Nervous Systems and Sensory Receptors

These flashcards cover key vocabulary related to nervous systems and sensory receptors, essential for understanding the structure and function of different types of nerve cells and their role in response to stimuli.

Sensory Receptors

Specialized cells that detect and respond to environmental stimuli; five major types include mechanoreceptors, photoreceptors, chemoreceptors, thermoreceptors, and nociceptors.

Mechanoreceptors

Sensory receptors that respond to mechanical pressure or distortion.

Photoreceptors

Sensory receptors that respond to light, enabling vision.

Chemoreceptors

Sensory receptors that respond to chemical substances, involved in the senses of taste and smell.

Thermoreceptors

Sensory receptors that respond to changes in temperature.

Nociceptors

Sensory receptors that respond to pain, signaling harmful stimuli.

Afferent Neurons

Nerve cells that carry sensory information from the peripheral nervous system to the central nervous system.

Interneurons

Nerve cells within the central nervous system that connect afferent and efferent neurons.

Efferent Neurons

Nerve cells that carry signals away from the central nervous system to effectors like muscles and glands.

Glial Cells

Supportive cells in the nervous system that provide nutrition, support, and insulation to neurons.

Synapse

The junction between two neurons where information is transmitted from one neuron to another.

Electrical Synapse

A type of synapse where ions flow directly between neurons through gap junctions, allowing rapid transmission of impulses.

Chemical Synapse

A synapse in which neurotransmitter molecules are released from the presynaptic neuron and bind to receptors on the postsynaptic neuron, generating an impulse.

Cnidarian

A simple invertebrate, such as a sea anemone, which has a nerve net for conducting impulses.

Cephalization

The evolutionary trend of concentrating nervous tissue and sensory organs at the anterior end of the organism, leading to the formation of a head.

Ganglia

Clusters of neuronal cell bodies, often functioning as processing centers in simpler nervous systems.

Peripheral Nervous System (PNS)

The part of the nervous system that consists of all the nerves that lie outside the central nervous system.

Central Nervous System (CNS)

The part of the nervous system that includes the brain and spinal cord, responsible for processing information and coordinating activity.