Important content for final Flashcards
According to my [v. broad] interpretation of what prof jacobus said
List the flow of CSF in order (7 steps)
Produced by choroid plexus in ventricles
1) Lateral ventricles
2) Foramen of Monro
3) 3rd ventricle
4) Sylvian aqueduct
5) 4th ventricle (joins cerebral aqueduct)
6) Foramen of Luschka and Magendie
7) SA space
[The arachnoid granulations then absorb]
What two arteries form the basilar artery? [at circle of willis]
Vertebral arteries
What connects the anterior cerebral arteries (ACAs) at the Circle of Willis?
Anterior communicating artery
What two arteries does the posterior communicating artery connect at the Circle of Willis?
Internal carotid a. and posterior cerebral a. (PCA)
What are the arteries that are always depicted in diagrams as numerous (6), short, and small that come off the basilar a?
[hint: b/t superior cerebellar and anterior inferior cerebellar arteries]
Pontine arteries
What artery comes off the basilar artery just posterior to the PCA?
Superior cerebellar
What arteries come off between the vertebral arteries just before they form the basilar artery [at circle of willis]?
Anterior spinal artery (medial) and posterior inferior cerebellar arteries (lateral)
Define anosmia
Loss of smell
What cranial nerve exits at the spinal cord?
CN XI (11)
What do CN III,IV, VI (oculomotor, trochlear and abducens) do?
Control the extraocular muscles
1) What does the CNIV (4) (trochlear nerve) do?
2) What is the trochlea?
1) Rotates the top of the eye medially and downward
2) Trochlea is a pulley-like structure
What does CNVI (6) (abducens) do?
Abducts the eye laterally in the horizontal direction
What does CN III (oculomotor nerve) do?
All other eye movements not done by the trochlear and abducens nerves, including pupillary control
1) What does CN V (trigeminal) mainly do? What does this include?
2) What does it also supply?
1) Supplies sensory to the face
-Nose, mouth, sinuses
-Anterior 2/3 of tongue
2) Motor to the mandible and the anterior portion of the external ear
What are the 3 branches of CNV? Where do they exit the skull?
V1-Ophthalmic
V2-Maxillary
V3-Mandibular
The branches each exit the skull in different places
1) Define Trigeminal Neuralgia (tic doulouruex) and what nerve branches are involved
2) When does it usually start and what causes episodes of it?
1) Recurrent episodes of brief pain, that last seconds to minutes in the distribution of V2/V3.
2) Usually begin after age 35, and are set off by chewing, shaving or touching a specific trigger point on the face.
1) What is a potential cause of tic douloureux (since cause is typically unknown)?
2) What two other disorders have this cause?
1) Demyelination of the nerve
2) MS and optic neuritis
What can cause CV sensory loss?
Trauma, tumors, herpes zoster, aneurysms of the internal carotid, schwannomas or meningiomas.
Do V2/V3 fibers cross over? What is the implication of that?
These fibers do not cross over, so lesions cause ipsilateral deficits
1) What does the facial nerve (CNVII) do?
2) What does a small branch of it do?
3) What is its path once it exits the brainstem?
1) Controls muscles of facial expression
2) Carries fibers for parasympathetic, visceral and somatosensory functions (tears, salivation, taste)
3) It runs through the auditory canal of the temporal bone, then takes a turn and runs in the facial canal, medial to the middle ear.
1) What are the facial nerve’s (CN7) sensory neurons for?
2) What is its path once it exits the skull?
1) Sensation of the external ear
2) Passes through the parotid gland and splits into 5 major branches that control the facial expressions.
1) What is Bell’s Palsy?
2) What does it cause?
3) Besides its symptoms, what do neuro exam and imaging studies look like with this condition?
1) Most common facial nerve disorder; all divisions of the facial nerve are impaired
2) Unilateral facial weakness
3) The remainder of the neuro exam and any imaging studies are typically normal.
1) What is Bell’s palsy recovery like?
2) What is its cause?
3) What are its other symptoms?
1) Gradual recovery, but ~ 80% of patients fully recover in 3 weeks.
2) Unknown cause - thought to be viral or inflammatory in nature.
3) Ear pain from the somatosensory component, dry eye from decreased lacrimation.
-Can also be associated with loss of taste
What is the most common facial nerve (CNVII) disorder?
Bell’s palsy
1) What can happen after Bell’s palsy recovery?
2) Give an example.
1) Sometimes when facial nerves recover, they reach the wrong target.
2) For example, rogue parasympathetic fibers may create “crocodile tears, In which these patients lacrimate instead of salivate when they see food.
Recurrent episodes of Bell’s Palsy warrant what?
An extensive work up to rule out tumors, infiltrating diseases, Lyme’s disease sarcoid, and HIV.
1) What does Vestibulocochlear Nerve VIII do?
2) Where does it go?
1) Hearing and vestibular sensation
2) Enters internal auditory and then travels with the facial nerve in the auditory canal to the cochlea and the vestibular organs (semicircular canals, utricle and saccule.)
What are the two types of hearing loss? Define each.
1) Conductive HL: abnormalities of the external auditory canal or middle ear
2) Sensorineural HL: disorders of the cochlea or CN VIII common
What are some common causes of sensorineural HL?
1) Exposure to loud sounds
2) Meningitis
3) Ototoxic drugs (like gentamicin)
4) Head trauma
5) Viral infection
6) Aging
7) Meniere’s disease
8) Acoustic neuroma
1) What most common tumor of the inner ear?
2) What is it? What CN is involved?
3) What is the average age of onset?
4) Does it cause unilateral or bilateral hearing loss?
1) Acoustic Neuroma
2) A slow growing tumor that occurs where CN VIII (8) enters the internal auditory meatus
3) 50 years old
4) Almost always unilateral.
A) What are the symptoms of acoustic neuroma?
B) What can it affect? What does this cause?
A1) Unilateral hearing loss
2) Tinnitus (ringing in the ear)
3) Unsteadiness (why?)
B) The trigeminal nerve that is nearby; causes facial pain and sensory loss
What 5 things does the glossopharyngeal nerve (CNIX) convey?
1) Parasympathetic (motor) to parotid gland
2) Sensation from ear (external auditory meatus,)
3) Pharynx and posterior 1/3 of tongue
4) Taste from posterior 1/3 of tongue
5) Chemo/baroreceptors of carotid body
Which nerve supplies anterior 2/3 of tongue?
CNV Trigeminal
1) What are the main functions of the vagus nerve (CNX)?
2) Name two of its branches and what they do
1) Swallowing and gag reflex
2) Recurrent and superior laryngeal nerves; control all laryngeal muscles and the cricothyroid
Besides its main functions, what else does the vagus nerve convey? (3 things)
1) Parasympathetics (motor) to heart, lung and GI tract to the splenic flexure
2) Sensation from the pharynx and small region near the external auditory meatus
3) Visceral sensory from chemo/baroreceptors in the aortic arch and GI tract
1) Where does the spinal accessory nerve (CN XI) arise from?
2) What is its function?
3) What would a lesion of it cause?
1) The cervical spinal cord
2) Motor innervation to sternocleidomastoid and trapezius muscles
3) Weakness of ipsilateral shoulder shrug and weakness of head turning AWAY from the lesion
1) What does the hypoglossal nerve (CNXII) provide?
2) What happens when there’s a lesion in it?
1) Motor to tongue
2) Weakness of tongue points towards the side of lesion when protruding
1) What is Glossopharyngeal Neuralgia?
2) What does it cause?
1) Similar to Trigeminal Neuralgia except in CN IX (9) distribution.
2) Episodes of severe throat and ear pain
1) What can occur during surgeries of the neck?
2) What does this cause?
1) Injury to the recurrent laryngeal nerve
2) Unilateral vocal cord paralysis and hoarseness
1) What nerve is responsible for palate elevation?
2) What happens if there’s a lesion in it?
1) CNX (vagus)
2) The soft palate and uvula will deviate towards the normal side, while the soft palate on the abnormal side hangs low (stage curtain sign).
List the 6 things secreted by the anterior pituitary
1) ACTH
2) PRL (prolactin)
3) GH (growth hormone)
4) TSH
5) LH (luteinizing hormone)
6) FSH
What is the endocrine gland that’s considered the “master gland” and secretes hormones that regulate many of our bodily functions?
Pituitary gland
List the 2 things secreted by the posterior pituitary
1) Oxytocin
2) Vasopressin
What part of the hypothalamus is the master clock of circadian rhythms?
Suprachiasmatic nucleus
What 2 things link the neural and endocrine systems?
Hypothalamus and pituitary
The hypothalamus the central regulator of what? How does it interact?
1) Homeostasis
2) Exerting influence over 4 other body systems:
-1-homeostatic mechanisms (that control hunger, thirst, sexual desire and sleep-wake cycles)
-2-endocrine control via the pituitary (controls release of hormones from the pituitary)
-3-autonomic control
-4-limbic mechanisms
List and describe the 4 systems the hypothalamus controls to maintain homeostasis
1) Homeostatic mechanisms: that control hunger, thirst, sexual desire and sleep-wake cycles
2) Endocrine control via the pituitary: controls release of hormones from the pituitary
3) Autonomic control
4) Limbic mechanisms
What two places does the hypothalamus receive inputs from?
The amygdala and regions of the limbic cortex
The regulator of circadian rhythms receives inputs from where? What do these contain?
Retinal ganglion cells containing photopigment melanopsin that contain information about day and night cycles.
1) What core survival function is partially regulated in the hypothalamus?
2) What can lesions in this part of the hypothalamus do?
1) Thirst
2) Decrease water intake
The limbic cortex forms what? What two things does it surround?
A ring–like limbic lobe surrounding the corpus collosum and upper brainstem
1) Structures of the limbic system regulate what 5 processes?
2) The limbic system contains what?
1) Emotions, olfaction, memory, drives and homeostasis.
2) Cortical and subcortical structures located mainly in the medial and central hemispheres
What are the 4 main categories of limbic system functions?
1) Homeostatic functions including autonomic and neuroendocrine control
2) Olfaction
3) Memory
4) Emotions and drives
HOME
What is the hippocampus’s:
1) Shape?
2) Location?
3) Function?
C-shaped structure buried in the medial temporal lobe important in memory functions
1) What is the amygdala?
2) Where is it?
3) What does it function in?
1) Complex of nuclei in the anteromedial temporal lobe
2) Tip of the hippocampus
3) Emotional, autonomic, and neuroendocrine circuits of the limbic system
Some fibers of the olfactory tract go where? Why?
Give an example of this function
Amygdala; some odors illicit old memories
**peppermint=> aids in memory and concentration
What are the 2 main regions in the brain that are critical for memory formations? What does each contain?
1) Medial temporal lobe memory area: contains the hippocampus
2) Forebrain: contains nuclei of the thalamus and hypothalamus.
-There are numerous pathways that connect the 2.
List the jobs of the pituitary hormones
Oxytocin: uterine contractions, milk letdown
PRL: milk production
FSH, LH: gonads
ACTH: adrenal cortex
TSH: thyroid (to make T3 and T4)
ADH (vasopressin): kidney water retention
GH: long bone growth
What does the posterior pituitary contain?
Axons whose cell bodies are located in the hypothalamus
1) What can the hypothalamus detect?
2) What can lesions there cause because of this?
3) What does the posterior hypothalamus do?
1) Increased body temperature
2) Hyperthermia
3) Conserves heat.
1) What is the amygdala? Where is it?
2) What two things does it play a big role in?
1) A group of nuclei in the anteromedial temporal lobe at the tip of the hippocampus
2) In emotions and drives.
What is an active participant in all 4 limbic functions?
Amygdala
What is the amygdala important in regarding emotions?
Attaching emotions to stimuli perceived by the association cortex.
1) What emotional states is the amygdala involved in?
2) What 2 structures have reciprocal interactions with the amygdala?
3) What do all 3 structures do together?
1) Fear, anxiety, aggression, pleasure, and rage
2) Hypothalamus and brainstem
3) Mediate changes in heart rate, peristalsis, gastric secretions, piloerections, and sweating
What NTs can be markedly imbalanced in bipolar depression/ mania?
Serotonin, norepinephrine, and dopamine
1) What structures being abnormal can cause schizophrenia?
2) What NT is can cause it, and what can improve symptoms?
1) Limbic system, frontal lobes, and thalamus.
2) An abnormality in dopamine, therefore symptoms can improve with antidopaminergic agents
What are the 3 primary divisions of the brain?
1) Forebrain (prosencephalon)
2) Midbrain (mesencephalon)
3) Hindbrain (rhombencephalon)
1) What is the largest part of the nervous system in humans?
2) What is it subdivided into? (2 things)
3) Where is it located?
1) The forebrain
2) Telencephalon and diencephalon.
3) Sits on top of midbrain.
Name the 2 parts of the forebrain and what they consist of
1) Telencephalon: cerebral hemispheres, cerebral cortex, white matter, basal ganglia
2) Diencephalon: thalamus, hypothalamus
1) Is the midbrain long or short? What does it connect?
2) What 3 things does the hindbrain consist of?
3) What 3 things does the brainstem consist of? What does it connect?
1) Midbrain: short, connects the fore and hind brains
2) Hindbrain: pons, cerebellum and medulla
3) Brainstem: midbrain, pons, medulla; connects brain to spinal cord
What does the brainstem do? Give examples
Controls most of the basic bodily functions needed for survival.
Ex: **respirations, BP, HR
1) What two parts of the brain are important in the regulation of consciousness level?
2) What 3 things are also involved in consciousness?
3) What happens if there are lesions in these two areas?
4) What is the clinical correlation?
1) Upper pons and midbrain
2) Cortical, thalamic and forebrain networks
3) Therefore, lesions in these areas cause lethargy and coma
4) Lesions of thalami, or large lesion/s in the hemispheres/areas above brainstem) can impair consciousness indirectly through mass effect -putting pressure on the brainstem and thereby distorting or compressing its systems
1) What’s the primary function of the cerebellum?
2) What two things does the pons do?
3) What two things does the medulla do?
4) What do these 3 parts have in common?
1) Integrates sensory and other inputs from brain and spinal cord; coordinates movements from those inputs
2) Connects brain and spinal cord, and regulates level of consciousness
3) Passes information between brain and spinal cord, and regulates cardiovascular and respiratory systems
4) They’re all part of hindbrain
What are the 3 primary divisions of the brain?
1) Forebrain (prosencephalon)
2) Midbrain (mesencephalon)
3) Hindbrain (rhombencephalon)
1) What 3 things make up the brainstem?
2) What 3 things is the brainstem connected to?
3) What arises from here? 4) What is the brainstem packed with? What do some of these things contain?
1) Midbrain, pons and medulla
2) Connected to the diencephalon, cerebellum and spinal cord.
3) Most of the cranial nerves arise from here
4) Also packed with other nuclei and white matter tracts; some nuclei contain neurotransmitters
1) What does the brainstem do? Give examples
2) What passes through the brainstem?
1) In charge of all vital functions needed to stay alive, ex/HR, BP, respirations; some of its nuclei contain neurotransmitters
2) ALL information passed between cerebral hemispheres and the spinal cord
List the 12 cranial nerves in order
1) Olfactory
2) Optic
3) Oculomotor
4) Trochlear
5) Trigeminal
6) Abducens
7) Facia
8) Vestibulocochlear
9) Glossopharyngeal
10) Vagus
11) Accessory
12) Hypoglossal
1) What is the most common excitatory NT in the CNS?
2) What is the most common inhibitory NT in the CNS?
3) What neurotransmitter is responsible for skeletal, smooth and cardiac muscle contractions
1) Glutamate
2) GABA (gamma-aminobutyric acid)
3) Acetylcholine
1) Describe the location of the frontal lobe
2) Describe the location of the temporal lobes in relation to the frontal lobe
3) What separates the frontal lobe and temporal lobes?
1) In the front, extends back to the central sulcus
2) Inferior and lateral to frontal lobe
3) A deep fissure called Sylvian (or lateral) fissure (a deep sulcus)
1) Where is the parietal lobe in relation to the central sulcus and Sylvian fissure?
2) Where is the occipital lobe in relation to the parietal lobe? What separates it from the parietal lobe when viewed medially?
1) Parietal lobe: posterior to the central sulcus and superior-posterior to the Sylvian fissure
2) Posterior to parietal; separated by parieto-occipital sulcus when viewed medially
What are the primary sensory and motor areas (4)?
1) Primary somatosensory cortex
2) Primary motor cortex
3) Primary visual cortex
4) Primary auditory cortex
1) Where is the primary motor cortex? What is it immediately anterior to?
2) What does the primary motor cortex control?
3) Where is the primary somatosensory cortex? What does it control?
1) Lies in precentral gyrus in frontal lobe, immediately anterior to central sulcus.
2) Controls movement to opposite side of body.
3) Lies in postcentral gyrus in the parietal lobe; involved in sensation for the opposite side of the body
1) Motor areas lie ________ to somatosensory areas
2) What lobe is the primary visual cortex in?
1) anterior
2) In occipital lobe
1) Describe the location of the primary auditory cortex
2) How are sensory and motor pathways usually organized?
1) Primary auditory cortex- transverse gyri of Heschl —2 fingerlike gyri inside the Sylvian fissure on superior surface of each temporal lobe
2) Usually topographically organized (adjacent receptors on motor surfaces are mapped to adjacent fibers in white matter pathways and to cortex ex/ motor and somatosensory regions controlling the hand are next to the arm, etc)
Is the primary auditory cortex lateralized?
It’s less lateralized and input from opposite ear is slightly stronger, but not clinically detectable
What is the acronym to remember whether the cranial nerves are sensory, motor, or both?
Some Say Money Matters, But My Brother Says Big Brains Matter More
1) What is the most important motor pathway?
2) Where does this pathway begin?
1) Corticospinal tract/ “pyramidal tract”
2) Begins in primary motor cortex where neurons project axons through cerebral white matter and brainstem to the spinal cord
1) What percent of fibers in the corticospinal tract cross over to control movement on the opposite side?
2) What is this crossing over called and where does it occur?
3) What happens if there’s a lesion above this? What about below?
1) About 85%
2) Pyramidal decussation; at junction of medulla and spinal cord
3) Lesions above will cause contralateral weakness; below will cause ipsilateral weakness
1) Lesions in the cerebellum cause what?
2) What do lesions in the basal ganglia cause?
3) Give 2 examples of the effects of basal ganglia lesions
1) Movement disorders (especially balance and coordination= ataxia)
2) Hypokinetic movement disorders
3) Slow and rigid as in Parkinsonism or hyperkinetic as in Huntington’s disease “dancelike” involuntary movements
What are the two pathways in the spinal cord for sensation? What 3 things do they each convey?
1) Posterior column pathway: conveys proprioception, vibration sense, and fine touch
2) Anterolateral pathway: conveys pain, temperature sense, and crude touch
What is conveyed by both somatosensory pathways? Why?
Touch sensation; so a lesion in one pathway does not completely eliminate touch sensation
1) Define posterior column pathway. What 3 things does it carry information about?
2) Where does it enter?
3) Where does it ascend?
4) Where does it end up?
1) Sensory motor neurons carrying information about proprioception, vibratory sense and fine touch. A somatosensory pathway.
2) Enters the spinal cord via the dorsal roots
3) Ascends ipsilateral white matter dorsal/posterior column [all the way up to]
4) The dorsal column nuclei in the medulla.
here they synapse to secondary sensory neurons whose axons cross over to the other side of the medulla
Where does the posterior column pathway continue onto after synapsing to secondary sensory neurons?
Continues up on the contralateral side to the thalamus into the primary somatosensory cortex.
1) Define anterolateral pathway. What 3 things does it carry information about?
2) Where does it enter the spinal cord?
3) Where do these axons initially synapse?
1) Primary sensory neurons carry information about pain, temperature sense and crude touch. A somatosensory pathway.
2) The dorsal root
3) Synapse in the gray matter.
1) What do the primary motor and somatosensory cortexes represent?
2) Why?
3) Why is this important?
4) What does the visual cortex represent?
1) The opposite side of the body to where they are located.
2) The somatosensory and motor pathways cross over in the nervous system
3) Knowing this information helps guide clinicians to area of abnormality
4) Visual input from opposite visual field; the left half of visual field for each eye is mapped to right visual cortex
The two pathways in the spinal cord for sensation are called what?
Somatosensory pathways (posterior and anterior)
1) What anterolateral pathway axons cross over to the other side of the spinal cord?
2) Where does this pathway synapse?
3) Where does this pathway terminate?
1) Axons from the secondary sensory neurons
2) The thalamus
3) The primary somatosensory cortex
1) What is the most important motor pathway?
2) Where does this pathway begin?
1) Corticospinal tract/ “pyramidal tract”
2) Begins in primary motor cortex where neurons project axons through cerebral white matter and brainstem to the spinal cord
1) What percent of fibers in the corticospinal tract cross over to control movement on the opposite side?
2) What is this crossing over called and where does it occur?
3) What happens if there’s a lesion above this? What about below?
1) About 85%
2) Pyramidal decussation; at junction of medulla and spinal cord
3) Lesions above will cause contralateral weakness; below will cause ipsilateral weakness
1) Define posterior column pathway. What 3 things does it carry information about?
2) Where does it enter?
3) Where does it ascend?
4) Where does it end up?
1) Sensory motor neurons carrying information about proprioception, vibratory sense and fine touch. A somatosensory pathway.
2) Enters the spinal cord via the dorsal roots
3) Ascends ipsilateral white matter dorsal/posterior column [all the way up to]
4) The dorsal column nuclei in the medulla.
here they synapse to secondary sensory neurons whose axons cross over to the other side of the medulla
Where does the posterior column pathway continue onto after synapsing to secondary sensory neurons?
Continues up on the contralateral side to the thalamus into the primary somatosensory cortex.
1) What sense is not relayed through the thalamus?
2) Where does it go instead?
3) What does the thalamus encompass?
1) Olfaction
2) Directly to the olfactory cortex.
3) The pineal gland
Where is the pineal gland? What does it do?
1) In the center of the brain
2) Receives information about light and dark and secretes melatonin as needed
1) Where is the association cortex?
2) What does it do?
1) Contained within the cerebral cortex
2) Processes higher order information
1) Motor planning is distributed among many areas of the association cortex. What does this mean in regards to lesions?
2) What type of lesions cause hemineglect (patients ignore objects or even their own body parts to one side)
1) That lesions in the cortex can cause apraxia (uncoordinated or disassociated movements.)
2) Right parietal lesions
1) What is the largest lobe? What does this mean?
2) What would lesions in the frontal lobe cause?
1) The frontal lobe; it contains the largest amount of the association cortex.
2) Many different problems with personality (lack of judgement, inappropriate joking, inhibition) and cognition
1) Where is the primary visual cortex?
2) What do lesions in this cortex cause?
3) What about seizures in this area?
1) In the parieto-occipital lobe
2) Inability to recognize faces, or colors or persistence or reappearance of an earlier viewed object.
3) Seizures cause visual hallucinations.
Name 6 arteries that compose the circle of Willis. Know their locations
1) Internal carotid arteries
2) Anterior cerebral arteries (ACAs)
3) Posterior cerebral arteries (PCAs)
4) Posterior communicating arteries (PCOMs)
5) Vertebral arteries
6) Middle cerebral arteries (MCAs)
1) What do the primary motor and somatosensory cortexes represent?
2) Why?
3) Why is this important?
4) What does the visual cortex represent?
1) The opposite side of the body to where they are located.
2) The somatosensory and motor pathways cross over in the nervous system
3) Knowing this information helps guide clinicians to area of abnormality
4) Visual input from opposite visual field; the left half of visual field for each eye is mapped to right visual cortex
The two pathways in the spinal cord for sensation are called what?
Somatosensory pathways (posterior and anterior)
1) What anterolateral pathway axons cross over to the other side of the spinal cord?
2) Where does this pathway synapse?
3) Where does this pathway terminate?
1) Axons from the secondary sensory neurons
2) The thalamus
3) The primary somatosensory cortex
Name 4 elements of the association cortex
1) Wernicke’s area
2) Broca’s area
3) Frontal lobe
4) Primary visual cortex
What is CN1?
Olfactory
What is CNVII?
Facial
What pathway conveys proprioception, fine touch, and vibration?
Posterior
What structure secretes melatonin?
Pineal gland
What structure is responsible for expressive language?
Broca’s
What structure is responsible for receptive language?
Wernicke’s
Damage to what structure causes hypo or hyperkinetic movement?
Basal ganglia
What drains blood from the brain?
Internal jugular
What supplies blood to the anterior portion of the brain?
Internal carotid arteries
What pathway conveys pain, temperature, and crude touch?
Anterolateral
