Quiz 2 Lecture Flashcards
(32 cards)
Spinal cord
Part of CNS Sends afferent/efferent signals Processes and integrates info Responsible for reflexes Extends to L2/L4 vertebrae
Spinal position in body
- Spinal Cord growth stops at about age 4
- Vertebral column ( bones) continues to grow until full height
- Tapers to conus medullaris- inferior end
- Filum terminale originates off of conus medullaris
conus medullaris
Cone shaped tapering of spinal cord
filum terminale
Fibrous thread extending from conus medullaris to sacrum
cauda equina
‘Horse’s tail’
• Comprised of spinal nerves and filum terminale
spinal cord enlargements
• Cervical enlargement
– More interneurons here innervating pectoral girdle and upper limbs
• Lumbosacral enlargement
– More interneurons here innervating pelvis and lower limbs
how many segments in the spinal cord? and what are they associated with?
spinal cord is divided into 31 segments: 8 cervical, 12 thoracic, 5 lumbar, and 1 coccyx. Each segment is associated with: 1. Dorsal root ganglion 2. Dorsal root 3. Ventral root
protection of spinal cord
- Epidural space- filled with connective tissue that separates dura mater from walls of vertebral canal
- Cerebral Spinal Fluid- cushions cord
- Meninges- Dura mater, Arachnoid, Pia mater
Denticulate ligaments
-lateral extensions of the pia mater that prevent spinal cord from moving laterally
transverse section of spinal cord
- Superficial white matter
- Deep gray matter butterfly wings shape
- D.A.V.E.
- Dorsal region of the spinal cord carry Afferent signals
- Ventral region of the spinal cord carry Efferent signals
gray matter of spinal cord
• Mostly cell bodies and interneurons that are unmyelinated
• The “wings” of the grey matter represent the:
– Dorsal (posterior) horn (somatic/visceral sensory nuclei)
– Ventral (anterior) horn (somatic-voluntary- motor cell bodies).
– Lateral horn (T1-L2) visceral motor neurons- sympathetic
• Gray commissures
– Axons of interneurons crossing from right & left sides
white matter of spinal cord
arranged in funiculi/columns – (lateral / anterior / posterior) – Each column contains tracts – Axons that share structural or functional similarities Tracts & Columns
• White matter in CNS – Tracts • Bundles of axons that share a common origin and destination – Columns • Several tracts together
clinical aspects
- Lumbar Punctures/Spinal Taps
- Between L3 & L4
- Small amt of CSF from Sub-Arachnoid space.
- Analysis- For presence of WBC, pathogens, metabolic wastes, etc.
- Epidural/Spinal Blocks
- anesthesia is placed into the epidural space
- In sacral region produces a “causal block” common for childbirth.
describe the adult brain
Adult brain Contains 95% of all neural tissue is about 3 pounds and is the texture of firm tofu
embryology
3 week embryo, 3 primary brain vesicles
3 primary vesicles grow to form 5 secondary vesicles.
Prosencephalon forms:
Telencephalon, & diencephalon
Mesencephalon->mesencephalon
Rhombencephalon forms:
Metencephalon, Myelencephalon
5 major regions of the brain
Telencephalon = cerebrum Diencephalon Includes the thalamus, hypothalamus Mesencephalon = midbrain Metencephalon Includes pons & cerebellum Myelencephalon = medulla oblongata
cranial meninges
Protective layers around the brain
Provide physical stability and shock absorption
Dura mater-2 Tough fibrous layers
Arachnoid mater-middle layer, with blood vessels
Pia mater-attached to CNS
Dura mater
Two sublayers with space in between
Dural sinuses: large veins found in between the 2 layers
Dura mater folds into the deep fissures of the brain called Falx cerebri and Tentorium cerebelli
arachnoid mater
Deep to arachnoid is subarachnoid space
Network of collagen and elastic fibers (arachnoid trabeculae)
Contains blood vessels
protection of brain
- Cranial meninges
- Cerebrospinal fluid
- Cranium = skull bones
- blood-brain barrier- astrocytes are responsible
ventricles of the brain
• Spaces that contain cerebrospinal fluid
• 4 ventricles
– 1) right lateral ventricle
– 2) left lateral ventricle
– 3) third ventricle
• Cerebral aqueduct connects 3rd and 4th ventricle
– 4) fourth ventricle
cerebral spinal fluid
- Cushions the CNS
- Supports the brain-the brain is floating in the CSF
- Transport nutrient/wastes etc.
- Fills ventricles
– Produced in choroid plexus within brain ventricles
– Drains into arachnoid granulations drain into superior sagittal sinus
Choroid Plexus
- Produces CSF 500 ml/day
- Composed of ependymal cells and capillaries
- Found at the edge of each ventricle
- Choroid = vascular
- Plexus = braid
cerebral lobes
– Frontal Controls skeletal muscles (primary motor cortex)
– Temporal auditory & olfactory cortex
– Insula Gustatory cortex (taste)
– Parietal Receives general sensory info (somatic sensory cortex)
– Occipital Visual cortex
