Homeostasis
What is the maintenance of relatively stable internal conditions called?
Homeostasis
Is the nervous system generally faster or slower than the endocrine system?
Faster
Hormones
Approximately what is normal human core temperature?
About 37°C.
What is the condition called when the body loses more water than it takes in?
Dehydration
What are two examples of conditions that the body maintains through homeostasis?
Temperature, water balance, blood glucose, pH, etc
What type of signals does the nervous system primarily use to communicate rapidly?
Electrical signals travelling along neurons, with neurotransmitters involved at synapses.
How do hormones travel around the body?
Through the blood stream
What happens to the blood vessels near the skin when you become too hot?
They widen - vasodilation
What hormone helps the body conserve water?
ADH - antidiuretic hormone
What is the correct order?
Response-Change-Detection-Return to normal
Change - Detection - Response - Return to normal
You touch a hot stove and immediately pull your hand away. Which system is primarily responsible for this response?
Nervous system
Which gland is often called the "master gland"?
Pituitary gland
Name two ways the body responds when it becomes cold
Shivering and vasoconstriction
When a person is dehydrated, does ADH increase or decrease?
Increase
Why is homeostasis important for enzyme activity?
Enzymes function best within particular conditions. Maintaining stable internal conditions helps biochemical reactions occur effectively
Why is the nervous system useful when the body needs to respond very quickly?
Signals can travel rapidly through neurons to specific parts of the body
What is the role of the hypothalamus in the endocrine system?
It helps regulate homeostasis and links the nervous and endocrine systems, including controlling the pituitary gland.
Explain how sweating cools the body
Sweat evaporates from the skin, removing thermal energy and therefore cooling the body
What happens to the urine of a dehydrated person?
They generally produce a smaller amount of more concentrated urine
A person's body temperature rises after exercising. Explain how this is an example of homeostasis
The temperature change is detected, the body activates cooling responses such as sweating and vasodilation. These responses increase heat loss returning temperature towards a normal range.
Nervous system responses are generally faster and often short lasting. Endocrine system responses are generally slower and can last longer
A hormone must be released by a gland, enter the bloodstream, travel to its target cells and produce a cellular response. This generally takes longer than rapid nervous signalling
A person is exercising heavily on a very hot day. Explain the sequence of events that helps prevent their body temperature from rising too far.
Temperature increases -> thermoreceptors detect the change - > hypothalamus coordinates the response -> sweating and vasodilation increase -> more heat is lost -> body temperatures move towards normal
Explain what happens to ADH and the kidneys when a person has too much water in their body
ADH decreases -> the kidneys reabsorb less water -> more water remains in the urine -> more diluted urine is produced -> excess water is removed