Railway Science (Biology – Nervous System)

Dendrite: This is a branch-like extension of a neuron that receives signals from other neurons. It is part of the neuron itself. The axon is the part of the neuron that transmits electrical impulses, and is received by other neurons. Cerebrospinal fluid (CSF) is an ultrafiltrate of plasma contained within the ventricles of the brain and the subarachnoid spaces of the cranium and spine.

Medulla is a long stem-like structure found in the bottom-most part of the brain. Function - Respiration, Cardiac function, Vasodilation, Reflexes (such as swallowing and sneezing).
Major parts of Brain - Forebrain (Cerebrum, Hypothalamus, Thalamus). Midbrain (Colliculi, Tegmentum, Cerebral Peduncles). Hindbrain (Pons, Cerebellum, medulla oblongata).

Cycling is not an involuntary action because it requires conscious choice and control of the muscles. Involuntary actions in human beings such as blood pressure, vomiting, salivation are controlled by medulla oblongata.

The myelinated axons are characterised by a covering of a fatty layer called the myelin sheath secreted by the Schwann cells. The myelin sheath is non-conducting. Therefore, small gaps are left between Schwann cells along the entire length of the axons.
These gaps are called Nodes of Ranvier. They allow saltation of the nerve impulse. Chondroblasts (cells): Play an important role in the formation of cartilage. A gland is a group of cells or a secreting organ that excretes a chemical substance. Osteoblasts are cells with a single nucleus that synthesize bone.

Parts of the brain - Forebrain, Midbrain and Hindbrain. The forebrain is responsible for a variety of functions including receiving and processing sensory information, thinking, perceiving, producing and understanding language, and controlling motor function.
Cerebrum (The largest part of the brain) - Thinking part of the brain and controls your voluntary muscles. Hindbrain - Controls the heart rate, breathing, blood pressure.
Midbrain connects the forebrain and the hindbrain. It transmits signals from hindbrain and forebrain. It is associated with vision, hearing, temperature regulation and alertness.

Voluntary action is under the control of one's will, means under the control of the brain. Example - Dancing, Eating and Writing. Involuntary action is not under the control of one's will, it is controlled by the spinal cord. Example - Respiration and Blinking eyelids.

Medulla is the connective tissue between the brain and spinal cord. Function - It controls involuntary activities (heartbeat, respiration etc) and maintains body posture and governs our reflexes.
Pons - Links between the medulla oblongata and the thalamus. Control unconscious processes, sleep-wake cycle and breathing. Hypothalamus - Controls body temperature, hunger, and thirst.

Cerebellum, also known as the little brain, is responsible for smooth, coordinated voluntary movements that receive information from the spinal cord and other parts of the brain.

The medulla oblongata is the connection between the brainstem and the spinal cord. It is found in the lowest region of the brain chiefly regulating the autonomic functions such as breathing, heartbeat and digestion.
The human brain consists of various parts that include: The Forebrain (Cerebrum, Thalamus, Hypothalamus), The Midbrain (Tectum, Tegmentum) and The Hindbrain (Cerebellum, Medulla, Pons).