Multicellular Organisms: Control & Communication Flashcards
What are the components of the nervous system?
The brain, spinal chord and neurons.
What are the two components of the CNS?
The brain and spinal chord.
What are the 3 main parts of the brain?
- Cerebrum - big part
- Cerebellum - little squidy looking bit
- Medulla - tube looking bit
What is the function of the cerebrum?
Controls memory, personality and reasoning.
What is the function of the cerebellum?
Controls balance and coordination of movement.
What is the function of the medulla?
Controls breathing and heart rate.
What are the 3 types of neuron?
- Sensory Neuron
- Inter Neuron
- Motor Neuron
What is the function of the sensory neuron?
To carry impulses from receptors located in the sense organs to the inter neuron in the CNS.
What is the function of the inter neuron?
To carry impulses from the sensory neuron to the motor neuron. Operates in the CNS.
What is the function of the motor neuron?
To carry impulses from the inter neuron in the CNS to the effectors (muscles/glands) which bring about a response.
What type of message is passed through the nervous system?
Electrical impulse
What is a receptor?
Cells located in the sense organs which detect stimuli and convert them into electrical impulses.
What is an effector? Give 2 examples
Effectors are the things which respond to stimuli. Muscles and glands are examples of these.
What is a synapse?
The gap between neurons.
How are impulses passed along the synapse?
Chemicals diffuse across the gap.
How are impulses transferred in a reflex arc?
- Sensory receptors in the skin are detected by heat.
- Impulse passes along the sensory neuron.
- Impulse crosses the synapse chemically.
- Impulse passes along the inter neuron in the CNS.
- Impulse crosses the synapse chemically.
- Muscle contracts (responds.)
What glands release hormones?
Endocrine glands.
How do hormones move around the body?
Through the bloodstream
Why are only target tissues/organs affected by specific hormones?
Target tissues/organs have specific receptors on their cell membrane. Each hormone ONLY fits the receptors of their target cell.
What is the role of the pancreas in blood glucose regulation?
The pancreas is the endocrine gland. When blood glucose levels are high, receptor cells on it detect it and release insulin. When blood glucose levels are low, receptor cells detect it and release glucagon.
What is the role of the liver in blood glucose regulation?
When glucagon reaches the liver, liver cells convert glycogen into glucose to increase glucose levels. When insulin reaches the liver, the liver is stimulated and it takes up glucose and converts it into glycogen.
What is the role of glucagon in blood glucose regulation?
It is released by the pancreas when blood glucose levels are low. It travels through the bloodstream to the liver where it causes liver cells to convert glycogen into glucose to increase blood glucose levels.
What is the role of insulin in blood glucose regulation?
It is released by the pancreas when blood glucose levels are high. It travels through the bloodstream to the liver where it stimulates the liver and causes it to take up and convert glucose into glycogen.
What is the role of glycogen in blood glucose regulation?
Storage carbohydrate for glucose.
