NU 545 Unit 2 Questions With Complete Solutions.

NU 545 Unit 2 Questions With Complete Solutions. Review the anatomy of the brain. Which portion is responsible for keeping you awake, controlling thought, speech, emotions and behavior, maintaining balance and posture? - ANSWER Broca Area in the inferior frontal lobe (Brodmann areas 44, 45) is an important center for speech and language processing. This area, rostral to the inferior edge of the premotor area (Brodmann area 6) o the inferior frontal gyrus, is usually most important in the left hemisphere. Injury to this area results in difficulty forming or inability to for words (expressive aphasia or dysphasia). Know the function of the arachnoid villi. - ANSWER The arachnoid villi protrude from the arachnoid space, through the dura mater, and lie within the blood flow of the venous sinuses. The villi function as one-way valves directing CSF outflow into the blood but preventing blood flow into the subarachnoid space. Thus CSF is formed from the blood and, after circulating throughout the CNS, it returns to the blood. Where is the primary defect in Parkinson's disease and Huntington's? - ANSWER Substania nigra (of the midbrain) synthesizes dopamine. The dysfunction of dopamine neurons is associated with PD and huntington's What is the function of the CSF? Where is it produced? Where is it absorbed? - ANSWER Cerebrospinal fluid (CSF) is a clear, colorless fluid similar to blood plasma and interstitial fluid. The intracranial and spinal cord structures float in CSF and are thereby partially protected from jolts and blows. The buoyant NU 545 Unit 2 Questions With Complete Solutions properties of the CSF also prevent the brain from tugging on meninges, nerve roots, and blood vessels. The chroid plexuses are the structures that produce CSF; they arise from the pia mater. The arachnoid villi reabsorb the CSF Review blood flow to the brain. eBook key search term: "blood supply to the brain - ANSWER The brain receives approximately 20% of the cardiac output, or 800 to 1000 mL of blood flow per minute. Carbon dioxide serves as a primary regulator for blood flow within the CNS. It is a potent vasodilator in the CNS, and its effects ensure an adequate blood supply. The brain derives its arterial supply from two systems: the internal carotid arteries (anterior circulation) and the vertebral arteries (posterior circulation) (Fig. 15.20). The internal carotid arteries supply a proportionately greater amount of blood flow. They originate at the common carotid arteries, enter the cranium through the base of the skull, and pass through the cavernous sinus. After entering the skull, these arteries divide into the anterior and middle cerebral arteries (Fig. 15.21). The vertebral arteries originate at the subclavian arteries and pass through the transverse foramina of the cervical vertebrae, entering the cranium through the foramen magnum. They join at the junction of the pons and medulla oblongata to form the basilar artery. The basilar artery divides at the level of the midbrain to form paired posterior cerebral arteries What is the gate control theory of pain? - ANSWER Gate control theory (GCT) integrates and builds upon features of the other theories to explain the complex multidimensional aspects of pain perception and pain modulation. Pain transmission is modulated by a balance of impulses conducted to the spinal cord where cells in the substantia gelatinosa function as a "gate." The spinal gate regulates pain transmission to higher centers in the CNS. Large myelinated A-delta fibers and small unmyelinated C fibers respond to a broad range of painful stimuli (mechanical, thermal, and chemical). These fibers terminate on interneurons in the substantia gelatinosa (laminae in the dorsal horn of the spinal cord) and "open" the spinal gate to transmit the perception of pain. Closure or partial closure of the spinal gates can occur from nonnociceptive stimulation (i.e., from touch sensors in the skin) carried on large A-beta fibers decreasing pain perception.