Lecture 1 Neuroanatomy

Question 1

Central Nervous System(CNS)
Within the ______ and the ______ which includes the brain and the spinal cord

The CNS is a derivative of _____

Peripheral Nervous System(PNS)
outside the skull and vertebral column includes the ______ and _____

Derivative of the _____

Answer 1

Central Nervous System(CNS)
Within the Skull and the Vertebral Canal which includes the brain and the spinal cord

The CNS is a derivative of Neural Tube

Peripheral Nervous System(PNS)
outside the skull and vertebral column includes the Cranial Nerves and spinal Nerves

Derivative of the Neural Crest

Question 2

The PNS and the CNS are functionally ______

Answer 2

The PNS and the CNS are functionally intergrated

Question 4

Org of NS

A. Somatic:
1. Motor - Control of ____ movements. CNS to PNS to ____
2. Sensory - Process sensation arising from the ____. ____ to PNS to ____

B. Visceral
1. Motor: _____ and _____. CNS to PNS to _____
2. Sensory: Process sensation from the ____ receptor to PNS to CNS

Answer 4

Question 5

Visceral Sensory: has _____ neruon(s) from the ____ to ____ w/ a cell body in the ____

Visceral Motor(autonomics) has _____ neuron(s) from the ____ to ____ which synapse in the ______

Somatic Sensory: has _____ neuron(s) from the ____ to ____ w/ cell bodies in the ____

Somatic Motor: has ____ from the ____ to the ____

Answer 5

Visceral Sensory: has one neruon(s) from the receptor to CNS w/ a cell body in the PRG

Visceral Motor(autonomics) has two neuron(s) from the CNS to Target which synapse in the Autonomic Gang

Somatic Sensory: has one neuron(s) from the Receptor to CNS w/ cell bodies in the PRG

Somatic Motor: has one multipolar neuron from the CNS to the Target

Question 6

Pseudounipolar – one process
- sensory neurons of the ____ systems as well as the gustatory (taste) system
- cell bodies in ____ and PRG

Answer 6

Pseudounipolar – one process
- sensory neurons of the somatic and visceral nervous systems as well as the gustatory (taste) system
- cell bodies in PNS (cranial nerve and posterior root ganglia)

Question 7

____ – two processes
- ____ of the olfactory, visual, auditory, and vestibular systems
- ____ in PNS (olfactory epithelium, retina, and ganglia associated with auditory and vestibular systems)

Answer 7

Bipolar – two processes
- sensory neurons of the olfactory, visual, auditory, and vestibular systems
- cell bodies in PNS (olfactory epithelium, retina, and ganglia associated with auditory and vestibular systems)

Question 8

_____ – many processes
- motor neurons in the * ___ and ___
** nervous systems
- interneurons in the **____* that synapse with other neurons
- cell bodies in CNS and autonomic ganglia of the PNS

Answer 8

Multipolar – many processes
- motor neurons in the somatic and autonomic nervous systems
- interneurons in the CNS that synapse with other neurons
- cell bodies in CNS and autonomic ganglia of the PNS

Question 9

What is ____ all sensations that arise in skin, connective tissue, skeletal muscle, periosteum, and teeth

Various somatosensory modalities are described: ____

Somatosensory modalities perceived are based on the type of ____ activated by a ______.

Answer 9

▪ What is somatosensation? all sensations that arise in skin, connective tissue, skeletal muscle, periosteum, and teeth
▪ Various somatosensory modalities are described: discriminative touch, vibratory sense, proprioception, pain, temperature
▪ Somatosensory modalities perceived are based on the type of somatosensory receptor(s) activated by a stimulus

Question 10

Sensory receptors: SA components

Exteroceptors
- cutaneous ____ (touch, pressure, vibration) - cutaneous thermoreceptors (temperature)
- cutaneous nociceptors (pain)
note: “cutaneous” = “skin”
Proprioceptors
- muscle spindles (muscle length)
- Golgi tendon organs (muscle tension)

Answer 10

Exteroceptors
- cutaneous mechanoreceptors (touch, pressure, vibration) - cutaneous thermoreceptors (temperature)
- cutaneous nociceptors (pain)
note: “cutaneous” = “skin”
Proprioceptors
- muscle spindles (muscle length)
- Golgi tendon organs (muscle tension)

Question 11

• cutaneous mechanoreceptors (exteroceptors): transduce physical stimuli from body wall; include low-threshold BLANK and high-threshold BLANK

Answer 11

• cutaneous mechanoreceptors (exteroceptors): transduce physical stimuli from body wall; include low-threshold* (Meissner, Pacinian, and Ruffini corpuscles, Merkel disks) and high-threshold (free nerve endings)

Question 12

___ (low threshold)
- transduce temperature changes in the skin

Answer 12

Thermoreceptors (low threshold)
- transduce temperature changes in the skin

Question 13

Deep Mechanoreceptors

High threshold receptors

Answer 13

Question 14

Somatomotor pathways_general overview

Neuron 1: upper motor neuron
- definition: synapses on another neuron
- ____ morphology
- cell body in cerebral cortex (primarymotorcortex) - synapses on ____ spinal cord

Neuron 2: lower motor neuron
- definition: synapses on skeletal muscle - ____ morphology
- cell body in spinal cord
- projects via ____
muscle to produce movement

Answer 14

Neuron 1: upper motor neuron
- definition: synapses on another neuron
- multipolar morphology
- cell body in cerebral cortex (primarymotorcortex) - synapses on lower motor neurons in spinal cord

Neuron 2: lower motor neuron
- definition: synapses on skeletal muscle - multipolar morphology
- cell body in spinal cord
- projects via peripheral nerves to skeletal
muscle to produce movement

Question 15

Cell bodies in the ____

Describe the route

Answer 15

Anterior horn

Question 16

a ____ is the area of skin innervated by all the ____ of a single ____
Lower extremity dermatomes ____

Answer 16

a dermatome is the area of skin innervated by all the sensory nerve fibers of a single spinal nerve
Lower extremity dermatomes:** L1, L2, L3, L4, L5, S1, S2**

Question 17

a ____ is the muscle mass innervated by all the ____of a ____ nerve
Lower extremity myotomes: ____

Answer 17

a myotome is the muscle mass innervated by all the motor nerve fibers of a single spinal nerve
Lower extremity myotomes: L1, L2, L3, L4, L5, S1, S2, S3

Question 18

Myotomes

Lateral Exteranal Hip Roation: ____
Medial Internal Hip Roation: ____
ADduction: ____
ABduction: ____

Answer 18

Lateral Exteranal Hip Roation: **L5 ans S1 **
Medial Internal Hip Roation: L5
ADduction: L2 L3 and L4
ABduction: L5 and S1

Question 19

Myotomes

Foot Inversion: ____
Foot Eversion: ____

Toe Extension: ____
Toe Flexion: ____

Answer 19

Foot Inversion: L4 and L5
Foot Eversion:L5 and S1

Toe Extension: L5 and S1
Toe Flexion: L5 and S1

Question 20

Myotomes

Hip extension: ____
Hip Flexion: ____
​
Flexion of the knee: ____
Extension of the Knee: ____

Answer 20

Hip extension: L5 S1 and S2
Hip Flexion:** L1 L2 L3 and L4 **

Flexion of the knee: L5 and S1
Extension of the Knee: **L3 and L4 **

Question 21

Clinical significance: knowing the innervation of peripheral nerves and dermatomes enables differential diagnosis of a spinal nerve or root lesion ____ from a peripheral nerve lesion ____

Answer 21

Clinical significance: knowing the innervation of peripheral nerves and dermatomes enables differential diagnosis of a spinal nerve or root lesion (radiculopathy) from a peripheral nerve lesion** (neuropathy)**

Question 22

▪ cutaneous sensation from different areas of the skin travels toward the ____ via specific named ____ nerves
▪ peripheral nerves contain ____ neurons with cell bodies in ____ of multiple spinal cord segments (this is the result of ____ formation)
▪ all the nerve fibers that have cell bodies in the PRG at L2 innervate the L2 dermatome, regardless of the peripheral nerve that carries them

Answer 22

▪ cutaneous sensation from different areas of the skin travels toward the CNS via specific named peripheral nerves
▪ peripheral nerves contain sensory neurons with cell bodies in PRG of multiple spinal cord segments (this is the result of plexus formation)
▪ all the nerve fibers that have cell bodies in the PRG at L2 innervate the L2 dermatome, regardless of the peripheral nerve that carries them

Question 23

lateral cutaneous n. of thigh (neurons from spinal cord)

Answer 23

lateral cutaneous n. of thigh (neurons from spinal cord levels L2, L3)

Question 24

femoral nerve
(neurons from spinal cord ____

Answer 24

femoral nerve
(neurons from spinal cord levels L2, L3, L4)

Question 25

1. Lesion of a spinal nerve root produces a ____:
   - all cutaneous sensation lost throughout ____
   - muscle weakness in muscles innervated by that ____

Answer 25

1. Lesion of a spinal nerve root produces a radiculopathy:
   - all cutaneous sensation lost throughout dermatome
   - muscle weakness in muscles innervated by that myotome

Question 26

Clinical note: lesion of a spinal nerve root is referred to as ____; results in loss of sensation throughout the associated dermatome and muscle weakness throughout the associated myotome; common causes are ____

Answer 26

Clinical note: lesion of a spinal nerve root is referred to as radiculopathy; results in loss of sensation throughout the associated dermatome and muscle weakness throughout the associated myotome; common causes are disc herniation and spinal stenosis

Question 27

Lesion of a peripheral nerve produces a ____
-____sensation lost in the distribution of the nerve distal to lesion
- ____ of muscles innervated by that nerve

Answer 27

Lesion of a peripheral nerve produces a neuropathy:
- cutaneous sensation lost in the distribution of the nerve distal to lesion
- flaccid paralysis of muscles innervated by that nerve

Question 28

Clinical note: lesion of a peripheral nerve is referred
to as a ____; results in anesthesia restricted to the cutaneous area innervated by the affected
nerve and paralysis of muscles innervated by that nerve; common cause ____

Answer 28

Clinical note: lesion of a peripheral nerve is referred
to as a neuropathy; results in anesthesia restricted to the cutaneous area innervated by the affected
nerve and paralysis of muscles innervated by that nerve; common cause diabetes (e.g., diabetic neuropathy) or trauma

Question 29

• sign: observed by the physician upon examination of the patient; objective indicator of departure from homeostasis - example: fever, muscle strength (power)
• negative signs: ____
• positive signs:____

Answer 29

• sign: observed by the physician upon examination of the patient; objective indicator of departure from homeostasis - example: fever, muscle strength (power)
• negative signs: clinical signs or symptoms that result from the failure of a system to produce a function
• positive signs: when an abnormal sign or symptom occurs in place of or in addition to normal function

Question 30

• effects of lesion may differ depending on type of lesion
• irritative lesions: ____
• destructive lesions: ____

Answer 30

• effects of lesion may differ depending on type of lesion
• irritative lesions: often produce positive signs
• destructive lesions: typically produce negative signs, but may produce positive signs

Question 32

• esthesia: refers to all types of cutaneous sensation (i.e., somatosensation)

Answer 32

• esthesia: refers to all types of cutaneous sensation (i.e., somatosensation)