Fever is defined as a measured body temperature Body Temperature The measure of the level of heat of a human or animal. Heatstroke of at least 38℃ (100.4℉). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E Prostaglandin E Three of the six naturally occurring prostaglandins. They are considered primary in that no one is derived from another in living organisms. Originally isolated from sheep seminal fluid and vesicles, they are found in many organs and tissues and play a major role in mediating various physiological activities. Eicosanoids2 in the hypothalamus Hypothalamus The hypothalamus is a collection of various nuclei within the diencephalon in the center of the brain. The hypothalamus plays a vital role in endocrine regulation as the primary regulator of the pituitary gland, and it is the major point of integration between the central nervous and endocrine systems. Hypothalamus. This process increases the physiologic “set-point” of body temperature Body Temperature The measure of the level of heat of a human or animal. Heatstroke. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions. Fever is a symptom of a wide array of diseases; therefore, an accurate history and review of other symptoms are crucial in finding the cause. The major etiologies of fever include infectious Infectious Febrile Infant (most common), non- infectious Infectious Febrile Infant, neurogenic, and drug-induced. High fever can have systemic effects that put the individual at risk of both short- and long-term dysfunction. In severe cases, fever may lead to death if untreated.
Last updated: 25 Jan, 2022
Mechanisms of fever generation
A stressor of the body (e.g., infection, injury, trauma) incites
lymphocytes
Lymphocytes
Lymphocytes are heterogeneous WBCs involved in immune response. Lymphocytes develop from the bone marrow, starting from hematopoietic stem cells (HSCs) and progressing to common lymphoid progenitors (CLPs). B and T lymphocytes and natural killer (NK) cells arise from the lineage.
Lymphocytes: Histology to
release
Release
Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane.
Virology
cytokines
Cytokines
Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.
Adaptive Immune Response which, in turn, stimulate the
hypothalamus
Hypothalamus
The hypothalamus is a collection of various nuclei within the diencephalon in the center of the brain. The hypothalamus plays a vital role in endocrine regulation as the primary regulator of the pituitary gland, and it is the major point of integration between the central nervous and endocrine systems.
Hypothalamus.
Within the
hypothalamus
Hypothalamus
The hypothalamus is a collection of various nuclei within the diencephalon in the center of the brain. The hypothalamus plays a vital role in endocrine regulation as the primary regulator of the pituitary gland, and it is the major point of integration between the central nervous and endocrine systems.
Hypothalamus, the vascular organ of lamina terminalis, or supraoptic crest (OVLT) activates cyclooxygenases (COX), which catalyzes the formation of
prostaglandins
Prostaglandins
A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes.
Eicosanoids (PGE2).
These hormone-like substances produce fever by activating cold-sensitive (CS)
neurons
Neurons
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system.
Nervous System: Histology and inhibiting warm-sensitive (
WS
WS
Williams syndrome (WS), also known as Williams-beuren syndrome (WBS), is a genetic disease caused by a microdeletion on chromosome 7. Affected individuals have a characteristic elfin facies and short stature. Cognitive, developmental, and behavioral issues are common. Additionally, cardiovascular, connective tissue, endocrine, and renal anomalies may be present.
Williams Syndrome)
neurons
Neurons
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system.
Nervous System: Histology.
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The following conditions are associated with elevated body temperature Body Temperature The measure of the level of heat of a human or animal. Heatstroke: