Lecture 6 - Brain Flashcards
What are the three parts of the brain?
Cerebrum, Brainstem, Cerebellum
What are the two parts of the CNS?
Brain & Spinal Cord
What is the spinal cord & where does it run?
Long, cylindrical bundle of nerve tissues that extends from the upper border of the atlas (C1) to the 1st/2nd lumbar vertebrae
What is at the end of the spinal cord where it narrows?
Conus Medullaris
What are the spinal nerves called that continue at the end of the spinal cord?
Cauda Equina
What are the two bulges/enlargements in the spinal cord? What do they supply?
Cervical & lumbar regions. They are motor & sensory nerves that come in & out of spinal cord to supply the arms & legs respectively.
What extends from the apex of the conus medullaris? What does it do?
CT filament called the filum terminale, anchors the cord to the 1st coccygeal segment
What are the 5 things that make up the cross section of the spinal cord?
White matter, grey matter, central canal, dorsal horns, ventral horns
What is the white matter vs. grey matter?
Mylinated, outer layer of spinal cord
Unmylinated, inner H-shaped portion of spinal cords
What is the central canal of the spinal cord?
Filled with CSF, runs longitudinally along length of spinal cord, continuous with ventricular system of the brain
What is the dorsal vs ventral horns?
Dorsal - sensory nerve tracts
Ventral - motor neurons
What does part of the medulla oblongata form?
4th ventricle
What nuclei are contained in the medulla oblongata
for CN IX, X, XI, XII
What is the decussation of the pyramids
Where the motor fibers from the right hemisphere cross to the left and vice versa
What are ‘pyramids’
The corticospinal tracts
What does the pons contain
fiber tracts connecting the medulla and cerebellum with upper portions of the brain, and respiratory center for determining volume of air in lungs
What nuclei does the pons contain
CN V (motor), VI, VII, and part of VIII
What are the 5 main things found in the midbrain
Cerebral peduncles, Substantia Nigra, Copora quadrigemina, Nuclei, cerebral aqueduct
What are cerebral peduncles
connecting tracts between the pons and cerebrum
What is the substantial nigra
Dopamine producing regions associated with reward addiction and movement
What is the corpora quadrigemina
Masses that make up the superior and inferior colliculi
What nuclei can be found in the mindbrain
for CN III, IV, V (sensory)
What is the cerebellum responsible for
balance/posture, learning of motions, cognitive functions, and motor coordination “fine tunes motions”
What happens if the cerebellum is damaged
Lack of coordination in gait, speech, etc
What connects the two hemispheres of the cerebrum
Corpus callosum
What are the lobes of the cerebrum
Frontal, occipital, temporal, parietal
What is a gyrus
Convolution of the cortex
What is a sulcus
Fissure between to gyri
What happens in the cerebral cortex
sensorimotor integration and erceptive qualities of our experiences
What is the longitudinal sulcus/fissure
Divides the brain into right and left halves
What is the lateral (sylvian) sulcus
separates temporal from frontal lobes
What is the central sulcus
Separates the frontal from parietal lobes
What is the frontal lobe responsible for
primary motor activity, behavior, speech production
What is the parietal lobe responsible for
primary somatosensory and proprioception; association of somatosensory, vision, audition; formation of egocentric space and sense of self
What is the occipital lobe responsible for
vision
What is the temporal lobe responsible for
Audition, olfaction, memory
What is a homunculus
“little man” area of the brain where we have a little map of ourselves, both sensory and motor. (proprioception center)
Where is the sensory homunculus
represented on the post central gyrus of the parietal lobe
Where is the motor homunculus
Represented on the pre central gyrus of the frontal lobe
What is the thalamus
relay center where all senses except smell integrate
What is the function of the hypothalamus
Chief region for integration of the autonomic nervous system; produces ADH and Oxytocin; regulates thirst and body temperature
What is CN I
Olfactory nerve; give us our sense of smell
How does one test CN I
Wafting a non-irritating scent under a patient’s nose
What is CN II
Optic Nerve; transmits retinal images to occipital lobe of brain
How does one test CN II
Smellen chart and fundoscopic examination
What is CN III
oculomotor nerve
What does the oculomotor nerve innervate
Superior, inferior, and medial recti, inferior oblique, levator palpebrae superioris, and muscles that control pupilary constriction
What is CN IV
troclear nerve; innervates superior oblique muscle of the eye
What is CN VI
Abducens Nerve; innervates lateral rectus muscle of the eye
How does one test CN III, IV, VI
Observe the alignment of the eyes and have a patient follow a moving object with their eyes. Shine a light in their eye to test for pupillary constriction
What is CN V
trigeminal nerve
What does CN V innervate
Sensory to most of the face, motor to the muscles of mastication; responsible for the corneal reflex
How does one test CN V
Lightly touching face and cornea with a cotton swab, observe bite strength
What are the branches of CN V
V1, V2, V3 Opthalmic, maxillary, and mandibular, respectively
What is CN VII
Facial nerve
What does CN VII innervate
Muscles of facial expression, parasympathetic motor innervation to lacrimal gland
What are two notable branches of CN VII
Nerve to the stapedius, Chorda tympani (anterior 2/3 of tongue)
How des one test CN VII
observe patient ability to make facial expressions; test taste with making them identify a flavor
How does the corneal reflex work
Sensory information from the cornea goes out on CN V, but the efferent response is activated by CN VII
What is CN VIII
Vestibulocochlear nerve (audibular)
What are the main divisions of CN VIII
Vestibular branch that determines head position/acceleration info from the middle ear; cochlear branch processes sound information from the inner ear
How does one test CN VIII
With a tuning fork. Head movements can be introduced and observe the patient for nystagmus
What is CN IX
Glossopharyngeal Nerve
What does CN IX provide sensory innervation for
Carotid bodies/sinus, posterior 1/3 of tongue, pharynx, middle ear, and fast from posterior 1/3 of tongue
What does CN IX provide motor innervation for
Stylopharyngeal muscle and parotid gland
How does one test CN IX
Assess ability to taste on posterior 1/3 of tongue; determine if sensation is intact on arches of the palate
What is CN X
Vagus nerve
What does CN X provide efferent parasympathetic innervation for
All organs below the neck down to the proximal half of the transverse colon, with the exception of the adrenal glands
What doe CN X provide motor innervation for
Muscles of speech such as the larynx, cricothyroid and pharyngeal constrictors
What is CN XI
Accessory nerve
What does CN XI innervate
Motor innervation to the trapezius and sternocleidomastoid
How is CN XI tested
Ask the patine to contract the trap or SCM against resistance
What is CN XII
Hypoglossal Nerve
What does CN XII innervate
Motor innervation to all the muscles of the tongue except palatoglossus
How does one test CN XII
Ask patient to stick out his tongue. If it deviates, that indicates a dysfunction
True/False. The Cerebellum initiates movements.
False. It does not initiates movements, but is responsible for fine tuning motions
What does the Longitudinal fissure divide?
divides brain into left and right halves
What do the lateral (Sylvian) sulcus separates?
Temporal from frontal lobes
What does the central sulcus separate?
The frontal from parietal lobe
