Coordination Flashcards
What is a stimulus and response?
After detecting a stimulus, organisms must provide a response in order to account for the change. A tropism is a response that an organism makes to a stimulus. E.g. phototropism
What are taxes?
An innate behavioural response by an organism to a directional stimulus or gradient of stimulus intensity
What is kinesis?
Kinesis is an animal’s non-directional response to a stimulus, for example humidity. The animal does not move toward or away from the stimulus but moves at either a slower or faster rate depending on it’s comfort zone
What are tropisms?
A tropism is a growth response of a biological organism in response to an environmental stimulus.
How does a simple reflex arc work?
- A sensory neurone carries the message from the receptor to the central nervous system (the spinal cord and brain).
- A motor neurone carries the message from the central nervous system to the effector.
- In a knee-jerk reflex arc the sensory neurone directly connects to the motor neurone in the spinal cord.
What roles do sensory neurones play in a reflex arc?
Sensory neurones are nerve cells within the nervous system responsible for converting texternal stimuli from the organism’s environment into internal electrical impulses.
What roles do motor neurones have in a reflex arc?
A motor neurone is a nerve cell whose cell body is located in the spinal cord and whose fibre (axon) projects outside the spinal cord to directly or indirectly control effector organs, mainly muscles and glands.
How do reflex arcs prevent damage to the body?
A reflex arc is the nerve pathway which makes a fast, automatic, response possible. It is innate
What is the autonomic nervous system?
The part of the nervous system responsible for control of the bodily functions not consciously directed, such as breathing, the heartbeat, and digestive processes.
How does the autonomic nervous system control rate?
Heart rate is controlled by the two branches of the autonomic nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS).
What role do chemical and pressure receptors play in the process?
- Chemoreceptor is a sensory receptor that transduces a chemical signal into an action potential.
- Baroreceptors are sensors located in the blood vessels of all vertebrate animals. They sense the blood pressure and relay the information to the brain, so that an appropriate blood pressure can be maintained.
What is a pacinian corpuscle?
Lamellar corpuscles or Pacinian corpuscles, are one of the four major types of mechanoreceptor. They are nerve endings in the skin responsible for sensitivity to vibration and pressure.
How does the Pacinian corpuscle work?
The central capsule is surrounded by lamellae. At the heart of the capsule lies the sensory nerve tube. Throughout the corpuscle you can see the capillaries branching out. When you tap your finger on a surface, the pressure exerted upon the lamallae of the pacinian corpuscles in your finger skin makes them bend and exert that pressureback onto the sensory neurone in the capsule. This physically forces out Na+ ions as the plasma membrane is deformed, which creates a generator potential. If this potential passes a threshold, an action potential is triggered.
