B5 - Homeostasis and Response Flashcards Preview

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Flashcards in B5 - Homeostasis and Response Deck (19):

What is homeostasis? 

Homeostasis is the regulation  of the conditions inside your body - to maintain a stable internal environment. 


Why do the internal conditions of the body need to be regulated? 

Cells need to be in the right conditions in order to function properly. 


What is negative feedback? 

When the level of something (e.g. water or glucose) gets too high or too low, the body uses negative feedback to bring it back to normal.


What are receptors? 

Receptors are the cells that detect stimuli. 


What is the function of the coordination centre? 

Receiving and processing the information, then organises a response. 


Name the two type of central nervous sytems (CNS).   

   The brain and spinal cord.


What is the function of sensory neurones? 

They carry information as electrical impulses from the receptors to the CNS. 


What is the function of the motor neurones? 

They carry electrical impulses from the CNS to the effectors. 


What are the effectors? 

All the muscles and glands, which respond to nervous impulses and bring about a change. 


What is a synapse? 

The connection between two neurones is called a synapse, the nerve signal is transferred by chemicals which diffuse across the gap. 


What are reflexes?

Reflexes are rapid, automatic responses to certain stimuli that don't involve the conscious part of the brain - reduces the chances of getting injured. 


Give three characteristics of hormones and nerves. 

Nerves : very fast action, act for a short time and act on a very precise area. 

Hormones : slower action, act for a long time, act in a more general way. 


What are hormones?           

       Hormones are chemical messengers sent in the blood. 


Give an example of a gland, and the hormone it produces. 

Adrenal gland produces adrenaline.

Ovaries produce oestrogen. 

The pancreas produces insulin. 

Testes produce testosterone. 


What happens if blood glucose level is too high? 

The pancreas will produce insulin to decrease blood glucose level. 


What happens if blood glucose level is too low? 

The pancreas produces glucagon to increase the blood glucose level. 


What is type 1 diabetes? 

When the pancreas produces little to no insulin - a person's blood glucose level can rise to a level that could kill them. 


What is type 2 diabetes? 

Type 2 diabetes is where a person becomes resistant to thier own insulin. 


Describe the menstrual cycle in 4 brief stages. 

1. FSH is produced in pituitary gland, causes egg to mature and uterus lining breaks down. 

2. Oestrogen is produced in ovaries, causes lining to grow back, stimulates the release of LH. 

3. LH is produced by pituitary gland, stimulates the release of an egg. 

4. Progesterone is produced in ovaries, maintains the uterus lining.