Approach To UMN Flashcards
UMN
Corticospinal ➕ Corticobulbar fibers ➕ Extra pyramidal fibers
🧠⚡he drove a hondaCRVTOdisneyland ⚡
Descending motor tracts (Corticospinal tract ➕ Extra pyramidal system) that merge on AHC or Cranial Nerve nuclei
⭐ Descending Tracts
Corticospinal tract (Lateral & Anterior)
Rubrospinal tract
Vestibulospinal tract
Tectospinal tract
Olivospinal tract
Descending Tracts in Lateral Column
🧠⚡ RL⚡
🧠⚡CR-v to ⚡
Rubrospinal Tract
Lateral Corticospinal tract
Descending Tracts in Anterior Column
🧠⚡ A VOTe⚡
Anterior Corticospinal tract
Vestibulospinal tract
Olivospinal tract
Tectospinal tract
All tracts in spinal cord is represented in ARRANGEMENT except
🧠⚡ ML ➡️ CTLS⚡
Cervical ➡️ Thoracic ➡️ Lumbar ➡️ Sacral
⭐ Dorsal Column
ML ➡️ SLTC
SACRAL ➡️ LUMBAR ➡️ THORACIC ➡️ CERVICAL
ViP makes you STAND UP
Sit on Rubber mat
- Vestibular spinal tract
- Pontine Reticulo-spinal tract
Sit down
1. Rubrospinal tract
2. Medullary Reticulo-spinal Tract
Vestibular Apparatus
Function
✨ For standing up
✨ Activates and Increases tone of ANTI-GRAVITY Muscles
Red Nucleus functions
Rubrospinal Tract
Increases tone of GRAVITY muscles
Flexors of Upper limb
Corticospinal Tract
Steps for Movement
Managed by?
Plan
Posture
Tone
Position of Proximal muscles
Inhibition of Opposite muscle
⭐ Integration of zskill: CST
⭐ Planning, Position and other things managed by EPS
Finesse to the movement is given by
Cerebellum
Corticospinal tract: Cortex
60% FIBERS FROM: FRONTAL LOBE
30% fibers: Originate from 1deg MOTOR CORTEX
30% FIBERS: Originate from PREMOTOR CORTEX (Area 6,8) and Supplementary Motor Cortex
40% fibers: Originate from Area 3,1,2 (SENSORY CORTEX): PARIETAL LOBE
Cell of BETZ
Giant pyramidal neurons WITH LARGE MYELINATED AXONS in Lamina 5 in MOTOR CORTEX
⬇️
LOWEST THRESHOLD FOR EXCITABILITY
Extra pyramidal fibers
Originate from
Pre-motor Cortex and Supplementary Motor Cortex
Corticobulbar fibers to the cranial nerve nuclei in the BRAINSTEM have B/L representation in the CORTEX
EXCEPT
7th CN: Facial Nerve
⭐ Cell of BETZ end on:
⭐ Other Corticospinal fibers end on:
⭐ Cell of BETZ end on: DIRECTLY ON ALPHA MOTOR NEURON
⭐ Other Corticospinal fibers end on: INTERNEURONS
UMN Lesion of 7th Cranial Nerve
LMN lesion of 7th CRANIAL NERVE
⭐ LOWER HALF of the FACE is affected while UPPER PART IS SPARED
➕
ANGLE OF MOUTH DEVIATED TO OPPOSITE SIDE
⭐ LMN lesion of 7th CRANIAL NERVE:
One HALF of the FACE AFFECTED
CORTICOBULBAR INVOLVEMENT ON ONE SIDE, CLINICAL FEATURES
No manifestation
Except: FACIAL NERVE
CORONA RADIATA: Packaging
Internal Capsule: Packaging
LOOSE PACKAGING: Fibers of CST descend
⭐ DENSE PACKAGING: IN INTERNAL CAPDULE
White MATTER in Cerebrum
Parts
🧠⚡ACP ⚡
⭐ Association Fibers
⭐ Commissural Fibers
⭐ Projection Fibers
Example of PROJECTION FIBER
Connects Cortical structure with Subcortical structures
Internal Capsule
Parts:
1. Ant Limb
2. Genu
3. Posterior Limb
Relations of INTERNAL CAPSULE
Fibers passing through INTERNAL CAPSULE
🧠⚡ROP ⚡
🧠⚡ SAU PPT⚡
If Corticospinal lesion at LEVEL OF INTERNAL CAPSULE, KNOWN AS
🧠⚡3H ⚡
DENSE HEMIPLEGIA
⭐ dense HEMIPLEGIA
⭐ Hemi-sensory loss
⭐ Homonymous Hemianopia
Main BLOOD SUPPLY of INTERNAL CAPSULE
Middle CEREBRAL ARTERY
Others:
Anterior Cerebral Artery
Anterior Choroidal Artery
Blood supply of INTERNAL CAPSULE
🧠⚡UPPER PART OF Each part is supplied by SAME ARTERY: LENTICULOSTRIATE BRANCH OF MIDDLE CEREBRAL ARTERY ⚡
⭐ Medial Striate Artery is a BRANCH OF
⭐ Lateral Striate Artery is a BRANCH OF
⭐ Posterior Striate Artery is a BRANCH OF
⭐ Medial Striate Artery is a BRANCH OF
ACA
⭐ Lateral Striate Artery is a BRANCH OF
MCA
⭐ Posterior Striate Artery is a BRANCH OF
PCA
CHARCOT BOUCHARD ANEURYSM
Aneurysm seen in STRIATE BRANCH OF MIDDLE CEREBRAL ARTERY
Artery of CHARCOT Hemorrhage
Lateral Striate Artery
Huebner’s Artery
Recurrent branch of ANTERIOR CEREBRAL Artery
CST in Midbrain
UMN Lesion in MIDBRAIN
Known as?
⭐ CROSSED HEMIPLEGIA (OR) ALTERNATING HEMIPLEGIA
⬇️
I/L LMN CN palsy
➕
C/L UMN LESION (Weakness)
CST in PONS
Present as DISJOINED FASICLES at BASILAR PART OF PONS
⚡ Why?
⭐ Fibers of Nuclei Pontis
⭐ Crossing fibers of MIDDLE CEREBRAL PEDUNCLES
Medulla Oblongata
Termination of Corticospinal Tract
⭐ % of Fibers of CST that end at CERVICAL REGION
⭐ % of Fibers of CST that end at THORACIC REGION
⭐ % of Fibers of CST that end at LUMBAR REGION
⭐ % of Fibers of CST that end at CERVICAL REGION
⚡⚡55%
⭐ % of Fibers of CST that end at THORACIC REGION
⚡⚡20%
⭐ % of Fibers of CST that end at LUMBAR REGION
⚡⚡25%
HEMIPLEGIA
Possible CAUSES
⭐ OPPOSITE CORTEX (CORTICAL)
🎯 MCA
🎯 ACA
⭐ OPPOSITE Subcortex
⭐ OPPOSITE Brainstem
