Exam 1 Neuro Flashcards
The Central Nervous system consists of the
Brain and Spinal Cord
The 3 Primary Brain Vesicles
Forebrain: Prosencephalon
Midbrain:Mesencephalon
Hindbrain: Rhombencephalon
Prosencephalon secondary vesicles
Telencephalon
Diencephalon
Rhombencephalon secondary vesicles
Metencephalon
Myelencephalon
Telencephalon: Adult brain structures and nerves
Cerebrum: cerebral hemispheres (cortex, white matter, basal nuclei)
CNI
Telencephalon: Adult neural canal regions
Lateral ventricles
Diencephalon: Adult Brain Structures and nerves
Diencephalon (thalamus, hypothalamus, epithalamus), Retina
CN II
Diencephalon: Adult Neural canal regions
Third ventricle
Mesencephalon: Adult Brain structures and Nerves
Brain stem: midbrain
CN III, IV
Mesencephalon: Adult Neural Canal Regions
Cerebral Aqueduct
Metencephalon: Adult brain structures and nerves
Brain stem: Pons
Cerebellum
CN V
Metencephalon : Adult Neural Canal Regions
Upper fourth ventricle
Myelencephalon: Adult Brain structures and nerves
Brain stem: Medulla Oblongata
CN VI, VII, VIII, IX, X, XI, XII
Myelencephalon: Adult Neural Canal Regions
Fourth ventricle
How many pairs of spinal nerves
36
How many pairs of cranial nerves
12
Peripheral Nervous system consists of
- Sensory (afferent) neurons
- Motor (efferent) neurons
- Afferent and efferent neurons can further break down into different categories
- Somatic- skin and skeletal muscle
- Visceral- organs
Cells of the Peripheral Nervous System
Satellite Cells
Schwann Cells
Cells of the Central Nervous System
Oligodendrocytes
Astrocytes
Microglia
Ependymal Cells
Neuron
Functional unit of the NS
Most important feature is ability to communicate with AP
Basic types of neurons
Unipolar (typically sensory)
Bipolar
Multipolar (most common, typically motor)
Supportive cells: Glia cells
Glial cells- non-excitable supportive cells; maintain homeostasis and form myelin (gives nerves white color)
1.Astrocytes
2.Satellite cells
3.Oligodendrocytes
4.Schwann cells
5.Microglial cells
6.Ependymal cells
Astrocytes
CNS; BBB, selective permeability
Satellite Cells
PNS; surround neurons’ sensory ANS ganglia
Oligodendrocytes
CNS; myelin sheath formation in CNS
Schwann Cells
PNS; myelin sheath formation in PNS
Microglial Cells
CNS; macrophages of the CNS
Ependymal Cells
CNS; surrounds ventricular system, secrete CSF
Motor Systems
Only 2 different ones: somatic efferent and visceral efferent
Function to target specific places
Somatic: Efferent
Voluntary motor
Goes to skeletal muscle, all spinal nerves, and CNN III, IV, VI, VII, IX, X, XI, XII
Visceral: Efferent
Autonomic motor
Goes to smooth muscle, cardiac muscle, glands, adipose tissue, all spinal nerves, splanchnic nerves, sacral spinal nerves, and CNN III, VII, IX and X
Sensory Systems
Somatic Afferent
Visceral Afferent
Proprioception
Somatic: Afferent
General: temperature, touch, noxious stimuli, all spinal nerves, CN V
Special: vision, hearing, CNN II and VIII
Visceral: Afferent
General: organ content, distention, and chemicals, splanchnic branches of spinal nerves, CNN VII, IX, X
Special: taste, olfaction, CNN I, VII, IX, X
Proprioception
General: muscle movement, joint movement, all spinal nerves, CN V
Special: vestibular system, CN VIII
Frontal Lobe
Parietal
Telencephalon function
Receives and processes sensory information
Voluntary motor control (UMN)
Memory and behavior
Cerebral Cortex
Neuronal cell bodies located on surface in layers
Basal Nuclei
Collections of neuronal cell bodies deeper in cerebrum
Diencephalon Function
Relays information to cerebral cortex
Alertness and awareness
Autonomic/regulatory control center
UMN
Vision pathways
The three structures in the epithalamus
Stria habenularis, Habenular nucleus, Pineal body
Interthalamic Adhesion
Thalamus
Hypothalamus
Metathalmus
Mesencephalic aqueduct (cerebral aqueduct)
Connects 3rd to 4th ventricles
Mesencephalon Structures
Tectum
Cerebral peduncles
Tectum
Rostral colliculus
Caudal Colliculus
Cerebral Peduncles
Metencephalon Function
Motor neurons
Coordination of motor functions
Pons functions
Alertness
Cerebellum
Pons
Myelencephalon Function
Motor neurons (UMN)
Ascending sensory and descending motor pathways through medulla oblongata
Alertness
Cardiovascular and respiratory control centers
Pyramid
Spinal Cord: Gray matter
cell bodies of LMN
The dorsal, lateral, and ventral horns
surrounds central canal
Spinal Cord: White Matter
axons
Descending and ascending horns
surrounds gray matter
Spinal Cord: Central Canal
Lined by ependymal cells
Spinal Nerves
Vertebral Formula
Spinal Cord Segments
Cord ends at L6 (cauda equina)
Regions of the Spinal Cord: Anatomical Regions
Cervical (C1-8)
Thoracic (T1-13)
Lumber (L1-7)
Sacral (S1-3)
Caudal (Cd1-5ish)
Regions of the Spinal Cord: Clinical Regions
Neck (C1-5)
Thoracic limb (C6-T2)
Thoracolumbar (T3-L3)
Pelvic limb (L4-S1)
Sacrocaudal (S1-Cd5)
Blood Supply: Brain
Internal carotid aa –> Common Carotid–> Brachiocephalic trunk
Vertebral artery –> Subclavian
- supplies brain and cervical part of spinal cord
Rostral cerebral
Middle cerebral
Caudal cerebral
Rostral cerebellar
Caudal cerebellar
Blood Supply: Spinal Cord
Cervical region : Vertebral Arteries
Thoracic region: Intercostal Arteries
Lumbar region : Lumbar Arteries
Spinal Artery
Spinal arteries enter the spinal cord through intervertebral foramina
spinal artery to Dorsal & Ventral branches (radicular) to either Right & Left Dorsal Spinal Arteries to Ventral Spinal Artery
What percentage of cardiac output is supplied to neural tissue?
15-20%
Basilar Artery Blood Flow
Basilar Artery to Internal Carotid Artery to Cerebral Arterial Circle (Circle of Willis)
The vertebral and ventral spinal arteries form the Basilar artery
Species Variations
Non-artiodactyls : canine, equine, humans
Artiodactyls : cattle, sheep, goats, camels, pigs
- Intracranial epidural rete mirabile
- Cats also have an external rete mirabile
Which artery is the major vessel to the cerebrum?
Middle cerebral artery
Most important vein to know
Dorsal Sagittal Sinus
Blood Brain Barrier
Modified capillary structure to protect the CNS from circulating substances
- Endothelial tight junctions
- Astrocyte processes
- Lack of fenestration
Clinical relevance:
- Protects against toxic substances
- Barriers to medications
- Tumors/inflammation break BBB
Which organs in the brain lack BBB?
- Circumventricular organs (median eminence, area postrema, pineal gland)
Circumventricular organs
Where physiologic stimuli are released into the bloodstream