Lab Practical #1 and 2 Flashcards
Lab Practical #1
What is 3?
Corpus callosum: The largest white matter structure connecting the left and right hemispheres of the brain.
- It facilitates communication between these hemispheres, allowing information, signals, and sensory data to be shared and processed between the two sides of the brain.
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Thalamus: Acts as a relay station for sensory information, receiving signals from various sensory receptors throughout the body (except smell) and then directing these signals to the relevant areas of the cerebral cortex for further processing.
- It’s often referred to as the “gateway to the cortex” due to its pivotal role in sensory relay.
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Hypothalamus:
- Hypothalamus serves as a control center for many essential bodily functions, including regulating body temperature, hunger, thirst, sleep, and the circadian rhythm.
- Plays a crucial role in controlling the release of hormones from the pituitary gland, which in turn influences various other glands throughout the body.
- Acts as your body’s smart control coordinating center.
- Its main function is to keep your body in a stable state called homeostasis.
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Brainstem - Midbrain:
- The midbrain serves as a vital relay center for auditory and visual information.
- It contains nuclei that process and relay sensory signals from the eyes and ears to higher brain regions responsible for perception and interpretation.
- Structures like the superior colliculus process visual information, while the inferior colliculus handles auditory information.
- The reticular formation, a network of neurons extending from the hindbrain to the midbrain, is responsible for regulating levels of consciousness and arousal.
- The midbrain lies the substantia nigra, a region crucial for the coordination and initiation of voluntary movements
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Brainstem - Pons:
- Relay Center for Communication
- Regulation of Breathing (with medulla)
- Sleep Regulation and Facial Sensation
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Brainstem - Medulla:
- Cardiovascular Control: Nuclei within the medulla control heart rate, the force of heart contractions, and blood vessel dilation/constriction.
- Respiratory Control: The medulla regulates the rate, depth, and rhythm of breathing.
- Reflex Actions: It coordinates various reflexes, including swallowing, coughing, sneezing, and vomiting
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Pineal gland (epithalamus):
Melatonin Production: The pineal gland is primarily known for its role in producing and secreting the hormone melatonin.
- Regulation of Biological Rhythms: The pineal gland influences various biological rhythms, including reproductive hormone cycles, body temperature, and some behavioral patterns
- Connection to Circadian Rhythms and Seasonal Changes:
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Pituitary gland:
- Master Gland: Located at the base of the brain, below the hypothalamus. It plays a central role in regulating various bodily functions by releasing hormones that control the activities of other endocrine glands throughout the body.
- Two Distinct Lobes: The pituitary gland consists of two main lobes—the anterior pituitary (or adenohypophysis) and the posterior pituitary (or neurohypophysis).
- Regulation by the Hypothalamus: The hypothalamus secretes “releasing” and “inhibiting” hormones that either stimulate or inhibit the pituitary gland’s hormone production and release.
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Foramen magnum: Serves as the passage through which the spinal cord connects to the brain.
- This opening allows the spinal cord to continue from the brainstem into the vertebral canal.
superior view
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Tentorium cerebelli:
- Anatomical Barrier: The tentorium cerebelli is a tough, crescent-shaped fold of dura mater—the tough outermost membrane covering the brain—that extends horizontally within the skull.
- Division of Brain Regions: This structure separates the cerebral hemispheres (specifically, the occipital lobes) located above from the cerebellum and brainstem below.
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Falx cerebei:
- Anatomical Partition: The falx cerebri is a tough, sickle-shaped fold of dura mater—the tough outermost membrane covering the brain—that lies within the longitudinal fissure between the two cerebral hemispheres.
- Division of Brain Regions: This structure serves as a structural partition between the right and left cerebral hemispheres.
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Parietooccipital sulcus:
- Anatomical Boundary: It forms a clear demarcation between the parietal and occipital lobes.
- Sensory and Visual Integration: The parietal lobe is primarily involved in sensory processing and integration, while the occipital lobe plays a crucial role in visual processing and perception.
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Tectum of midbrain
- Structure and Components:
- The tectum comprises four rounded elevations known as colliculi (singular: colliculus). There are two superior colliculi and two inferior colliculi.
- The superior colliculi are involved in visual processing, particularly in coordinating eye movements and visual attention.
- The inferior colliculi are crucial for auditory processing, receiving and relaying auditory information from the brainstem to higher auditory centers.
- Sensory Integration and Reflexes: The tectum, with its colliculi, plays a fundamental role in sensory integration and reflexive responses.
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Cingulate gyrus (limbic lobe):
- Emotional and Cognitive Functions: The anterior cingulate gyrus is primarily involved in emotional processing, including regulation of emotions, motivation, and social behavior.
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Sagittal fissure / Longitudinal fissure link:
- This is the prominent groove that divides the brain into two distinct hemispheres, the right and left cerebral hemispheres.
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Central sulcus:
- The central sulcus is a significant anatomical landmark in the brain that separates the frontal lobe from the parietal lobe.
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Lateral fissure:
- Also known as the Sylvian fissure, is a significant groove that separates the temporal lobe from both the frontal and parietal lobes in the brain.
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Precentral gyrus:
- Prominent structure in the brain that houses the primary motor cortex, a region responsible for controlling voluntary movements.
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Post central gyrus:
- Contains the primary somatosensory cortex, responsible for processing sensory information from the body
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Inferior frontal gyrus:
- A crucial region in the frontal lobe, contributing significantly to various higher-order cognitive processes: language processing, social cognition, and executive functions.
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Temporal lobe:
- Memory, Emotion, and Language: The temporal lobes play a crucial role in memory formation and retrieval.
- Auditory Processing: The primary auditory cortex, responsible for receiving and processing auditory information, is located in the temporal lobes. This region allows us to perceive and interpret sounds, including speech and other auditory stimuli.
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Frontal lobe:
- Motor Control and Personality: The primary motor cortex, responsible for voluntary movements, is located in the frontal lobe, specifically in the precentral gyrus.
- Lesions or abnormalities in this region can lead to changes in behavior, decision-making, and personality.
- Medial Dorsal Prefrontal (medial 8, 9; 10)
- Dorsolateral Prefrontal (lateral 8, 9; 46)
- Ventral prefrontal (11, 44, 45, 47)
- Parietotemporal Association (39, 40, parts of 7, 19, 21, 22, 37).
- Executive Functions: The frontal lobe is associated with higher cognitive functions known as executive functions, which include planning, problem-solving, decision-making, reasoning, and judgment.
- Plays a role in working memory, attention, and cognitive flexibility, allowing individuals to adapt to changing circumstances.
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Parietal lobe:
- Sensory Integration: The parietal lobe plays a crucial role in integrating sensory information from various modalities, including touch, temperature, pain, and proprioception (awareness of body position).
- Spatial Processing and Attention: This lobe is involved in spatial perception
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Parietal lobe:
- Sensory Integration: The parietal lobe plays a crucial role in integrating sensory information from various modalities, including touch, temperature, pain, and proprioception (awareness of body position).
- Spatial Processing and Attention: This lobe is involved in spatial perception
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Brainstem link:
- The brainstem is essential for fundamental bodily functions, including regulating vital autonomic functions such as breathing, heart rate, blood pressure, and digestion. It also serves as a conduit for sensory and motor pathways, allowing signals to travel between the brain and the rest of the body.
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What view?
Cerebellum - anterior view
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What view?
Cerebellum - posterior view
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What view?
Cerebellum - midsagittal view
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Cerebellum - cerebellar peduncle (superior):
- structure connecting the cerebellum to the midbrain
- Motor Output Pathway: The fibers within the superior cerebellar peduncle carry efferent fibers, transmitting signals from the cerebellum to various regions involved in motor control
Lateral view
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Cerebellum - cerebellar peduncle (middle):
- Link the cerebellum to the brainstem.
- Transmission of Cortical Input: The middle cerebellar peduncle carries fibers that originate mainly from the pontine nuclei and relay information from the cerebral cortex to the cerebellum. These fibers transmit signals related to planned movements and motor coordination from the motor and premotor areas of the cerebral cortex to the cerebellum.
Lateral / superior view
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Cerebellum - cerebellar peduncle (inferior) link
- It connects the medulla (specifically the medullary reticular formation and spinal cord) to the cerebellum.
- Transmission of Sensory Information: The inferior cerebellar peduncle primarily carries sensory information to the cerebellum. It transmits proprioceptive input from the spinal cord and medulla, conveying information about body position, muscle tone, limb movements, and other sensory data necessary for coordination and motor control.
Lateral / superior view
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Cerebellum - vermis:
- Motor Control: Vermis contributes more to axial and proximal muscle control.
- Balance and Posture: The vermis is particularly essential for maintaining balance and regulating posture.
superior view
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Cerebellum - vermis:
- Motor Control: Vermis contributes more to axial and proximal muscle control.
- Balance and Posture: The vermis is particularly essential for maintaining balance and regulating posture.
mid sagittal / posterior view
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Cerebellum - lateral hemisphere:
- Primarily influence distal limb movements and motor coordination.
- Motor Coordination: The lateral hemisphere of the cerebellum contributes significantly to motor coordination and fine-tuning of movements.
- Motor Learning: The lateral hemisphere of the cerebellum is also involved in motor learning and adaptation. It plays a role in acquiring new motor skills, adjusting movements based on feedback, and automating previously learned motor tasks
Inferior / lateral / superior view
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Tegmentum of midbrain:
- Location and Composition: The tegmentum is a region within the brainstem, situated dorsally (toward the back) to the ventricular system.
- Role in Motor Control: Within the tegmentum, there are nuclei and pathways involved in motor control and coordination.
- Integration of Sensory and Autonomic Functions: The tegmentum contains sensory nuclei and pathways that process sensory information, particularly from the cranial nerves.
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arachnoid matter = a fine, delicate membrane, the middle one of the three membranes or meninges that surround the brain and spinal cord, situated between the dura mater and the pia mater. link
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Cranial nerve?
Olfactory nerve (CN I)
- sensory
- sense of smell
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Cranial nerve?
Optic nerve (CN II)
- sensory
- vision
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Cranial nerve?
Oculomotor nerve (CN III)
- motor
- eye movements; papillary constriction and accommodation; muscles of eyelid
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Cranial nerve?
Trochlear nerve (CN IV)
- motor
- eye movements (intorsion, downward gaze)
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Cranial nerve?
Trigeminal nerve (CN V)
- sensory and motor
- somatic sensation from face, mouth, cornea; muscles of mastication
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Cranial nerve?
Abducens nerve (CN VI)
- motor
- eye movements (abduction or lateral movements)
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Cranial nerve?
Facial nerve (CN VII)
- sensory and motor
- controls muscles of facial expression; taste from anterior tongue, lacrimal and salivary glands
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Cranial nerve?
vestibulocochlear nerve (CN VIII)
- sensory
- hearing; sense of balance
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Cranial nerve?
Glossopharyngeal nerve (CN IX)
- sensory and motor
- sensation from posterior tongue and pharynx; taste form posterior tongue; carotid and baroreceptors
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Cranial nerve?
Vagus nerve (CN X)
- sensory and motor
- autonomic = gut, sensation from larynx and pharynx; muscles of vocal cards; swallowing
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Cranial nerve?
Accessory nerve (CN XI)
- motor
- shoulder and neck muscles
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Cranial nerve?
Hypoglossal nerve (CN XII)
- motor
- movements of tongue
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Cortical area?
Primary Somatosensory: located within central sulcus and on adjacent postcentral gyrus.
- Function = Location of stimuli and discriminate among various sizes, shapes and textures of objects.
- Lesion = Loss of tactile localization and conscious proprioception.
3-1-2
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Cortical area?
Secondary Somatosensory (5,7):
- Function = Stereognosis (the mental perception of depth or three-dimensionality by the senses, usually in reference to the ability to perceive the form of solid objects by touch) and memory of the tactile and spatial envirnment.
- Lesion = Astereognosis (the inability to discriminate shape and size by touch and the inability to recognize objects by touch)
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Cortical area?
Primary Auditory (41): Located in the lateral fissure and on adjacent superior temporal gyrus.
- Conscious awareness of the intensity of sound
- Function = Conscious discrimination of loudness and pitch of soundness.
- Lesion = Loss of localization of sounds.
41
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Cortical area?
Secondary Auditory (22, 42):
- Function = Classification of sounds.
- Lesion = Auditory agnosia (Impairments in sound perception and identification despite intact hearing, cognitive functioning, and language abilities).
22,42
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Cortical area?
Primary Vestibular (40):
- Function = Discriminates among head positions and head movements, contributes to perception of vertical.
- Lesion = Change in awareness of head position and movement and perception of vertical.
anterior 40
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Cortical area?
Primary Visual (17): located in calcarine sulcus and on the adjacent gyrus.
- Function = Light/ dark, various shapes, locations of object and movements of object.
- Lesion = Homonymous hemianopia (visual field defect that involves vision loss on the same side of the visual field in both eyes)
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Cortical area?
Secondary Visual (22, 42):
- Function = Analysis of motion, color; recognition of visual objects; understanding of visual spatial relationships; control of visual fixation.
Lesion =
- Visual agnosia: Difficulty recognizing or identifying objects or people visually, despite having normal vision.
- Optic ataxia: Condition characterized by difficulties in visually guiding movements, particularly reaching and grasping objects accurately.
18-21
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Cortical area?
Primary Motor (4):
- Function = Voluntary controlled movements
- Lesion = Paresis, loss of fine motor control, spastic dysarthria
4
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Cortical area?
Supplementary Motor:
- Function = Initiation of movement, orientation planning, bimanual and sequential movements
- Lesion = Apraxia (condition that affects the ability to perform purposeful movements or sequences of movements, despite having the physical ability and understanding of the task)
superomedial 6
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Cortical area?
Premotor Area:
- Function = Control of trunk and girdle muscles, anticipatory postural adjustments
- Lesion = Apraxia (loss of ability to execute or carry out skilled movement and gestures, despite having the physical ability and desire to perform them).
lateral 6
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Cortical area?
Broca’s Area:
- Function = Motor programming of speech (left hemi)
- Lesion = Broca’s aphasia
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Spinal-cerebellum ?
Spinalcerebellum:
- vermis and paravermal regions
- coordinate trunk/gross limb movements
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Cerebro-cerebellum ?
- lateral hemisphere
- distal voluntary movements
- coordination
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vestibulo-cerebellum ?
- flocculus and nodulus
- equilibrium
- input to coordinate motor activites for posture, head and eye movements
Lab Practical #2
Identify
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Cornea:
- The cornea is the transparent outermost layer of the eye that covers the iris and the pupil.
- It helps to focus light into the eye and plays a significant role in vision by bending or refracting light as it enters the eye.
Visual System
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Identify
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Sclera:
- The sclera is the tough, white outer layer of the eyeball.
- It provides structural support to the eye and helps maintain its shape.
Visual System
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Identify
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Lens:
- The lens is a transparent, flexible structure situated behind the iris.
- It focuses light onto the retina by changing its shape through a process called accommodation, allowing for clear vision at various distances
Visual System
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Identify
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Pupil:
- The pupil is the black circular opening in the center of the iris.
- It regulates the amount of light entering the eye by adjusting its size in response to varying light conditions.
Visual System
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Identify
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Retina:
- The retina is the light-sensitive inner lining at the back of the eye.
- It contains photoreceptor cells (rods and cones) that convert light into electrical signals, which are then transmitted via the optic nerve to the brain for visual processing.
Visual System
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Identify
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Optic nerve:
- The optic nerve is a bundle of nerve fibers that carries visual information from the retina to the brain.
- It acts as the communication pathway between the eye and the brain, allowing for visual perception.
Visual System
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Identify
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Iris:
- The iris is a ring-shaped muscle responsible for controlling the size of the pupil.
- It adjusts the size of the pupil in response to different lighting conditions to regulate the amount of light entering the eye.
Visual System
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Identify
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Superior rectus:
- This is one of the six extraocular muscles that control eye movements.
- It primarily aids in upward movement and slight inward rotation of the eye.
Visual System
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Identify
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Inferior rectus:
- Helps in downward movement and slight inward rotation of the eye.
Visual System
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Identify
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Lateral rectus:
- This muscle is responsible for outward movement or abduction of the eye.
Visual System
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Identify
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Medial rectus:
- Facilitates inward movement or adduction of the eye.
Visual System
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Identify
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Superior oblique:
- This muscle aids in downward and outward rotation of the eye.
- Intorsion (IR), depression, and abduction.
Visual System
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Identify
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Inferior oblique:
- The inferior oblique muscle contributes to upward and outward rotation of the eye.
Visual System
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Nerve roots (ventral):
- Ventral nerve roots carry motor information from the spinal cord to the body.
- They exit the anterior side of the spinal cord and contain motor neurons controlling muscle movement.
Spinal region
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Nerve roots (dorsal):
- Dorsal nerve roots carry sensory information from the body to the spinal cord.
- They enter the posterior side of the spinal cord and contain sensory neurons transmitting information like touch, temperature, and pain.
Spinal region
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Dorsal root ganglion:
- Cluster of nerve cell bodies located just outside the spinal cord where the dorsal nerve root enters.
- It contains the cell bodies of sensory neurons whose axons extend into the spinal cord.
Spinal region
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Anterior view of spinal cord:
Spinal region
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Posterior view of spinal cord:
Spinal region
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Posterior Horn (on model):
- These areas contain interneurons and incoming axons of sensory neurons. They receive and process sensory information such as touch, temperature, pain, and proprioception (awareness of body position), before relaying this information to other parts of the nervous system for further processing and response.
Spinal region
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Lateral Horn (on model):
- These sections are found only in the thoracic and upper lumbar segments of the spinal cord.
- They contain autonomic neurons that regulate involuntary functions like heart rate, digestion, and respiration.
Spinal region
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Anterior Horn (on model):
- These regions contain cell bodies of motor neurons that send signals to control skeletal muscles.
- They are responsible for initiating and coordinating voluntary muscle movements throughout the body.
Spinal region
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Conus medullaris:
- Its location marks the endpoint of the spinal cord proper and is crucial in surgical procedures, as damage beyond this point might not affect the spinal cord itself but can impact the nerves composing the cauda equina.
Spinal region
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Cauda equine:
- This bundle of nerves is important because it carries signals to and from the lower limbs and pelvic organs.
- Injuries or conditions affecting the cauda equina can result in motor or sensory deficits in the lower extremities.
Spinal region
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Filum terminale:
Spinal region
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Dura matter (Spinal):
- The tough outer layer provides protection for the spinal cord.
- It’s a durable, fibrous membrane that encases the spinal cord, shielding it from potential physical damage or trauma.
Spinal region
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Arachnoid matter:
- Positioned beneath the dura mater, the arachnoid mater forms a protective layer and, along with the subarachnoid space, contains cerebrospinal fluid (CSF).
- This fluid provides cushioning and shock absorption for the spinal cord against sudden movements or impacts.
Spinal region
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Pia matter:
- The innermost layer closely envelops the spinal cord’s surface, providing support and nourishment.
- It’s highly vascular and supplies essential nutrients and oxygen to the spinal cord tissues.
Spinal region
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Lumbar enlargement:
- Situated in the lumbar region (L1-S3 segments), the lumbar enlargement is another widened portion of the spinal cord. Similar to the cervical enlargement, it houses more gray matter and is responsible for giving rise to nerves that supply the lower limbs, especially critical for motor and sensory functions in the legs.
Spinal region
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Cervical enlargement:
- This enlargement occurs in the cervical region of the spinal cord (C4-T1 segments). It’s characterized by a widened area in the spinal cord’s diameter and contains more gray matter.
- This region gives rise to nerves that supply the upper limbs, particularly important for motor and sensory functions in the arms.
Spinal region
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Anterior semicircular canal:
- Receptors in semicircular canals detect rotational movement of the head by sensing the motion of endolymph (a fluid in membranous labyrinth).
- Anterior Canal = Detects the rotation of head up and down, yes motion, sagittal plane
Vestibular system
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Posterior semicircular canal:
- Receptors in semicircular canals detect rotational movement of the head by sensing the motion of endolymph (a fluid in membranous labyrinth).
- Posterior Canal = Detects the rotation of head up and down to side, coronal plane.
Vestibular system
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Lateral semicircular canal:
- Receptors in semicircular canals detect rotational movement of the head by sensing the motion of endolymph (a fluid in membranous labyrinth).
- Lateral Canal = Detects the rotation of the head from side to side, no motion, transverse plane.
Vestibular system
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Otolith organs:
- Anatomic site of sensory receptors (utricle, saccule) that respond to head position relative to gravity and to linear acceleration and deceleration of the head.
Vestibular system
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What nerve?
yellow
Vestibulocochlear nerve:
- Vestibulocochlear nerve contains afferents for hearing and equilibrium
- Part of inner ear
Vestibular system
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Cochlea:
- A spiral-shaped, fluid-filled structure in the inner ear responsible for converting sound waves into electrical signals.
- It’s a key component in the process of hearing.
Vestibular system
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Pinna:
- The visible outer part of the ear.
- It helps collect and funnel sound waves into the ear canal.
Vestibular system
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External auditory meatus:
- The ear canal, a tube-like structure leading from the pinna to the eardrum.
- It conducts sound waves to the middle ear.
Vestibular system
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Ossicles:
- These are the three tiny bones (malleus, incus, and stapes) in the middle ear that transmit sound vibrations from the eardrum to the inner ear, amplifying the sound along the way.
Vestibular system
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Ear drum:
- Also called the tympanic membrane, it’s a thin membrane that separates the outer ear from the middle ear.
- It vibrates in response to sound waves, transmitting these vibrations to the ossicles.
Vestibular system
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What artery?
Anterior cerebral artery:
- Supplies blood to the medial portions of the frontal and parietal lobes.
- An injury to this artery might result in weakness or sensory loss in the contralateral lower limb.
Blood Flow
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What artery?
Posterior cerebral artery:
- Supplies blood to the occipital lobe, part of the temporal lobe, and the midbrain.
- Damage to this artery could lead to visual disturbances, such as cortical blindness or deficits in visual perception.
Blood Flow
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What artery?
Middle cerebral artery:
- Provides blood to a large part of the lateral surface of the brain, including parts of the frontal, parietal, and temporal lobes.
- An injury here could cause weakness or sensory deficits in the contralateral face and arm, as well as language impairments if in the dominant hemisphere.
Blood Flow
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What artery?
Vertebral artery:
- Supplies blood to the brainstem, cerebellum, and posterior part of the brain.
- Damage may result in dizziness, double vision, and even problems with coordination and balance.
Blood Flow
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What artery?
Basilar artery:
- Supplies the brainstem and cerebellum.
- An injury could lead to symptoms such as difficulty swallowing, facial weakness, double vision, and issues with speech and balance.
Blood Flow
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What artery?
Internal carotid artery:
- Supplies blood to the majority of the anterior cerebrum.
- Damage here might cause weakness or sensory loss in the face, as well as potential issues with higher cognitive functions.
Blood Flow
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What artery?
Posterior communicating artery:
- This artery connects the internal carotid artery to the posterior cerebral artery.
- Damage may result in vision problems, particularly affecting the ability to see the periphery of the visual field.
Blood Flow
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What artery?
Anterior communicating artery:
- Joins the two anterior cerebral arteries.
- Injury here might lead to changes in personality, cognitive deficits, and potentially problems with movement or sensation.
Blood Flow
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What artery?
green
Pontine arteries:
- Supply blood to the pons, and an injury could cause various neurological deficits like paralysis, difficulty swallowing, and disturbances in eye movement.
Blood Flow
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What artery?
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Anterior inferior cerebellar artery:
- Supplies the anterior and inferior portions of the cerebellum.
- Damage may cause balance and coordination issues, as well as hearing problems or facial weakness.
Blood Flow
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What artery?
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Superior cerebellar artery:
- Supplies the superior part of the cerebellum.
- An injury here could result in coordination difficulties, tremors, and problems with voluntary movement.
Blood Flow
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Lateral ventricle:
- The brain’s largest ventricles, consisting of two, one in each hemisphere.
- They produce cerebrospinal fluid (CSF) and are located deep within the cerebral hemispheres.
Ventricular system
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Interventricular foramen/ foramen of Monro (on paper):
- These are small channels connecting the lateral ventricles to the third ventricle.
- They allow for the flow of cerebrospinal fluid between these ventricles.
Ventricular system
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Third ventricle:
- A narrow cavity in the midline of the brain, positioned between the two thalami.
- It communicates with the lateral ventricles via the interventricular foramina and with the fourth ventricle through the cerebral aqueduct.
Ventricular system
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Cerebral aqueduct:
- Also known as the aqueduct of Sylvius, it’s a slender canal that connects the third ventricle to the fourth ventricle.
- It runs through the midbrain and allows the flow of cerebrospinal fluid.
Ventricular system
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Fourth ventricle:
- Located between the brainstem and the cerebellum, the fourth ventricle is continuous with the central canal of the spinal cord.
- It’s responsible for producing cerebrospinal fluid and allows it to flow around the brain and spinal cord.
Ventricular system
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Projection fibers:
- These fibers carry information to and from the cerebral cortex and other parts of the brain and spinal cord.
- They project vertically, connecting the cortex to subcortical structures or to the brainstem and spinal cord.
- For example, the corticospinal tract is a projection fiber that carries motor signals from the motor cortex to the spinal cord, controlling voluntary movements.
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What kind of fibers
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Association fibers:
- These fibers connect different parts of the cerebral cortex within the same hemisphere.
- They’re responsible for communication between different regions within a hemisphere, enabling functions like language, memory, and perception.
- There are short association fibers, connecting adjacent gyri, and long association fibers, linking more distant cortical areas. The arcuate fasciculus, for instance, is an association fiber that connects Wernicke’s area and Broca’s area, playing a role in language processing.
Lab Practical #2
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Internal capsule and their function:
- This is a compact bundle of projection fibers that pass between the thalamus and various cortical areas.
- It’s a crucial pathway for motor and sensory information traveling to and from the cerebral cortex.
- The internal capsule contains both ascending fibers (sensory inputs) and descending fibers (motor outputs), including the corticospinal tract, thalamocortical fibers, and more.
Lab Practical #2
What loop?
Goal Directed Behavior Loop:
- Evaluating information for making decisions, planning and choosing actions
- Head of caudate = Part of decision making loop
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What loop?
Social Behavior Loop:
- Head of caudate is part of loop that recognizes social cues, regulates self control, and parses out relevant from irrelevant information
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What loop?
Emotion Loop
- Loop is responsible for integrating emotions and facial expression (partly responsible for mask like face), seeking rewards, predictions when outcome is unknown, addictions.
- Basal ganglia stroke = depression, emotional blunting
Lab Practical #2
Differentiate between oculomotor and motor loops.
Oculomotor Loop:
- Body of the caudate is part of an oculomotor loop
- Makes decision about spatial attention and eye movements; specifically determining weather to use fast eye movements to direct attention towards an object
- In basal ganglia pathology: demonstrate impaired saccadic eye movements
Motor Loops: Direct
- Direct / GO Pathway: Consists of signals transmitted from the cortex to putamen/ substantia nigra reticulata to Globus pallidus, to ventrolateral (VL) nucleus of the thalamus, and back to cortex
- Serves to activate the motor and premotor cortex and assists in the initiation of voluntary movement.
- Motor Loops:
- Indirect / NoGo: Through the BG involves the GPe, subthalamic nucleus, GPi, substantia nigra reticuclata.
- Serves to decrease thalamocortical activation.
- Suppresses unwanted movements.
