Term
| Why is internal communication needed? |
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Definition
| For survival of multicellular organisms because cells in multicellular organisms do not work independently. |
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Term
| What is the nervous system made of? |
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Definition
| The central nervous system (CNS, made of the brain and the spinal cord.) and the nerves. |
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Term
| What is a stimulus? Other name for it? |
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Definition
| A change in conditions that is detected by a receptor. Other name: sensory input. |
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Term
| Job of the sensory neuron and consequence? |
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Definition
To pass the message to the CNS.
The CNS processes the information from our senses which needs a response |
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Term
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Definition
| Motor neurons enable a response brought about by the CNS to occur. It can be a rapid action from a muscle or a slower response from a gland. |
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Term
| What is a relay/intermediate neuron? |
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Definition
| A nerve cell which is found between a sensory and a motor neuron. The relay neuron is part of the CNS (i.e. brain and spinal cord). |
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Term
| In what form is the message carried along a neuron? |
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Definition
| Electrical impulses carry messages along neurons. |
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Term
| What is the name of the gap found between 2 neurons? |
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Definition
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Term
| How is the message passed from on neuron to the next? |
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Definition
| Chemicals transfer these messages across synapses. |
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Term
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Definition
| It is a fast automatic responses which require no input from the brain. |
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Term
| Describe examples of reflex actions. |
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Definition
| Reflex actions either protect the body from damage (e.g. removing hand from heat, pupil of the eye becoming smaller in bright light to protect the sensitive cells at the back of the eye from damage, sneeze) or help its normal functioning (e.g. swallowing). |
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Term
| Describe how a reflex action works, using the simple model of a reflex arc. |
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Definition
| It is the passage of an impulse from a sensory neuron, across a relay neuron to a motor neuron. |
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Term
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Definition
Receptors (1) are stimulated (e.g. pain) and send a nerve impulse though the sensory neuron (2).
From the sensory neuron, the message has to pass through a synapse (junction, 3) before it reaches the intermediate neuron or relay neuron (4) in the spinal cord.
From the intermediate/relay neuron, it crosses another synapse (5) and travels down a motor neuron (6) which stimulates a muscle to contract (7) (e.g. jerking movement of the hand). |
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Term
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Definition
- they are chemical messengers
- Made of protein
- Carried in the blood |
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Term
| What releases hormones directly into the blood stream and why? |
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Definition
| Endocrine glands release hormones in the blood stream so that they can travel to target tissues. |
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Term
| How are hormones perceived by the target tissue? |
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Definition
| Cells have receptors on their surface. |
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Term
| Why are hormones ignored by non-target tissues? |
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Definition
| Because non-target tissues don’t have receptors for them. |
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Term
| Which organ detects changes in blood glucose level? |
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Definition
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Term
| How and where is glucose stored in the body? |
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Definition
| As glycogen (many glucose molecules chemically bound) in the liver. |
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Term
| Explain the role of insulin in the control of blood glucose levels. |
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Definition
| When blood glucose level increases, the pancreas releases more insulin, which travels to the liver where it activates enzymes in the liver cells to convert glucose into glycogen. |
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Term
| Explain the role of glucagon in the control of blood glucose levels. |
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Definition
| When the blood glucose level decreases, the pancreas releases more glucagon, which travels to the liver where it activates enzymes in the liver cells to convert glycogen into glucose. |
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Term
| What can happen if blood glucose levels are not controlled? (2 answers) |
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Definition
- it is important to control blood glucose levels since, if they are high, they can cause damage to blood vessels and affect the functioning of the eyes and kidneys in particular.
- uncontrolled blood glucose levels can cause problems with osmosis in cells. |
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Term
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Definition
| A communication pathway that has failed due to a fault in release or a failure to respond to insulin |
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Term
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Definition
| High blood glucose levels (see above n.22) |
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Term
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Definition
| Injections of insulin to help the uptake of glucose from the blood to the cells. |
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Term
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Definition
1- Cerebrum: the largest part, divided into two halves.
Different regions are responsible for memory, conscious thought, reasoning, intelligence, personality.
2- Cerebellum: controls balance and co-ordination.
3- Medulla: controls automatic functions of the body: breathing, heart beat, etc… |
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Term
| Give two reasons for the recent increase in the number of people with diabetes in Scotland |
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Definition
- Poor diet
- Lack of exercise |
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