Control And Communication and reproduction Flashcards
Organs that make up CNS
Brain
Spinal cord
Describe brain structure in terms of different parts
Cerebrum is the largest part and is on top of the brain
The cerebellum is at the back of the brain
The medulla is connected to the spinal cord
The function of the cerebrum
Enables conscious thought, memory and intelligence
Function of cerebellum
Controls balance and muscular coordination
Function of medulla
Controls breathing and heart rate
Describe the function of a neurone
Transport electrical impulses from the sense organ to the effector
Define a reflex action
Reflex actions prevent the body from damage
A rapid action from a muscle e.g. Limb withdrawal
Slower response from a gland e.g. The release of a hormone
Describe a reflex are
The neural pathway that controls a reflex action involves 3 types of neurone
Sensory neurone carries impulse from sense organ to the relay neurone in the spinal cord
Relay neurone carries impulse from sensory neurone to the motor neurone
Motor neurone carries impulse from the relay neurone in the spinal cord to the effector
And the gap that occurs between neurones
Synapse a tiny gap occurs between neurones
Describe how electrical impulses are maintained through the synapse
Chemicals diffuse across this space captured by receptors
Triggers off an impulse in the receiving neurone
Describe the function of the endocrine system
Endocrine glands release hormones into the blood stream.
Hormones are chemical messengers.
They are slower than electrical impulses
Target cells have receptor proteins for hormones so only some tissues are affected by specific
Pituitary gland
Release growth hormone
Target tissues are bones, muscles and liver
Hormone stimulates growth during development.
Ovary gland
Releases oestrogen
Target tissues are the uterus and pituitary gland
Hormone repairs uterus lining, regulates menstrual cycle and stimulates pituitary gland to make utenising hormone
Islets of langerhans in pancreas
Produces insulin hormone
Target tissues are liver
Hormone controls conversion of excess glucose in the bloodstream to glycogen
Describe how glucose concentration is regulated in the body
After eating a big meal = high blood glucose level therefore pancreas produces more insulin than glucagon, glucose is converted to glycogen, glycogen is stored in the liver and blood glucose levels return to normal.
If not eaten in a while = low blood glucose level therefore pancreas produces more glucagon than insulin, glycogen in liver is converted back to glucose therefore glucose is released into the bloodstream and blood glucose levels return to normal
