B5 Flashcards
What is homeostasis?
Maintaining a stable internal environment in response to changes in both internal and external conditions.
Homeostasis is critical for the proper functioning of cells and processes like enzyme action.
Why is homeostasis important for cells?
Cells need the right conditions to function properly.
This includes optimal conditions for enzyme action.
What are the main components of automatic control systems in the body?
Receptors, coordination centres, and effectors.
Coordination centres include the brain, spinal cord, and pancreas.
What mechanism do automatic control systems use to maintain stability?
Negative feedback.
Negative feedback helps counteract changes that disrupt homeostasis.
What is a stimulus in the context of homeostasis?
A change in the environment.
Stimuli can be related to various factors like temperature, glucose levels, or water content.
What role does the coordination centre play in homeostasis?
Receives and processes information, then organizes a response.
It acts as a control hub for responding to stimuli detected by receptors.
How do effectors contribute to homeostasis?
They produce a response that counteracts changes and restores optimum levels.
Effectors can include muscles or glands that enact the necessary changes.
Fill in the blank: The level of something that is too high or too low is detected by a _______.
receptor
True or False: Negative feedback mechanisms operate consciously.
False.
Negative feedback processes occur automatically without conscious thought.
What happens if effectors continue to be stimulated without regulation?
They may cause the level to change too much away from the ideal.
This highlights the importance of continuous feedback in maintaining homeostasis.
What is the primary function of the nervous system?
To respond to stimuli and coordinate behavior
Organisms need to respond to changes in the environment to survive.
What are receptors?
Cells that detect stimuli
Different types of receptors include taste receptors and sound receptors.
What is the Central Nervous System (CNS) composed of in vertebrates?
The brain and spinal cord
The CNS is connected to the body by sensory and motor neurones.
What do sensory neurones do?
Carry information as electrical impulses from receptors to the CNS
They play a crucial role in transmitting sensory information.
What are effectors?
Muscles and glands that respond to nervous impulses
Effectors can contract muscles or secrete hormones.
What is the role of motor neurones?
Carry electrical impulses from the CNS to effectors
They facilitate the response of muscles and glands.
How does the CNS coordinate a response?
Receives information from receptors and decides on a response
The response is executed by effectors.
Fill in the blank: The CNS is a __________ centre.
coordination
It integrates sensory input and determines appropriate actions.
What is a stimulus?
A change in the environment that triggers a response
Examples include spotting a predator or changes in light.
Describe the pathway of information from a stimulus to a response.
Stimulus → Receptor → Sensory neurone → CNS → Motor neurone → Effector
This pathway illustrates how the nervous system processes information.
True or False: All effectors are muscles.
False
Effectors include both muscles and glands.
What happens when a bird spots a cat?
The bird’s receptors are stimulated, and it flies away
This is an example of the nervous system responding to a threat.
What type of cells cover the retina of the eye?
Light receptor cells
These cells are essential for vision.
What is the connection between two neurones called?
A synapse
