Neuroscience Anatomy Flashcards
Somatic Nervous System
peripheral nerve fibers send sensory information to the CNS
• motor nerve fibers send information to skeletal muscles
• somatic motor neurons travel directly to skeletal muscle without intervening synapses
controls voluntary movements and provides the ability to sense touch, smell,
sight, taste, and sound
• all five senses are influenced by the SNS
Limbic System
corpus collosum, olfactory tract, mammillary bodies, fornix, thalamic nuclei, amygdala, hippocampus, aprahippocampal gyrus, cingulate gyrus, hypothalamic nuclei
- involved in the control and expression of mood and emotion, processing and storage of recent memory, olfaction, control of appetite, and emotional responses to food
- lesions to the limbic system can also result in a variety of behaviors including aggression, extreme fearfulness, altered sexual behavior, and changes in motivation
Frontal lobe (function and impairment)
Function:
* voluntary movement, intellect, orientation
* Broca’s area (typically located in the left hemisphere): speech, concentration
personality, temper, judgment, executive functions, reasoning, behavior, self-awareness
Impairment:
* contralateral weakness
* perseveration, inattention
* personality changes, antisocial behavior
* Broca’s aphasia (expressive deficits)
* delayed or poor initiation, emotional lability
Parietal lobe
Function:
*associated with sensation of touch, kinesthesia, perception of vibration, and temperature
* receives information from other areas of the brain regarding hearing, vision, motor, sensory, and memory
* interprets language and words
* spatial and visual perception
* provides meaning for objects
Impairment:
* dominant hemisphere (typically located in the left hemisphere):
agraphia, alexia, agnosia
* non-dominant hemisphere (typically located in the right hemisphere): dressing apraxia, anosognosia
* contralateral sensory deficits
* impaired language comprehension
Temporal lobe
Function:
primary auditory processing and olfaction
* Wernicke’s area (typically located in the left hemisphere): ability to understand and produce meaningful speech, verbal and general memory, assists with understanding language
*the rear of the temporal lobe enables humans to interpret other people’s emotions and reactions
Impairment:
* learning deficits
* Wernicke’s aphasia (receptive deficits)
* antisocial, aggressive behaviors
* difficulty with facial recognition
* difficulty with memory, memory lOss
* inability to categorize objects
Occipital Lobe
Function:
* main processing center for visual information
* processes visual information regarding colors, light, and shapes
* judgment of distance, seeing in three dimensions
Impairment:
* homonymous hemianopsia
* impaired extraocular muscle movement and visual deficits
* reading and writing impairment
* cortical blindness with bilateral lobe involvement
What are the meninges
3 layers of connective tissue covering the brain and spinal cord.
Provide protection from contusion and infection.
There are blood vessels and cerebrospinal fluid (CSF) within the meninges.
What are the 3 types of meninges
*dura mater: outermost meninx; has four folds; lines the periosteum of the skull and protects the brain; subdural space separates this from the arachnoid mater
*arachnoid mater: the middle meninx; the arachnoid is impermeable; surrounds the brain in a loose manner; subarachnoid space separates this from the pia mater
- pia mater: innermost meninx; covers the contours of the brain;
forms the choroid plexus in the ventricular system
What are the dural spaces
- epidural space: an area between the skull and outer dura mater that can be abnormally occupied; also the area in the spinal cord between the dura mater and the periosteum of the vertebrae
- subdural space: the area between the dura and arachnoid meninges
- subarachnoid space: the area between the arachnoid and pia mater that contains CSF and the circulatory system for the cerebral cortex
Cerebrospinal Fluid (CSF)
- clear, fluid-like substance
- cushions the brain and spinal cord from injury and provides mechanical buoyancy and support.
- produced constantly: 500-700 ml/day.
- Provides nutrition to the central nervous system, serves as a conduit for removal of metabolites, and is constantly being absorbed and replenished within the brain and spinal cord.
Blood brain barrier
- consists of the meninges, protective glial cells, and capillary beds of the brain.
- It is responsible for exchange of nutrients between the central nervous system and the vascular system.
- Provides protection for the CNS by restricting certain molecules from crossing the barrier while others are able to do so freely.
Right hemisphere specialization/dominance
- Nonverbal processing
- Process information in a holistic manner
- Artistic abilities
- General concept comprehension
- Hand-eye coordination
- Spatial relationships
- Kinesthetic awareness
- Understand music
- Understand nonverbal communication
- Mathematical reasoning
- Express negative emotions
- Body image awareness
Left hemisphere specialization/dominance
- Language
- Sequence and perform movements
- Understand language
- Produce written and spoken language
- Analytical
- Controlled
- Logical
- Rational
- Mathematical calculations
- Express positive emotions such as love and happiness
- Process verbally coded information in an organized, logical, and sequential manner
Hippocampus
- in the lower temporal lobe
- responsible for forming and storing new memories of personal hx and other declarative memory.
- sends memories to appropriates areas of the cerebral hemispheres for long-term storage.
Basal Ganglia
- includes: caudate, putamen, globus pallidus, substantia nigra, and subthalamic nuclei.
- voluntary movement, regulation of ANS, posture, m tone, and control of motor responses
- Dysfunction: PD, Huntington’s disease, tourette’s syndrome, ADD, Obsessive-compulsive disorder, and many addictions
Amygdala
- in the temporal lobes
- emotional and social processing.
- Involved in fear and pleasure responses, arousal, processing of memory, and formation of emotional memories
Thalamus
- relay or processing station
- coordinates sensory perception and mvmt with other parts of the brain and SC.
- Receives info from cerebellum, BG, and all sensory pathways except olfactory tract.
- Then relays to appropriate association cortex
- can produce thalamic pain syndrome where there is spontaneous pain on the contralateral side of the body to the thalamic lesion.
Hypothalamus
- receives and integrates info from ANS and assists with regulating hormones
- controls functions such as hunger, thirst, sexual behavior, and sleeping.
- Regulates temperature, adrenal glands, pituitary gland, and other vital activities.
Impairments:
* Obesity, sexual disinterest, poor temperature control, and diabetes insipidus.
Subthalamus
- regulating movement produced by skeletal m.
- Has association with the basal ganglia and substantia nigra.
Epithalamus
- pineal gland
*secretes melatonin and involved in circadian rhythm (internal clock), selected regulation of motor pathways, and emotions.
Midbrain
- large relay area for info passing from cerebrum, cerebellum, and SC
- also reflex center for visual, auditory, and tactile responses
Cerebellum
- responsible for fine tuning of movement and assists with maintaining posture and balance, controlling m tone and positioning of the extremities in space
- control ability to perform rapidly alternating movement
- Damage to one side of cerebellum will produce IPSILATERAL deficits.
- Lesion produces: ataxia, nystagmus, tremor, hypermetria, poor coordination, and deficits in postural reflexes, balance, and equilibrium.
Pons
- regulation of respiration rate and orientation of the head in relation to visual and auditory stimuli
- CN V- CV VIII
Medulla Oblongata
- influences ANS and regulates respiration and HR.
- reflex centers for vomiting, coughing, and sneezing are found in medulla.
- responsible for relaying somatic sensory information for internal organs and the control of arousal and sleep
- Damage produces contralateral impairment.
- CN IX, X, XI, XII
Anterior Cerebral Artery (ACA)
- anterior frontal lobe
- medial surface of frontal and parietal lobe
Anterior Cerebral Artery (ACA) expected possible impairment based on extent of vascular involvement
- Contralateral lower extremity motor and sensory involvement
- Loss of bowel and bladder control
- Loss of behavioral inhibition (personality changes)
- Significant mental changes
- Neglect
- Aphasia
- Apraxia and agraphia
- Perseveration
- Akinetic mutism with significant bilateral involvement
Middle Cerebral Artery (ACA) supplies
Most of outer cerebrum
* Basal ganglia
* Posterior and anterior internal capsule
* Putamen
* Pallidum
* Lentiform nucleus
Middle Cerebral Artery (MCA) expected possible impairment based on extent of vascular invovlement
- Most common site of a CVA
- Wernicke’s aphasia in dominant hemisphere
- Homonymous hemianopsia
- Apraxia
- Flat affect with right hemisphere damage
- Contralateral weakness and sensory loss of face and upper extremity with lesser involvement in the lower extremity
- Impaired spatial relations
- Anosognosia in non-dominant hemisphere
- Impaired body schema
Posterior Cerebral Artery (PCA) supplies
Most of outer cerebrum
* Basal ganglia
* Posterior and anterior internal capsule
* Putamen
* Pallidum
* Lentiform nucleus
Posterior Cerebral Artery (PCA) expected possible impairment based on extent of vascular involvement
- Contralateral pain and temperature sensory loss
- Contralateral hemiplegia (central area), mild hemiparesis
- Ataxia, athetosis or choreiform movement
Quality of movement is impaired - Thalamic pain syndrome
- Anomia
- Prosopagnosia with occipital infarct
- Hemiballismus
- Visual agnosia
- Homonymous hemianopsia
- Memory impairment
- Alexia, dyslexia
- Cortical blindness from bilateral involvement
Vertebral-basilar artery supplies
- Lateral aspect of pons and midbrain together with superior surface of cerebellum
- Cerebellum - branches from the basilar artery (posterior inferior cerebellar, anterior inferior cerebellar, and superior cerebellar arteries)
. Medulla - posterior inferior cerebellar artery, smaller branches from the vertebral arteries . Pons - branches from the basilar artery . Midbrain and thalamus - posterior cerebral arteries . Occipital cortex - posterior cerebral artery, basilar artery
Vertebral-basilar artery expected possible impairment based on extent of vascular involvement
- Loss of consciousness
- Hemiplegia or tetraplegia
- Comatose or vegetative state
- Inability to speak
- Locked-in syndrome
- Vertigo
- Nystagmus
- Dysphagia
- Dysarthria
- Syncope
- Ataxia
Wallenberg syndrome secondary to lateral medullary infarct - ipsilateral facial pain and temperature impairment, ipsilateral ataxia, vertigo, contralateral pain and temperature impairment of the body.
