wk 5- nervous system

Question 1

major sub divisions of the nervous system and what is included in them?

Answer 1

CNS- brain and spinal cord+
PNS- nervous tissue outside of CNS structures

Question 2

where are sensory receptors found, what is their function and what types are there?

Answer 2

Where are sensory receptors found?
– Skin, joint capsules, ligaments, tendons, along muscle fibres
• What is the general function of sensory receptors?
– To detect a stimulus
• What types of sensory receptors are there?
– Pain
– Mechanical (touch, pressure, vibration)
– Temperature
– Stretch
– Force

Question 3

types of skin sensory receptors 3

Answer 3

pain, thermoreceptors, mechanoreceptors

Question 4

sensory receptors of lower limb 3

Answer 4

stretch receptors (in muscle belly)
force receptors (in tendons)
mechanoreceptors (in joint capsule and ligaments)

Question 5

different spinal nerves and how many pairs in each region and total

Answer 5

Cervical nerves 8 pairs
Thoracic nerves 12 pairs
Lumbar nerves 5 pairs
Sacral nerves 5 pairs
Coccygeal nerves 1 pair

total = 31 pairs

Question 6

what is a nerve composed of?

Answer 6

main component is axons of neurons

Question 7

what type of neuron fibers may be found in nerves? 3 and what do they do?

Answer 7

• (Somatic) Motor neurons axons carrying instructions from the
  CNS to skeletal muscles
  – (Autonomic) Motor neurons axons carrying instructions from CNS
  to smooth muscle and glands
  – Sensory neurons process carrying information from sensory
  receptors to CNS

Question 8

sensory neuronal pathway 6

Answer 8

6. Brain
   Spinal cord
   Spinal nerve
   Nerve plexus
   Peripheral nerve
7. Receptor

Question 9

main function of nerves 2

Answer 9

-Highway connecting peripheral organs to spinal cord
– Carries bidirectional traffic

Question 10

where do majority of lower limb nerves arise from?

Answer 10

All major peripheral nerves of the
lower limb arise from the lumbar &
sacral plexuses

Question 11

what parts of the body does the posterior ramus innervate?

Answer 11

all tissues of back
region/dorsum of
body (posterior to
vertebral column)

Question 12

What parts of the
body does the
Anterior ramus
innervate?

Answer 12

All tissues anterior to
vertebral column
including trunk
(thorax/abdomen/
pelvis) and upper &
lower limb

Question 13

what are ascending tracts

Answer 13

sensory information traveling to brain, functionally localised

Question 14

motor neuronal pathway

Answer 14

Brain
Spinal cord
Spinal nerve
Nerve plexus
Peripheral nerve
Neuromuscular
junction

Question 15

motor pathway through CNS

Answer 15

white matter of spinal cord descending tracts sending motor messages from brain to muscles

Question 16

upper motor neuron lesions 4

Answer 16

Cell body in cerebral cortex
– Corticospinal tract involvement
• Varying degrees of paralysis (severest
in upper limb)
• Spasticity with exaggerated tendon
reflexes
• Sign of Babinski – upturning and
spreading of the toes on stroking sole
of foot (extensor plantar response)
instead of normal babinski reflex

Question 17

lower motor neuron lesions 4

Answer 17

• Cell bodies within ventral horn of
spinal cord
• Flaccid paralysis of affected muscles
• Diminished or absent tendon reflexes
• Progressive atrophy of deprived
muscles

Question 18

poliomyelitis

Answer 18

-infantile paralysis
-viral infection of lower motor neuron
-LMN syndrome at level of lesion
-lower motor neuron disease

Question 19

motor unit of skeletal muscles are

Answer 19

one motor neuron and all muscle fibers inverted by it

Question 20

types of spinal reflex arcs 2

Answer 20

• Stretch Reflex:
– Acts to maintain posture and prevent falling to the
ground
– Prevents excessive tension building up in a muscle
• Withdrawal/Pain Reflex
– Acts to remove painful stimulus and protect body from
further injury
• Extremely fast response
• No input from brain

Question 21

do lumbar nerve plexus lie in the belly of the posts major muscle?

Answer 21

yes

Question 22

nerves that arise from the lumbar plexus

Answer 22

genitofemoral, lateral femoral cutaneous, femoral nerve, obturator

Question 23

nerves that arise from the sacral plexus

Answer 23

superior/inferior gluteal, sciatic, posterior femoral cutaneous

Question 24

nerves that pass through the lesser sciatic foramen

Answer 24

pudendal nerve

Question 25

nerve that passes through obturator canal

Answer 25

obturator nerve

Question 26

nerves that passs through the greater sciatic foramen, above the piriformis muscle

Answer 26

superior gluteal nerve

Question 27

nerves that pass through the greater sciatic foramen below piriformis

Answer 27

inferior gluteal nerve, sciatic nerve pudendal nerve

Question 28

what are the branches of nerve from the femoral nerve

Answer 28

medial femoral cutaneous nerve of thigh, intermediate femoral cutaneous nerve of thigh and the saphenous nerve

Question 29

what is a cutaneous nerve

Answer 29

provides nerve supply to the skin

Question 30

the posterior femoral cutaneous nerve accompanies what vein, anastomoses with what nerve, and passes medial to what nerve

Answer 30

saphenous vein
sural nerve
sciatic nerve

Question 31

sciatic nerve innverates what muscles?

Answer 31

hamstrings (long head only), hamstring part of adductor Magnus

Question 32

what nerve gives rise to the sural communicating nerve

Answer 32

common fibular nerve

Question 33

how does the common fibula nerve orientate in the body

Answer 33

passes deep to the long head of biceps femoris, crosses superficially over the lateral head of gastrocnemius, winds around the neck of fibula and terminates deep to the fibulas longus

Question 34

what nerves does the common fibular give rise to

Answer 34

lateral cutaneous rural nerve, superficial fibula nerve, deep fibula nerve, sural communicating nerve

Question 35

deep fibula nerve supplies what muscles

Answer 35

fibulas terminus, extensor hallucis longus, tibialis anterior

Question 36

the tibial nerve gives rise to

Answer 36

medial plantar nerve
medial sural cutaneous nerve
medial calcanea nerve
lateral plantar nerve

Question 37

tibial nerve innervates

Answer 37

posterior comp of leg, two headed gastocnemius and soleus), plantaris, Popliteus, tibialis posterior, flexor digitorum longus and flexor hallucis longus

Question 38

what nerves go to the dorsal of the foot

Answer 38

femoral, deep fib, superficial fib, sural