Ch. 12 - CNS
What brain lobe is deep to the others?
Insulas
What is the function of the occipital lobe?
Processing of visual information
What are Golgi Tendon organs?
Mechanoreceptors in tendons near muscle-tendon junctions that monitor muscle tension.
What type of receptor detects pain stimuli?
Nociceptor
What is the difference in how gray & white matter are organized in the brain & spinal cord?
Gray matter is, generally, on the superficial parts of the brain & is deep in the spinal cord.
White matter is deep in the brain & superficial in the spinal cord.
What do the spinocerebellar tracts do?
Carry proprioceptive stimuli up the spinal cord to the cerebellum.
What functional class of neurons would you expect to find in the posterior root ganglion of a spinal nerve?
Afferent (Sensory); anterior root is efferent
What is the difference between upper and lower motor neurons?
Upper motor neurons are in the primary motor cortex of the cerebrum to make the "decision" for movement.
Lower motor neurons release acetylcholine (ACh) onto muscle fibers to initiate contraction.
What are the parts of the brain of an early embryo?
Forebrain, Midbrain, Hindbrain
How do sensory pathways differ from effector (muscle/gland) pathways?
Sensory pathways have: first-order neuron (detects stimulus), second-order neuron (interneuron spinal cord/brainstem), third-order neurons (interneuron that connects to cerebral cortex)
Effector pathways have: upper motor neuron in cerebral cortex & lower motor neuron that synapses directly with muscle/gland.
Which does the vestibulocochlear nerve do?
Vestibulo-: Help maintain balance
Cochlear: Hearing
A patient with "lazy eye" (amblyopia) could be having an issue with what?
Oculomotor nerve (III)
What are the main types of memory?
Declarative - Readily available to consciousness & can be loudly expressed
Nondeclarative - Procedural or skill
Immediate - Few seconds
Short-term (Working) - Several minutes
Long-term - More permanent (days, weeks, lifetime)
How do spinal meninges differ from cranial meninges?
Spinal dura mater lacks a periosteal layer & only has a meningeal layer.
Spinal pia mater helps anchor the spinal cord to the vertebral cavity; cranial pia mater doesn't anchor the brain to anything.
Spinal pia mater have outward extensions that attach to the spinal dura called denticulate ligaments.
The anterior root of a spinal nerve would be associated with which divisions of the PNS?
Somatic Motor
Autonomic Nervous System (ANS)/Visceral Motor
How are individual neurons organized into spinal nerves?
Multiple neurons, each individually wrapped by endoneurium, are bundled together & wrapped by a perineurium to form a fascicle.
Multiple fascicles & some blood vessels are bundled together & wrapped by an epineurium to form a nerve.
What structures within the skull help protect the brain and how?
Cranial Meninges are membranes that surround the brain to help provide physical protection & support. Also circulates CSF.
Cerebrospinal fluid (CSF) surrounds the brain to reduce its buoyancy (prevent the brain from being crushed) & removes wastes.
Blood brain barrier - Astrocytes surrounding blood vessels control what substances enter or leave the brain tissue.
In the process of falling asleep, what happens after neurons in the eye detect decreasing light levels?
The suprachiasmatic nucleus (SCN) it synapses with will trigger melatonin production from the epithalamus.
The melatonin will decrease activity of the SCN & cerebral cortex.
Decreased SCN activity will cause areas of the reticular formation to be suppressed that promote wakefulness & lead to sleep.
How does the pathway of the stimulus in the simple stretch reflex differ from that of the flexion & crossed-extension spinal reflex.
In the simple stretch reflex, the afferent neurons synapse directly to efferent motor neurons.
In the flexion & crossed-extension spinal reflex, the afferent neurons synapse with interneurons, located within the spinal cord, which then synapse with motor neurons.
Why might a patient having a heart attack perceive pain in the anterior chest wall & left arm?
Via referred pain; many spinal nerves carry both first-order somatic & visceral sensory neurons, where stimuli in the different types of neurons could travel together.