Biology Chapter 4 Co-ordination and control Flashcards
What is a stimulus
Outside change that body responds to eg heat, light, sound
What is the receptor
Part of the body that receives the stimulus eg. eye is receptor and light is the stimulus
What is an effector
The part of the body that responds to the stimulus - usually a muscle or gland
What 2 parts make up the Central nervous system
Brain and Spinal cord
What is a reflex action
Rapid
Does not involve concious control (automatic)
Needed to escape harm
What is a volutary response
Involves conscious - thinking about it
Much slower than reflex
What are the 3 neurones in a reflex action (in order)
S.A.M.
Sensory
Association
Motor
What is a hormone
A chemical
produced by a gland
travels through the blood
to reach target ORGAN
How does a hormonal response differ from nervous response
Hormones - slower
Hormones involve chemical but nervous is electrical impulse
Hormones travel through blood but nervous response trave through neurones
What is insulin
Hormone made in PANCREAS
travels through blood to
LIVER (Target organ)
What is function of insulin
To lower blood glucose levels
Describe how insulin works
Person eats carbohydrate rich meal
Levels of glucose in blood INCREASE
Pancreas produces more insulin
Insulin causes:
1 - liver cells to absorb more glucose and store as GLYCOGEN
2 Cells take up more glucose and RESPIRATION rates increase
Blood glucose levels decrease back to normal
What are the symptoms of diabetes
High blood glucose levels
Glucose in urine
Lethargic
Extreme thirst
What causes Type 1 diabetes and how is it treated
Pancreas stops making insulin
Occurs in childhood
Treated with insulin injections
What causes Type 2 diabetes
and how to treat it
Pancreas produces less insulin
Occurs in adults
Linked to obesity - can be controlled with diet (but later may require injections of insulin)
To prevent it - exercise more, eat less sugary foods and avoid obesity
