Homeostasis
What is homeostasis?
The process by which the body maintains a stable internal environment.
What is the basic unit of the nervous system?
The neuron.
Hormones travel through this
Blood
What is the main function of the immune system?
To protect the body from infections and diseases.
What is hypothermia?
Low body temperature (below 35 degrees).
How does the body respond to an increase in body temperature?
By sweating, increased blood flow to skin etc.
What is a stimulus in the context of the nervous system?
A change in the environment that triggers a response.
What is the name of the endocrine disease where insulin is not produced?
Diabetes
3rd
This hormone is released during a fight or flight response
Adrenaline
What is an example of positive feedback in the human body?
Childbirth, blood clotting etc.
Describe the pathway of a reflex
Stimulus --> receptor → Sensory neuron → Spinal cord → Motor neuron → Effector --> response
What are the 3 main components of the endocrine system?
Hormones, glands, receptors (or target organs)
What is the role of the 1st line of defense?
This chemical is released in an allergic reaction
Histamine
What happens to blood vessels near the skin when the body is too cold?
They constrict to reduce heat loss.
How does the nervous system transmit signals between neurons?
Through chemical neurotransmitters across synapses.
Which hormone lowers blood sugar levels, and which hormone raises them? [Both needed for points]
Insulin lowers blood sugar levels, and glucagon raises them.
What is an antigen?
Oh no! You've rolled your ankle! Why is it swelling?
Increased blood flow = increased white blood cells and oxygen for healing.
Explain how negative feedback works in maintaining homeostasis.
Negative feedback detects changes in the body and triggers responses to reverse those changes, bringing conditions back to normal.
What are two differences between reflexes and reactions?
Any 2:
1. Reflexes are automatic, no conscious thought
2. Reflexes are fast
3. Reflexes don't travel to the brain
4. Reflexes protect us
How does the body respond to low blood sugar levels? [Gland, hormone and receptor needed]
The pancreas releases glucagon, which signals the liver to release stored glucose into the bloodstream.
Describe how vaccines help in building immunity.
Vaccines introduce a harmless part of a pathogen to stimulate the immune system to produce a response and memory cells, so the body can recognize and fight the pathogen more effectively if exposed in the future.
The only way to treat an infection is....
Antibiotics!