Control and Coordination Flashcards
what do we see movement as?
(or)
why are movements seen as indicator of life
t we think of movement as a response to a change in the
environment of the organism.we also think of movement as an attempt
by living organisms to use changes in their environment to their
advantage.
what is the characteristic of movements shown by living things?
all this
movement, in response to the environment, is carefully controlled.. Each
kind of a change in the environment evokes an appropriate movement
in response.the movement to be made depends
on the event that is triggering it. Therefore, such controlled movement
must be connected to the recognition of various events in the
environment, followed by only the correct movement in response. In other
words, living organisms must use systems providing control and
coordination. In keeping with the general principles of body organisation
in multicellular organisms, specialised tissues are used to provide these
control and coordination activities.
define nervous system
The body system that collects, processes, and responds to information/changes in the environment using electrical signals.It is the system of conducting tissues that receives the stimulus and transmits it to other parts of
the body forming a network of nerves. It is involved in receiving information (sensation) and generating responses
to that information (motor response).
what is the central and peripheral nervous sytem
the nervous system can be dvided into 2: central and peripheral nervous system. The central nervous system consists of brain and spinal cord. It helps to process information and changes in environment.
The peripheral nervous system consists of the nerves which can be further divided into cranial and spinal nerves.These send info to cns and transmit response from cns to effector. Cranial(12)nerves originate from the brain while spinal(31 pairS) nerves orginate from spinal cord.
what are receptor
All
information from our environment is
detected by the specialised tips of some
nerve cells. These receptors are usually
located in our sense organs, such as the
inner ear, the nose, the tongue, and so
on.
Receptors are the chemical structures made up of proteins that receive signals from both external and internal
environment.
define neuron
the structural, functional and basic unit of human nervous system is called the neruon.
what are the parts of a neuron
-dendrites
-cell body
-axon
-schwann cells
-myelin sheath
-node of ranvier
-axon terminal
-synapse
what are dendrites and its function?
These are long tendrils projecting from the cell body and are responsible for picking up signal from the outside environment or other neurons.
what is cell body?
the cell body has granules and contains the nucleus and many organelles. It is responsible for protein production,the cell body contains genetic information, maintains the neuron’s structure, and provides energy to drive activities.
what is an axon
An axon is a long, tail-like structure. It carries the electrical impulse to the axon terminal.
What are schwann cells and ufucntion
schwann cells are cells that wrap the axon of the neuron and are responsible for the production of myelin sheath
what is the myelin sheath
It is a white coloured layer on the axon that is made of myelin and phospholipids. It is responsible for insulating the axon and help in quicker conduction of impulse.
what is node of ranvier
These are small gaps of exposed axon in between schwann cells. These nodes help for the quickest conduction of the electrical impulse. The impulse jumps from node to node. They speed up the impulse.
define saltatory conduction
Saltatory conduction describes the way the electrical impulse jumps from node to node speeding the arrival of it at the axon terminal
what is axon terminal
These are the bulb like ends of the axon. They convert the electrical impulse into the chemical neurotransmitters and release them into the synapse.
what is the synapse
It is the junction/point of contact between two neurons( axon of one to dendirte of another) consisting of a minute gap across which the neurotransmitters pass through diffusion.
give a brief overiew of how nervous impulses travel through the body?
Specialised tips of some nerve fibres receive information from external environment called receptors.This information, acquired at the
end of the dendritic tip of a nerve cell
[Fig. 7.1 (a)], sets off a chemical reaction
that creates an electrical impulse. This
impulse travels from the dendrite to the
cell body, and then along the axon to its
end. At the end of the axon, the electrical
impulse sets off the release of some
chemicals. These chemicals cross the
gap, or synapse, and start a similar
electrical impulse in a dendrite of the next
neuron. This is a general scheme of how
nervous impulses travel in the body.
where do these electrical signals from brain reach
A
similar synapse finally allows delivery of such impulses from neurons to
other cells, such as muscles cells or gland
what is a nervous tissue made of
nervous tissue is made up of an organised
network of nerve cells or neurons, and is specialised for conducting
information via electrical impulses from one part of the body to another.
what are receptors and effectors?
A receptor is a cell (or a group of cells) in a sense organ which is sensitive to a particular type of stimulus and initiate transmission of impulse via sensory nerves.Example: Nose and ears.
An effector is a part of the body which can respond to a stimulus according to the instructions sent from the nervous system (spinal cord and brain). Example: Glands and muscles.
what are sensory neurons?
It is a neuron that transmits information from the receptors to the central nervous syetms
what are motor neurons
It is a neuron that transmits informtaion from the central nervous systems to the effectors
what are internueonrs
it is a neuron that connected the sensory and motor neurons,
what is a stimulus
Refers to any change in the internal or external environment of the organism that provokes a physiological or behavioural response from the organism
