Lecture 8 Flashcards
Neurons?
-Different neuron shapes allows for different functions
-Different synapse types allows for different functions
-Human Brain has ~100B neurons and ~100T synapses
Few Dendrites allows for?
Specificity
Many Dendrites allows for?
Intensity or Integration
Chemical Synapse allows for?
Adaptability
Electrical Synapse allows for?
Speed
Brain has 3 Cortexes?
-Neocortex
-Mesocortex
-Allocortex
Neocortex?
Highly evolved and responsible for decision making personality, and other higher order thinking
Mesocortex?
Limbic system responsible for emotion and memory function
Allocortex?
Within mesocortex and critical for creating new memories
Cortical Lobes?
-Frontal Lobe
-Parietal Lobe
-Occipital Lobe
-Temporal Lobe
(Cortical Lobes)
Frontal Lobe?
-Movement (motor cortex - posterior portion of frontal lobe)
-Complex behaviors: planning, changing strategies, self awareness, attention to emotionally related stimuli and spontaneity of behavior
-Production of speech (Broca’s area)
(Cortical Lobes) Parietal Lobe?
-Somatosensory perception
-Some visually and acoustically related functions
-Perception of space and in monitoring the body’s position in space
(Cortical Lobes) Occipital Lobe?
Vision
(Cortical Lobes) Temporal Lobe?
-Hearing
-Some functions in vision, memory and factors of personality and social behavior
-Comprehending spoken words (Wernicke’s area)
Subcortical Structures?
-Thalamus
-Hypothalamus
-Limbic System
-Basal Ganglia
(Subcortical Structures)
Thalamus?
Information “relay station”
(Subcortical Structures)
Hypothalamus?
Maintain homeostasis via hormones
(Subcortical Structures)
Limbic System?
Emotion and memory (Hippocampus and Amygdala)
(Subcortical Structures)
Basal Ganglia?
Decide whether to initiate movement or not
Cerebellum?
-Motor control and coordination
-Has its own cortex and subcortical structures (deep nuclei)
(Brainstem)
Cranial Nerves?
(Cerebrum)
-CN I (Olfactory)
-CN II (Optic)
(Midbrain)
-CN III (Oculomotor)
-CN IV (Trochlear)
(Pons)
-CN V (Trigeminal)
-CN VI (Abducens)
-CN VII (Facial)
-CN VIII (Vestibulo.)
(Medulla Oblongata)
-CN IX (Glosso.)
-CN X (Vagus)
-CN XI (Accessory)
-CN XII (Hypoglossal)
Midbrain?
Sits on dorsal surface of Brainstem, behind Cerebellum
(Quadrigeminal Plate)
Pons?
-Floor of 4th ventricle
-Consists of cerebellar peduncles which connect hemispheres of cerebellum (Superior (under colliculi)) (Middle (Bridge of Pons)) (Inferior (Inferior/Medial to Middle))
Medulla?
-Pyramidal and lemniscal decussations (Gracile and Cuneate nucleus)
-Inferior olive
-Reticular formation
-Obex
(Medulla) Inferior olive?
Motor control
(Medulla) Reticular formation?
Arousal, consciousness (Extends into pons and midbrain)
(Medulla) Obex?
4th ventricle narrows to central canal
Spinal Cord?
-Sensory (afferent) tracts from nerve endings to CNS
-Motor (efferent) tracts from CNS to effector muscles/organs
(Dorsal Root ganglia)
(Ventral Horn)
(Spinal Cord)
Dorsal Root ganglia?
Receive sensory information
(Spinal Cord)
Ventral Horn?
Sends out motor information
Upper Motor Neurons?
-Originate in motor cortex or brainstem
-Control signal output (spastic paresis during injury)
Lower Motor Neurons?
-Spinal nerves and motor cranial nerves
-Signal output (flaccid paralysis during injury)
(CNS Support)
Protective Layers?
1) BBB
2) Meninges
3) CSF
(Protective Layers) Blood Brain Barrier?
Astrocytes + Endothelial Cells
(Protective Layers)
Meninges?
-Dura Mater
-Arachnoid Mater
-Pia Mater
(Protective Layers)
Cerebrospinal Fluid?
-Cushion/buoyancy
-Maintains intracranial pressure
-Waste clearance
Cerebrovascular Supply?
-Despite heavily redundant paths, common injuries include: (Stroke (Ischemia, Hemorrhage), Aneurysm, Malformations)
-Anterior choroidal artery (a distal branch of internal carotid) supplies varies subcortical structures
(Imaging Techniques)
Computerized Axial Tomograph (CT) Scan?
-360 degree X-Ray
-Hypodense (dark) = edema/infarction
-Hyperdense (bright) = calcification, hemorrhage, and bone trauma
(Imaging Techniques)
Electroencephalogram (EEG)?
Brain waves from an electrode array
(Imaging Techniques)
Functional Magnetic Resonance Imaging (fMRI)?
Shows oxygenated blood flow activity
(Imaging Techniques)
Positron Emission Tomography (PET) Scan?
Positron-emitting radioactive molecules are fused with substance of interest and consumed/applied (Glucose –> detects activity) (Precursors (ex. AA) –> detect proteins) (Ligands –> detect receptor activity)
(Imaging Techniques)
Magnetoencephalography (MEG)?
(Direct measure of Brain Function)
-Very high temporal and spatial resolution (millimeter precision)
-Better than fMRI, PET, and SPECT
(Imaging Techniques)
Magnetic Resonance Imaging (MRI)?
(MRI shows anatomical structures, TISSUE and FLUID)
-Magnetic field excites atoms, which release radio frequency, which is absorbed and recorded
