Chapter 8 - Central Nervous System Flashcards
The [] within the brain and spinal cord are in a position to associate appropriate motor responses with sensory stimuli, and thus to maintain homeostasis in the internal environment and the continued existence of the organism in a changing external environment.
Association Neurons
- What are the cavities of the brain and spinal cord called?
- What are these cavities filled with?
- Brain = Ventricles, Spinal Cord = Central Canal
- Cerebrospinal fluid (CSF)
These thin structures protruding into the ventricles form CSF through diffusion and active transport, keeping CSF at a constant composition that is slightly hypertonic with some ions floating around.
Choroid Plexuses
What is a grouping of grey matter deeper than the cortex called?
Nuclei
- Which portion of the brain is the largest portion of the brain and primarily responsible for higher mental functions?
- This portion has 2 spheres, what axon tract connects the 2 spheres?
- Cerebrum
- Corpus Callosum
What are the elevated folds of convolutions called, what are the depressed grooves of convolutions called?
Gyri
sulci
What are the 5 Lobes of the Cerebrum (4 visable, 1 covered up)
- Frontal
- Parietal
- Occipital
- Temporal
- Insula (covered up)
The frontal and parietal lobes are “split” by 2 fissures. One helps control motor function, the other helps with sensory reception. What are these 2 zones called?
- Precentral gyrus - helps with motor control
- Postcentral gyrus - helps with sensory reception
Where are upper motor neurons found? Why is this called the somatosensory cortex?
- Precentral Gyrus of the central sulcus.
- It is not, the precental gyrus is considered the “motor cortex” since it is involved in helping with motor control.
What 2 fissues make up the Central Sulcus? Which fissue is part of the temporal lobe?
- Precentral Gyrus and Postcentral gyrus
- Neither. The Precentral is located in the frontal lobe before the central sulcus and the Post central is located in the parietal lobe behind the central sulcus
Which portion of the brain contains the somatosensory cortex, or the primary area responsible for sensations arising from cutaneous, muscle, tendon and joint receptors.
PostCentral Gyrus of the central sulcus
Briefly list the functions of the Frontal Lobe
- voluntary motor control of skeletal muscles
- Personality
- Higher intellectual processes (concentratoin, decision making)
- verbal communication
Briefly list the functions of the Parietal Lobe-
- Somatesthetic Interpretation
- cutaneous and muscular sensations
- Understanding Speech
- Formulating words to express thoughts and emotinos
- Interpretation of textures and shapes
Briefly list functions of the Temporal Lobe-
- Interpretation of auditory sensations
- Memory storage of auditory and visual experiences
Briefly list functions of the Occipital Lobe
- integration of movements in focusing the eye
- correlation of visual images
- Conscious perception of vision
Briefly list functions of the Insula Lobe -
- Memory
- Sensory (pain) - and the visceral response
This lobe receives olfactory, gustatory (taste), auditory, and somatosensory information, and helps control autonomic responses to the viscera and cardiovasular sysem
Insula Lobe
Where are the basal nuclei/ganglia found?
- Underneath a lot of white matter in the cerebrum
- Kind of near the motor cortex of the precentral gyrus
What circuit are the basal nuclei apart of that allows intedned movements to occur and inhibit unintended movements?
What is a brief outline of the circuit?
- A motor circuit
- Motor cortex (precentral gyrus) axons –> Basal nuclei –> Thalmus sends excitatory neurotransmitters –> motor area of cerebral cortex….causing movement
What is aphasias?
speech and laguage disorders caused by damage to the brain through head injury or stoke.
This Gyrus is believed to be a center for the integration of auditory, visual, and somatesthetic information? (Gyrus is located in an area that starts with a W!)
Angular Gyrus
Which portions of the brain are the neural basis of emotional states?
hypothalmus
Limbic system
Give a brief outline of the Papez circuit in the limbic system ….
- The fornix (fiber tract) connects –> hippocampus to the mammillary bodies of hypothalamus, this projects to the –> anterior nuclei of the thalamus…which send fibers to the cingulate gyrus….which finishes circuit by sending fibers to the —> hippocampu.
What are 5 feelings/behaviors that the limbic system is in charge of?
- Aggression
- Fear
- Feeding
- Sex
- Goal-directed behavior
Long-term memory depends on the synthesis of new [] and [], so that drugs that disrupt genetic transcription or translation intergere with long-term memory.
RNA and Proteins
Which part of the brain is important to consolidate recent memories into long-term memory (but may not be needed for storage or retention of these long-term memories.)
hippocampus
What two sections, primarily make up the “medial Temporal Lobe” and are involved in memory…
Hippocampus
Amygdala - memory of fear response!
Which receptor for glutamate is central in the formation of memories that depend on the hippcampus (LTP)?
NMDA
Why does calcium concentration in a post-synaptic cell matter for Long-Term potentiation?
- Increased Ca2+ concentration, will activate more CaMKII –> phosyphorylate more proteins in post synaptic membrane, allowing more AMPA Na+ channels into membrane –> increased permeability to Na+—> bringing in even more Ca2+
- This allows the synapse to act even quicker between pre and post.
If a endocannabinoid is released from a postsynaptic neuron via a depolarization, and it goes to inhibit the release of GABA at another inhibitory synapse….what is this called?
Depolarization - induced suppression of inhibition
The hypothalamus controls a lot of shit. Try to name them all from the book:
- contains neural centers for hungr and thirst
- regulation of body temperature
- regulation of hormone secretion from pituitary gland
- Regulation of sleep, wakefullness, sexual arousal and performance
- Emotions like - anger, fear, pain, pleasure
- Works with the limbic system to do all this.
Which portion of the brain acts primarily as a relay center through whcih all sensory infromation (except smell) passes on its way to the cerebrum?
Thalamus
Chronic stimulation of the lateral hypothalamus will cause a rat to what?
Stimulation of the medial hypothalamus Causes a rat to what?
- Eat and become obese
- Inhibits eating
Which neurons create the hormones - ADH and oxytocin - created?
Where are these hormones stored?
How are the released?
- Supraoptic, paraventricular
- Neurohypophysis (posterior pituitary)
- Hypothalamic stimulation
The hypothalamus also contains these [] that can stimulate thirst or relase of [] from teh posterior pituitary
- osmoreceptors
- ADH - antidiuretic hormone (retention of water from urine)
How does the Thalamus regulate the secretions of the anterior pituitary?
- The Thalamus does not regulate the anterior pituitary…the hypthalamus does
- The hypothalamus neuclei produce hormones known as releasing hormones and inhibiting hormones.
- These hormones are transported to the anterior pituitary by blood and then regulate what the adenohypophysis (anterior pituitary) secretes
What is the Suprachiasmatic Nuclei? Where are they located?
What do they do?
- Located in anterior hypothalamus. Functions as the master regulator of the body’s circadian rhythems
- physiological processes - metabolism, sleep, body temp, blood pressure, hormone secretion - that repeat approximately every 24 hours.
How is the midbrain involved in motor coordination?
- The nigrostriatal system projects from the substantia nigra to teh corpus striatum of the basal nuclei
- degradation of these fibers that produces Parkinsons
How does the midbrain control goal-directed behavior?
- The VTA (ventral tegmental area) a dopaminergic neuron, part of the mesolimbic system, projects dopaminergic input to the limbic system.
- Implicated in drug addiction…
- VTA can also project dopaminergic shit to the nucleus accumbens.
The Pons have several cranial nerves - try them
- Trigeminal (V)
- Abducens (VI)
- Facial (VII)
- Vestibulocochlear (VIII)
The Pons cooperate with the medulla oblongata to regulate breathing…what are the two respiratory control centers in the pons known as??
- Apneustic
- pneumotaxic
- This portion of the brain……[]
- receives input from proprioceptors (joints, tendons, and mescle recepts) and works with basal nuclei and cerebral cortex to coordinate movement
- 2nd [] structure of the brain
- Several fiber tracts connect it with the pons, medulla oblongata, and spinal cord
Cerebellum
largest
What kind of effects does the cerebellum cause onto the motor area of the cerebral cortex? Why?
- Inhibitory effects
- The cerebellum helps coordinate complex motor skills by inhibiting the motor areas of the cerebral cortex…so the cerebral cortex doesnt go crazy!
- balance, posute
- muscle tone
- Eye movement
- Skilled movements basically
What type of neurons provide the only out from the cerebellum?
Purkinje Cells
Ataxia (fill in the blank) is characteristic of what type of disorders?
Loss of [], resulting in disorders of gait, balance, eye movements, []
- Cerebellum disorders
- coordination, swallowing
All of the descending and ascending fiber tracts that provide communication between the spinal cord and the brain must pass through……
The medulla Oblongata
The medula contains groupings of neurons required for regulation of breathing and cardiovascular response: 3 of them, what are they called?
- Vasomotor Center - autonomic innervation of blood vessels
- Cardiac Control Center - regulates autonomic nerve control of heart
- Respiratory Center - work with centers in the pons to control breathing.
The grey matter of the spinal cord forms an H with 2 types of “canals” called….
- dorsal horns
- Ventral horns
Ascending spinal tracts are usually what type of neurons?
What is their prefix and ending?
- Sensory
- prefix - spino…ending is whatever part of the brain the spinal cord fibers first synaps
- Ex: anterio spinothalamic
Descending Spinal Tracts are usually what kind of neurons?
What is their suffix and prefix?
- Motor neurons
- Prefix - denotes region of brain that gives rise to fibers…..suffix - spinal
- Ex: lateral corticospinal
- beings in cerebral cortex
- Ex: lateral corticospinal
How many total spinal nerves?
- 62……31 pairs.
How many nerves?
Cervical
Thoracic
Lumbar
Sacral
Coccygeal
- Cervical - 8 pairs
- Thoracic - 12 pairs
- Lumbar - 5 pairs
- Sacral - 5 pairs
- Cocygeal -1 pair
In spinal nerves -
The dorsal root is composed of [] fibers
The ventral root is composed of [] Fibers
- Dorsal - sensory
- Ventral - motor
Where are the cell bodies of a sensory neuron located along the ventral root of the spinal cord?
- They are not located on teh ventral root!
- Dorsal Root ganglion - an enlargement of the dorsal root, contains the cell bodies of sensory neurons
What is a basic reflex arc?
- Stimulation of sensory receptor
- Action potentials are conducted into spinal cord along Afferent neurons
- Sensory neuron interacts with interneuron which synapses with a motor (somatic) neuron.
- Somatic motor neuron conducts impulse out of spinal cord to muscle and stimualtes a refelx contraction
What is a mixed nerve composed of?
sensory and motor fibers
What is decussation?
Crossing over….so like the left part of your brain controls/regulated/receives input from the right hand or right side of the body.
What are the primary functions of the Cerebral Cortex?
- Voluntary control of movement
- Sensory perception
- Language
- Personality traits
- Sophisticated mental events, such as thinking, memory, decision making, creativity, and self-consciousness
What are the primary functions of the Basal Nuclei
- Coordination of slow, sustained movements
- Inhibition of muscle tone
- Suppression of useless patterns of movement
What are the primary functions of the Thalamus?
- Relay station for all synaptic input
- Crude awareness of sensation
- Some degree of consciousness
- Role in motor control
What are the primary functions of the Hypothalamus?
- Regulation of many homeostatic functions, such as temperature control, thirst, urine output, and food intake
- Extensive involvement with emotion and basic behavioral patterns
- Important link between nervous and endocrine systems
What are the primary functions of the Limbic System?
- Basic emotional expression
- Learning
- Motivation
- Sociosexual behavioral patterns
What are the primary functions of the cerebellum?
- Regulation of muscle tone
- Maintenance of balance and posture
- Coordination and planning of skilled voluntary muscle activity
- Control of eye movements
What are the primary functions of the Brain Stem (pons, midbrain, medulla)?
- Reception and integration of all synaptic input from spinal cord
- Arousal and activation of cerebral cortex
- Sleep centers (pons)
- Cardiovascular control center (medulla)
- Respiratory centers (Medulla & Pons)
- Centers for many digestive activities, such as swallowing, salivation, and vomiting. (Medulla)
- Origin of majority of peripheral cranial nerves
- Regulation of muscle reflexes involved with equilibrium and posture
- Modulation of pain sensation
