FUNCTIONAL ANATOMY - Sensory Inputs and Motor Outputs Flashcards
What are the three functional classifications of neurones?
Sensory (afferent) neurones
Inter-neurones
Motor (efferent) neurones
What is the dendritic zone?
The receptive surface of a neurone
What is the dendritic zone of sensory (afferent) neurones?
Sensory receptor
What are the three classifications of sensory receptors?
Exteroceptors
Proprioceptors
Interoceptors
What are exteroceptors?
Exteroceptors are sensory receptors on or close to the body’s surface and detect changes in the external environment
What are proprioceptors?
Proprioceptors are sensory receptors which sense movement of muscles, tendons and joints
What are interoceptors?
Interoceptors are sensory receptors located in the viscera and thus sense changes in the internal environment
How are sensory (afferent) neurones classified in the peripheral nervous system (PNS)?
In the peripheral nervous system (PNS) the sensory (afferent) neurones are classified based on the location of the dendritic zone (sensory receptor) within the body
What are the two main classifications of the sensory (afferent) neurones in the peripheral nervous system?
Somatic afferent neurones
Visceral afferent neurones
What is the difference between somatic and visceral afferent neurones?
The dendritic zone of somatic afferent neurones is located on or near the surface of the body, whereas the dendritic zone of visceral afferent neurones is located in the viscera
What are the two subdivisions of somatic afferent neurones?
General somatic afferent (GSA) neurones
Special somatic afferent (SSA) neurones
Which four sensory stimuli are detected by general somatic afferent (GSA) neurones?
Touch
Temperature
Pain
Proprioception
Which cranial nerves have general somatic afferent (GSA) neurones?
Cranial nerve V (Trigeminal nerve)
Cranial nerve VII (Facial nerve)
Which spinal nerves have general somatic afferent (GSA) neurones?
All spinal nerves
Which two sensory stimuli are detected by special somatic afferent (GSA) neurones?
Vision
Sound
Which two cranial nerves have special somatic afferent (SSA) neurones?
Cranial nerve II (Optic nerve)
Cranial nerve VIII (Vestibulocochlear nerve)
What are the two subdivisions of visceral afferent neurones?
General visceral afferent (GVA) neurones
Special visceral afferent (SVA) neurones
Which three sensory stimuli are detected by general visceral afferent (GVA) neurones?
Organ content
Distention
Chemicals
Which three cranial nerves have general visceral afferent (GVA) neurones?
Cranial nerve VII (Facial nerve)
Cranial nerve IX (Glossopharyngeal nerve)
Cranial nerve X (Vagus nerve)
Which spinal nerves have general visceral afferent (GSA) neurones?
All spinal nerves
Which two sensory stimuli are detected by special visceral afferent (SVA) neurones?
Olfaction (smell)
Taste
Which four cranial nerves have special visceral afferent (SVA) neurones?
Cranial nerve I (Olfactory nerve)
Cranial nerve VII (Facial nerve)
Cranial nerve IX (Glossopharyngeal)
Cranial nerve X (Vagus nerve)
What are sensory spinal tracts?
Sensory spinal tracts are neural pathways in the spinal cord which transmit sensory information from the periphery to the brain
List four sensory spinal tracts
Fasciculus gracilis
Fasciculus cuneatus
Spinocerebellar tracts
Spinothalamic tracts
What sensory information is transported from the spinal cord to the brain by the fasciculus gracilis?
Proprioceptive information from the hindlimbs
What sensory information is transported from the spinal cord to the brain by the fasciculus cuneatus?
Proprioceptive information from the forelimbs
In which anatomical region of the brain does the spinocerebellar tracts transport sensory information to?
Cerebellum
In which anatomical region of the brain does the spinothalamic tracts transport sensory information to?
Thalamus
What is the dendritic zone of motor (efferent) neurones?
Dendrites
How are motor (efferent) neurones classified in the peripheral nervous system (PNS)?
In the peripheral nervous system (PNS) the motor (efferent) neurones are classified based on the location of the axon terminal within the body
What are the two classifications of the motor (efferent) neurones in the peripheral nervous system?
General somatic efferent (GSE) neurones
General visceral efferent (GVE) neurones
What is the different between general somatic and general visceral efferent neurones?
The axon terminals of general somatic efferent (GSE) neurones are located in skeletal and cardiac muscle fibres, however the axon terminals of general visceral efferent (GVE) fibres are located in smooth muscle fibres
Which cranial nerves have general somatic efferent (GSE) neurones?
All cranial nerves except I, II and VIII
Which spinal nerves have general somatic efferent (GSE) neurones?
All spinal nerves
Which cranial nerves have general visceral efferent (GSE) neurones?
Cranial nerve III (Oculomotor nerve)
Cranial nerve VII (Facial nerve)
Cranial nerve IX (Glossopharyngeal nerve)
Cranial nerve X (Vagus nerve)
Cranial nerve XI (Accessory nerve)
Which spinal nerves have general visceral efferent (GSE) neurones?
All spinal nerves
What are motor spinal tracts?
Motor spinal tracts are neuronal pathways within the spinal cord which transmit motor information from the brain to the periphery
List five motor spinal tracts
Corticospinal tracts
Rubrospinal tracts
Reticulospinal tracts
Vestibulospinal tracts
Tectospinal tracts
From where in the brain does the corticospinal tract transport motor information to the spinal cord?
Cerebral cortex
From where in the brain does the rubrospinal tract transport motor information to the spinal cord?
Red nucleus in the brainstem
From where in the brain does the reticulospinal tract transport motor information to the spinal cord?
Reticular formation in the brainstem
From where in the brain does the vestibulospinal tract transport motor information to the spinal cord?
Vestibular nuclei in the brainstem
From where in the brain does the tectospinal tract transport motor information to the spinal cord?
Tectum region of the brainstem
What is the main test used to assess proprioception?
Proprioceptive placing
Describe the proprioceptive placing test
Flex the paw so the dorsal surface is on the floor and the animal should immediately return the paw to the normal position
What is the disadvantage of proprioceptive testing?
Proprioceptive testing identifies that the problem is neurological, however it does not localise the lesion
What are the four tests that can be used to assess motor function?
Gait
Muscle tone assessment
Patellar reflex
Withdrawal reflex
Describe the grading scale for spinal cord injuries
0: Normal
1: Pain
2: Ambulatory paresis (weak but can walk)
3. Non-ambulatory paresis (cannot walk)
4. Plegia (paralysis)
5: Plegia with an absent pain sensation
