Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different.When pathogens invade the body, cytokines produced as a result cause the hypothalamus to reset the body temperature by increasing the body's setpoint.The increase in set-point causes a feeling of cold or chills and triggers increased muscle contractions. This results in greater heat production and efforts to conserve heat.Most pathogens reproduce best at about 37°C.The specific immune response works best at higher temperatures.Fevers start at about 38°C and are usually below 40°C. Extremely high fevers can raise the body temperature to 41°C-42°C.
Read the text
Read the text and highlight anything you think is important. When you go on, the text is hidden and you answer from memory.
Specification: OCR Biology A (H020), AS-level, 4.1.1 Communicable diseases, disease prevention and the immune system. Topic: Communicable Diseases.
Key terms in this lesson
- meiosis
- Nuclear division that halves the chromosome number, producing four genetically different haploid daughter cells for use as gametes.
- chromatid
- One of two identical copies of a chromosome, joined by a centromere, formed after DNA replication.
- homologous chromosomes
- A pair of chromosomes, one from each parent, that carry the same genes at the same loci but may carry different alleles.
- crossing over
- The exchange of sections of DNA between non-sister chromatids of homologous chromosomes during prophase I of meiosis, creating genetic variation.
More in Communicable Diseases
- Plant Defences against Pathogens
- Mammals - non-Specific Defences
- Blood Clotting
- Inflammatory Response
- Phagocytosis
- Counting Blood Cells
- Cytokines
- Opsonins
All 40 lessons in Communicable Diseases · All OCR AS-level Biology topics