Physiology
10 questions tagged Physiology — spanning every one of the seven Ws.
Why do we get goosebumps when we are cold or afraid?
Goosebumps happen when tiny muscles at the base of body hairs contract. In humans, the response is a leftover from our hairier ancestors.
Which organ in the human body uses the most energy?
The brain uses the most energy, consuming about 20% of the body's energy at rest. Even though it is only about 2% of body mass, it is the body's biggest energy user.
How does blood clotting work after a cut?
When a blood vessel is damaged, platelets gather and clotting proteins form a mesh that seals the wound. This stops bleeding and creates a temporary repair.
What is thermal regulation in reptiles?
Thermal regulation is how reptiles control body temperature by using their environment, such as basking in the sun or hiding in shade.
When was the human circulatory system first accurately described?
It was accurately described in 1628, when William Harvey published his theory of blood circulation.
Whose work first mapped the human blood circulation in detail?
William Harvey published the first detailed account of blood circulation in 1628. He showed that the heart pumps blood in a closed system.
Whose research first connected mammalian hibernation with dramatic drops in metabolism?
Scientists such as Knut Schmidt-Nielsen and others helped explain hibernation physiology in mammals in the 20th century.
How does blood clot after a cut?
Platelets stick to the wound, and clotting proteins form a fibrin mesh that seals it. This rapid response reduces blood loss.
How do spiders breathe if they do not have lungs like ours?
Many spiders breathe through book lungs, tracheae, or both, depending on the species. These structures move oxygen into the body without true mammalian lungs.
How do freshwater fish keep the right amount of salt in their bodies?
Freshwater fish absorb salts through their gills and kidneys while producing lots of dilute urine. This helps them avoid losing too much salt to the surrounding water.