Neural tissue Questions in English

(A) Schwann cells and Nodes of Ranvier are characteristic features of the neurons found in the $Nervous \text{ } tissue$.
$1$. $Nervous \text{ } tissue$ forms the nervous system,including the brain,spinal cord,and nerves.
$2$. Nerve fibers consist of a central core called the $axon$,which is often surrounded by a myelin sheath.
$3$. $Schwann \text{ } cells$ are responsible for the formation of the myelin sheath in the peripheral nervous system.
$4$. The $Node \text{ } of \text{ } Ranvier$ refers to the periodic gaps or interruptions in the myelin sheath along the $axon$,which facilitate the rapid conduction of nerve impulses.

(B) The correct answer is $B$.
Nervous tissue is highly specialized for the reception of stimuli (irritability) and the transmission of nerve impulses (conductivity).
These tissues form the nervous system,which coordinates and controls body activities by processing information through these two fundamental properties.

(A) The nervous tissue is composed of neurons and neuroglial cells.
Neurons are the structural and functional units of the nervous system and lack the ability to divide.
Glial cells (or neuroglia) are non-neuronal cells that provide support,protection,and nutrition to neurons.
Crucially,glial cells retain the power of division,which allows them to perform the function of repairing and regenerating nervous tissue after injury.

(D) Regeneration capacity varies significantly among different tissues in mammals.
$1$. Epithelial tissue of the skin and endothelium of blood vessels have a high capacity for regeneration due to constant cell turnover.
$2$. Skeletal tissue of long bones has a moderate capacity for regeneration,especially during fracture healing.
$3$. Nervous tissue of the brain consists of neurons that are highly specialized and generally lose their ability to divide (mitosis) once they reach maturity. Therefore,they show the least capacity for regeneration compared to other tissues listed.

(C) Nervous tissue possesses highly developed properties of irritability (responsiveness) and conductivity,which are fundamental characteristics of protoplasm. While all living cells exhibit these properties to some extent,they are most specialized and prominent in nervous tissue.

(A) The primary function of nervous tissue is to detect stimuli from the environment and transmit impulses to the central nervous system,which then coordinates a response. This property of responding to stimuli is known as irritability or responsiveness. While 'irritability' and 'responsiveness' are closely related,'irritability' is the fundamental property of living cells to respond to stimuli,and nervous tissue is highly specialized for this function. Among the given options,'Irritability' is the most accurate description of the fundamental physiological property of nervous tissue.

(A) The power of regeneration is the ability of tissues to replace damaged or lost cells through cell division.
Epithelial tissues have the highest power of regeneration due to constant wear and tear.
Connective tissues also possess significant regenerative capacity.
Neural tissue (nervous tissue) consists of neurons which are highly specialized cells that lose their ability to divide once they reach maturity.
Therefore,neural tissue has the minimum or almost negligible power of regeneration compared to other tissue types.

(A) Regeneration is the process of renewal,restoration,and growth that makes genomes,cells,organisms,and ecosystems resilient to natural fluctuations or events that cause disturbance or damage.
In the human body,nervous tissue (specifically neurons in the central nervous system) has a very limited or absent capacity for regeneration after a significant injury.
While the epidermis of the skin,tendons,and smooth muscles possess significant regenerative capabilities to repair damage,mature neurons in the brain and spinal cord generally do not regenerate,leading to permanent loss of function in those areas.

(A) The nervous system in vertebrates is derived from the $Ectoderm$.
During embryonic development,a process called neurulation occurs where the neural plate forms from the ectoderm and eventually folds to form the neural tube,which gives rise to the central nervous system (brain and spinal cord).

(A) Neural tissue is specialized for the conduction of nerve impulses. The primary characteristics of neural tissue are excitability and conductivity. Excitability refers to the ability of the cells to respond to stimuli,while conductivity refers to the ability to transmit these impulses. Among the given options,excitability is the fundamental property that allows the nervous system to function.

(B) Neural tissue exerts the greatest control over the body's responsiveness to changing conditions.
It consists of neurons,which are excitable cells that receive,conduct,and transmit impulses.
These impulses allow the body to perceive changes in the environment and respond to them rapidly and effectively.
Connective tissues,bone,and cartilage primarily provide structural support,protection,and connection,rather than rapid control of responsiveness.

(C) Neurons (nerve cells) are the structural and functional units of the neural tissue. Unlike epithelial cells,which form continuous sheets or layers to cover surfaces or line cavities,neurons are specialized cells that remain structurally distinct. They are designed to receive,process,and transmit electrical impulses throughout the body. While they are supported by neuroglial cells,they do not form layers themselves.

(C) Areolar tissue,blood,and tendons are all types of connective tissues.
Neuron is a specialized cell that forms the neural tissue.
Therefore,neuron is the odd one out.

(N/A) $\Rightarrow$ Neural tissue exerts the greatest control over the body's responsiveness to changing conditions.
$\Rightarrow$ Neurons,the unit of the neural system,are excitable cells.
$\Rightarrow$ The neuroglial cells,which constitute the rest of the neural system,protect and support neurons. Neuroglia make up more than one-half the volume of neural tissue in our body.
$\Rightarrow$ When a neuron is suitably stimulated,an electrical disturbance is generated,which swiftly travels along its plasma membrane. Arrival of the disturbance at the neuron's endings or output zone triggers events that may cause stimulation or inhibition of adjacent neurons and other cells.

(B) Neurons are the structural and functional units of the neural system and are excitable cells. Chondrocytes are specialized cells found in cartilage,not the neural system. Therefore,the statement claiming chondrocytes are the unit of the neural system is incorrect.

(C) Neural tissue is specialized for the conduction of nerve impulses. It is responsible for the control and coordination of the body's activities by responding to changing internal and external conditions. It provides the highest level of control and integration in the body.

(B) The figure shows a cell with a central body (soma) and multiple branched extensions (dendrites and an axon). This characteristic morphology is typical of a nerve cell (neuron),which is specialized for transmitting electrical impulses throughout the body. Therefore,the correct option is $B$.

(C) Statement $I$ is correct because the central nervous system lacks a traditional lymphatic drainage system; instead,it utilizes the glymphatic system for waste clearance.
Statement $II$ is incorrect because nervous tissue is ectodermal in origin,not endodermal. The entire nervous system develops from the embryonic ectoderm.