What happens when you step on a pin?

What happens when you step on a pin?

Stepping on a nail causes a puncture wound, which often looks like a small hole in the foot. It may not bleed as much as a cut, but due to the risk of infection, this type of wound often requires medical attention. A person can reduce the risk of complications with first aid.

Where do afferent neurons carry impulses to?

Afferent, or sensory, neurons carry impulses from peripheral sense receptors to the CNS. They usually have long dendrites and relatively short axons. Efferent, or motor, neurons transmit impulses from the CNS to effector organs such as muscles and glands.

What happens in the nervous system when your finger is hurt?

You prick your finger on something sharp. This causes tissue damage, which is registered by microscopic pain receptors (nociceptors) in your skin. Each pain receptor forms one end of a nerve cell (neurone). It is connected to the other end in the spinal cord by a long nerve fibre or axon.

Where do afferent neurons cross over?

The 2° afferent generates action potentials that are conducted by its axon, which decussates in the anterior white commissure of the spinal cord. The crossed 2° neospinothalamic afferent axons form the lateral component of the spinothalamic tract.

How do afferent neurons work?

Afferent signals come from outside stimuli and tell your brain what they are sensing, such as temperature. Afferent neurons bring stimuli to the brain, where the signal is integrated and processed. The brain then coordinates a response via efferent signals back to the rest of the body.

How does the nervous system process pain?

Pain is a complex physiological process. A pain message is transmitted to the brain by specialized nerve cells known as nociceptors, or pain receptors (pictured in the circle to the right). When pain receptors are stimulated by temperature, pressure or chemicals, they release neurotransmitters within the cells.

What is a afferent neuron?

Afferent neurons, also called sensory neurons, are the nerve fibers responsible for bringing sensory information from the outside world into the brain. Sensory information may involve special senses, such as vision, hearing, smell, or taste, as well as the sense of touch, pain, and temperature.

How are afferent neurons and efferent neurons related?

Afferent neurons: they conduct the nerve impulses from the receptor organs to the spinal cord. Efferent neurons: they conduct the nerve impulses from the brain or spinal cord to the muscles or glands, i.e. the effector organs. Q1. Describe reflex action and reflex arc.

What is the path taken by nerve impulses in a reflex?

Reflex arc: The path taken by the nerve impulses in a reflex is called a reflex arc. This is shown here in response to a pin in the paw of an animal, but it is equally adaptable to any situation and animal (including humans).

Where do second order neurones carry sensory information?

The second order neurones carry the sensory information from the substantia gelatinosa to the thalamus. After synapsing with the first order neurones, these fibres decussate within the spinal cord, and then form two distinct tracts: Crude touch and pressure fibres – enter the anterior spinothalamic tract.

Where are the first order neurones in the spinal cord?

The first order neurones arise from the sensory receptors in the periphery. They enter the spinal cord, ascend 1-2 vertebral levels, and synapse at the tip of the dorsal horn – an area known as the substantia gelatinosa. Fig 2 – The spinothalamic tracts, which carry the sensory modalities of crude touch, pressure, pain and temperature.