to actin)
- Power Stroke
- ADP + Pi released
- Myosin-ATPase binds ATP
- Detach from actin
- ATP hydrolysed
- Myosin head ‘cocks’
Define motor unit
group of muscle fibres and single motoneuron
What is the function on Gs
↑CAMP via adenylate cyclase
Which band disappears when the muscle contracts
I band
Sympathetic nervous system is always…
Adrenergic
The autonomic nervous system is divided into what two branches
parasympathetic and sympathetic
What does the sodium influx caused because of the Ach binding to the nicotinic receptors generate
Mini-endplate potential
What is the subunit for Gs and Gi
α
Why is the H band lighter than the A band
presence of myosin
What type of post-ganglionic neuron does the PNS have
1 short
How many pairs of vertebrae protect the spinal cord
23
What are the 4 sections of the spine
- Cervical (C1-C8)
- Thoracic (T1-T12)
- Lumbar (L1-L5)
- Sacral (S1-S5)
Are M3 Gαi or Gαq
Gαq
What does CSF contain
proteins, glucose, urea and salts, as well as some lymphocytes
Define dermatome
a group of muscles a single nerve innervates
Define neuromuscular disease
Due to disease or damage of somatic motor neurons, neuromuscular junctions, or muscle fibres
Describe neural tube closing steps
- The neural plate is formed (thickening of the ectoderm) when the cells change shape and the edges curl in to the midline to form a tube
- The cells at the tip of the neural folds come to lie between the neural tube and epidermis
- These cells become the neural crest cells
How can botox affect incontinence
Botox blocks the actions of Ach and paralyses the bladder muscle to reduce over-reactive bladder symptoms
Where can CSF move between
brain and spinal cord via the sub-arachnoid space and through the ventricles of the brain
How does the parasympathetic pathway effect micturition
Causes the upper part (detrusor muscle )of the bladder to contract, neck to relax assisting micturition
What receptor is on the target organ of the PNS
Muscarinic Ach
Do these relax or contract?
M2 Heart M3 Smooth Muscle Bladder Detrusor Airways GI tract
M2- relax
M3- contract
When the α is active, what happens to the β and Ƴ subunits
They diffuse away
Give 2 functions of the sympathetic division
- dilatespupils
- inhibits saliva production
- dilates bronchi
- increases heart rate
- inhibits GI function
- inhibits urination
- stimulates adrenaline/noradrenaline release
- stimulates glucose release
What length post-ganglionic neuron does the sympathetic NS have
Long
How many pairs of spinal nerves are there
31
Example receptors for Gq
Muscarinic AchR
M3 and α1
mGluR
What do the cervical spinal nerves control
supply muscles of the neck, shoulders, arms, hands and diaphragm
e.g. extending elbow/fingers
How do M3 muscarinic agonists effect micturition
they keep the detrusor muscle relaxed and the internal sphincter closed.
What happens after a mini-endplate potentail
This depolarises the sarcolemma and causes and end plate potential.
True or False: Muscle fibres act in syncytium
True
