L3: Intro to gross neuroanatomy
Amygdala
A limbic system structure involved in memory and emotion, particularly fear and aggression.
Corpus callosum
A thick band of axons that connects the two cerebral hemispheres and acts as a communication link between them.
Function of insula
Addiction (lesions lead to less addictive behavior and addicts have reduced gray matter volume) Sensorymotor, socioemotional, cognitive
What are included in the limbic system?
Amygdala Hypothalamus Hippocampus Fornix Mammillary body (Cingulate gyrus)
Substantia nigra
An area of the midbrain that is involved in motor control and contains a large concentration of dopamine-producing neurons
CSF drains through...
Arachnoid granulation
What are 3 kinds of fibers in the brain and what are their functions?
Association fiber: communication within one hemisphere Commissural fibers: communication from left / right Projection fibers: communication between spinal cord and cortex
How does CSF go to the venous blood?
By arachnoid villi of dural venous sinuses
What produces noradrenaline / norepinephrine?
Caudal raphe nuclei and locus coeruleus
Cause and the signs of thalamic syndrome
Cause: Occlusion of a posterior thalamoperforating artery. Classic signs: Contralateral hemiparesis (paralysis), contralateral hemianesthesia, elevated pain threshold, spontaneous, agonizing, burning pain (hyperpathia), involuntary posturing of the hand (thalamic hand)
CSF is produced from?
Choroid plexus
Split brain
Communication between right and left hemispheres is absent. So when you see / feel something in the left, you cannot tell if you are seeing it because the the visual information is processed by the right hemisphere and the language functions in the left hemisphere. Might help relieve epilepsy Cause: corpus callosum destruction
What is Parkinson's?
Destruction of dopaminergic neurons that are located in the substantia nigra
What is an excitatory and inhibitory neurotransmitter?
Excitatory: Glutamate Inhibitory: GABA (gamma aminobutyric acid). GABA also does muscle contraction, memory formation, and learning
Fibers of corona radiata goes _____ to ______
Medially to laterally (medial to putamen, lateral to caudate)
Function of basal ganglia (nuclei)
Movement initiation Important in voluntary movements and adjusting posture. Receives cortical input, provides negative feedback to cortex to modulate movement.
What is the function of acetylcholine?
Muscle contraction, memory formation (hippocampus), learning
What are 3 circumventricular organs (crosses blood brain barrier)
Pituitary gland Pineal gland Area postrema (induces vomiting in the presence of toxins, like alcohol)
Medial geniculate nucleus
the part of the thalamus that relays auditory signals to the temporal cortex and receives input from the auditory cortex
Primary auditory cortex
the region of the superior temporal lobe whose primary input is from the auditory system
Putamen
large subcortical structure, part of the basal ganglia. Prepares and aids in movement of the limbs
Mammillary body
one of a pair of limbic system structures that are connected to the hippocampus, Recollective memory
Caudate nucleus
one of the major nuclei that make up the basal ganglia, storing and processing of memories
Hypothalamus
•Homeostasis (thermal regulation, sleep etc.) •Feeding •Sexual behavior •sympathetic/parasympathetic processes
Superior colliculus
receives visual sensory input (fixation, smooth pursuit, saccades, vergence)
Insula
regions of cortex located at the junction of the frontal and temporal lobes. Addiction: lesions --> less addictive behavior Addicts have reduced gray matter volume Sensory motor Socioemotional Cognitive
Thalamus
Flinch The thalamus has multiple functions, generally believed to act as a relay station, or hub, relaying information between different subcortical areas and the cerebral cortex.
Corpus callosum Lateral ventricle Caudate nucleus Internal capsul Claustrum Putamen Globus pallidus Optic tract Amygdaloid nuclei Hypothalamus Insula
Identify clockwise
Dura mater Arachnoid mater Pia mater Subarachnoid space Superior sagittal sinus Arachnoid granulation
Identify clockwise
Somatic motor association area (premotor cortex) Primary motor cortex (precentral gyrus) Primary sensory cortex (postcentral gyrus) Somatic sensory association area Visual association area Visual cortex Wernicke's area (understanding speech) Auditory cortex Auditory association area Broca's area (production of speech)
Identify clockwise
Left top-bottom: Internal carotid artery Posterior cerebral artery Superior cerebellar artery Right top-bottom: Anterior cerebral artery Middle cerebral artery Basilar artery Anterior inferior cerebellar artery Posterior inferior cerebellar artery Vertebral artery
Identify from left top-bottom and right top-bottom
Lateral ventricles Interventricular foramina Third ventricle Cerebral aqueduct Fourth ventricle Central canal
Identify from the top
Lateral ventricles Third ventricle Fourth ventricle
Identify from the top
Striatum Globus pallidus externa Globus pallidus interna Thalamus STN (Subthalamic nucleus) SNc (Substantia nigra pars compacta) SNr (Substantia nigra pars reticulata)
Identify from top to bottom
Cingulate gyrus
Information processing and behavioral execution
Function of cingulate gyrus
Information processing and behavioral execution
Two blood supplies to the brain
Internal carotid and vertebral
Where does CSF go to go to the subarachnoid part?
Lateral and median aperture
What are included in striatum?
Lentiform and caudate
Primary vs Associative cortex
Primary is the main sensory / motor (contract the muscle to kick the ball, sense of the world around us) Associative is the detail (face recognition, other details)
Cortical blindness (blindsight)
Primary visual cortex is impaired and the brain does not know that you see things. So if you are asked to guess where the flashing light is, you are able to guess it right, but you say you don't know.
What does lentiform include?
Putamen & globus pallidus (lateral and medial)
What produces serotonin and what is the function of serotonin?
Raphe nuclei Sleep, mood, eating
Hippocampus
Response inhibition, episodic memory, and spatial cognition
Limbic system
Responsible for Feeding, Fleeing, Fighting, Feeling, and Sex. Collection of neural structures involved in emotion, long-term memory, olfaction, behavior modulation, ANS function. Consists of, amygdalae, mammillary bodies, anterior thalamic nuclei, cingulate gyrus, entorhinal cortex.
What is Huntington's?
Severe degeneration of the cholinergic and GABA-ergic neurons, which are located in the caudate nucleus and putamen (genetic mutation. Motor, cognitive, and emotional impairments)
Arachnoid granulation
Small projections of the arachnoid membrane through the dura mater into the superior sagittal sinus; CSF flows through them to be reabsorbed into the blood supply.
Internal capsule
The anterior limb of the internal capsule contains: 1) Frontopontine fibers project from frontal cortex to the pons; 2) Thalamocortical radiations are the fibers that connect the medial and anterior nuclei of the thalamus to the frontal lobes (these are severed during a prefrontal lobotomy). The genu contains corticobulbar fibers, which run between the cortex and the brainstem. The posterior limb of the internal capsule contains corticospinal fibers, sensory fibers (including the medial lemniscus and the anterolateral system) from the body and a few corticobulbar fibers.
Calcarine sulcus
The calcarine sulcus is where the primary visual cortex (V1) is concentrated.
Pons function
The functions of these four cranial nerves (V-VIII) include regulation of respiration, controls involuntary actions, sensory roles in hearing, equilibrium, and taste, and in facial sensations such as touch and pain, as well as motor roles in eye movement, facial expressions, chewing, swallowing, and the secretion of saliva and tears. The pons contains nuclei that relay signals from the forebrain to the cerebellum, along with nuclei that deal primarily with sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture
Medulla oblongata
The medulla oblongata connects the higher levels of the brain to the spinal cord, and is responsible for several functions of the autonomous nervous system
Optic radiation
The optic radiation contains tracts which transmit visual information from the retina of the eye to the visual cortex.
What produces dopamine and what is the function of dopamine?
Ventral tegmental area and substantia nigra Reward, learning/memory, attention, voluntary movement initiation
Medullar structures (ventral and dorsal)
Ventral: Olive, pyramid, decussation of pyramids Dorsal: Cuneate tubercle (upper limbs sensory), gracile tubercle (lower limbs sensory), fasciculus cuneatus, fasciculus gracilis
Midbrain structures (ventral and dorsal)
Ventral: mammillary body and crus cerebri Dorsal: trochlear nerve, superior and inferior colliculus, thalamus
Pons structures (ventral and dorsal)
Ventral: middle cerebellar peduncle Dorsal: superior, middle, inferior cerebellar peduncle, floor of fourth ventricle
Fornix
a fiber tract that extends from the hippocampus to the mammillary body Recall memory
Inferior colliculus
a midbrain nucleus in the auditory pathway
Lateral geniculate nucleus
a place in the thalamus that receives impulses from the optic nerve
Globus pallidus
component of the basal ganglia that connects to the thalamus which relays information to the motor areas and the prefrontal cortex
Optic chiasm
point at which optic nerve fibers cross in the brain
Choroid plexus
produces CSF
Pineal gland
secretes melatonin
Lateral fissure
the fissure that separates the temporal lobe from the overlying frontal and parietal lobes
