The Nervous system
Q: What are the three main functions of the nervous system?
Detects change, or stimuli, inside the body an in the environment.
Processes and stores information.
Initiates response.
Q: What is a stimulus?
A detectable change in the internal or external environment of an organism which
produces a response in that organism.
Q: Why are sensory receptors transducers?
Because they detect energy in one form and convert it into electrical energy.
Q: How are electrical impulses transmitted?
Along neurones, and they are called nervous impulses.
Q: What are the two main parts of the nervous system?
1. The Central Nervous System
2. Peripheral nervous system.
Q: Describe the CNS:
Comprising the brain and spinal cord.
Processes information provided by a stimulus.
Both the brain and spinal cord are protected by meninges (tough protective
membrane)
Q: Describe the PNS and the two components it comprises of;
1. The somatic nervous system: pairs of nerves that originate in the brain or spinal cord
and their branches. These nerves contain the fibres of sensory neurones which carry
impulses from receptors to the CNS and motor neurones, which carry it to effectors.
2. The autonomic nervous system provides unconscious control of the functions of
internal organs.
Q: What is a reflex arc?
A reflex arc is the simplest type of nervous response. It is the neural pathway taken
by the nervous impulses of a reflex action.
Q: What is a reflex action?
Rapid automatic response resulting from nervous impulses initiated by a stimulus.
Q: What are the sequence of elements of a reflex arc.
Stimulus, receptor, sensory neurone, relay neurones in CNS, motor neurone,
effector, response.
, Q: What is a nerve net?
Simplest type of nervous system. It is a diffuse network of cells that group into
ganglia but do not form a brain.
Q: What are the two types of cells in a nerve net?
Ganglion cells = provide connections in several directions.
Sensory cells = detect stimuli.
Q: What model organism do we study to understand nerve nets, give a reason?
Hydra
Reasons are: simple pattern, easy to manipulate, regenerates rapidly.
Q: Where is Hydra’s nerve net located?
The outer two layers of cells of its body wall.
Q: What can the nerve net of hydra sense? And name the responses:
It can sense light, physical contact and chemicals.
Its response is that it can contract, perform locomotion, hunt and feed.
Q: What are nerve cells/neurones? What is their function?
from one part of the body to another.
Q: Name the three types of neurones?
Sensory, motor, relay.
Q: Describe the functions of the organisms in a neurone:
Q: Describe the structure of the myelinated motor neurone:
Q: What are the three main functions of the nervous system?
Detects change, or stimuli, inside the body an in the environment.
Processes and stores information.
Initiates response.
Q: What is a stimulus?
A detectable change in the internal or external environment of an organism which
produces a response in that organism.
Q: Why are sensory receptors transducers?
Because they detect energy in one form and convert it into electrical energy.
Q: How are electrical impulses transmitted?
Along neurones, and they are called nervous impulses.
Q: What are the two main parts of the nervous system?
1. The Central Nervous System
2. Peripheral nervous system.
Q: Describe the CNS:
Comprising the brain and spinal cord.
Processes information provided by a stimulus.
Both the brain and spinal cord are protected by meninges (tough protective
membrane)
Q: Describe the PNS and the two components it comprises of;
1. The somatic nervous system: pairs of nerves that originate in the brain or spinal cord
and their branches. These nerves contain the fibres of sensory neurones which carry
impulses from receptors to the CNS and motor neurones, which carry it to effectors.
2. The autonomic nervous system provides unconscious control of the functions of
internal organs.
Q: What is a reflex arc?
A reflex arc is the simplest type of nervous response. It is the neural pathway taken
by the nervous impulses of a reflex action.
Q: What is a reflex action?
Rapid automatic response resulting from nervous impulses initiated by a stimulus.
Q: What are the sequence of elements of a reflex arc.
Stimulus, receptor, sensory neurone, relay neurones in CNS, motor neurone,
effector, response.
, Q: What is a nerve net?
Simplest type of nervous system. It is a diffuse network of cells that group into
ganglia but do not form a brain.
Q: What are the two types of cells in a nerve net?
Ganglion cells = provide connections in several directions.
Sensory cells = detect stimuli.
Q: What model organism do we study to understand nerve nets, give a reason?
Hydra
Reasons are: simple pattern, easy to manipulate, regenerates rapidly.
Q: Where is Hydra’s nerve net located?
The outer two layers of cells of its body wall.
Q: What can the nerve net of hydra sense? And name the responses:
It can sense light, physical contact and chemicals.
Its response is that it can contract, perform locomotion, hunt and feed.
Q: What are nerve cells/neurones? What is their function?
from one part of the body to another.
Q: Name the three types of neurones?
Sensory, motor, relay.
Q: Describe the functions of the organisms in a neurone:
Q: Describe the structure of the myelinated motor neurone:
