Somatosensory system
List the Mechanoreceptors in order from superficial to deep and which two have larger receptor fields?
Which two are rapidly adapting?
1. Meissners Corpuscle (rapid)
2. Merkel's Disc
3. Ruffini Endings **
4. Pacinian Corpuscles ** (rapid)
what do muscle fibers consist of?
sensory endings
motor endings
intrafusal fibers
embedded in extrafusal fibers
what type of pain is used to describe pins & needles, sharp burning pain
neuropathic pain
Metencephalon aka
mesencephalon aka
Pons
Midbrain
What is dysphagia and when is it present in cranial nerves
difficulty swallowing
CN IX-XII
Which mechanoreceptor will help us to feel a coffee cup slipping out of our hands?
Ruffini Endings
what are the two types of intrafussal fibers
nuclear BAG (changes in muscle length and speed)
nuclear CHAIN (static length of muscle)
When there is damage to the cortex what results?
loss of sensory awareness
Where is the 4th ventricle located and what is it connected by?
Medulla
cerebral aqueduct
what is your abducens nerve responsible for
lateral eye movements
Why is the first thing we feel when playin got potato is the texture of the potato?
The axons for texture (A delta) travel faster to the brain because they are lightly myelinated whereas C fibers are not myelinated (pain)
What are the two types of neurons
Primary endings= Type 1a afferent (change muscle length info)
Type 2 afferent (responds to speed of change)
What happens when you have phantom limb?
Your cortical map remains same and leaves void in the homunculus so brain creates own sensory input for missing limb
What are the three parts of the midbrain?
1. Cerebral peduncles
2. Tegmentum (red nucleus, periaqueductal gray, substantia nigra)
3. Tectum (superior colliculi and inferior)
what is strabismus and when does this occur?
malalignment
lesion to oculomotor, trochlear, abducens cranial nerve
What kind of receptor field is densely packed with the most receptors? Give example
Small receptor feel (Meissners & Merkel)
Able to decipher alphabet on hands or foot
what is being utilized when you are holding onto a shopping bag for too long and feel it getting heavier and heavier
Golgi Tendon Organs
What is it called when you are having a heart attack but experience pain in your arm
Referred visceral pain
what cranial nerves control what part of the brainstem
CN 3-4 = midbrain
CN 5-8=pons
CN 9-12= medulla
what happens when there is a lesion in the Vagus CN?
-dyspnea (difficulty breathing)
-dysphagia (difficulty swallowing)
-dysarthria (slurring words)
-Dysphonia (hoarse voice)
Define Dermatomes and do the myotome dance
sensory innervation on skin innervated by single spinal nerve
(C5- elbow flexion, C6-wrist flexion, C7- elbow extension, C8-finger flexion, T1- finger ab/add)
Explain alpha-gamma coactivation
When alpha and gamma neurons contract at same time to allow spindles to be reactive & contraction active
(gamma motor neurons send efferent info and innervate intrafusal fibers)
If there is radiculopathy resulting in arm numbness where is the nerve root compression occurring at
Cervical numbness
Name the 4 types of reticular formation
1. Ventral Tegmental Area (dopamine)
2. Pedunculopontine Nucleus (Ach)
3. Raphe Nuclei
4. Locus Coeruleus (Ne)
what two tracts involve the anterior and posterior 1/3 of the tongue
Facial, Glossopharyngeal