Nervous System Flashcards
Differences between nerves and hormones cell communications
Nerves is faster, localised, specific. Hormones is slower but effects last longer
Paracrine
1 -> few
Endocrine
1 to many
Autocrine
Feedback
Synapse
1 to 1
Electrical synapse
Contact via gap junctions, ions can flow in both directions
G proteins function
Since peptide transmitters cannot pass through the cell membrane, it binds to receptors on the surface and activates G proteins. These G proteins activate 2nd messenger systems such as cAMP and calcium ions
Calcium-calmodulin and cAMP as second messengers
Is the inside or outside of the cell more positive?
Outside of the cell. Therefore resting membrane potential is -70.
Sodium potassium pump
3 sodium ions out 2 potassium ions in
Depolarisation
Closer towards zero
Hyperpolarisation
Further away from zero
Action potential occurs at what membrane potential
-55. If below -55, just graded potential
When do voltage gated sodium ion channels shut
+35. Potassium channels open
Why is there Hyperpolarisation?
Potassium ion channels are slow to shut
What constitutes the refractory period?
Repolarisation (sodium ion channels shut) and Hyperpolarisation (potassium ion channels slow to shut)
How does local anaesthetic work?
Blocks the sodium ion channels from opening
What is EPSP
Excitatory post synaptic potential
IPSP
Inhibitory post synaptic potential. Transmitter causes Hyperpolarisation
Temporal and spatial summation
Spatial - many neurones connect to one neurone
Temporal - nerve impulses arrive in quick succession from the same presynaptic neurone
3 special features of NMJ
- Many folds in postsynaptic membrane to store AchE to return to presynaptic
- More receptors
- Ach is always excitatory
Organisation of nervous system
CNS brain and spinal cord
PNS cranial and spinal nerves
The name for autonomic pathway
Visceral Afferent and efferent
How many pairs of spinal nerves
31
How many pairs of cranial nerves
12
Name the 12 cranial nerves
Olfactory
Optic
Oculomotor
Trochlear
Trigeminal
Abducens
Facial
Vestibulocochlear
GGlossopharyngeal
Vagus
Accessory
Hypoglossal
Peripheral nerve histological components
Endo peri and epineurium
Grey matter
Unmyelinated
White matter
Myelinated. Rmb that myelin has fat so white
What are the different fibres and myelination of fibres
A fibres are myelinated c fibres are not. A fibres are much wider in the diameter
Dermatomes
The region where sensory nerves act
Myotomes
The region where motor nerves act
Other than smooth and cardiac muscle. What two other comes under the autonomic nervous system
Glands and adipose tissues
What is one transmitter than can pass through the cell membrane
Steroid transmitter are lipids
Act on receptor inside the target cell
3 meninges
PAD
PIA MATER
ARACHNOID MATER
DURA MATER
5 regions in the spinal cord
Cervical
Thoracic
Lumbar
Sacral
Coccygeal
Which root for motor
Ventral horn, ventral root
What is the dorsal root ganglion
Collection of cell bodies of sensory neurons, pseudounipolar
What is ramus
Posterior ramus connects the back part of the body and anterior ramus connects the front of the body
What is somatic Afferent
External sensory afferent . Visceral effects are for internal body
4 parts of the brain
Cerebrum
Cerebellum
Diencephalon (thalamus and hypothalamus)
Brain stem (pons, medulla oblongata, midbrain)
4 lobes of the brain
Frontal
Parietal
Temporal
Occipital
Try to rmb that parietal sounds like parents and parents on top. Occipital is the back
What is part of the forebrain
Cerebrum and diencephalon
What is part of the hindbrain
Cerebellum pons medulla
Function of hypothalamus
Homeostasis thermoregulation osmolarity
Hormones (RH=releasing hormones)
Assoc with pituitary gland
Circadian rhythms
Thirst
Emotions
Sexual behaviour
Cerebrum
Biggest part, associated with motor
Language memory perceptions emotions
Sensory and motor functions
Where is grey matter found in the brain
Cerebral cortex , outer layer
Where is the white matter found in brain
Corpus callosum
The corpus callosum is a large bundle of more than 200 million myelinated nerve fibers that connect the two brain hemispheres, permitting communication between the right and left sides of the brain.
Cortical sensory areas in the brain
Somastatory ie touch , is located at the parietal region, next to the frontal lobe
Visual is located at the occipital region (back)
Auditory is at the temporal lobe, right underneath the parietal lobe
Taste ie gustatory is below the frontal
Smell ie olfactory is below the gustatory
What is somatosensory
Touch
Exteroceptors
Information about external environment
Proprioceptors
Report positions and movements of skeletal muscles and joints
Interoceptors
Monitor visceral organs and functions
Function of the cerebrum
Sensory and motor functions, most Complex
Memory, language
Perception
Integration
Emotions
Function of the thalamus
Sensory processing
Function of cerebellum
Control of balance and posture
Function of midbrain
Processes visual and auditory data
Function of pons
Relays sensory information to cerebellum and thalamus
What is the adrenal medulla part of
Sympathetic NS
Where are the Preganglionic neurons of the sympathetic nervous system located in the spinal cord
T1-L2
Where are the Preganglionic neurons of the parasympathetic nervous system located in the spinal cord
brainstem, CN 3 7 9 10 , S2-4
Which system has long pre and short post ganglionic fibres
Parasympathetic
Which system has short pre and long post ganglioninc fibres, why
Sympathetic. Ganglia located near spinal cord
Where does Ach act on
Nicotinic and muscarinic receptors (2 types of cholinergic receptors)
Where does noradrenaline and A act on
Adrenergic receptors (alpha and beta)
What nerves control breathing
Somatic nerves (phrenic nerve)
Diff between sympathetic and para
Sympathetic has widespread actions around the body
Parasympathetic has discreet actions on single organs
What is vascular tone
Control of the dilation of blood vessels by sympathetic nerves
Which nerves control heart rate
Parasympathetic nerves (vagus) and sympathetic nerves in dual control. Vagus bring heart rate down and sumo nerves increase heart rate
Which nerve innervates the temporalis and masseter
Trigeminal , mandibular division (V3)
What nerves innervates the parotid gland
NOT facial but Glossopharyngeal
What nerves innervate the sublingual and submandibular gland
Chorda tympani nerve in the mandibular region of the FACIAL NERVE
What supplies the buccinator
Buccal branch of the facial nerve
What supplies the orbicularis oculi
Zygomatic branch of the facial nerve
What supplied the muscles of lower lip
Mandibular branch of the facial nerve
What does the Glossopharyngeal nerve supply
Parotid gland
What cranial nerves Carries taste sensation
Anterior 2/3 facial nerve
Posterior 1/3 Glossopharyngeal
Nerve supply of the pharynx
MVSG
motor vagus except stylopharngeus
Sensory Glossopharyngeal
Nerve fibres mostly common,y associated with tooth pain
A delta and c fibres
Functions of CSF
supports the Brian
Cushions the brain against trauma
Transports nutrients chemical messengers and waste
