1. The document discusses the motor system and different types of motor neurons. It describes upper motor neurons that originate in the brain and carry signals to lower motor neurons. 2. Lower motor neurons are located in the spinal cord and brainstem and innervate skeletal muscles. Lesions or damage to lower motor neurons or their axons result in flaccid paralysis, muscle wasting, and loss of reflexes. 3. Specific conditions that damage lower motor neurons or their connections to muscles are also mentioned, including polio and peripheral neuropathies. Tests for lower motor neuron lesions include assessing for muscle fasciculations and reactions to electric stimulation.

2.  HAFSA KHALID
 LAIBA ROOP PAUL
 AQSA MUSHTAQ
 MARYAM KHALID
 LAREB SATTAR
 SABIHA MANZOOR
 NOOR FAIZA

4. The motor system is the part of the central nervous
system that is involved with movement.
 It consists of :
 Pyramidal and extrapyramidal system tracts from
UMN & LMN

5.  A motor neuron is a nerve cell (neuron)
whose cell body is located in the spinal
cord and whose fiber (axon) projects
outside the spinal cord to directly or
indirectly control effector organs, mainly
muscles and glands.
 Motor neurons' axons are efferent
nerve fibers that carry signals from the
spinal cord to the effectors to produce
effects.

7. Types of motor neurons
 There are two types of motor neurons:
1. Upper motor neuron
2. Lower motor neuron

8. Upper motor neurons (UMNs)
 are motor neurons that originate either in
the motor region of the cerebral cortex or in
the brain stem and carry motor information
down to the lower motor neurons.

10. LOWER MOTOR NEURON
 are neurons whose cells bodies are located in
either the ventral (anterior) horn of the spinal
cord gray matter and in the motor nuclei of
the cranial nerves in the brainstem.

11.  All voluntary movement depend
upon excitation of lower motor
neuron by upper motor neuron .
 These are the only neurons that
innervate the skeletal muscle
fibers, they function as the final
common pathway, the final link
between the CNS and skeletal
muscles

13.  A lesion is any abnormal
damage or change in the
tissue of an organism,
usually caused by disease
or trauma.
 Lesion is derived from the
Latin word laesio meaning
injury.

14.  Destruction of motors
which supply the
muscles.
 It starts from anterior
horn cell ends at the
muscles.

15.  Lower motor neurons are classified based on
the type of muscle fiber they innervate:
 Alpha motor neurons (α-MNs)
 Gamma motor neurons (γ-MNs)

16. Alpha motor neurons (α-MNs)
 Alpha motor neurons (α-MNs)
innervate extra fusal muscle
fibers, the most numerous type
of muscle fiber and the one
involved in muscle contraction.

17. Gamma motor neurons
(γ-MNs)
 Gamma motor neurons (γ-MNs)
innervate intrafusal muscle fibers,
which together with sensory
afferents compose muscle
spindles.
 These are part of the system for
sensing body position
(proprioception)

18. 1. Destruction in the anterior horn
cell : Poliomyelitis, motor neuron
diseases
2. Motor nerve (peripheral) is affected
: Traumatic stress, peripheral
neuropathy.
3. Abnormal stimulation at
Neuromuscular junction:
Myasthenia gravis
4. Myomatous for muscles : Neoplasm
"Truma“, muscular dystrophies.

19. 1- Motor affection:
2- Reflex affection in LMNL:
3- Reaction of degeneration (Electric
current):

20. 1- Motor affection:
1. Flaccid paralysis : Defection in
the muscle. Loss of ability to a
body part.
2. Muscle wasting : Atrophy in the
muscle due to losing of muscle
function (Muscle can not contract
voluntary but reflex).
3. Atonia : complete loss of muscle
tone as the nerve fibers is
affected.
4. Facial nerve: it affects one half
of face.(Bells palsy)

21. Bell's palsy
 Bell's palsy is a condition in
which the muscles on one side of
your face become weak or
paralyzed.
 It affects only one side of the face
at a time, causing it to droop or
become stiff on that side.
 It's caused by some kind of
trauma to the seventh cranial
nerve. This is also called the
“facial nerve.”

22.  The electrotherapy modalities included:
 Electrical stimulation (ES),
 Ultrasound,
 Electromyography

23.  No evidence support electrical
stimulation benefit for acute
facial paralysis but it's effective
for chronic condition
 Ultrasound can be beneficial for
acute conditions

24. 2- Reflex affection in LMNL:
1. Deep reflex : Loss of deep
reflex.
2. Superficial reflex : still going
if the muscle isn’t affected.
Bibinski sign is negative.
3. Absence of tonic neck
reflex

26. Tonic neck reflex Fencing
posture
 When newborn lie on their backs,
their head usually turn to one side or
the other.
 The arm and the legs on the side
toward which the head turns extend,
and the opposite arm and leg
contract.
 This is also called the boxer or
fencing reflex.
 The reflex disappears between the
second and third months of life

27. 3- Reaction of degeneration
(Electric current):
1. Prolonged chronaxie "Time
to get stimulation“
2. Respond to faraday current
only without galvanic
current.
3. Fibrillation: Irregular
unorganized invisible
spontaneous contraction of
muscle.

28. 3. Fasciculation: Irregular
unorganized visible spontaneous
contraction of muscle.
4. Anodal closure contraction IS
BIGGER THAN cathode closure
contraction

29. Fasciculation

30. Anodal closure contraction IS BIGGER
THAN cathode closure contraction

31.  Flaccid paralysis
 Dec. tone,
 focal muscle atrophy
 Focal muscle weakness
 Dec. or absent reflexes
 Fasciculations