Intro To Neuroanatomy Flashcards
Nervous system has three major functions:
•
•
•
Nervous system has three major functions:
• Sensory - monitors internal & external environment through presence of receptors
• Integration - interpretation of sensory information (information processing); complex (higher order) functions
• Motor - response to information processed through stimulation of effectors
• muscle contraction
“ glandular secretion
Nervous system has three major functions:
• ——— - monitors internal & external environment through presence of receptors
• ——— - interpretation of sensory information (information processing); complex (higher order) functions
• ——— - response to information processed through stimulation of effectors
• muscle contraction
“ glandular secretion
Nervous system has three major functions:
• Sensory - monitors internal & external environment through presence of receptors
• Integration - interpretation of sensory information (information processing); complex (higher order) functions
• Motor - response to information processed through stimulation of effectors
• muscle contraction
“ glandular secretion
General Organization of the nervous system
• Two Anatomical classifications and their divisions
General Organization of the nervous system
• Two Anatomical Divisions
• Central nervous system (CNS)
• Brain
• Spinal cord
• Peripheral nervous system (PNS)
• All the neural tissue outside CNS
• Afferent division (sensory input)
• Efferent division (motor output)
-somatic nervous system
-autonomic nervous system
Types of neural cells in the nervous system
Neurons
Neuroglia
List the CNS and PNS Neuroglia cells
CNS:
-astrocytes
- oligodendrocytes
-microglia
-ependymal cells
PNS:
-Schwann cells (neurolemmocytes)
Satellite cells
Functions of Astrocytes
Astrocytes
• create supportive framework for neurons
• create “blood-brain barrier”
• monitor & regulate interstitial fluid surrounding neurons
• secrete chemicals for embryological neuron formation
• stimulate the formation of scar tissue secondary to CNS injury
Function of oligodendrocytes
Oligodendrocytes
• create myelin sheath around axons of neurons in the CNS.
Myelinated axons transmit impulses faster than unmyelinated axons
Function of microglia
Brain macrophages
Phagocytize cellular wastes and pathogens
Function of ependymal cells
Line ventricles of brain and central canal of spinal cord
Produce, monitor and help circulate CSF
Function of Schwann cells
Schwann cells
• surround all axons of neurons in the
PNS creating a neurilemma around them. Neurilemma allows for potential regeneration of damaged axons
• creates myelin sheath around most axons of PNS
Function of Satellite cells
Satellite cells
• support groups of cell bodies of neurons within ganglia of the PNS
•Most axons of the nervous system are surrounded by a ——— (myelinated axons)
•The presence of ——— speeds up the transmission of action potential along the axon
Myelin will get laid down in segments (internodes) along the axon, leaving unmyelinated gaps known as “———”
•Regions of the nervous system containing groupings of myelinated axons make up the “———”
•”———” is mainly comprised of groups of neuron cell bodies, dendrites & synapses (connections hetween neurons)
•Most axons of the nervous system are surrounded by a myelin sheath (myelinated axons)
•The presence of myelin speeds up the transmission of action potential along the axon
Myelin will get laid down in segments (internodes) along the axon, leaving unmyelinated gaps known as “nodes of Ranvier”
•Regions of the nervous system containing groupings of myelinated axons make up the “white matter”
•”gray matter” is mainly comprised of groups of neuron cell bodies, dendrites & synapses (connections hetween neurons)
——— perform all of the communication, information processing, and control functions of the nervous system. ——— outnumber neurons and have functions essential to preserving the physical and biochemical structure of neural tissue and the survival of neurons
Neurons perform all of the communication, information processing, and control functions of the nervous system. Neuroglia À outnumber neurons and have functions essential to preserving the physical and biochemical structure of neural tissue and the survival of neurons
Structural classification based on number of processes coming off of the cell body:
Anaxonic neuron
Bipolar neuron
Pseudopolar neuron
Multipolar neuron
Anatomical organization of neurons
Neurons of the nervous system tend to group together into organized bundles
The axons of neurons are bundled together to form ——— in the
PNS & ——— in the CNS. Most axons are myelinated so these structures will be part of “———”
The cell bodies of neurons are clustered together into ——— in the PNS & ——— in the CNS. These are unmyelinated structures and will be part of “———”
Anatomical organization of neurons
Neurons of the nervous system tend to group together into organized bundles
The axons of neurons are bundled together to form nerves in the
PNS & tracts/pathways in the CNS. Most axons are myelinated so these structures will be part of “white matter”
The cell bodies of neurons are clustered together into ganglia in the PNS & nuclei/centers in the CNS. These are unmyelinated structures and will be part of “gray matter”
———Gray matter on the surface of the brain
Neural Cortex
———Collections of neuron cell bodies in the CNS; each center has specific processing functions
Centers
———- The most complex centers in the brain
High centers
———Several tracts that form an anatomically distinct mass
Tracts
The brain and spinal cord are invested by three concentric membranes
1.
2.
3.
The brain and spinal cord are invested by three concentric membranes
1. The outermost layer is the dural matter.
2. The middle layer is the archnoid matter.
3. The innermost layer is the pia matter
DURA MATER
•The cranial dura is a —— layered tough, fibrous membrane that surrounds the brain.
• It is formed of two layers; ——— and ———.
•The ——— layer is attached to the skull.
•The ——— layer is folded forming the dural folds; ———, and ———
•Sensory innervation of the dura is mostly from the three branches of the ——— and ——— nerves & C— to C—.
DURA MATER
•The cranial dura is a two layered tough, fibrous membrane that surrounds the brain.
• It is formed of two layers; periosteal and meningeal.
•The periosteal layer is attached to the skull.
•The meningeal layer is folded forming the dural folds; falx cerebri, and tentoriam cerebelli
•Sensory innervation of the dura is mostly from the three branches of the trigeminal and vagus nerves & C1 to C3.
Dura matter
Two large reflection of dura extend into the cranial cavity;
Dura matter
Two large reflection of dura extend into the cranial cavity;
-Falx cerebri;
- tentorium cerebelli
Dura matter
-Falx cerebri;
•It is a vertical ——— shaped sheet of dura, in the midline
Extends from the ———- into the ——— fissure between the two ———hemispheres.
•It has an attached border adherent to the ——.
•And a free border lies above the———
Dura matter
Two large reflection of dura extend into the cranial cavity;
-Falx cerebri;
•It is a vertical sickle shaped sheet of dura, in the midline
Extends from the cranial roof into the great longitudinal fissure between the two cerebral hemispheres.
•It has an attached border adherent to the skull.
•And a free border lies above the corpus callosum.
Tentorium cerebelli;
• A horizontal shelf of dura, lies between the posterior part of the ——— hemispheres and the ———.
• It has a free border that encircles the ———.
• Its superior surface in the middle line it is continuous with the ———, separated by the ———
Tentorium cerebelli;
• A horizontal shelf of dura, lies between the posterior part of the cerebral hemispheres and the cerebellum.
• It has a free border that encircles the midbrain.
• Its superior surface in the middle line it is continuous with the falx cerebri, separated by the straight sinus
Arachnoid Mater& Pia Mater
•———- mater; is a soft translucent membrane loosely envelops the brain.
• It is separated from the dura by a narrow ——— space.
• ——— mater; is a thin, delicate & highly vascular membrane that is closely adherent to the gyri and fitted into the sulci.
• Between the pia and arachnoid mater lies the ———- space which contains; fibrous trabechulae, main blood vessels and CSF.
Arachnoid Mater& Pia Mater
•Arachnoid mater;
is a soft translucent membrane loosely envelops the brain.
• It is separated from the dura by a narrow subdural space.
• Pia mater; is a thin, delicate & highly vascular membrane that is closely adherent to the gyri and fitted into the sulci.
• Between the pia and arachnoid mater lies the subarachnoid space which contains; fibrous trabechulae, main blood vessels and CSF.
Subarachnoid Space
•The subarachnoid space is varied in depth forming; ————.
• The ———, or ——— which lies between the inferior surface of the cerebellum and the back of the medulla.
• from this cistern CSF flows out of the ——— ventricle.
Subarachnoid Space
•The subarachnoid space is varied in depth forming; subarachnoid cisterns.
• The cisterna magna, or cerebllomedullary cistern which lies between the inferior surface of the cerebellum and the back of the medulla.
• from this cistern CSF flows out of the fourth ventricle.
Subarachnoid Space
—————;
• Is located at the base of the brain, where the arachnoid spans the space between the two cerebral peduncles.
• It contains the ———— & ————
Subarachnoid Space
Interpeduncular cistern;
• Is located at the base of the brain, where the arachnoid spans the space between the two cerebral peduncles.
• It contains the optic chiasma & circulus arteriosus of Wills.
Subarachnoid Space
Interpeduncular cistern;
• Is located at the ——— of the brain, where the arachnoid spans the space between the ————-.
• It contains the optic chiasma & circulus arteriosus of Wills.
Subarachnoid Space
Interpeduncular cistern;
• Is located at the base of the brain, where the arachnoid spans the space between the two cerebral peduncles.
• It contains the optic chiasma & circulus arteriosus of Wills.
Spinal meninges
-The spinal cord, is invested by three meningeal coverings: the ———, ——— and ———.
-Dura mater, the outer covering, is a (single/double?), tough fibrous membrane.
-It envelopes the cord (loosely/firmly?)
-It is separated from arachnoid matter by the ———- space, and from the bony wall of the vertebral canal by the ———
-Arachnoid matter, is a ——— type of
membrane, lies between the ——— and ———
-Between it and pia lies the ———— space contains CSF.
-Pia mater, is a ——— type of membrane
membrane, lies closely envelops the cord and nerve
-it is attached through the arachnoid to
the dura by the ————.
Spinal meninges
-The spinal cord, is invested by three meningeal coverings: the pia mater, arachnoid mater and dura mater.
-Dura mater, the outer covering, is a single, tough fibrous membrane.
-It envelopes the cord loosely
-It is separated from arachnoid matter by the subdural space, and from the bony wall of the vertebral canal by the epidural
-Arachnoid matter, is a translucent
membrane, lies between the pia and dura
-Between it and pia lies the subarachnoid space contains CSF.
-Pia mater, is a delicate membrane
membrane, lies closely envelops the cord and nerve
-it is attached through the arachnoid to
the dura by the denticulate ligament.
Spinal meninges
-Spinal cord terminates at vertebral level — to —, while
-Arachnoid and dural and, subarachnoid space, continue caudally to — vertebral level .
-Pia extends downwards forming the ——— which pierces the ——— and ——— and passes through the ——— to be attached to the back of the coccyx.
Spinal meninges
-Spinal cord terminates at level L1-L2, while
-Arachnoid and dural and, subarachnoid space, continue caudally to S2.
-Pia extends downwards forming the filum terminalis which pierces the arachnoid and dural sacs and passes through the sacral hiatus to be attached to the back of the coccyx.
Ventricular system
-Interconnecting channels within the CNS.
-in the spinal cord; represented by the ———.
-Within the brain; a system of ventricles is found.
-The central canal of the spinal cord is continuous upwards to the ———ventricle.
-On each side of the forth ventricle laterally, lateral recess extend to open into ——— (also called——) or ——— (also called——)
Ventricular system
-Interconnecting channels within the CNS.
-in the spinal cord; represented by the central canal.
-Within the brain; a system of ventricles is found.
-The central canal of the spinal cord is continuous upwards to the forth ventricle.
-On each side of the forth ventricle laterally, lateral recess extend to open into lateral aperture (foramen of Luscka), central defect in its roof (foramen of Magendie)
VENTRICULAR SYSTEM
The forth ventricle is continuous with the ————, that opens in the —— ventricle
The third ventricle is continuous with the lateral ventricle through the ———.
VENTRICULAR SYSTEM
The forth ventricle is continuous with the cerebral aqueduct, that opens in the third ventricle
The third ventricle is continuous with the lateral ventricle through the interventricular toramen.
Cerebrospinal fluid
-Present in the ——- system, together with the —— and ——-spaces
-It is colourless fluid containing little —— and few ——.
-lt is about —— ml.
- list a function
Cerebrospinal fluid
-Present in the ventricular system, together with the cranial and spinal subarachnoid spaces
-It is colourless fluid containing little protein and few cells.
-lt is about 150 ml.
-lt serves to cushion the brain from sudden movements of the head
——— It is colourless fluid containing little protein and few cells.
CSF
Cerebrospinal fluid
-lt is produced by the ———, which is located in the ———, ——- & ——- ventricles.
• explain the flow of CSF
Cerebrospinal fluid
-lt is produced by the choroid plexus, which is located in the lateral, third & fourth ventricles.
• From there it flows:
through the interventricular foramen to the third ventricle and, by way of the cerebral aqueduct, to the fourth ventricle.
Cerebrospinal fluid
-lt leaves the ventricular system through how many apertures of the 4th ventricle; which are:
.
Cerebrospinal fluid
-lt leaves the ventricular system through the three apertures of the 4th ventricle;
• median foramen of Magindi &
•2 lateral foramina of Leushka), to enters the subarachnoid space.
Cerebrospinal fluid
• Reabsorbed into the venous system along;
• ——-, and
•———
“that project into the ———, mainly ——— sinus.
Cerebrospinal fluid
• Reabsorbed into the venous system along;
• arachnoid villi, and
•arachnoid granulation
“that project into the dural venous sinuses, mainly superior saggital sinus.
CEREBROSPINAL FLUID clinical point
• Obstruction of the flow of CSF leads to
a rise in fluid pressure causing swelling of the ventricles (hydrocephalus).
