CD 422 Exam 1

• a neurogenic communication disorder is a communication difficulty that stems from the brain.
• aphasia is an acquired communication disorder caused by brain damage; characterized by an impairment of language modalities such as speaking, listening, reading, and writing.

  • most commonly occurs following a stroke.
• early terms used to describe aphasia included aphonia, speech amnesia, and aphemia. we still use the term "aphonia" today, as it is now related to voice difficulty.
• the localizationist approach to aphasia views specific function to specific anatomic structure within the brain; lesions in specific areas affect particular functions.
• the holistic approach to aphasia advocates that the brain functions as an integrated unit and that a lesion in one area affects functions of most, if not all areas.
• the cognitive approach argues that aphasia is not limited to impaired language, and can cause intellectual and cognitive deficits.
• neurons are the basic building block of the nervous system. also known as nerve cells, they allow for the transmission of information.
• the cell body contains the nucleus and cytoplasm.
• the dendrites extend from the cell body and receive information from axons to transmit to the cell body.
• axons are a single, long nerve fiber that originates from the cell body, carrying messages away from the cell body.
• dendrites are classified as afferent.
• axons are classified as efferent.
• neurotransmitters are chemical compounds within the axon terminal buttons that help transmit info across the synaptic space.

  • can excite or inhibit the next neuron.
  • three main types: amino acides, amines, peptides
  • most common ones include Ach, GABA, glutamate
• motor nerves cause muscle contraction/glandular secretion, and are classified as efferent.
• sensory nerves carry information from the peripheral sense organs towards the brain, and are classified as afferent.
• glial cells are non-neuronal cells of the nervous system that provide structural framework for the neural cells. they outnumber neural cells 5:1, and they DO NOT transmit nerve impulses.
• the PNS consists of the cranial nerves, spinal nerves, and the autonomic nervous system.
• the sympathetic branch of the ANS activates the fight or flight under stressful situations.
• the parasympathetic branch of the ANS calms the body down after fight or flight ends.
• the CNS contains the brain and spinal cord.
• the medulla is the lowest part of the brainstem, and includes centers that control digestion, breathing, blood pressure, and heart rate.
• the pons allows for connections to the cerebellum, and is concerned with hearing and balance.
• the midbrain controls many sensory and motor functions.
• the diencephalon includes the thalamus and the hypothalamus.
• the thalamus integrates sensory information and relays it to cortical areas.
• the basal ganglia inhibits involuntary movement and controls movement by producing neurotransmitters.
• often referred to as the "little brain," the cerebellum coordinates and monitors the force/range of body movement.
• projection fibers connect cortical structures with the brain stem and spinal cord.
• association fibers connect areas within one hemisphere.
• the arcuate fasciculus connects Broca's area with Wernicke's area in the left hemisphere.
• commissural fibers connect two corresponding areas of two hemispheres (i.e., the corpus callosum)
• also known as the neocortex, the cerebrum is responsible for all higher brain functions.
• the pia is the thinnest, innermost layer of the meninges.
• the arachnoid is the weblike middle layer of the meninges, and is separated from the pia with the CSF-filled subarachnoid space.
• the dura is the strongest, most external layer of the meninges, and is directly adhered to the skull.
• the internal carotid artery is the major blood supplier to the brain, branching into the ACA and MCA.
• the vertebral arteries merge to form the basilar artery, which divides into two PCAs.
• blockage below the circle of willis does minimal damage
• blockage above the circle of willis does significant damage.
• electroencephalography tracks the brain waves of the cerebral cortex.