诊断学课件-发热

发病机理 Pathogenesis
发病机理 Pathogenesis
➢ 致热源机制 ➢ 非致热源机制
病理生理机制
外源性致热原
（exogenous pyrogen ）
机体 产热＞散热
内源性致热原
（endogenous pyrogen）
发热
致热源性 Pyrogen
外源性致热源
通过激活 白细胞
内源性致热源
➢ Muscle activity：Exercise ➢ Age： very young> adult> elderly ➢ Others：Stress、having meal、environment
Body temperature change < 1℃/24Hr
Body temperature
如中暑
➢ 植物神经功能紊乱:
感染后低热、神经功能性低热
Non-infective fever
➢ Absorption of aseptic necrosis substance ➢ Antigen and antibody reaction ➢ Endocrine and metabolic disease ➢ Decrease of heat loss through skin ➢ Abnormity of heat regulating center ➢ Abnormal automatic nerve function
Cold stimulus
Blood cooler than set point
Body temperature
increases
Skin blood vessels constrict
Skeletal muscles activated, shivering begins
Activates heatpromoting center in
Axillary temperature Oral temperature Rectal temperature
36℃ ～37℃
36.3 ～37.2℃
36.5℃ ～37.7℃
直肠体温最准确
体温调节 Thermoregulation
Heat Production
Basal metabolism Muscular activity
发热的相关概念 发热的病因及发病机制 发热的临床表现及热型 发热的诊断及处理原则
概 述 Summary
定义 Definition
发热
是机体在内、外致热源的作用 下或由各种病因导致体温调节中枢 功能障碍，体温超出正常范围，一 般认为，口腔温度＞37.3℃、直肠温 度＞37.6℃
正常体温 Normal body temperature
通过血脑 屏障
体温调节中枢
微生物病原体 炎症渗出物 无菌坏死物、抗原抗体复合物
(不能直接作用于体温调节中枢)
白细胞致热源：白介素、肿瘤 坏死因子、干扰素
产热>散热
发热
Pathogenesis of fever
Thermoregulation center in hypothalamus
Set- point
(shivering) Thyroxine and
epinephrine Specific dynamic effect
Heat loss
Radiation Conduction Convection Evaporation
secrete perspiration sweating
Skin blood vessels dilate
hypothalamus
生理变化 Physical variation
➢ Circadian rhythm：Lowest between 2 and 6 AM;
Highest around 6 PM
➢ Sex：Women higher than men，body
temperature increases during ovulation and pregnancy phase
临床表现 Clinical manifestation
分类 Classification
病因 Etiology
infective fever：50～60%
Bacteria Viruses Mycoplasma Rickettsia Fungi Spirochete Parasite
B
O
D
Diseases
Y
非感染性发热 Non-infectiFra biblioteke fever
➢ 无菌性坏死物质吸收: 如大面积烧伤 ➢ 抗原抗体反应: 风湿病 ➢ 产热过多或散热障碍: 如甲状腺功能亢进症 ➢ 体温调节中枢功能异常的中枢性发热:
Activates heat-loss center in hypothalamus
Sweat glands activated
Body temperature
decreases
Hot stimulus
Blood warmer than set point
Homeostasis (36℃ ～37℃）
Monoluclear phagocyte
Fever
非致热源性发热
➢ 体温调节中枢直接受损：
颅脑外伤、出血、炎症
➢ 产热过多的疾病：
如癫痫持续状态、甲亢等
➢ 散热减少的疾病：
广泛性皮肤病、心力衰竭等
Fever 利与弊
？
发热的概念 发热的病因及发病机制 发热的临床表现及热型 发热的诊断及处理原则
Sympathetic nerve
Leucocyte
Lymphokines
Endogenous
pyrogen Receptors
IL-1
in skin
Blood vessels
constriction Shivering
TNF
IFN
Heat production ＞ Heat loss
Exogenous pyrogen
physiological
pathological
ovulation pregnancy
exercise
fever
hyperthermia
发热的概念 发热的病因及发病机制 发热的临床表现及热型 发热的诊断及处理原则
病 因 Etiology
病因 Etiology
感染性发热 ( infective fever ) 非感染性发热 ( non-infective fever )