Question | Answer |
What condition is known as a herniated disc? | If the anterior and posterior ligaments of the discs become injured or weakened, the pressure developed in the nucleus pulposus may be great enough to rupture annulus fibrosus. |
Study the structure of a typical vertebra | has a body and vertebral arch
which consists of Two pendicles and two laminae |
what are the 7 processes of a typical vertebra? | a)Two transverse processes
b)One spinous process (spine)
c)Two superior articular processes with facets
d)Two inferior articular processes with facets |
What are the functions of the dura matter? | a) its composed of dense, irregular connective tissue.
b)Its extents from the foramen of the magnum to the second sacral vertebra where it is closed-ended |
What its the epidural space? | Its filled with fat and connective tissue which provide additional protection to the spinal cord. between the bone and the dura matter |
What are the functions of the arachnoid matter? | a)It consists of connective tissue with a spider web like arrangement of collagen fibers and some elastic fibers
b)surrounding it is the subdural space filled with interstitial fluid |
What are the funtions of the pia matter? | a)It is attached to the surface of the spinal cord (and brain)
b)It is a layer of connective tissue that contains collagen fibers and some elastic fibers as well as many blood vessels that provide nutrients and oxygen to the spinal cord |
What is the subarachnoid space? | located in the pia matter and contains cerebrospinal fluid |
Define denticulate ligament | Is the membranous extensions of the pia matter. suspend the spinal cord in the middle of its dural sheath to provide protection against sudden displacement that could result in shock |
Define filum terminale | Its an extension of the pia matter. Extends inferiorly from the conus medullaries to attach the spinal cord to the coccyx |
Define Conus Medullaries | Located on the lower end of the spinal cord, its a tapering, cone shaped portion. Ends at the level of the invertebral disc between the first and second lumbar vertebrae in an adult |
Define Cauda Equina | Nerves that arise from the lumbar, sacral, and coccygeal regions do not leave the vertebra column at the same level they exit the cord. the roots of these lower spinal nerves angle inferiorly in the vertebral canal like wisps of hair. |
The adult spinal cord extents only to which vertebral level? | to the second lumbar vertebra (L2) |
Where is a spinal tap normally performed? | Between the L3 and L4 or L4 and L5 lumbar vertebrae |
Define white matter | Consistsof bundles of myelinated axons of motor neurons, interneurons and sensory neurons |
Define gray matter
Where is the central canal located? | Consists primarly of cell bodies of neurons, neuroglia, unmyelinated axons and dendrites of interneurons and motor neurons. grey comissure |
Define the anterior horn | Contain cell bodies of somatic motor neurons and motor nuclei which provide nerve impulses for contraction of skeletal muscles. |
Define the posterior horn | Contain somatic and autonomic sensory nuclei |
Define the lateral horn | It is only present in the thoracic , upper lumbar, and sacral segments of the spinal cord, contains cell bodies of the autonomic motor neurons that regulate activities of involuntary effectors. |
How many pairs of the spinal nerves? | 31 pairs of spinal nerves from a spinal segment |
How many in each segment of the spinal nerves? | 8 pairs of cervical nerves
12 pairs of thoracic nerves
5 pair of lumbar nerves
5 pairs of sacral nerves
1 pair of coccygeal nerves |
What does a ventral root of a spinal nerve contain? | Contains motor neuron axons, which transmit nerve impulses from the spinal cord to the effector organs and cells |
What does a dorsal root of a spinal nerve contain? | Contains sensori nerve fibers, which transmits impulses from the periphery into the spinal cord. |
What does posterior root ganglion contain? | Contains cell bodies of sensory nerve fibers |
How are the spinal nerves formed? | They form in the posterior root and an anterior root, results on every spinal nerve being a mixed nerve called a spinal nerve trunk |
Where do spinal nerves exit? | At an Interventebral foramen |
What are the rami of the spinal nerves? | There are 3 rami of the spinal nerves
-Posterior (Dorsal) ramus
-Anterior (ventral) ramus
-Meningeal branch
-Rami communicates |
What region does posterior ramus serve? | serves the DEEP muscles and skin of the posterior surface of the trunk |
What region does anterior ramus serve? | Serves the muscles, structures of the limb and the skin of the lateral and anterior surfaces of the trunk. |
What are the plexuses? | The anterior rami of spinal nerves, that form networks on both right and left sides of the body. |
Do the anterior rami from all of the spinal cord segments from plexuses? | T2-T12 DO NOT form plexuses |
How do the spinal nerves T2-T12 differ from all other spinal nerves? | This nerves called intercostal or thoracic nerves travel directly to the interccostal regions and the nearby muscles and skin regions. |
Define the dermatome | Are the areas of the skin that provides sensory input to one pair of spinal nerves or to the cranial nerve V (for the face and scalp) |
Define endonerium | Layer where each axon is wrapped |
Define Perineurium | Layer where each fasciculus (groups of axons with their endoneuria) are wrapped |
Define Epineurium | groups of fasciculi collectively form a nerve which is covered by this layer. |
What are the components of a typical reflex arc? 1 | a)Sensory receptor: Responds by producing a receptor potential
b)Sensory neuron: Axon sends info from receptos to integrating center |
What are the components of a typical reflex arc?2 | c)Integrating center: gray matter in CNS
d)Motor neuron: Axon conducts impulses from integrating center to effectors
e)Effector: Muscle or gland |
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