B10: The Human Nervous System Flashcards
(51 cards)
What are the conditions inside our body known as?
Internal Environment
What is homeostasis?
The regulation of internal conditions of a cell or organism to maintain optimum conditions for function.
What are some internal conditions that are controlled? (3)
Body temperature, the water content of the body and blood glucose concentration.
Homeostasis involves c———— and c————-.
Coordination and control.
What are receptors?
Cells that detect changes in the internal or external environment (the changes are called stimuli).
What are coordination centres?
Areas that receive and process the information from the receptors.
What does the brain act as a control centre for?
The nervous system, parts of the hormonal system, the spinal cord and some organs like the pancreas.
What are effectors?
Muscles or glands that bring about responses to the stimulus that has been received.
How fast do electrical impulses move in the nervous system?
Between 1 and 120 metres per second.
What 3 parts do receptors cells have?
Nucleus, cytoplasm and a cell membrane.
How does the nervous system work? (4 steps)
- Sensory receptor detects a stimulus and is sent as an electrical impulse along neurones.
- The impulse travels along the neurone until it reaches the CNS.
- The motor neurones carry the impulses to the right bits of your body (so the effectors can respond).
4.
What is the CNS made up of?
The brain and spinal cord.
What are the cells that carry impulses from sense organs to the CNS called?
Sensory neurones
Effectors may be m——— or g——-.
Muscles or glands
How do muscles respond to the arrival of impulses?
By contracting.
How do glands respond to impulses?
By secreting chemical substances (e.g. salivary glands release extra saliva when you smell food cooking)
How can the nervous system be summed up?
Stimulus➡️receptor➡️CNS➡️
Effector
What are reflexes for?
They help you avoid danger or harm because they happen so fast.
Reflexes do not involve the c————— part of your brain.
Conscious
What 3 types of neurones do simple reflex actions involve?
Sensory neurones, motor neurones and relay neurones.
What are the meninges?
Protective membranes that encase your brain.
What is the purpose of the cerebral cortex?
It’s concerned with consciousness, intelligence, memory and language.
What is the purpose of the cerebellum?
It’s concerned with coordinating muscular activity and balance.
What is the purpose of the medulla?
It’s concerned with unconscious activities (e.g. controlling the heartbeat, movements of the gut and breathing).