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Flashcards in THALAMUS Deck (41)
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1
Q

What are the 4 major divisions of the diencephalon?

A
  1. Epithalamus (pineal gland,etc)
  2. DORSAL THALAMUS (true)
  3. Subthalamus
  4. Hypothalamus
2
Q

What are the 4 major divisions of the THALAMUS itself?

A
  1. Internal Medullary Lamina
  2. Intralaminal Nuclei.
  3. Thalamic Reticular Nucleus
  4. Midline Nuclei
3
Q

What are the 3 functional groups of the thalamus?

A
  1. Specific/relay
  2. Association
  3. Non -Specific
4
Q

What various nuclei fall within the 3 functional groups of the thalamus?

  1. Specific/Relay
  2. Association
  3. Non-specific
A
  1. VPL, VPM, VA/VL, MEDIAL GENICULATE, LATERAL GENICULATE, LD (lateral dorsal)
    • Lateral Posterior
    • Pulvinar
    • Dorsomedial
  2. Intralaminar & Reticular
5
Q

What is the function of the RETICULAR NUCLEUS OF THE THALAMUS? Which thalamic functional group does it fall in?

A

HiGHLIGHT certain novel/new sensory info, and ignore background info
(relays to other areas)

  • NON -SPECIFIC group
    (does not relay directly to cortex, only relay to THALAMUS)
6
Q

Which nucleus does not relay directly to the CORTEX, but ONLY to the THALAMUS?

A

RETICULAR NUCLEUS

7
Q

What are the afferents for the following THALAMIC NUCLEI, where do these nuclei project?

  1. VA/VL
  2. VPL
  3. VPM
  4. Medial Geniculate
  5. Lateral Geniculate
  6. Anterior
A
  1. Basal Ganglia/Cerebellum
  2. Medial Lemniscus/ STT of the BODY
  3. Medial Lemniscus/ STT of the FACE
  4. Inferior Colliculus
  5. Optic tract (Superior Colliculus)
  6. Mamillothalamic Tract
8
Q

Where do these nuclei project? (efferents)

  1. VA/VL
  2. VPL
  3. VPM
  4. Medial Geniculate
  5. Lateral Geniculate
  6. Anterior
A
  1. Motor Areas (pre-central gyrus + frontal area)
  2. Somatosensory cortex
    (AREA 312 of Post-central gyrus)
  3. Somatosensory cortex
    (AREA 312 of Post-central gyrus)
  4. Auditory cortex (Transverse temporal gyri)
  5. Visual Cortex (occipital lobe –> calcarene fissure area 17)
  6. CINGULATE gyrus
9
Q

What is the auditory cortex of the brain?

A

Transverse Temporal Gyrus

10
Q

What is the only sensory information NOT traveling through the Thalamus?

A

SMELL

11
Q

What is the function of the cerebellum?

A

coordinates voluntary movements such as posture, balance, coordination, and speech, resulting in smooth, balanced muscular activity.

  • makes sure that motor functions you want to do HAPPEN (monitors & adjusts motor function)
12
Q

What is the function of basal ganglia?

A

Coordination of motor activity between agonist and antagonist

ex: activates the bicep (agonist), i& inactivates the function of the tricep (antagonist)

13
Q

What is the function of the thalamus?

A

Receives sensory information & passes this on either DIRECTLY or INDIRECTLY
- decides what info to pass on

14
Q

What are the majority of thalamic neurons?

A

MAJORITY = PROJECTION

rest = inhibitory

15
Q

What type of inputs exist into the THALAMUS? Which of these 2 is the MAJOR input?

A
  1. Specific (ex: medial lemniscus pathway)
    - use GLUTAMATE
  2. REGULATORY
    = MAJORITY!!
16
Q

What is the major output and input of the thalamus?

A

Output = PROJECTION neurons

Input = REGULATORY
control thalamus & turn parts of it on/off

17
Q

which nuclei of the thalamus is split into ANTERIOR, MEDIAL, & LATERAL and forms a Y SHAPE?

A

INTERNAL MEDULLARY LAMINA

  • collection of myelinated fibers
18
Q

The thalamus forms the wall of which structure?

A

3rd ventricle

19
Q

What is the nuclei that is referred to as the “thin sheet draped over the thalamus”

A

THALAMIC RETICULAR NUCLEUS

c-shape around the image of the thalamus like a bean

20
Q

Which nuclei are embedded in the Internal medullary Lamina?

A

INTRALAMINAR Nuclei

21
Q

The thalamus lies behind what structure? it forms the wall of which structure?

A
  1. behind the INTERVENTRICULAR FORAMEN

2. walls of the 3rd VENTRICLE

22
Q

What is the pineal gland responsible for?

A

Circadian Rhythms, melatonin

23
Q

What separates the thalamus from the lentiform nucleus?

A

INTERNAL CAPSULE

24
Q

What structures compose the lentiform nucleus? What does it look like?

A

Putamen & Globus Pallidus

  • it is the ball at the end of the CAUDATE

(part of basal ganglia)

25
Q

What makes the decision of which possible behaviors to execute at any given time? (motor function)

A

LENTIFORM NUCLEUS

26
Q

Which functional group of the thalamus has clear inputs & projections & ALOT OF TOPOGRAPHIC organization?

A

Specific/Relay Nuclei

27
Q

Which thalamic nuclei is used to project visual info to the visual cortex of the brain (occipital lobe)? Which Brodman’s zone is this?

A
  1. LATERAL GENICULATE

(SLO AIM)

AREA 17 - Calcarene fissure

28
Q

In the thalamus, which Specific/Relay nucleus shows somatotopic organization in regards to the face & the body?

A

VPM (FACE) & VPL(body)

  • face is more medial
29
Q

Which nuclei can perform higher level of analysis?

A

ASSOCIATION NUCLEI

  1. Lateral Posterior
  2. Pulvinar
  3. Medial Dorsal Nuclei
30
Q

Where do the ASSOCIATION NUCLEI receive input from? Do they receive input from sensory info?

A

DIRECTLY FROM CORTEX

  • NO INPUT FROM PRIMARY SENSORY INFO

(does not project to spinal cord; no SUBCORTICAL organs)

  • only talks back & forth to cortex
31
Q
Which functional nuclei of the thalamus is responsible for consciousness, emotional state etc?
1. Specific
2. Association
3. Non-specific 
Which nuclei are within this category?
A

NON-SPECIFIC NUCLEI

  1. Intralaminar (alertness, sensory awareness)
  2. Thalamic Reticular Nuclei
32
Q

Which Non-specific nuclei project ONLY to the thalamus? (not to the cortex or anywhere else)

A

THALAMIC RETICULAR FORMATION*

  • can inhibit or excite

(look at name)

33
Q

What is the function of the Reticular Formation of the Thalamus?

A

serves as a FILTER

  • highlights certain sensory info, turns off info around the area
    = control flow of info IN & OUT
34
Q

The top of the internal capsule is called what?

A

Corona Radiata

fibers connect the lentiform nucleus to the caudate

35
Q

What are the 3 divisions of the internal capsule?

A
  1. Anterior Limb
  2. GENU (bend)
  3. Posterior Limb (mostly sensory)
36
Q

What is the MAIN blood supply to the thalamus?

A

Posterior Cerebral Artery

PCA
- but SMALL Perforating arteries supply the thalamus from PCA

37
Q

If there is hypertension in the perforating arteries, what could occur?

A
  • lose function of the THALAMUS

- lose sensory info from contralateral side of the body

38
Q

What is sensory ataxia?

A

Loss of proprioception (where the limbs are in relation)
- postiive Romberg’s sign - can’t maintain balance with eyes closed = SENSORY ATAXIA

  • not cerebellar ataxia
39
Q

If the vision is lost in an individual, which THALAMIC NUCLEI is likely responsible?

A

Lateral Geniculate Nuclei

40
Q

If a stroke occurs that affects the VPL nucleus? What would be lost?

A
  • loss of PROPRIOCEPTION (vibration/2 pt. touch) on CONTRALATERAL side of the body
  • (VPM = same side of face)
41
Q

What artery is likely occluded in a LATERAL MEDULLARY STROKE? (Wallenburg Syndrome) If the VPM & VPL were damaged, what symptoms would be apparent?

A
  1. PICA (posterior inferior cerebellar artery)
  2. VPM = loss of pain sensation on SAME SIDE of face

VPL = loss of sensation on OPPOSITE SIDE OF BODY
(contralateral)