Nerves

Again: Nerves are whitish cords made up of bundles of nerve fibers held together by: connective tissue, through which impulses (electrical signals) are transmitted.

Nerve originate in the brains and spinal cord, and thier branches extend to all parts of the body.

There are 2 Types of Nerves:

▶ Sensory nerves = this nerve carries impulses or messages from the sense organs to the brain(where sensations such as touch, cold, heat, sight, hearing, taste, smell, pain, and pressure are experienced

Sensory nerve endings are called: receptors which is located lose to the surface of the skin. As impulses pass from the sensory nerves to the brain and back through the motor nerves to the muscles, a complete circuit is established resulting in movement of the muscles.

▶ Motor nerves = This nerve carries impulses from the brain to the: muscles or glands. These transmitted impulses produce (make) movements.

Reflex ⤵

A reflex is an automatic reaction to a stimulus that involved the movement of an impulse from a sensory receptor along with the sensory nerve to the spinal cord.

Irresponsive impulse is sent along a motor neuron to a muscle, causing a reaction (ex: the quick removal of the hand from a hot object). Reflexes do not have to be learned; they are automatic.

(NYS Additional Notes)

• Dendrites — receive impulses from neurons

• Axon — sends impulses to other neurons, glands, and muscles.