Physiology Flashcards
1
Q
- Name the four types of neurons
- How are they defined?
- Define each
- What are the four functional regions of neurons
A
- Unipolar, pseudounipolar, bipolar, multipolar
- Number of neurites
- Unipolar-one neurite
Pseudounipolar- one neurite that bifurcates
Bipolar-two neurites
Multipolar-three or more neurites - Input, integrative, conductive and output
2
Q
- The upstroke of an action potential is caused by an _______ of _________ ions through voltage gated _______ ion channels.
- The downstroke of an action potential is caused by an ______ of _________ ions through voltage gated ______ ion channels.
- Myelinated axons exhibit __________ conduction between the nodes of __________.
A
- Influx, sodium, sodium
- Efflux, potassium, potassium
- Saltatory, Ranvier
3
Q
- What are the three different morphological types of synapses?
- What are the two different functional types of synapse?
- What are the two possible potentials called?
- What is the difference between spatial summation and Temporal summation
- Name the two types of neurotransmitter receptors
A
- Axodendritic, Axosomatic, Axoaxonic
- Inhibitory and excitatory synapses
- Excitatory and Inhibitory Post-synaptic Potential
- Spatial- many inputs converge on a neuron to determine its output.
Temporal- one input modulates the output of one neuron - Ionotropic- act on ion channels directly
Metabotropic- act on ion channels indirectly
4
Q
- Somatosensory neurones are mostly composed of ______ neurones in series.
- What is meant by modality?
- What is meant by threshold?
A
- Three
- The type of stimuli that excites a sensory nerve e.g. nociception/mechanoreception
- The intensity of stimuli necessary to elicit a response- some neurones low threshold, others high
4.
5
Q
- Define adaptation
- What is meant by Slowly Adapting (SA)
- What is meant by Fast Adapting (FA)
A
- is a feature of sensory units that determines whether they change their firing rate only in response to a stimulus of changing intensity, or fire continuously throughout a constant stimulus
- The units discharge action potentials at a constant, or very gradually reducing, frequency throughout the period of a suprathreshold stimulus.
- action potentials are discharged initially, but then the unit becomes become ‘silent’ despite the stimulus persisting
6
Q
- What does RF stand for?
- What does it mean?
- ______ _____ is the ability to discriminate between stimuli that are separated in space
A
- Receptive field
- Target territory from which a sensory unit can be excited.
- Spatial Acuity,
7
Q
- Identify some sensory receptors found in the skin
A
- free nerve endings, Pacinian corpuscles, Meissners Corpuscules, Merkel’s discs, Krause end bulbs, Ruffini endings
8
Q
- Spinal cord consists of _______ (cell bodies and sensory afferent terminals) and ______(fibre tracts) matter the relative proportions of which vary along its length. _____ matter subdivided into ______(posterior) and ______ (anterior) horns and ten distinct _______ of ______.
- Name the two somatic sensory pathways.
- What information is carries by each?
A
- Grey, white, Grey, dorsal, ventral, laminae of Rexed
- DCML (Dorsal Column Medial Lemniscal pathway) and STT (Spinothalamic tract)
- DCML– Discriminatory touch (stereognosis), pressure, vibration, conscious proprioception
STT– Pain, thermosensation, crude touch, itch, tickle
9
Q
- Name the two ascending tracts of the dorsal column
- The decussation of the DCML occurs at the _________, whereas the decussation of the STT occurs at all levels on the spinal cord.
- What happens to the somatosensory cortex if a finger (say D3) is lost in an accident, or amputated?
A
- Gracile and Cuneate tracts
- Brainstem
- The area formerly representing D3, after several months, now responds to stimulation of the adjacent digits (D2 and D4 – their cortical representation expands into the territory formerly representing D3).
10
Q
- Name the cortex which deciphers information received from the post-central gyrus?
- What is the name given to the different areas of the somatosensory cortex?
A
- Posterior parietal cortex
2. Brodmann areas
11
Q
- Name the two lateral pathways of the spinal cord
2. Name the four ventromedial pathways
A
- Lateral corticospinal tract and rubrospinal tract
2. Pontine and medullary reticulospinal tract, tectospinal tract, vestibulospinal tract.
12
Q
- What does the somatic motor system consist of?
- Upper motor neurones (UMNs) are within the _____ and lower motor neurones (LMNs) are with soma within the brain stem and _____ horn of the spinal cord. UMNs supply input to LMNs to ________ their activity
- LMNs comprise _______ ______ ________ (α-MNs) that innervate the bulk of fibres within a muscle that generate force. _________ motor neurones (γ-MNs) innervate a sensory organ within the muscle known as a _______ ________.
A
- Skeletal muscle and Upper/Lower motor neurones
- Brain, ventral, modulate.
- alpha motor neurones, Gamma, muscle spindle
13
Q
- Muscles that work together to perform an action are called ________. Meanwhile muscles that work against these are called _________.
- Define a motor unit.
- Define a motor neuron pool
A
- Synergists, antagonists
- A single alpha motor neuron and all the skeletal muscle it innervates
- A collection of motor neurons that innervate a single muscle
4.
14
Q
- What are the four graded stages of muscle activation
2. What are the two major types of skeletal muscle and what colour is each? What other three divisions are there?
A
- Twitch (one action potential), wave summation (collection), unfused tetanus, fused tetanus.
- Slow-oxidative (red meat) and Fast-glycolytic (white meat). Fast fatiguing, fatigue resistant and slow fatiguing
15
Q
Activation of an upper motor neurone (UMN) causes the \_\_\_\_\_\_\_motor neurones that it supplies to be excited. Motor units (LMNs and the muscle fibres that they innervate) are recruited in the order of their \_\_\_\_ (i.e. progressively increasing – small LMNs are more easily excited than large LMNs) Activation in such an order allows for a \_\_\_\_\_ \_\_\_\_\_\_ of muscle force across a wide range of \_\_\_\_\_\_\_ developed.
A
Lower, size, fine control, tensions