广东海洋大学：《兽医内科学》课程教学课件（讲稿）Chapter 6 Diseases of the nervous system

★7Chapter6Diseases of the nervous systemVIMChapter 6 Diseases of the nervous system$Chapter Main ContentsConspectus Section 1 Encephalitis &Meningitis →Section 2 Heat stroke →Guangdong Ocean University

1 Chapter 6 Diseases of the nervous system Chapter Main Contents • Conspectus • Section 1 Encephalitis & Meningitis • Section 2 Heat stroke Chapter 6 Diseases of the nervous system

ZChapter6Diseases of thenervous systemVIM$ConspectusComposition:Thenervoussystemiscomposed of billions of neuronS神经元 withlong,interconnectingprocessesthatform complex integratedelectrochemical circuits.It is throughtheseneuronalcircuitsthatanimalsexperience sensations and respondappropriately.Guangdong Ocean University

2 Conspectus The nervous system is composed of billions of neurons神经元 with long, interconnecting processes that form complex integrated electrochemical circuits. It is through these neuronal circuits that animals experience sensations and respond appropriately. Chapter 6 Diseases of the nervous system

★ Chapter 6Diseases of thenervous systemVIMComposition---ContinuedNeuronal processes that transmit electrical alterations to the cellbody are called dendrites树突. Dendrites have receptor sites thatreceive stimulation or inhibition from outside sources. If electricalstimulation of the cell body reaches a critical threshold, anelectricaldischargecalledanactionpotential动作电位develops.Theaction potential spontaneouslytravels away fromthe cellbody along an outgoing process called an axon轴突. When theaction potential reaches the terminal branches of the axon,chemicalscalledneurotransmitters神经递质arereleased.Neurotransmitters either stimulate or inhibit receptor sites onother neurons, muscles, or glandsGuangdong Ocean University

3 l Neuronal processes that transmit electrical alterations to the cell body are called dendrites树突. Dendrites have receptor sites that receive stimulation or inhibition from outside sources. If electrical stimulation of the cell body reaches a critical threshold, an electrical discharge called an action potential动作电位develops. The action potential spontaneously travels away from the cell body along an outgoing process called an axon轴突. When the action potential reaches the terminal branches of the axon, chemicals called neurotransmitters神经递质 are released. Neurotransmitters either stimulate or inhibit receptor sites on other neurons, muscles, or glands. Chapter 6 Diseases of the nervous system

ZChapter6Diseases ofthenervous systemVIM中间神经元传入神经元传出神经元反射（反射弧）感受器→传入神经元效应器→中枢一→传出神经元感受器→效应器Guangdong Ocean University

4 Chapter 6 Diseases of the nervous system 反射（反射弧） 感受器→传入神经元 →中枢→传出神经元 →效应器

★7Chapter6Diseases of the nervous systemVIMMechanismsofDisease> Infections of the nervous system are due to specific virusesfungi,protozoa, bacteria, and algae.Nonspecific inflammationssuch as steroid类固醇-responsivemeningoencephalomyelitis脑膜脑脊髓炎 may be immune-mediated.≥ Toxicity of the nervous system is caused by organophosphates,pyrethrins拟除虫菊酯，carbamates氨基甲酸酯，andsedatives镇静剂.Metabolic alterations of nervous system function most commonlyresultfromhypoglycemia低血糖，hypoxiaoranoxia(组织)缺氧，hepatic dysfunction, hypocalcemia, hypomagnesemia,hypernatremia高钠血症，hypokalemia，anduremia尿毒症》Thiamine硫胺素(VB1)deficiencyresults inataxia共济失调，stupor恍，and coma or seizures突发(蜷缩) in dogs, cats, and cattle.Guangdong Ocean University

5 uMechanisms of Disease Ø Infections of the nervous system are due to specific viruses, fungi, protozoa, bacteria, and algae. Nonspecific inflammations such as steroid类固醇-responsive meningoencephalomyelitis脑膜脑脊 髓炎 may be immune-mediated. Ø Toxicity of the nervous system is caused by organophosphates, pyrethrins拟除虫菊酯, carbamates氨基甲酸酯, and sedatives镇静剂. Ø Metabolic alterations of nervous system function most commonly result from hypoglycemia低血糖, hypoxia or anoxia(组织)缺氧, hepatic dysfunction, hypocalcemia, hypomagnesemia, hypernatremia高钠血症, hypokalemia, and uremia尿毒症. Ø Thiamine硫胺素(VB1) deficiency results in ataxia共济失调, stupor恍惚, and coma or seizures突发(蜷缩) in dogs, cats, and cattle. Chapter 6 Diseases of the nervous system

ZChapter6Diseases of the nervous systemVIMNeurologic ExaminationsTheneurologicexaminationconsistsofevaluation of the following: 1) the head, 2)thegait运步态，3)theneckandthoraciclimbs胸肢，and 4)the trunk躯干，anuS肛门,and tail.Initially,anattemptshouldbemadetorelateall deficits缺损toafocal anatomiclesion.GuangdongOcean University

6 uNeurologic Examinations • The neurologic examination consists of evaluation of the following: 1) the head, 2) the gait运步态, 3) the neck and thoracic limbs 胸肢, and 4) the trunk躯干, anus肛门, and tail. • Initially, an attempt should be made to relate all deficits缺损 to a focal anatomic lesion. Chapter 6 Diseases of the nervous system

7Chapter6Diseases of thenervous systemVIMClinical PathologyAbnormalities of serum glucose, liver enzymes, BUN血液尿素氮,bile acids,ammonia,electrolytes,or blood gases can occurwith metabolic dysfunctions.Serum cholinesterase胆碱酯酶 is2014/03/1721:58Guangdong Ocean University

7 uClinical Pathology • Abnormalities of serum glucose, liver enzymes, BUN血液尿素氮, bile acids, ammonia, electrolytes, or blood gases can occur with metabolic dysfunctions. Serum cholinesterase胆碱酯酶 is decreased in acute organophosphate toxicity, and serum lead determinations are increased in lead toxicity. Serum thyroid甲状 腺 and cortisol皮质醇 determinations and stimulation tests are useful to detect endocrinopathies. • Computed tomography (CT) and magnetic resonance imaging (MRI) scans are useful to evaluate lesions of the brain and spinal cord in small animals. Chapter 6 Diseases of the nervous system

ZChapter6Diseases of thenervous systemVIMPrinciples of Therapy· Status epilepticus瓣痛持续状态 in dogs and catsmay be interrupted by diazepam安定, given at 0.5mg/kg (not to exceed 10 mg at one time), IV. Sodiumpentobarbital戊巴比妥 to effect, not to exceed 3-15mg/kg, IV, may also be used, followed by phenobarbital at 2-4抗惊厥药（如咪达mg/kg, IM, every 6 hr. Oral anticonvulsants唑仑) should be resumed as soon as possible ifcurrently being given.Guangdong Ocean University

8 uPrinciples of Therapy • Status epilepticus癫痫持续状态 in dogs and cats may be interrupted by diazepam 安定 , given at 0.5 mg/kg (not to exceed 10 mg at one time), IV. Sodium pentobarbital戊巴比妥 to effect, not to exceed 3-15 mg/kg, IV, may also be used, followed by phenobarbital at 2-4 mg/kg, IM, every 6 hr. Oral anticonvulsants抗惊厥药(如咪达 唑仑) should be resumed as soon as possible if currently being given. Chapter 6 Diseases of the nervous system

Chapter6Diseases ofthenervoussystemVIMNursing CareAnimals with paraplegia截瘫 and quadriplegia四肢瘫痪 needintensivenursingcareThe animal should be maintained on padding and turned every4-6 hr to avoid decubital ulcers褥疮. The bladder must beexpressed or catheterized every 6-8 hr. Urine must be monitoredforevidence of cystitis.The skin must be kept clean and free of urine and feces toprevent dermatitis皮炎.Quadriplegic animals may need to be hand fed nutritious foodand given plenty of water.Manual extension and flexion of jointsandmusclemassagewillhelpdelaycontractures痉挛andmuscleatrophy in paralyzed limbs.GuangdongOcean University

9 uNursing Care Ø Animals with paraplegia截瘫 and quadriplegia四肢瘫痪 need intensive nursing care. • The animal should be maintained on padding and turned every 4-6 hr to avoid decubital ulcers褥疮. The bladder must be expressed or catheterized every 6-8 hr. Urine must be monitored for evidence of cystitis. • The skin must be kept clean and free of urine and feces to prevent dermatitis皮炎. • Quadriplegic animals may need to be hand fed nutritious food and given plenty of water. Manual extension and flexion of joints and muscle massage will help delay contractures痉挛 and muscle atrophy in paralyzed limbs. Chapter 6 Diseases of the nervous system

Chapter6Diseasesofthenervous systemVIMSection 1 Meningitis& EncephalitisInflammation of the meninges (meningitis)andLinflammation of thebrain(encephalitis)oftenareseensimultaneously (meningoencephalitis脑膜脑炎) in the sameanimal, although either can be seen separatelyCauses of meningitis,encephalitis,and meningoencephalitis includebacteria,viruses,fungi,protozoa,parasitemigrations,chemical agents,and idiopathic先天的or immune-mediated diseases.10Guangdong Ocean University

10 Section 1 Meningitis & Encephalitis u Inflammation of the meninges (meningiti s ) and inflammation of the brain (encephalitis) often are seen simultaneously (meningoencephalitis脑膜脑炎) in the same animal, although either can be seen separately. • Causes of meningitis, encephalitis, and meningoencephalitis include bacteria, viruses, fungi, protozoa, parasite migrations, chemical agents, and idiopathic先天的 or immune-mediated diseases. Chapter 6 Diseases of the nervous system