Week 1 Flashcards
What are the parts that the brain can be divided into?
- Forebrain
- Midbrain
- Hindbrain
The ____ is the forward most portion of the brain
The forebrain/ prosencephalon
What divides the frontal lobe from the parietal lobe?
The central sulcus
What fissure is between the parietal and frontal lobe and the temporal lobe?
Lateral (Sylvian) fissure
The ____ fissure separates the two hemisphere of the brain
Interhemispheric fissure
What are the bumps/grooves in the brain called?
Gyri
What are the crevices in the brain called?
Sulci
The ____ gyrus is the motor cortex
The pre-central gyrus is the motor cortex
The ____ gyrus is the somatosensory cortex
The post-central gyrus is the somatosensory cortex
The ____ gyrus is the auditory cortex
The superior temporal gyrus gyrus is the auditory cortex
What is the largest lobe of the brain?
The frontal lobe
Where is the frontal lobe located?
In front of the parietal and temporal lobe
What part of the frontal lobe is directly anterior to the central sulcus?
The precentral gyrus
___ plays a large role in voluntary motion, planning, motivation and has alot of dopamines
The frontal lobe plays a large role in voluntary motion, has alot of dopamines
What is the function of the frontal lobe?
Involves the ability to project future consequences resulting from current actions.
____ is the thinking part of the brain, helps up choose between good and bad, can override or suppress socially unacceptable responses
The frontal lobe is the thinking part of the brain, helps up choose between good and bad, can override or suppress socially unacceptable responses
Where is the parietal lobe located?
Above the occipital lobe and behind the frontal lobe
____ integrates all the sensory information including spatial sense, navigation and awareness of where our body parts are
The parietal lobe integrates all the sensory information including spatial sense, navigation and awareness of where our body parts are
What are the main sensory inputs that we get from the skin?
Touch, temp, and nociception
The main sensory inputs we get from the skin is related through the __ to the parietal lobe
The main sensory inputs we get from the skin is related through the thalamus to the parietal lobe
Several areas of the ___ are involved in language processing
Several areas of the parietal lobe are involved in language processing
What are the areas with huge devotion to the somatosensory cortex?
Lips, face, and hand
What are some of the primary areas of body and spatial awareness where we’re aware of our body and we use when driving a vehicle to know the boundaries of the vehicle?
Superior parietal and inferior parietal lobules
What is hemi-neglect/left sided hemineglect?
When the right side of the parietal lobe is affected in an injury
Where is the temporal lobe?
Beneath the lateral/sylvian fissure on both hemispheres of the brain
The temporal lobe is mainly involved in…?
Processing sensory input, assigning meaning to all the appropriate visual memory, language comprehension, emotional association, etc
What are the functions of the temporal lobe?
Memory, auditory perception and processing, interpretation, visual stimuli, and establishing object recognition.
____ is the visual processing center of the brain
The occipital lobe
What is the primary visual cortex and where is it located?
- Broadman’s area 17 commonly called V1/visual 1.
- Located on the medial side of the occipital lobe within the calcarine sulcus into the posterior pull of the occipital lobe
Bi-lateral lesions of the occipital lobe can lead to ____
Bi-lateral lesions of the occipital lobe can lead to cortico-blindness
The cingulate sulcus separates the ____
The cingulate sulcus separates the telencephalon from the diencephalon
What does the parieto-occipital sulcus do?
It separates the occipital lobe from the rest of the brain
What does the calcarine sulcus do?
It separates the occipital lobe into two
What are the 2 parts of the forebrain?
The telencephalon(cerebral hemispheres) and the diencephalon
What is in the diencephalon?
The thalamus, epithalamus and hypothalamus
What is included in the epithalamus?
The pineal gland, and the subthalamus
What does the diencephalon do?
It relays sensory information from brain regions and controls the autonomic functions of the peripheral nervous system
What is included in the telencephalon?
The cerebrum
___ is the portion of the brainstem that connects the forebrain and the hindbrain
The midbrain is the portion of the brainstem that connects the forebrain and the hindbrain
What is the major function of the midbrain?
To aid in movement, visual and auditory stimulus
What are the structures in the mesencephalon/midbrain?
- Substantia nigra
- Red nucleus
- Corpora quadrigemina
- Tectum
What are the structures thought to be very involved in the development of parkinson’s disease?
- Substantia nigra
- Red nucleus
What is the tectum?
The region of the brain that is specifically the dorsal(upper) part of the midbrain.
What is the tegmentum?
The ventral (lower) part of the midbrain
The superior and inferior colliculi are in the ____
The superior and inferior colliculi are in the tectum
There are a pair of colliculi on each part of the brain and when all 4 parts are together they form the ___
There are a pair of colliculi on each part of the brain and when all 4 parts are together they form the corpora quadrigemina
What is the cerebral peduncle?
The bundle of nerve fibers that connects the forebrain and the hindbrain
____ has nerve connections with the frontal lobes
Substantia nigra has nerve connections with the frontal lobes
The ____ also has a structure in the rostral midbrain that is involved in motor coordination which forms the base of the midbrain
The red nucleus also has a structure in the rostral midbrain that is involved in motor coordination which forms the base of the midbrain
Where is the red nucleus located?
In the tegmentum
The corpora quadrigemina is in the ____
The corpora quadrigemina is in the tectum
What are the structures in the hindbrain/rhombencephalon?
- Cerebellum
- Pons
- Medulla
____ is a developmental organization/categorization of the CNS
The hindbrain/ rhombencephalon is a developmental organization/categorization of the CNS
The hindbrain can be divided into…?
The hindbrain can be divided into * a variable number of transverse swellings called rhombomeres*
What is the central canal?
The little opening that travels down the middle of the spinal cord for the passage way of cerebral spinal fluid
The spinal cord starts from the ____
The spinal cord starts from the bottom of the medulla oblongata
What is the sagittal falx cerebri?
The folding in of the duramater to create baffles to maintain the brain within the cranium.
What is the superior sagittal sinus?
A cavern along the top of the sagittal falx cerebri
What is the inferior sagittal sinus?
The venous drainage along the bottom of the falx cerebri
____ contains the straight sinus
The tentorium cerebelli contains the straight sinus
What is the tentorium cerebelli?
A fold of the duramater that separates the cerebellum from the cerebrum
The ____ separates cerebrum
The falx cerebri separates cerebrum
The ____ separates the two lobes of the cerebellum
The falx cerebelli separates the two lobes of the cerebellum
How many arteries are along the front of the spinal cord and how many are along the back?
There is 1 artery along the front and 2 along the back
The PNS consists of __ and ___
The PNS consists of carnial nerves and spinal nerves
How many pairs of cranial nerves are there?
12 pairs
How may spinal nerves are there and what forms them?
There are 31 pairs of spinal nerves, formed by ventral and dorsal roots
The ___root of the spinal nerve is the efferent part and are the outgoing messaging
The ventral root of the spinal nerve is the afferent part
The cells of the efferent sensory nerves sit in the ____
The cells of the ventral root sit in the anterior horn of the spinal cord
Incoming messaging or ____ fibers, are sensory nerves that are coming into the spinal cord and their cell bodies sit in the ____
Incoming messaging or afferent fibers, are sensory nerves that are coming into the spinal cord and their cell bodies sit in the dorsal root ganglion
Afferent cell bodies sit in the dorsal root ganglion, and will synapse with inter-neurons in the ____
Afferent cell bodies sit in the dorsal root ganglion, and will synapse with inter-neurons in the dorsal horn
What are the two divisions of the autonomic nervous system (ANS)?
Sympathetic division and parasympathetic division
What is the fight or flight component of the ANS and why?
The sympathetic division is the fight or flight division of the ANS, because it is the system that changes the homeostasis and prepares us to fight or flight
What is the parasympathetic division of the ANS responsible for?
- Rest and digest
- Feed and breed
it slows us down, changes ur homeostasis system to prepare us for things listed above
What are the 2 kinds of neurons involved in the transmission of signals through the sympathetic system?
- Pre-ganglionic and post-ganglionic neurons
Why do pre-ganglionic and post-ganglionic neurons have their names?
Because they are nerves that go to a ganglion and nerves that go from a ganglion
Pre-ganglionic neurons go from the ___ to the ____
Pre-ganglionic neurons go from the spinal cord to the sympathetic chain of ganglion
Post-ganglionic neurons go from the ___ to the ____
Post-ganglionic neurons go from the sympathetic chain of ganglion to the end organ
There are shorter pre-ganglionic neurons in the SNS that originate from ___
There are shorter pre-ganglionic neurons in the SNS that originate from the thoracolumbar region of the spinal cord(T1-L2/3)
The SNS is often called the ___, because its pre-ganglionic system comes from there
The SNS is often called the Thoracolumbar system, because its pre-ganglionic system comes from there
What happens at the synapses within the ganglia as it relates to the pre-ganglionic neurons?
The pre-ganglionic neurons release Ach, a neurotransmitter that activates nicotinic acetyl-choline receptors on the post ganglionic neurons
What does the post-ganglionic neurons do in response to the stimulus made by Ach?
The post-ganglionic neurons release norepinephrine, which activates adrenergic receptors that are present on the peripheral target tissues
What does the activation of adrenergic receptors on target tissues cause?
They cause the effects that are associated with the sympathetic system
What is the sympathetic response?
An increase in heart rate, BP, respiration, dilation of pupils, sweat response, preparation of the body to fight or flight
Where are the three primary areas that the parasympathetic nervous supply arise from?
- Cranial nerves
- Vagus nerve
- Pelvic, splancnic, efferent pre-ganglionic nerve cells
What nerves in the parasympathetic nervous supply come from the cranial nerves?
The pre-ganglionic sympathetic fibers from the 3rd(occulomotor), 7th(facial), and the 9th(glosso-pharyngyeal) cranial nerves
Where do nerves in the parasympathetic nervous supply that come from the cranial nerves arise from and synapse?
Usually arise from specific nuclei within the CNS, and then synapse at one of the 4 ganglia
What are the 4 ganglia that the parasympathetic nervous supply that come from the cranial nerves synapse?
- Ciliary ganglion
- Ptergopalatine ganglion
- Submandibular ganglion
- Otic ganglion
Where do the nervous supply that arise from the vagus nerve go?
Towards a broader ray of ganglia on or near thoracic viscera.
What does the nervous supply that arise from the vagus nerve innervate?
- Esophagus
- Trachea
- Heart
- Lungs
- Most of the abdominal viscera(stomach, pancreas, liver, kidney, small and 1/2 of the large intestines)
Where does the vagus innervation end?
Ends at the between the mid gut and the hind gut, just before the splenic flexure of the transverse colon
Where do the Pelvic, splancnic, efferent pre-ganglionic nerve cells reside in?
Reside in the lateral horn of the spinal cord at the T12-L1 vertebral levels.
How do the Pelvic, splancnic, efferent pre-ganglionic nerve axons exit the vertebral column?
They exit the vertebral column as S2-S4 spinal nerve through the sacral foramina
Unlike in the sympathetic system, the parasympathetic system has ___ pre-ganglionic and ____ post-ganglionic
Unlike in the sympathetic system, the parasympathetic system has long pre-ganglionic and short post-ganglionic
___ are protective layers around the CNS
meninges are protective layers around the CNS
The __ and ___ have dura mater, pia mater and arachnoid mater protective coverings
The brain and spinal cord have dura mater, pia mater and arachnoid mater protective coverings
What is the space between the dura and the arachnoid membrane called?
The subdural space
The ___ is the outermost layer of skin and tissues that protects the cranium
The scalp is the outermost layer of skin and tissues that protects the cranium
What are the layers of tissue that make up the scalp in order of the outermost layer to the inner most layer?
- Skin
- Connective tissue
- Epicranial Aponeurosis
- Loose connective tissue
- Periosteum of the cranium/ pericranium
What are the two muscles found outside the cranium, what separates them and where are they?
- The frontalis muscle and the occipitalis muscle
- Separated by the epicranial aponeurosis
- One is on the frontal region and the other is in the back in the occipital region.
What do the frontalis and occipitalis muscle do?
They can contract to raise/scrunch the forehead and allows the scalp to be able to be moved forward and back
The bone of the cranium has little air-like cells called ____
The bone of the cranium has little air-like cells called diploe
What is found deep to the bone of cranium?
The dura mater
What do arachnoid granulations do?
They reabsorb the CSF
____ produces the CSF
The choroid plexus int he lateral 3rd and 4th ventricles produces the CSF
Why are the superior and inferior sagittal sinuses formed?
The dura around the brain divides into two types
What are the two types that the dura in the cranium divide into?
- The periosteal dura
- The meningeal dura
The ____ is connected firmly to the inner layer of the periosteum
The periosteal dura is connected firmly to the inner layer of the periosteum
The folding of the periosteal and meningeal dura form the ___
The folding of the periosteal and meningeal dura form the falx cerebri
____ acts as a cushion or buffer, providing basic mechanical and immunological protection
Cerebrospinal fluid (CSF) acts as a cushion or buffer, providing basic mechanical and immunological protection
___ is the basic working unit of the brain, it is a specialized cell designed to transmit info to other nerve cells. They have a cell body, axon, and dendrites
A neuron is the basic working unit of the brain, it is a specialized cell designed to transmit info to other nerve cells. They have a cell body, axon, and dendrites
A group of neurons form a ____
A group of neurons form a nerve
What are the two types of neurons?
Sensory and motor neurons
What are the 3 types of nerves?
- Afferent, efferent, and mixed nerves
Nerves are found in the ___
Nerves are found in the PNS
Neurons are found in the ___
Neurons are found in the brain, spinal cord, and peripheral nerves
____ conduct nerve impulse. while ___ transmit information to various parts of the body
neurons conduct nerve impulse. while nerves transmit information information to various parts of the body
____are non-neuronal cells that maintain homeostasis. They can form myelin and provide support and protection for neurons in the CNS and PNS
Neuroglia are non-neuronal cells that maintain homeostasis. They can form myelin and provide support and protection for neurons in the CNS and PNS
What are the neuroglia in the CNS?
- Oligodendrocytes
- Astrocytes
- Ependymal cells
- Microglia
What are the neuroglia in the PNS?
- Schwann cells
- Satellite cells
What are the 4 main functions of neuroglia cells?
- Surround nerves and hold them in place
- Supply nutrients and oxygens to neurons
- Insulate one neuron from another
- Destroy pathogens and remove dead neurons
What is a ganglion?
Compact group of nerve cell bodies located in the ANS and the sensory system.
A ganglion houses the cell bodies of __ and ____ from the ANS
A ganglion houses the cell bodies of afferent and efferent cells from the ANS
What is a pseudo-ganglion?
Something that looks like a ganglion but has no cell bodies
___ is made up of nerve fibers (axons) and their myelin covering
White mater is made up of nerve fibers (axons) and their myelin covering
___ is made up of masses of cell bodies that contain pigments associated with the nucleus of the cell
Gray mater is made up of masses of cell bodies that contain pigments associated with the nucleus of the cell
___ is when messaging move out of an axon
Orthodromic is when messaging move out of an axon
___ is when messaging move into an axon
Antidromic is when messaging move into an axon
The tissues of the nervous system are ___
The tissues of the nervous system are tracts
What are tracts?
Nerve fibers that course over a pathway and share similar connections and functions
What is a nuclei?
Islands in white mater of a fairly compact group of nerve cell bodies within the CNS
The entire nervous system originates from the _____
The entire nervous system originates from the neural plate
What is the neural plate?
An ectodermal thickening of the floor of the amniotic sac, bathed in amniotic fluid
During the 3rd week after fertilization, the neural plate forms ____
During the 3rd week after fertilization, the neural plate forms neural folds
The neural folds unite to create a ____ in the neck region of the embryo
The neural folds unite to create a neural tube in the neck region of the embryo
Where does the neural tube proceed to?
It proceeds to the rostral region and the caudal region
What is neurulation?
The process of neural plates turning to a neural tube
The open ends of neural tubes are called ___ and they get closed off by the end of the ____. Their closure coincides with establishment of ____
The open ends of neural tubes are called neuropores and they get closed off by the end of the 4th week. Their closure coincides with establishment of blood supply
What is a neural crest and what do they become?
Neural crest are cells from the neural folds and they become cranial and spinal nerves, and schwann cells
In neurulation, the walls of the neural tube thicken to become the __ and ___.
The lumen becomes ___ and ____
In neurulation, the walls of the neural tube thicken to become the brain and spinal cord.
The lumen becomes ventricular system and central canal
The dorsal tube is called the ____
The dorsal tube is called the alar plate
The ventral tube is called the ____
The ventral tube is called the basal tube
The neurons coming from the alar plate are mostly ___, they receive ____ nerve roots growing in from ____ and they become the ___
The neurons coming from the alar plate are mostly sensory, they receive dorsal nerve roots growing in from spinal ganglia and they become the dorsal horn
The neurons coming from the basal plate are mostly __, they receive ____ nerve roots growing in from ____ and they become the ___
The neurons coming from the basal plate are mostly motor, they receive ventral nerve roots growing in from spinal ganglia and they become the ventral horn
___ are multi- potent stem cells that can differentiate into a variety of stem cells like osteoblast, chondrocytes, myocytes, and adipocytes
Mesenchymal stem cells
Osteoblast cells form ____
Osteoblast cells form bone cells
Chondrocytes form __
Chondrocytes form cartilage cells
Myocytes form ___
Myocytes form muscle cells
Adipocytes form ___
Adipocytes form fat cells
What happens late in the 4th week of the embryology of neuroanatomy?
The rostral part of the neural tube undergoes flexion at the level of the future midbrain.
What happens to the alar plate of the prosencephalon (forebrain) late in the 6th week of the embryology of neuroanatomy?
The alar plate of the forebrain(prosencephalon) expands on the side to form the telencephalon
What happens to the basal plate of the prosencephalon (forebrain) late in the 6th week of the embryology of neuroanatomy?
It remain in place as the diencephalon
An optic growth, which is the forerunner of the retina and optic nerve comes out from the ___
An optic growth, which is the forerunner of the retina and optic nerve comes out from the diencephalon
The diencephalon, mesencephalon, and rhombencephalon constitute the ____
The diencephalon, mesencephalon, and rhombencephalon constitute the brain stem
The rostral part of the rhombencephalon gives rise to the ____
The rostral part of the rhombencephalon gives rise to the pons and the cerebellum
The caudal part of the rhombencephalon gives rise to the ____
The caudal part of the rhombencephalon gives rise to the medulla oblongata
What are the brain vesicles?
Prosencephalon(forebrain), Mesencephalon(midbrain), Rhombencephalon(hindbrain)
What is included in the prosencephalon?
- Telencephalon
- Diencephalon
What does the telencephalon form?
- Cerebral cortex
- Corpus striatum
- White matter
- Basal ganglia
What does the diencephalon form?
- Dorsal thalamus
- Hypothalamus (pituitary)
- Optic growth
- Epithalamus (pineal gland)
- Subthalamus
What is included in the rhombencephalon?
- Metencephalon
- Myelencephalon
What does the metencephalon form?
- Pons
- Cerebellum
What does the myelencephalon form?
- Medulla
What does the mesencephalon form?
- Tectum
- Tegmentum
- Cerebral peduncles
What do pons form?
- Nuclei
- Fiber tracts
What does the cerebellum form?
- Cerebellar cortex
- Cerebellar nuclei
- Cerebellar peduncles
What does the medulla oblongata form?
- Nuclei
- Fiber tract
The neural canal dilates within the ____ and form the ___
The neural canal dilates within the cerebral hemisphere and form the lateral ventricles
The lateral ventricles communicate with the ___ in the diencephalon
The lateral ventricles communicate with the 3rd ventricle in the diencephalon
The 3rd and 4th ventricles communicate through an ___ in the midbrain
The 3rd and 4th ventricles communicate through an Aquaduct in the midbrain
The thin roof of the forebrain and the hindbrain are invaginated with toughs of capillaries which form the ____
The thin roof of the forebrain and the hindbrain are invaginated with toughs of capillaries which form the choroid plexus
What is happening at 8 weeks of embryology of neuroanatomy?
The cerebellum is emerging from the 4th ventricle
What is happening at 12 weeks of embryology of neuroanatomy?
The ventricle is becoming hidden by the cerebellum, and three apertures have appeared in the roof plate
What is happening at 14 weeks of embryology of neuroanatomy?
The frontal, parietal, temporal and occipital lobes are identified
The corpus striatum splits to form what?
Forms the caudate nucleus and the lentiform nucleus
What happens at the 28th week of embryology of neuroanatomy?
The lateral, central, and calcarine sulci are noticeable
What is hydrocephalus/water in the brain?
An excess of CSF in the ventricular system
What causes hydrocephalus?
- The obstruction of normal CSF circulation and consequent dilation of the ventricles.
- Obstruction of the foramina opening from the 4th ventricle into the subarachnoid space.
- Meningitis
A major cause of the obstruction of the foramina opening from the 4th ventricle into the subarachnoid space in infancy is ___. What causes it?
- Arnold- Chiari malformation.
The cerebellum is partly extruded into the vertebral canal during fetal life, because the posterior cranial fossa is under-developed
What happens during a case of hydrocephalus?
Thinning of the bones of the calvaria, prominence of the forehead, atrophy of the cerebral cortex and white matter, and compression of the basal ganglia and diencephalon
How can hydrocephalus treated?
- Early identification is imperative
- Pressure sensitive catheter or shunt into internal jugular
vein
What is microcephaly?
A condition where the brain doesn’t develop properly, resulting in a smaller than normal head
What happens during the 1st year of microcephaly?
Fontanelles close during early infancy and sutures close. Causing the brain to be under-developed
What does microcephaly cause?
Gross mental retardation
What is anencephaly?
When there is an absence of the major part of the brain, skull and scalp.
Anencephaly results from ___
Anencephaly results from failure of the rostral neuro-pore to close during the 4th week of development
People with anencephaly usually lack the ____
People with anencephaly usually lack the telencephalon
In anencephaly, the ___ is abnormal and the calvaria is defective
In anencephaly, the forebrain is abnormal and the calvaria is defective
In anencephaly, the forebrain being abnormal and the calvaria is defective is due to…?
- Due to the abnormal structure and vascularization the nervous tissue undergoes degeneration
What is the brain like in the case of anencephaly?
Brain is a spongy mass consisting mostly of hindbrain structures with no bone or skin covering
What are the causes of anencephaly?
- Genetic factors
- High exposure to nickel, chromium, lead, mercury
- Higher in areas where depleted uranium and
man-made isotopes - Can be induced in rats by teratogenic agents
How is anencephaly prevented?
- Folic acid
- Before pregnancy
How is anencephaly diagnosed?
- Ultrasound
- Alpha- fetoproteins in amniotic fluid
• Fetal counterpart to serum
albumen
• Increased in neural tube
defects
• Decrease in Down
syndrome
What foods do folate occur nature in?
- Beans and legumes
- Citrus fruits and juices
- Wheat bran and other whole grains
- Dark green leafy vegetables
- Poultry, pork, shellfish
- Liver
____ is the most common congenital anomaly involving the lower brain stem and cerebellum
Arnold- Chiari malformation is the most common congenital anomaly involving the lower brain stem and cerebellum
____ is a structural defect of the cerebellum with herniation of the medulla and part of cerebellum through the foramen magnum
Arnold- Chiari malformation is a structural defect of the cerebellum with herniation of the medulla and part of cerebellum through the foramen magnum
Arnold- Chiari malformation consist of ____
Arnold- Chiari malformation consist of downward displacement of the cerebellum tonsils through the foramen magnum
Arnold chiari malformation is frequently associated with ___
Arnold chiari malformation is frequently associated with spina bifida and syringomyelia
Why are the signs and symptoms of arnold-chiari malformation?
– Neck pain, balance problems, muscle weakness, numbness or other abnormal feelings in the arms or legs, dizziness, vision problems, difficulty swallowing, ringing or buzzing in the ears, hearing loss, vomiting, insomnia, depression, or headache made worse by coughing or
straining
– Hand coordination and fine motor skills may be affected
What is spina bifida?
Non-fusion of the embryonic halves of the vertebral arches during 4th week of development
What are the types of spina bifida?
– Spina bifida occulta
– Spina bifida cystica
– Spina bifida with myelocele
What are the two types of spina bifida cystica?
- Spina bifida with meningocele
* Spina bifida with myelomeningocele
What happens in spina bifida occulta?
The lamina does not fuse together to form the spinous process
What happens in spina bifida cystica with meningocele?
The dura mater, arachnoid mater, and pia mater form a cyst/bubble in the back through the vertebral arch, just underneath the skin, but the neural elements are not within the cyst
What happens in spina bifida cystica with myelomeningocele?
The dura mater, arachnoid mater, and pia mater form a cyst/bubble in the back through the vertebral arch, just underneath the skin, and the neural elements are within the cyst
What happens in spina bifida with myelocele?
The neural plate sticks out and there is no formation of the spinal cord or the cauda equna
____ is usually clinically unimportant, occurs in L5 or S1 in about 10% of otherwise normal people, it presents as a small dimple with a tuft of hair, and a small percentage may have functional deficits
Spina bifida occulta is usually clinically unimportant, occurs in L5 or S1 in about 10% of otherwise normal people, it presents as a small dimple with a tuft of hair, and a small percentage may have functional deficits
___ is a cystlike sac. It is covered by skin or a thin easily ruptured membrane and is most common in the lumbar region
Spina bifida cystica is a cyst-like sac. It is covered by skin or a thin easily ruptured membrane and is most common in the lumbar region
What are the causes of spina bifida cystica?
– Combination of genetic and environmental factors • Diabetic and anticonvulsant medication • Fever or external temperatures during neural tube development • Obesity
10% of cyst is a ____
10% of cyst is a meningocele
90% of cyst is ____
90% of cyst is a myelomeningocele
____ is the most severe form of spina bifida. This is where the neural folds have remained open, CSF leaks out and the clinical outlook is poor
Spina bifida with myelocele is the most severe form of spina bifida. This is where the neural folds have remained open, CSF leaks out and the clinical outlook is poor
____ is sometimes known as cranium bifidum and is the herniation of the brain and/or meninges
Encephalocele is sometimes known as cranium bifidum and is the herniation of the brain and/or meninges
What causes encephalocele?
Failure of the neural tube to close completely during the fetal development
What are some of the genetic factors affecting brain development?
– Down syndrome – brachycephaly • Maternal infection – Congenital rubella – mental retardation – Toxoplasmosis – microcephaly, hydrocephaly, cerebral calcification
What are some of the environmental factors affecting brain development?
– Radiation – cell depletion
– Steroids
– Chemical substances
• Alcohol = microcephaly (most common cause of mental retardation)
• Smoking = smaller frontal lobes and cerebellar volumes
• Marijuana = impairs nerve development and guidance
– Permanent cognitive
deficits, concentration
disorders, hyperactivity
Cranial nerves are covered by the ____ and they emerge from ___
Cranial nerves are covered by the meninges and they emerge from foramina/fissures in the cranium
What are the 5 main functional components of the cranial nerves?
- Motor fibers to voluntary (striated) muscle
- Motor fibers to involuntary (smooth) muscles or glands
- Fibers transmitting general sensation
- Fibers conveying sensation from the viscera
- Fibers transmitting unique sensations
What are the motor(efferent) fibers that can be motor fibers to striated (voluntary) muscle?
- Somatic motor
- Branchial motor
What are somatic motor fibers responsible for?
Orbit(move the eyes, open/close the eyelids), tongue and external muscles of the neck, and move the face
What are branchial motor fibers?
Axons to striated muscles of mastication derived from pharyngeal arches
What are the motor fibers to smooth(involuntary) muscle and glands?
• Cranial outflow of parasympathetic division of the autonomic nervous
system
• Presynaptic fibers emerging from brain synapse outside CNS in parasympathetic ganglia
Sensory (afferent) fibers are those that convey sensation from the viscera such as ___
- Carotid body and sinus
* Pharynx, larynx, trachea, bronchi, heart, GI
General sensation (nociception, temp, touch) from skin and mucous membranes come from __
- Somatic sensory fibers mainly from CN V
* Some sensory fibers also in CNs VII, IX, X
There is a crossing of optic nerves at the _____. The right optic nerve will cross to the left occipital region and vice versa.
There is a crossing of optic nerves at the optic chiasma . The right optic nerve will cross to the left occipital region and vice versa.
What is the name for CN I, what is is main action, where is its nerve cell body and where is its cranial exit?
- Olfactory nerve
- Action: sense of smell
- Nerve cell body: Olfactory epithelium
- Cranial Exit: foramina in cribriform plate of ethmoid bone
What is the name for CN II, what is is main action, where is its nerve cell body and where is its cranial exit?
- Optic nerve
- Action: Sense of vision
- Nerve cell body: Retina
- Cranial exit: optic canal via sphenoid bone
What is the name for CN III, what is is main action, where is its nerve cell body and where is its cranial exit?
- Occulomotor nerve
- Action:
• Motor to superior, inferior,
and medial rectus, inferior
oblique, levator palpabrae
superioris
• Raises eyelid
• Turns eye superiorly,
inferiorly, and medially - Nerve cell bodies: Midbrain
- Cranial exit: Superior orbital fissure
What is the name for CN IV, what is is main action, where is its nerve cell body and where is its cranial exit?
- Trochlear nerve
- Action:
• Motor to superior oblique
• Turns eye inferorlaterally - Nerve cell bodies: Midbrain
- Cranial exit: Superior orbital fissure
What is the name for CN V and what are its 3 main divisions?
- Trigeminal Nerve
- Divisions: Ophthalmic nerve, Maxillary nerve, Mandibular nerve
What is the main action, nerve cell body and cranial exit of V1: ophthalmic nerve?
- Action: Sensory from cornea, skin of forehead, scalp, eyelids, nose, mucosa of nasal cavity and paranasal sinuses
- Nerve cell body: Trigeminal ganglion
- Cranial exit: Superior orbital fissure
What is the main action, nerve cell body and cranial exit of V2: Maxillary nerve?
- Action: Sensory from skin over maxilla, upper teeth, mucosa of nose, maxillary sinuses, palate
- Nerve cell body: Trigeminal ganglion
- Cranial exit: Foramen rotundum
What is the main action, nerve cell body and cranial exit of V3: Mandibular nerve?
- Sensory actions: • Skin over mandible, lower lip, side of
head, mandibular teeth, TMJ, mucosa of mouth, anterior 2/3rd tongue - Motor actions: Muscles of mastication, mylohyoid,
anterior belly digastric, tensor veli palatine, tensor tympany - Nerve cell body:
• Sensory – Trigeminal
ganglion
• Motor - Pons - Cranial exit: Foramen ovale
Where is the cranial exit for CN V: Trigeminal nerve?
- Superior orbital fissure
- Foramen Rotundum
- Foramen Ovale
What is the name for CN VI, what is is main action, where is its nerve cell body and where is its cranial exit?
- Abducent nerve
- Action:
• Motor to lateral rectus
• Turns eye laterally - Nerve cell bodies: Pons
- Cranial exit: Superior orbital fissure
What is the name for CN VII, what is is main action, where is its nerve cell body and where is its cranial exit?
- Facial nerve
- Action: Motor to muscles of facial expression, scalp, stapedius, stylohyoid, posterior
belly of digastric - Nerve cell body: Pons
- Cranial exit: Internal acoustic meatus, facial canal,
stylomastoid foramen
Where do the branches of the facial nerves go?
- Temporal
- Zygomatic
- Buccal
- Marginal mandibular
- Cervical
What are the special sensory, sensory, and parasympathetic actions of facial nerve: nerve intermedius?
- Special sensory action: Taste from anterior 2/3rd of tongue and palate
- Sensory: Sensation from external acoustic meatus
- Parasympathetic: Submandibular, salivary, lacrimal, nose and palate glands
What is the nerve cell body of facial nerve: nerve intermedius?
- Special sensory and sensory
• Geniculate ganglion - Parasympathetic
• Pons
What is the cranial exit of facial nerve: nerve intermedius?
Internal acoustic meatus, facial canal, stylomastoid foramen
What is the name for CN VIII and where is its cranial exit?
- Vestibulocochlear/ auditory nerve
- Exit: Internal acoustic meatus
What are the main actions and nerve cell body of the Vestibulocochlear/ auditory nerve: vestibular nerve?
- Actions: Balance, sensation from semicircular ducts,
utricle, and saccule - Nerve Cell Bodies: vestibular ganglion
What are the main actions and nerve cell body of the Vestibulocochlear/ auditory nerve: cochlear nerve?
- Actions: Hearing from spiral organ
- Nerve cell body: Spiral ganglion
What is the name for CN IX and where is its cranial exit?
- Glossopharyngeal nerve
- Exit: Jugular foramen
What is the main motor action and the nerve cell body of CN IX: glossopharyngeal nerve?
- Action: Motor to stylopharyngeus to assist
swallowing - Cell bodies: Medulla
What is the main parasympathetic action and the nerve cell body of CN IX: glossopharyngeal nerve?
- Action: Parasympathetic to parotid gland
- Nerve bodies: presynaptic cell bodies in medulla,
postsynaptic cell bodies in otic
ganglion
What is the main special sensory action and the nerve cell body of CN IX: glossopharyngeal nerve?
- Action: Special sensory taste from posterior
1/3rd tongue - Nerve cell body: sensory ganglion
What is the main sensory action and the nerve cell body of CN IX: glossopharyngeal nerve?
- Action: • Sensory from carotid body and sinus
- Nerve cell body: sensory ganglion
What is the main general sensory action and the nerve cell body of CN IX: glossopharyngeal nerve?
- Action: General sensory from external ear, pharynx, middle ear
- Nerve cell body: sensory ganglion
What is CN X called, and as it travels down the neck, what does it travel with?
- Vagus nerve
- Travels with the internal carotid artery and the jugular vein in a vascular sheath
What happens to the vagus nerve on the right side once it gets close to the subclavian vein?
It sends a nerve branch to supply the larynx, forming the right recurrent laryngeal nerve
What happens to the vagus nerve on the left side once it gets close to the subclavian vein?
It continues into the chest, and into the mediastum and sends the left recurrent laryngeal nerve after it passes under the arch of the aorta
The anterior vagal trunk supplies the ___
The anterior vagal trunk supplies the stomach
The posterior vagal trunk supplies the ___
The posterior vagal trunk supplies the rest of the viscera
What is the cranial exit of the vagal nerve?
Jugular foramen
What is the name for CN XI, what is is main action, where is its nerve cell body and where is its cranial entry and exit?
- Spinal accessory
- Action: Motor to sternocleidomastoid and
trapezius - Nerve cell bodies: Spinal cord
- Cranial Entry: Foramen magnum
- Cranial Exit: Jugular foramen
What is the name for CN XII, what is is main action, where is its nerve cell body and where is its cranial exit?
- Hypoglossal nerve
- Action: Motor to intrinsic and extrinsic muscles of tongue (except palatoglossus)
- Nerve cell bodies: Medulla
- Cranial exit: Hypoglossal canal
What are the purely sensory cranial nerves?
- CN I: olfactory nerve
- CN II: optic nerve
- CN VIII: Vestibulocochlear nerve
What are the purely motor cranial nerves?
- CN III: occulomotor nerve
- CN IV: Trochlear Nerve
- CN VI: Abducent Nerve
- CN XI: Spinal Accessory
- CN XII: Hypoglossal Nerve
What are the mixed cranial nerves?
- CN V: Trigeminal Nerve
- CN VII: facial nerve
- CN IX: glossopharyngeal nerve
- CN X: vagus nerve
What are the cranial nerve with parasympathetic fibers:
- CN III: oculomotor nerve
- CN VII: facial nerve
- CN IX: glossopharyngeal nerve
- CN X: vagus nerve
Where do the parasympathetic fibers of the vagus nerve go?
• To smooth muscle of trachea, bronchi, GI tract and cardiac muscle of heart
