Поиск
Озвучить текст Озвучить книгу
Изменить режим чтения
Изменить размер шрифта
Оглавление
Для озвучивания и цитирования книги перейдите в режим постраничного просмотра.

6. TYPICAL DISORDERS OF THERMOREGULATION. FEVER

Disorders of thermoregulation derive from the readjustment of the hypothalamic thermoregulatory center or failure of the thermoregulatory physiological mechanisms to meet the environmental challenges. As a result the normal body temperature may decrease (hypothermic state) or increase (hyperthermic state). Either of these states may take several forms.

Hypothermic states

Hyperthermic states

Hypothermic reaction

Hyperthermic reaction

Hypothermia

Hyperthermia

Fever

HYPOTHERMIA

Hypothermia is arbitrarily defined as a core body temperature of 35 °C or below.

Causes of hypothermia:

 decreased heat loss, and

 inadequate heat production.

Decreased heat loss may be the result of:

 extreme environmental conditions;

 enhanced blood flow to the skin (burns, psoriasis).

Inadequate heat production may result from:

 decreased metabolism;

 altered thermoregulation;

 ingestion of certain drugs.

Patterns of fever

On the basis of the extent of temperature elevation:

 subfebrile (<38 °C during axillary measuring);

 febrile (from 38 to 39 °C);

 pyretic (from 39 to 41 °C);

 hyperpyretic (more than 41 °C).

On the basis of temperature fluctuation:

 sustained (circadian fluctuation <10 °C);

 remittent (fluctuation 1-2 °C);

 hectic (fluctuation 3 °C and more);

 intermittent (great fluctuations with falls in the morning up to normal values);

 relapsing (febrile episodes are separated by intervals of normal temperature).

Biological significance of fever:

Positive aspects:

Negative aspects:

the growth and virulence of several bacterial species are impaired

caloric and fluid requirements are increased

the phagocytic and bactericidal activity of neutrophils is increased

increased muscle catabolism leading to negative nitrogen balance

the cytotoxic effects of lymphocytes are increased

fever may produce stupor or delirium

the increase in the liver detoxication activity

stress to the fetuses

stress to the heart and the respiratory system

children are prone to fevers

fever in the first trimester of pregnancy increases the risk of neural tube defects in the fetus

HYPERTHERMIA

Hyperthermia is an elevation of body temperature above the hypothalamic set point due to insufficient heat dissipation (e.g. in association with exercise, perspiration-inhibiting drugs, or a hot environment).

HYPERTHERMIC REACTION

Hyperthermic reactions refer to changes in the hypothalamic set point in the absence of pyrogens.

Для продолжения работы требуется Registration
На предыдущую страницу

Предыдущая страница

Следующая страница

На следующую страницу
6. TYPICAL DISORDERS OF THERMOREGULATION. FEVER
На предыдущую главу Предыдущая глава
оглавление
Следующая глава На следующую главу

Table of contents

Данный блок поддерживает скрол*