Animal Health Science Weeks 1-13
,Gait & Posture
Neurological Examination:
• Neurological or orthopaedic issue?
• Brain or spinal cord issue?
• Level of spinal cord issue?
Muscle Tone Testing:
• Flex & Extend muscles
• Palpate muscles for atrophy
• Visually examine locomotion
Reflex Testing:
• Patella Reflex (Pull Tail in Horses)
• With-drawl flexor reflex (Pinch distal skin)
• Perineal Reflex
• Cutaneous Trunci Reflex (Skin Twitch)
Brain Diseases
(Effect Upper Motor Neurones)
• Midbrain (Red Nucleus & Substantia Nigra)
• Pons (Reticulospinal tract)
• Medulla (Reticulospinal tract)
• Cerebrum (Ataxia)
Spinal Diseases
(Effects upper & lower Motor Neurones)
• Vertebral malformations
• More common in certain breeds e.g. Great
Danes & Arabian Horses
,Sensory Pathways (Gait & Posture) Mechanoreceptors: activated
by touch or pressure.
Decuss
other s
Gait: pattern of movement during locomotion, The Medial Lemniscal Tract
Posture: normal positions of limbs or body within an animal.
involves lots of neuronal systems. This pathway is important for conveying inform
about touch, pressure & conscious perception.
Motor Afferent Pathways Medial Lemniscal Tract • 3 neurone tract
Conscious Sensations:
• Special senses (Vision, olfaction, hearing, balance)
Neurone One (Dorsal Column Pathway)
• Touch, pressure, proprioception (Medial Lemniscal Tract)
• Long fibres run length of spinal cord
• Pain (Spinoreticular Tract)
• Run in dorsal column of spinal cord
Clinical Examination Proprioception Red: Gracile Fasciculi = transmit
Tests the animals ability to determine if its information from lower trunk & hindlimbs.
body is the right position & ability to correct it.
• Paw replacement reaction Yellow: Cuneate Fasciculi = transmit
• Hopping response information from upper trunk & forelimbs.
• Wheelbarrowing
Pain Pathways Neurone Two
Pain has pathways through all the funiculi: Found in dorsal medulla as swellings.
• Spinoreticular
• Spinothalamic There are 2 nuclei in this pathway:
• Spinomesencephalic • Gracile Nuclei
• Spinocervicothalamic • Cuneate Nuclei
After this point the axons of neurone 2
Conscious Perception: all pathways project decussate & run in tracts called the medial
to somatosensory cortex via thalamus. lemniscus.
Clinical Assessment of Pain
Neurone Three
• Compress skin at base of digit
This neurone is found in the Thalamus. It projects
• Lightly touch nasal mucosa
to the sensory cortex via the internal capsule
Hyporeflexia: loss of reflexes.
where sensation is perceived.
Hypoalgesia: reduction of pain sensation (Nociception)
, Neurological Tracts Somatic Efferent Systems CNS (Motor Pathways)
Pyramidal/Corticospinal:
• Conscious control
Extra Pyramidal (Rubrospinal) Extrapyramidal: • Upper Motor Neurones
• Rubrospinal Tract • Neurones originate from cerebral cortex
• Neurones originate in subcortical regions
• Vestibulospinal Tract • Neurones descend into ventral brain stem through pyramids.
• Multi-synaptic neurones
• Tectospinal Tract [Important Tract for humans/primates in distal limb movement]
• Neurones sit outside pyramidal structures
• Originates from red nucleus • Reticulospinal Tract
[Rubrospinal tract & Reticulospinal tract]
• Important for animals who require Paresis = poor gait generation/weight support.
gait/posture/balance. Tectospinal tract
Upper Lesion = Spastic Paralysis
closely
Lower Lesion = Flaccid Paralysis associated with
Ventral Horn: when fibres reach the desired Paralysis/Plegia = complete loss of voluntary function. optic nerve.
location in the spinal cord, they leave into Ataxia = incoordination.
the periphery via the ventral horns.
Upper: poor gait, normal or increased reflexes, disuse atrophy, increased tone, tetany & spastic paralysis.
Lower: flaccid paralysis, poor weight support, decreased tone & decreased reflexes. (Motor Neurone Disease).
Upper & Lower Motor Neurones
Upper:
Lower Motor Neurones • Completely contained within the CNS When uppe
As an upper motor neurone is leaving the spinal cord it will • Initiate voluntary movement neurones a
join a lower neurone. • Maintain muscle tone & Regulate posture removes th
action of lo
Lower motor neurones can be Alpha or Gamma. Lower: (Spinal Nerve or Cranial Nerve)
Alpha = voluntary contractions/reflexes. • General somatic efferent fibres to Skeletal muscle
neurones &
Gamma = resting muscle tone & sensitivity of muscle spindles. • Cell bodies in ventral horn of spinal cord or cranial nerve nuclei there is inc
• Axons project into peripheral nervous system via spinal/cranial nerves. reflexes.
,Gait & Posture
Neurological Examination:
• Neurological or orthopaedic issue?
• Brain or spinal cord issue?
• Level of spinal cord issue?
Muscle Tone Testing:
• Flex & Extend muscles
• Palpate muscles for atrophy
• Visually examine locomotion
Reflex Testing:
• Patella Reflex (Pull Tail in Horses)
• With-drawl flexor reflex (Pinch distal skin)
• Perineal Reflex
• Cutaneous Trunci Reflex (Skin Twitch)
Brain Diseases
(Effect Upper Motor Neurones)
• Midbrain (Red Nucleus & Substantia Nigra)
• Pons (Reticulospinal tract)
• Medulla (Reticulospinal tract)
• Cerebrum (Ataxia)
Spinal Diseases
(Effects upper & lower Motor Neurones)
• Vertebral malformations
• More common in certain breeds e.g. Great
Danes & Arabian Horses
,Sensory Pathways (Gait & Posture) Mechanoreceptors: activated
by touch or pressure.
Decuss
other s
Gait: pattern of movement during locomotion, The Medial Lemniscal Tract
Posture: normal positions of limbs or body within an animal.
involves lots of neuronal systems. This pathway is important for conveying inform
about touch, pressure & conscious perception.
Motor Afferent Pathways Medial Lemniscal Tract • 3 neurone tract
Conscious Sensations:
• Special senses (Vision, olfaction, hearing, balance)
Neurone One (Dorsal Column Pathway)
• Touch, pressure, proprioception (Medial Lemniscal Tract)
• Long fibres run length of spinal cord
• Pain (Spinoreticular Tract)
• Run in dorsal column of spinal cord
Clinical Examination Proprioception Red: Gracile Fasciculi = transmit
Tests the animals ability to determine if its information from lower trunk & hindlimbs.
body is the right position & ability to correct it.
• Paw replacement reaction Yellow: Cuneate Fasciculi = transmit
• Hopping response information from upper trunk & forelimbs.
• Wheelbarrowing
Pain Pathways Neurone Two
Pain has pathways through all the funiculi: Found in dorsal medulla as swellings.
• Spinoreticular
• Spinothalamic There are 2 nuclei in this pathway:
• Spinomesencephalic • Gracile Nuclei
• Spinocervicothalamic • Cuneate Nuclei
After this point the axons of neurone 2
Conscious Perception: all pathways project decussate & run in tracts called the medial
to somatosensory cortex via thalamus. lemniscus.
Clinical Assessment of Pain
Neurone Three
• Compress skin at base of digit
This neurone is found in the Thalamus. It projects
• Lightly touch nasal mucosa
to the sensory cortex via the internal capsule
Hyporeflexia: loss of reflexes.
where sensation is perceived.
Hypoalgesia: reduction of pain sensation (Nociception)
, Neurological Tracts Somatic Efferent Systems CNS (Motor Pathways)
Pyramidal/Corticospinal:
• Conscious control
Extra Pyramidal (Rubrospinal) Extrapyramidal: • Upper Motor Neurones
• Rubrospinal Tract • Neurones originate from cerebral cortex
• Neurones originate in subcortical regions
• Vestibulospinal Tract • Neurones descend into ventral brain stem through pyramids.
• Multi-synaptic neurones
• Tectospinal Tract [Important Tract for humans/primates in distal limb movement]
• Neurones sit outside pyramidal structures
• Originates from red nucleus • Reticulospinal Tract
[Rubrospinal tract & Reticulospinal tract]
• Important for animals who require Paresis = poor gait generation/weight support.
gait/posture/balance. Tectospinal tract
Upper Lesion = Spastic Paralysis
closely
Lower Lesion = Flaccid Paralysis associated with
Ventral Horn: when fibres reach the desired Paralysis/Plegia = complete loss of voluntary function. optic nerve.
location in the spinal cord, they leave into Ataxia = incoordination.
the periphery via the ventral horns.
Upper: poor gait, normal or increased reflexes, disuse atrophy, increased tone, tetany & spastic paralysis.
Lower: flaccid paralysis, poor weight support, decreased tone & decreased reflexes. (Motor Neurone Disease).
Upper & Lower Motor Neurones
Upper:
Lower Motor Neurones • Completely contained within the CNS When uppe
As an upper motor neurone is leaving the spinal cord it will • Initiate voluntary movement neurones a
join a lower neurone. • Maintain muscle tone & Regulate posture removes th
action of lo
Lower motor neurones can be Alpha or Gamma. Lower: (Spinal Nerve or Cranial Nerve)
Alpha = voluntary contractions/reflexes. • General somatic efferent fibres to Skeletal muscle
neurones &
Gamma = resting muscle tone & sensitivity of muscle spindles. • Cell bodies in ventral horn of spinal cord or cranial nerve nuclei there is inc
• Axons project into peripheral nervous system via spinal/cranial nerves. reflexes.
