CNS Flashcards
Describe a general reflex
an involuntary and nearly instantaneous movement in response to a stimulus
What is found between a sensory and motor neuron in a polysynaptic reflex?
interneurons
What is CSF and how is it produced? Where is it produced?
- Floats and cushions CNS, thereby preventing injury, Provides nutrients, removes wastes from CNS
- Produced by ependymal cells of the capillary-rich choroid plexus
How is CSF returned to blood circulation?
Filtrate moves through ependymal cells, into ventricles
Describe the flow of CSF through the ventricles and passageways within/around the brain’s?.
- Produced by filtration of plasma from blood capillaries in pia mater
- Filtrate moves through ependymal cells, into ventricles
- Some CSF enters central canal (spinal cord)
Most CSF enters subarachnoid space, bathing brain and spinal cord surfaces - CSF continuously produced by filtration of blood plasma
What is hydrocephalus? Why does a baby’s head swell and not an adult’s?
CSF is overproduced and/or not removed properly
Increased intracranial pressure causes brain damage
- their skull bones have not fully grown together yet.
What is meningitis? What can cause it?
Inflammation of meninges, often by infection (viral or bacterial)
What are ways that the CNS is/has been studied?
- Study brain damage
- fMRI: blood flow
- PET: glucose utilization
List, from superficial to deep, the meninges
Dura mater
Arachnoid mater
Pia mater
What is a subdural hematoma? Where is it located?
In the Subdural space between dura mater and arachnoid mater it fills with fluid from disease or trauma
What kinds of cell junctions help form the blood brain barrier
Astrocytes
Which kinds of substances can cross the BBB?
Lipid soluble substances
What forms “white matter”? What forms “gray matter”? How does this vary between the brain
and the spinal cord?
White: myelinates axons
Gray: Dendrites, Cell bodies, Glial cells, Unmyelinated axons
Spinal cord: Outer white matter is fiber tracts, Inner gray matter
The gray matter in the brain is called ______ and ______. The white matter in the brain is called
__________.
- cerebral cortex and basal ganglia
- nuclei
What do these secondary vesicles develop into?
* Metencephalon
* Myelencephalon
* Diencephalon
* Telencephalon
* Mesencephalon
- Pons and Cerebellum
- Medulla oblongata
- thalamus, hypothalamus, epithalamus
- Cerebral hemisphere
- Mid brain: fiber tracts, superior and inferior colliculi
Name two primary functions of the temporal lobe
Primary auditory cortex: Conscious awareness of sound
Auditory association area: Evaluation of sound
What would happen if damage to Wernicke’s area occurred?
Would not be able to recognize spoken words
Which lobe has the primary olfactory cortex?
Temporal Lobe
Why do some smells elicit memories?
Scents bypass the thalamus and go straight to the brain’s smell center, known as the olfactory bulb. The olfactory bulb is directly connected to the amygdala and hippocampus
What are the functions of association areas?
receive and integrate info from multiple areas; stores memories, assist with coordinated responses
What are the different types of processing areas of the cerebral cortex?
- Sensory areas (interpret sensory information coming into brain)
- Motor areas (dictate motor responses)
- Association areas
Damage to Broca’s area could result in:
Would not be able to speak
What are functions of the somatosensory association area? Premotor cortex?
Receives input from somatic sensory receptors of body (touch, pressure, vibration, pain, temperature)
What are functions of prefrontal cortex? What would damage to this area cause?
Functions: Processes emotions related to personal and social interactions, Personality, Working memory for object, recall tasks, Cognition , Solving complex, multitask problems, Intellect
Damage: mental and personality disorders
What are some functions of the insula? Where is it located?
Receives sensory input (pain, pressure, hunger, etc.) from thoracic and abdominal organs, Involved with the processing of emotions, Self-recognition
Located “under” other lobes
What are some functions of the basal nuclei? How are they related to Parkinson’s disease?
Functions: Work with cerebral cortex to control motor movements, Allow for unconscious control of skeletal muscles = muscle tone, Starts, stops, and regulates intensity of movements
Parkinson’s: Difficulty starting and controlling movement. neural pathways from substantia nigra to basal nuclei degenerates
What are some functions of the basal forebrain nuclei? How are they involved with Alzheimer’s
disease?
Functions: Arousal, Learning and memory, Motor control
Alzheimer’s: Reduced acetylcholine, Loss of memories, Language skill deterioration, Reduced abstract thinking, judgement, Changes in personality and emotion
Where are the cell bodies of visceral and somatic sensory neurons located? Somatic motor
neurons? Visceral motor neurons?
Visceral: Cell bodies from lateral horns exit through ventral root
Somatic: Cell bodies are in ventral horns Axons exit via ventral root
What are structures of the limbic system? What is a primary function of the limbic system?
What significance does the hypothalamus have with the limbic system?
found in the cerebrum and diencephalon
Considered the emotional brain
Hypothalamus: Reason why emotional stress can cause high blood pressure and heart burn
Name 3 structures of the diencephalon and function(s) for each
Thalamus: Relay center for most sensory information to cerebral cortex
Hypothalamus: hunger, body temp, smooth cardiac
Epithalamus: Secretes melatonin
What is a stroke? What happens to brain tissue with a stroke?
Interruption of blood flow to a region of the brain resulting in neuronal cell death
What could result if damage to the medulla oblongata occurred?
Automatic BSL functions would not happen (heart rate, blood pressure, breathing)
What kind of information travels through descending pathways? Ascending pathways?
Ascending: carry sensory information from the body, like pain
Descending: carry motor information from the brain down the spinal cord to the body
What is a decussation and why is it significant?
fibers cross over from right to left lobes or vice versa. significant for brain communication
Where do sensory neurons synapse in the spinal cord? What kind of neuron do they synapse with?
