Cell Communication and Cell Cycle

They activate gene transcription pathways altering protein synthesis rates which can adjust cellular functions for maintaining homeostasis.

They bind external antigens presenting them on cell surfaces initiating immune responses unrelated directly with internal hormone signaling mechanisms.

They degrade incoming steroid hormones negating their effect entirely preventing them from impacting cell function.

They secrete additional steroid hormones into extracellular fluid further increasing hormone concentration outside cells.

High progesterone levels inhibit uterine muscle contraction until labor begins naturally.

Stretch receptors in the uterus signal the release of oxytocin, which intensifies contractions.

Drop in fetal heart rate reduces contractions strength to conserve fetal oxygen supply.

Decreased estrogen levels signal reduced uterine contractions and slow labor progression.

No significant effect on phenotype as other genes quickly compensate for lost function without any issues.

Compensatory mutations entirely restoring original function within one generation span.

Disrupted homeostasis potentially leading to decreased individual fitness or adaptability.

Immediate increase in genetic variation enhancing adaptive potential at the population level.

Prevent a further reaction

Create a stronger reaction

Stop a reaction

Return to homeostasis

Hair follicles contract to raise hairs and trap more air for insulation.

Skeletal muscles contract rapidly causing shivering to generate heat.

Adipose tissue increases insulation by producing a thicker fat layer.

Sweat glands produce sweat that evaporates and cools the body down.

75%

100%

50%

25%

Chemoreceptors detect changes in blood pH due to infection, triggering an increase in metabolic rate that raises body temperature even more.

Thermoreceptors detect increased body temperature, leading to vasodilation and sweating, which promote heat loss and return the temperature to its set point.

Thermoreceptors detect increased body temperature, resulting in vasoconstriction and shivering, further increasing body heat and worsening the fever.

Osmoreceptors sense decreased blood plasma volume during dehydration, causing an increase in body temperature as a result of reduced sweating.

Insulin release reduces blood glucose levels limiting available energy substrates for thermogenesis thereby minimizing internal heat production while conserving water through reduced urination.

Leptin secretion suppresses appetite reducing caloric intake which diminishes overall metabolism thus conserving bodily fluids but impairing thermogenic capacity amid cold stress.

Glucagon secretion enhances glycogenolysis providing more glucose for cellular respiration hence amplifying dehydration due to higher metabolic water loss from increased respiration rates.

Vasopressin release causes water reabsorption while simultaneously shivering thermogenesis increases metabolic heat production despite conflicting signals for water conservation and heat generation.

Skeletal system.

Nervous system.

Excretory system.

Muscular system.

Negative feedback loop

Positive feedback loop

Mitosis

Meiosis