PNS Flashcards
Individual axons within a nn (myelinated or not) are wrapped in what?
Endoneurium, the inner most layer of a nerve.
What does Endoneurium consist of?
A mesh of collagen fibers, fibroblast & Macrophages.
Groups of Axons held to gather by their Endoneurium are held together in bundles called What?
Fasicles, These are wrapped in “Perineurium”.
What is the thicker layer of CT & Consist of what?
Up to 15 layers of fibroblast within a network of collagen fibers.
What is the Cervical Plexus?
C1 - C5, It supplies skin and mm of the Head, Neck & Superior part of the Shoulders and Chest.
What is the Nerve that arises from the Cervical Plexus and supplies the Diaphragm?
This is the “Phrenic Nerve”.
This supplies Motor fibers of the Diaphragm.
What are the nn’s and interventions of the Cervical Plexus?
Superficial (Sensory) branches
Deep (Largely Motor) Branches
What is involved in the Superficial (Sensory) Branches of the cervical plexus?
Nerves:
Lessor Occipital, Greater Auricular, Transvers Cervical, Superclavicular.
What is involved in the Deep (Largely Motor) Branches of the Cervical plexus?
Nerves:
Ansa Cervicalis, Phrenic, Segmental Branches.
When sensory impulses reach the lower part of the brain stem elicit complex reflexes Such as?
When the sensory impulsulses reach this area of the brain stem Reflexes such as:
Changes in HR and breathing occur.
What are Sensory modalities?
Each Unique type of sensation is called a “Sensory Modality”.
What happens when sensory impulses reach the Cerebral cortex?
When this happens we become consciously aware of the sensory Stimuli and can precisely locate and identify specific sensations such as touch…
How many sensory neuron carries how many sensory modalities?
One sensory nerouns carry info for only one sensory modality.
What are the 2 Sensory modalities classes grouped into?
General Senses & Special senses.
What is involved in “General Senses”?
Refer to both Somatic & Visceral Sensations.
What is involved in “Special Senses”?
This includes sensations modalities of smell, taste, vision, hearing & Balance.
What are Somatic Senses?
These are referring to:
Tactile Sensations Such as Touch, pressure and vibrations.
Thermal sensations, Pain & proprioceptive sensations.
What are Visceral Sensations?
They provide info about conditions within Internal organs.
For Ex:
Pressure, stretch, Chemicals, Hunger and Temp.
What is the process of sensation?
Stimulation of Receptors, Transduction of Stimulus, Generation of nn impulses (Action Potentials), Integration of Sensory input.
What occurs during the first step of “Process of Stimulation”?
Stimulus of Receptors:
Stimulation must occur within the nn’s receptive field.
What occurs within the Second step of the “Process of Stimulation”?
Transduction of Stimulus:
Sensory receptors transduce (Converts) in a stimulus into a graded potential.
each type of sensory receptor exhibits selectively, it can transduce only one type of stimulus.
What occurs within the third step of the “Process of Stimulation”?
Generation of nn impulses:
When graded potentials in sensory neurons reach a threshold, this triggers an action potential which propagate towards the CNS.
What occurs within the fourth step of “Process of Stimulation”?
Integration of Sensory input:
A particular region of the CNS receives and integrates the sensory nn impulses.
What is a characteristic that most sensory receptors have?
Adaptation, in which the generated action potential or receptor potential decreases in amplitude during maintained / consistent stimulus.
What is a characteristic that most sensory receptors have?
Adaptation, in which the generated action potential or receptor potential decreases in amplitude during maintained / consistent stimulus.
What happens during “Adaptation” of sensory receptors?
This causes the frequency of the nn impulses in the first order neuron to decrease.
Because of Adaption the perception of a sensation may fade or disappear even if the stimulus persist.
What is the Lumbar Plexus?
L1 - L4, Passing outward between the Superficial and deep heads of Psoas major and anterior to the QL.
Where does the Lumbar plexus dived into anterior & Posterior divisions?
Between the heads of Psoas major the Roots of the lumbar plexus split into anterior and posterior division.
This gives rise to Peripheral branches of the plexus.
What does the Lumbar plexus supply?
The Anterolateral abdominal wall, External genitals & Part of the lower limbs.
What are the Nerves and innervations of the lumbar plexus?
Iliohypogastric, Ilioingual, Genitofemoral, Lateral cutaneous nn of the thigh, Femoral, Obturator.
What are conditions of the PNS?
ERB’s Palsy, Sciatic nn Lesions, TOS, Ulnar nn Lesion, Radial nn Lesion, Bell’s palsy, DDD/Herniation.
What is ERB’s Palsy?
Weakness of the mm’s innervated by the Brachial Plexus, most often C5 & C6 nn roots, due to an overstretch from Neck to Shoulder.
What are Sciatic nn Lesions?
Disease or damage involving the Sciatic nn.
It may present itself as pain local to the hip or down the leg as Sciatica.
What are Ulnar nn Lesions?
A compression or impingement of the ulnar nn caused by an abnormal tissue growth / space occupying lesion.
Further causes may include: Fractures, dislocations, surgical complications, prolonged compression, repetitive action & trauma.
What are Radial nn Lesions?
A injury to the Radial nn, resulting in motor loss, weakness, sensory loss, sensory impairment, or pain along with autonomic Dysfunction.
What is Bell’s palsy?
A condition involving a lesion of the Facial nn (VII). it results in Flaccid paralysis of the facial mm for expression on the same side as the lesion.
What is DDD/Herniation?
DDD is degeneration of the Annular fibers.
Degeneration of the disc is normal with age because of wear and tear.
How long could it take for a Newborn to recover from ERB’s palsy?
Up to 2 years and the affected arm may be smaller than the opposite one.
How long could it take for a Newborn to recover from ERB’s palsy?
Up to 2 years and the affected arm may be smaller than the opposite one.
The size difference would be permanent.
How long could it take for a Newborn to recover from ERB’s palsy?
Up to 2 years and the affected arm may be smaller than the opposite one.
The size difference would be permanent.
If an adult develops ERB’s palsy how would the heal from it?
If the nn’s were completely ruptured they wouldn’t heal on their own.
If only a stretch injury they would heal on their own.
What would special conditions for treatment on a client with ERB’s palsy include?
Affected arm may need pillowing or support on the table.
Do not lay the client on the affected side.
What would special conditions for treatment on a client with ERB’s palsy include?
Affected arm may need pillowing or support on the table.
Do not lay the client on the affected side.