Lecture 1 Neuroanatomy Flashcards
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 _____
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
The PNS and the CNS are functionally ______
The PNS and the CNS are functionally intergrated
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
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 ____
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
Pseudounipolar – one process
- sensory neurons of the ____ systems as well as the gustatory (taste) system
- cell bodies in ____ and PRG
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)
____ – two processes
- ____ of the olfactory, visual, auditory, and vestibular systems
- ____ in PNS (olfactory epithelium, retina, and ganglia associated with auditory and vestibular systems)
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)
_____ – 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
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
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 ______.
▪ 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
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)
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)
- cutaneous mechanoreceptors (exteroceptors): transduce physical stimuli from body wall; include low-threshold BLANK and high-threshold BLANK
- 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)
___ (low threshold)
- transduce temperature changes in the skin
Thermoreceptors (low threshold)
- transduce temperature changes in the skin
Deep Mechanoreceptors
High threshold receptors
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
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
Cell bodies in the ____
Describe the route
Anterior horn
a ____ is the area of skin innervated by all the ____ of a single ____
Lower extremity dermatomes ____
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**
a ____ is the muscle mass innervated by all the ____of a ____ nerve
Lower extremity myotomes: ____
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
Myotomes
Lateral Exteranal Hip Roation: ____
Medial Internal Hip Roation: ____
ADduction: ____
ABduction: ____
Lateral Exteranal Hip Roation: **L5 ans S1 **
Medial Internal Hip Roation: L5
ADduction: L2 L3 and L4
ABduction: L5 and S1
Myotomes
Foot Inversion: ____
Foot Eversion: ____
Toe Extension: ____
Toe Flexion: ____
Foot Inversion: L4 and L5
Foot Eversion:L5 and S1
Toe Extension: L5 and S1
Toe Flexion: L5 and S1
Myotomes
Hip extension: ____
Hip Flexion: ____
Flexion of the knee: ____
Extension of the Knee: ____
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 **
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 ____
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)**
▪ 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
▪ 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
lateral cutaneous n. of thigh (neurons from spinal cord)
lateral cutaneous n. of thigh (neurons from spinal cord levels L2, L3)
femoral nerve
(neurons from spinal cord ____
femoral nerve
(neurons from spinal cord levels L2, L3, L4)
- Lesion of a spinal nerve root produces a ____:
- all cutaneous sensation lost throughout ____
- muscle weakness in muscles innervated by that ____
- Lesion of a spinal nerve root produces a radiculopathy:
- all cutaneous sensation lost throughout dermatome
- muscle weakness in muscles innervated by that myotome
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 ____
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
Lesion of a peripheral nerve produces a ____
-____sensation lost in the distribution of the nerve distal to lesion
- ____ of muscles innervated by that nerve
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
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 ____
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
- 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:____
- 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
- effects of lesion may differ depending on type of lesion
- irritative lesions: ____
- destructive lesions: ____
- 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
- esthesia: refers to all types of cutaneous sensation (i.e., somatosensation)
- esthesia: refers to all types of cutaneous sensation (i.e., somatosensation)
