بسم الله الرحمن الرحیم

Beginning: Beginning: At the foramen magnum as a continuation of At the foramen magnum as a continuation of the the Medulla Oblongata of the brain. Medulla Oblongata of the brain. Shape: Shape: Cylindrical. Cylindrical. Length: Length: About (45) cm. About (45) cm. Occupies: Occupies: Upper 2/3 of the vertebral (spinal) canal of the vertebral column. Upper 2/3 of the vertebral (spinal) canal of the vertebral column.

(1) Up till the 3 rd month of Fetal Life: (1) Up till the 3 rd month of Fetal Life: The spinal cord occupies the Entire Length of the vertebral canal. The spinal cord occupies the Entire Length of the vertebral canal. (2) At birth : (2) At birth : It terminates at the level of L3. It terminates at the level of L3.

(3) Children : (3) Children : It ends at the Upper Border of the 3 rd Lumbar vertebra. It ends at the Upper Border of the 3 rd Lumbar vertebra. (4) Adults : (4) Adults : It terminates at the Intervertebral disc (1 st- 2nd ) Lumbar vertebrae. It terminates at the Intervertebral disc (1 st- 2nd ) Lumbar vertebrae.

Cervical: (C3- T1) Segments. For the Brachial Plexus. For the Brachial Plexus.Lumbar: (L1- S3) Segments. For the For the Lumbar and Sacral Plexuses. Lumbar and Sacral Plexuses.

Conus Medullaris: Conus Medullaris: A conical termination Caudal to the Lumbar Enlargement. A conical termination Caudal to the Lumbar Enlargement. FilumTerminale: FilumTerminale: A filament of connective tissue arises from the tip of the conus. A filament of connective tissue arises from the tip of the conus. It is attached to the 1 st Coccygeal Vertebra. It is attached to the 1 st Coccygeal Vertebra.

Anterior: Anterior: Deep Anterior (Ventral) Deep Anterior (Ventral) Median Fissure. Posterior: Median Fissure. Posterior: Shallow Posterior Shallow Posterior Median Sulcus. Median Sulcus.

The Spinal Cord receives The Spinal Cord receives Information from and Controls the Movement of the Trunk and Limbs. Information from and Controls the Movement of the Trunk and Limbs. It has (31) paired Spinal Nerves. It has (31) paired Spinal Nerves.

Two linear series (6-8) of Nerve Fascicles are attached to the Dorsolateral and Ventrolateral aspects of the cord. Two linear series (6-8) of Nerve Fascicles are attached to the Dorsolateral and Ventrolateral aspects of the cord. The Fascicles coalesce to form Dorsal and Ventral Nerve Roots. The Fascicles coalesce to form Dorsal and Ventral Nerve Roots.

The Roots pass to their corresponding Inter vertebral Foramena. The Roots pass to their corresponding Inter vertebral Foramena. Near which they join to form the Spinal Nerve Proper. Near which they join to form the Spinal Nerve Proper.

Carry: Carry: Primary Afferent Neurons from the peripheral sensory receptors to the spinal cord and brain stem. Primary Afferent Neurons from the peripheral sensory receptors to the spinal cord and brain stem. Their cell bodies are in the Dorsal Root Ganglia. Their cell bodies are in the Dorsal Root Ganglia.

Carry : Carry : 1.Efferent neurons (Lower Motor Neurons) 1.Efferent neurons (Lower Motor Neurons) Their cell bodies are located in the Spinal Gray matter. Their cell bodies are located in the Spinal Gray matter. 2.Preganglionic Autonomic neurons. 2.Preganglionic Autonomic neurons.

Spinal Nerves are Mixed. Spinal Nerves are Mixed. Contain: Contain: Both Afferent and Efferent fibers. Both Afferent and Efferent fibers. Each spinal nerve is divided into Each spinal nerve is divided into Dorsal and Ventral Rami. Dorsal and Ventral Rami.

Dorsal Ramus : Dorsal Ramus : Thin. Thin. Supplies muscles and skin of the back. Supplies muscles and skin of the back. Ventral Ramus : Ventral Ramus : Larger. Larger. Supplies muscles and skin of the Front of the body and limbs. Supplies muscles and skin of the Front of the body and limbs. Connected to the Sympathetic Chain by the White and Grey Rami. Connected to the Sympathetic Chain by the White and Grey Rami.

The spinal cord is Segmented. The spinal cord is Segmented. In the Living In the Living The approximate level of the segments is identified by the Posterior Spinous Process of the vertebrae. The approximate level of the segments is identified by the Posterior Spinous Process of the vertebrae.

Cervical Segments: Cervical Segments: One spine Higher than their corresponding vertebrae. One spine Higher than their corresponding vertebrae. C7 Segment is adjacent to C6 Vertebra. C7 Segment is adjacent to C6 Vertebra. Thoracic segments : Thoracic segments : Two spines Higher. Two spines Higher. Lumbar segments : Lumbar segments : Three- Four spines Higher. Three- Four spines Higher.

Cervical Region : Cervical Region : Cervical segments lie adjacent to their corresponding Vertebral Bodies. Cervical segments lie adjacent to their corresponding Vertebral Bodies.

1-7 C : Above the Upper Seven Cervical Vertebrae. 1-7 C : Above the Upper Seven Cervical Vertebrae. C8 : Below 7 th Cervical Vertebra. C8 : Below 7 th Cervical Vertebra. T1 and the rest of the nerves: Below their Corresponding Vertebrae. T1 and the rest of the nerves: Below their Corresponding Vertebrae.

The Lumbar and Sacral nerves take an Oblique Course to reach the intervertebral foramina. The Lumbar and Sacral nerves take an Oblique Course to reach the intervertebral foramina. The resulting leash of nerve roots forms the Cauda Equina. The resulting leash of nerve roots forms the Cauda Equina.

Pia Mater Pia Mater The inner most layer. The inner most layer. A delicate,vascular membrane. A delicate,vascular membrane. It is Closely applied to the surface of the spinal cord. It is Closely applied to the surface of the spinal cord. It extends inferiorly as the Filum Terminale. It extends inferiorly as the Filum Terminale.

A flat membrane formed from Pia Mater. A flat membrane formed from Pia Mater. Extension: Extension: Along a midway line between the dorsal and ventral nerve roots. Along a midway line between the dorsal and ventral nerve roots. Laterally to adhere to the Arachnoid and Dura. Laterally to adhere to the Arachnoid and Dura. The spinal cord is suspended in the middle of the dural sheath. The spinal cord is suspended in the middle of the dural sheath.

Arachnoid: Arachnoid: A a fibrous membrane. A a fibrous membrane. It Loosely covers the spinal cord. It Loosely covers the spinal cord. Dura: Dura: A dense, strong fibrous membrane. A dense, strong fibrous membrane. It is continuous superiorly with the Meningeal layer of the Cranial Dura. It is continuous superiorly with the Meningeal layer of the Cranial Dura.

They extend along Each Nerve Root and become continuous with its Epineurium. They extend along Each Nerve Root and become continuous with its Epineurium. Inferiorly Inferiorly They extend to the 2 nd sacral vertebra. They extend to the 2 nd sacral vertebra.

Epidural Epidural Separates Dural Sheath from the Vertebral Canal. Separates Dural Sheath from the Vertebral Canal. Contains the Internal Vertebral Venous Plexus. Contains the Internal Vertebral Venous Plexus. Subdural Subdural A thin space. A thin space. Separates Dura from Arachnoid. Separates Dura from Arachnoid.

Subarachnoid Subarachnoid Contains Cerebro Spinal Fluid. Contains Cerebro Spinal Fluid. Terminates Terminates At the level of S2 At the level of S2

Held in position by : Held in position by : Laterally : Denticulate Ligament. Laterally : Denticulate Ligament. Inferiorly : Filum Terminale. Inferiorly : Filum Terminale. The spinal cord is Cushioned against Trauma by: Cerebrospinal Fluid. The spinal cord is Cushioned against Trauma by: Cerebrospinal Fluid.

Site : Site : Subarachnoid Space (L2-L3 or L3 –L4). Subarachnoid Space (L2-L3 or L3 –L4). Not Allowed in Children. Not Allowed in Children. Indications: Indications: 1. Diagnostic purposes. 1. Diagnostic purposes. 2. Radiological study (Myelography). 2. Radiological study (Myelography).

Injection of Anaesthetics into the Epidural Space It is for Surgical Procedures as in Labour. Injection of Anaesthetics into the Epidural Space It is for Surgical Procedures as in Labour.

1. Anterior spinal artery. 1. Anterior spinal artery. 2. Posterior spinal Arteries. 2. Posterior spinal Arteries. 3. Radicular Arteries. 3. Radicular Arteries.

A single Y shaped artery. Arises from :Vertebral artery at the level of the medulla. Supplies the cord at the Cervical Level. Supplies the cord at the Cervical Level. It is most vulnerable in the anterior part of the cord particularly in the Thoracic Segment. It is most vulnerable in the anterior part of the cord particularly in the Thoracic Segment. Its Occlusion causes Acute Thoracic Syndrome with Paraplegia and Incontinence. Its Occlusion causes Acute Thoracic Syndrome with Paraplegia and Incontinence.

Two arteries. Two arteries. Arise from Arise from. Vertebral Or. Vertebral Or Posterior Inferior Cerebellar arteries. Posterior Inferior Cerebellar arteries. Spinal Arteries (Anterior &Posterior) are Insufficient alone to supply the cord Below the Cervical Level. Spinal Arteries (Anterior &Posterior) are Insufficient alone to supply the cord Below the Cervical Level.

Origin from following arteries : Origin from following arteries : 1. Ascending cervical 2. Intercostal. 1. Ascending cervical 2. Intercostal. 3. Lumbar. 3. Lumbar. They share in the arterial supply of the cord Below the Cervical Level. They share in the arterial supply of the cord Below the Cervical Level. They Anastomose freely with the Spinal Arteries. They Anastomose freely with the Spinal Arteries.

Artery of Adamkiewicz. Artery of Adamkiewicz. It may arise from: Intercostal or Lumbar arteries. It may arise from: Intercostal or Lumbar arteries. It supplies It supplies Lower half of the spinal cord (T8 –L3). Lower half of the spinal cord (T8 –L3). These are Vulnerable Segments. These are Vulnerable Segments. Occlusion of the artery may cause Muscle weakness and Paralysis. Occlusion of the artery may cause Muscle weakness and Paralysis.

Six Longitudinal Interconnecting Venous Channels. Six Longitudinal Interconnecting Venous Channels. (1) Anterior and Posterior Spinal veins in the midline. (1) Anterior and Posterior Spinal veins in the midline. (2) Anterolateral and Posterolateral paired veins situated near the lines of attachment of the (2) Anterolateral and Posterolateral paired veins situated near the lines of attachment of the Ventral and Ventral and Dorsal roots. Dorsal roots. (3) Anterior and Posterior Radicular Veins. (3) Anterior and Posterior Radicular Veins.

(4) Internal vertebral venous plexus in the Epidural Space. (4) Internal vertebral venous plexus in the Epidural Space. (5) External Vertebral Venous Plexus. (5) External Vertebral Venous Plexus. (6) Ascending Lumbar, Azygos and Hemiazygos Veins. (6) Ascending Lumbar, Azygos and Hemiazygos Veins.

The spinal nerve roots can be injured by Compression of Prolapsed Intervertebral Discs. The spinal nerve roots can be injured by Compression of Prolapsed Intervertebral Discs. It is manifested by: It is manifested by: 1. Paraesthesia (tingling sensations). 1. Paraesthesia (tingling sensations). 2. Weakness and wasting of the muscles. 2. Weakness and wasting of the muscles. 3. Numbness of the skin corresponding to the dermatomal distribution. 3. Numbness of the skin corresponding to the dermatomal distribution. 4. Loss of Tendon Reflexes. 4. Loss of Tendon Reflexes.

(A) Cervical (A) Cervical Pain in the neck radiating to the arm and hand. Pain in the neck radiating to the arm and hand. (B) Lumbar (B) Lumbar 1. Back pain. 1. Back pain. 2. Sciatica ( radiation of pain into the legs). 2. Sciatica ( radiation of pain into the legs). A large Lumbosacral prolapsed disc can cause paralysis of the bladder and incontinence. A large Lumbosacral prolapsed disc can cause paralysis of the bladder and incontinence.