Neural Control and Coordination: Class 11 Biology NCERT Chapter 21
Key Features of NCERT Solutions for Class 11 Biology Chapter 21 – Neural Control and Coordination
In chapter 20 of NCERT class 11 Biology: Locomotion and Movement you studied about locomotion and development, we regularly utilize one for the other. In this chapter: Neural Control and Coordination, you will get to know about neurons and how it gets controllation by the body.
At some random time your body is performing different capacities at the same time. Every neuron in your body fires around 200 times each second! The coordination is constrained by the human mind which is the preparing unit of the human body. What’s more, it is bolstered by the focal sensory system and fringe sensory system. Let us have a definite look.
Quick Revision Notes
Human Nervous System
Neurons and their Types
|Types of Neurons|
|Basis their function||Basis the number of nerve processes|
Types of Axons
|Myelinated Axons||Non-myelinated Axons|
Conduction of Nerve Impulse
- A nerve motivation is led over the length of a nerve fiber in a sorted out way.
- On the nerve fiber during the conduction of a motivation, an area is constantly depolarised and a district close to it will be energized.
- To send the motivation forward, the depolarised area repolarises and the captivated district depolarises. This is rehashed over the length of the nerve fiber which helps in the conduction of drive.
- Transmission on Nerve Impulse
- A neurotransmitter is framed by the layers of the pre-synaptic neuron and the post-synaptic neuron.
- There are two sorts of neural connections—electrical neurotransmitter and concoction neurotransmitter.
- Involuntary actions in response to external or internal stimuli are termed reflex actions.
- Thereafter, the path travelled by the impulse during a reflex action is called a reflex arc.
Stimulus → Receptor in the sense organ → Afferent (sensory) nerve fibre → CNS (spinal cord) → Efferent (motor) nerve fibre → Muscle/gland → Response
Function of Parts of the Human Brain
|Cerebrum||Centre of intelligence, memory, consciousness, will power and voluntary actions|
|Thalamus||Relays motor and sensory impulses to the cerebrum|
|Hypothalamus||Contains the centres which control body temperature, blood pressure and homeostasis|
|Midbrain||Controls the movement of the head and eye|
|Cerebellum||Coordinates muscular activity and the balance of the body|
|Pons varolii||Coordinates between the two lobes of the cerebellum|
|Medulla oblongata||Controls the activities of the internal organs, heartbeat and breathing|
Mechanism of Vision
- Light beams reflected from the article enter the eyes through straightforward structures.
- The light vitality produces compound changes in poles and cones which send the nerve motivation.
- This nerve motivation is sent to the cerebrum through the optic nerve. The cerebrum gives the impression of sight.
- Photosensitive mixes like opsin and retinal produce expected contrasts in photoreceptor cells.
- The mind deciphers the modified picture on the retina, and the article is seen upstanding.
Mechanism of Hearing
- The pinna gathers sound waves and leads them through the outside hear-able waterway. They at long last strike the eardrum and the vibration is set.
- The Eustachian tube levels the gaseous tension on either side of the eardrum permitting it to vibrate uninhibitedly.
- The vibrating eardrum sets the three ear ossicles into vibration. The vibration of the initial two ossicles, for example malleus and incus, amplifies the vibration in the stapes.
- The stapes communicates the vibration to the film of the oval window which sets the liquid in the cochlea into vibration.
- The vibrating development in the liquid animates hair-like procedures of sense cells of the cochlea and the driving forces are communicated to the cerebrum through the hear-able nerve.
(Neural Control and Coordination: Class 11)
What is neural coordination?
Coordination is the procedure through which at least two organs collaborate and supplement the elements of each other. Therefore, the neural framework gives a sorted out system of highlight point associations for a speedy coordination.