12
Spinal cord – Medulla spinalis
2 Macroscopic view
1 Enlargement (intumescentia) – is situated in the parts of the spinal cord where segments for limbs plexuses are placed 1.1 Cervical enlargement (intumescentia cervicalis) C8–T2 – for the brachial plexus of upper extremity 1.1 1.2 Lumbosacral enlargement (intumescentia lumbosacralis) L4–S2 – for the lumbar and sacral plexus of lower extremity 2 Fissures (fissurae) and groove (sulci) which separate spinal cord fascicles 2.4 2.1 Anterior median fissure (fissura mediana anterior) 2.4 2.3 2.3 – a ventrally situated deep fissure 2.2 2.2 Anteriolateral (ventrolateral) sulcus (sulcus anterolateralis) – for centrifugal axons of motor and visceromotor neurons (fila radicularia anteriora) 2.3 Posterolateral (dorsolateral) sulcus (sulcus posterolateralis) – for centripetal projections of pseudounipolar neurons of spinal ganglia (fila radicularia posteriora) 2.1 2.4 Posterior intermediate sulcus (sulcus intermedius posterior) – separates the gracile and cuneate fasciculus
• • • •
2.3
1.1
2.4
• •
Spinal cord segment
2.2
2.1
Cross-section
2.2
1.2
1.2
1 Grey substance (substantia grisea) 1.1 Anterior horn (cornu anterius) – somatomotor neurons 1.2 Lateral horn (cornu laterale) – visceromotor neurons Anterior and posterior view 1.3 Posterior horn (cornu posterius) – sensory neurons and interneurons 1.3.1 Apex – a dorsal narrowing of the posterior horn 1.3.2 Head – a central widening 1.3.3 Neck – a ventral narrowing in the area of the intermedial column (columna intermedia) 1.3.4 Base – nearby the lateral horn 1.4 Intermedial column (columna intermedia) – grey substance between the posterior and anterior horn 1.5 Central zone (zona centralis) 2.1 2.3 – grey substance around the central canal 3 3 – interconnects the right and left part of the spinal cord 1.5.1 Anterior grey commissure (commissura grisea anterior) – in front of the central canal 1.5.2 Posterior grey commissure (commissura grisea posterior) 2.2 2.2 – behind the central canal 1.6 Columns (columnae) – three dimensional grey substance distribution 1.6.1 Anterior column (columna anterior) 2.3 2.1 – 3-D organization of the anterior horn 1.6.2 Intermedial column (columna intermedia) – 3-D intermedial horn Posterolateral view Anterolateral view 1.6.3 Posterior column (columna posterior) – 3-D posterior horn 2 White substance (substantia alba) – is divided by the course of the axons of the ventral and dorsal roots 2.1 Anterior (ventral) funiculus (funiculus anterior) 2.3.1 2.3.2 – situated between the anterior median fissure and anterolateral sulcus – it is formed by motor and sensory tracts 1.3 2.2 Lateral funiculus (funiculus lateralis) – situated between the anterolateral and posterolateral sulcus – it is formed by motor and sensory tracts as well as the anterior funiculus 2.3 Posterior (dorsal) funiculus (funiculus posterior) – situated between the posterolateral sulcus and posterior median sulcus 2.4 – it is divided by the posterior intermediate sulcus into 2.3.1 Gracile fasciculus of Goll (fasciculus gracilis) 2.3.2 Cuneate fasciculus of Burdach (fasciculus cuneatus) 2.4 Fasciculi proprii – spino-spinal tracts 1.4 1.2 – a bilateral connection of the spinal segments 3 Central canal (canalis centralis) 3.1 Anterior white commissure (commissura alba anterior) 3 1.5 1.1 – in front of the central canal Cross-section 3.2 Posterior white commissure (commissura alba posterior) – behind the central canal
• • • • •
• • •
•
• •
•
399