T7.2 Touch Flashcards
Which of the following has the highest sensory acuity
A. Upper Trunk
B. Middle Trunk
C. Back of neck
D. Back of Hand
RFA
ANS. Back of Hand 31,5
A 53,0
B and C least both 67,5
A man is getting dressed and feels his shoes is loose. Via what brings this sensation to the medulla?
A. Internal capsule
B. Fasciculus gracilis
C. Fasciculus cuneatus
D. Medial lemniscus
RFA
Ans B. Fasciculus gracilis brings sensory of the lower limbs to the medulla
A. Internal capsule i part of the tertiary neuron and carries sensory info from the thalamus to the postcentral gyrus.
C. Fasciculus cuneatus while bring sensory information to the medulla from the upper limbs.
D. Medial lemniscus is part of the secondary neuron arnd connects the medulla to the thalamus.
Sensory information to the body will enter the spinal cord from the….
A. Dorsal Column B. Dorsal Root C. Dorsal Ramus D. Ventral Column E. Ventral Root F. Ventral Ramus
RFA
Ans. B: Dorsal Root
A. Dorsal Column: is the tract the sensory information will ascend to the medulla by
C. Dorsal Ramus: contain both sensory (coming from the back) and motor fibers(going to the back )
D. Ventral column: is associated with motor and pain stimuli
E. Ventral root: is were motor neurons exit the spinal cord
F. Ventral Ramus: has sensory fibers of the (anterior body) and motor fiber (anterior body)
A women with a trigeminal lesion comes in with difficulty chewing and sensory loss of the entire face. Where are the cell bodies for the sensory nerves of proprioception of the muscles of mastication?
A. VPM nucleus of the thalamus B. Trigeminal ganglian C. Primary Sensory nucleus D. Mesencephalic nucleus E. Motor nucleus of the Trigeminal
FA
D. The nerves of proprioception of the mastication muscles are unipolar and the cell bodies are located in the mesencephalic nucleus of the Trigeminal nerve.
The sense of pain, touch, and temperature of the face are located in the Trigeminal ganglia.
The cell bodies of the second order sensory nerves of face are located in the VPM of the the thalamus
Tabes Dorsalis is a syphilitic myelopathy that effects which sensory pathway? Describe the symptoms seen in this disorder
FA
Tabes dorsalis is a disease that effects mainly the dorsal column, thus effects two pt discrimination, proprioception, fine touch and vibration. You would observe a gait disturbance, reduced patellar reflex and ipsilateral paresthesia.
Ahmed has a crazy night out taking 40 shots and getting rejected by all the girls. When he goes into Ryan’s room he finds him snorting mad lines of coke and rips a line with him. His anterior choroidal artery blows up. He develops contralateral sensory loss in a somatotopic pattern. Which part of the brain is affected? (mm)
A) Anterior Internal Capsule B) Posterior Internal Capsule C) Putnam D) Globus Pallidus E) Lentiform
Answer - B
The anterior choroidal artery is a branch of the middle cerebral artery and supplies the posterior internal capsule
Explain how and why neurons die in diabetic peripheral neuropathy. (mm)
Diabetic Peripheral Neuropathy is a metabolic disease. It gives stocking glove symptoms. The longest neurons (ie. in your hands and feet) have the highest metabolic demand and fail earlier
Ryan has a long break without Marissa and gets a little frisky. He decides that his best bet is stick his dong in the garbage disposal and it accidentally gets chopped off. He experiences pleasure in his dick’s corona even though its gone when ever someone shakes his hand. Explain this. (mm)
The cortical area for the dick is altered after amputation. so the hand region areas spread out to the dick region. So when the hand neurons are activated it also activated the dick neurons which accounts for the perception of pleasure to his dick
Patient has an infarction of the Anterior Parietal Artery from the Middle Cerebral Artery. Which of the following areas on the body are likely affected within the primary somatosensory cortex (S1/post-central gyrus)?
A. Hip B. Neck C. Elbow D. Trunk E. Pharynx
AA
CORRECT ANSWER = E. Pharynx
Pharynx are more on the laterally located on the primary somatosensory cortex (S1/post-central gyrus).
General cheatsheet for cortical blood flow is Middle Cerebral Artery for most lateral portion of gyri, Anterior Cerebral Artery for most medial portion of gyri and Posterior Cerebral Artery for cortical areas in the posterior portion of the brain.
Hip, neck, elbow, and trunks are all found more medially on the postcentral gyrus.
Patient has an infarction of the Anterior Cerebral Artery. Which of the following areas on the body are likely affected within the primary somatosensory cortex on the posterior paracentral lobule?
A. Penis B. Nose C. Intra-abdominal D. Pharynx E. Tongue
AA
CORRECT ANSWER = A. Penis
Penis is the most medial structure on the posterior paracentral lobule. The other choices are located at the Postcentral gyrus.
General cheatsheet for cortical blood flow is Middle Cerebral Artery for most lateral portion of gyri, Anterior Cerebral Artery for most medial portion of gyri and Posterior Cerebral Artery for cortical areas in the posterior area of the brain.
Patient has a lesion from an ischemic event in the postcentral gyrus. Which of the following conditions is the patient likely to have?
A. Contra-lateral touch, vibration, proprioception, pain and temperature loss in penis.
B. Ipsilateral touch, vibration, proprioception, pain and temperature loss in penis.
C. Contra-lateral touch, vibration, proprioception, pain and temperature loss in the elbow.
D. Ipsilateral touch, vibration, proprioception, pain and temperature loss in the elbow.
E. Contra-lateral touch, vibration, and proprioception loss in the elbow.
AA
CORRECT ANSWER = C. Contra-lateral touch, vibration, proprioception, pain and temperature loss in the elbow.
Lesions to the Primary Somatosensory Cortex (S1) cause CONTRA-LATERAL SENSORY LOSS. This rules out options B and D.
The penis is located in the paracentral lobule. The paracentral lobule controls motor and sensory innervations of the contralateral lower extremity. It is also responsible for control of defecation and urination. This rules out option A.
Somatosensory cortex (S1) is responsible for all sensations such as touch, vibration, proprioception, pain and temperature. Therefore option E is less correct than option C.
