Synapses and Sensory receptors

Synapses

Junctions between the synaptic terminal of one neuron and another cell.

Types of Synapses

Electrical synapses involve direct flow of current from cell to cell, while chemical synapses use neurotransmitters.

Presynaptic Neuron

Neuron that synthesizes neurotransmitters and packages them into vesicles for transmission.

Neurotransmitters

Chemical messengers that diffuse across the synaptic cleft and bind to specific post-synaptic receptors.

Post-synaptic Potentials (PSPs)

Changes in membrane potential in postsynaptic cells triggered by ligand gated ion channels.

Excitatory Postsynaptic Potential (EPSP)

A depolarizing potential in postsynaptic neurons that increases the probability of action potentials.

Inhibitory Postsynaptic Potential (IPSP)

A hyperpolarizing potential in postsynaptic neurons that decreases the probability of action potentials.

Temporal Summation

The process where two EPSPs at one synapse occur in rapid succession, potentially leading to an action potential.

Spatial Summation

The process where two or more EPSPs occurring nearly simultaneously at different synapses can lead to an action potential.

Long Term Potentiation (LTP)

A lasting increase in synaptic transmission strength, essential for memory and learning.

Short Term Memory

Involves the cerebral cortex and is accessed by temporary links through the hippocampus.

Sensory Reception

The process by which sensory receptors detect changes in the environment.

Sensory Transduction

The conversion of the energy of a stimulus into a receptor potential by sensory receptors.

Mechanoreceptors

Sensory receptors that respond to mechanical stimuli like pressure, stretch, and vibration.

Photoreceptors

Sensory receptors that respond to light.

Chemoreceptors

Sensory receptors that respond to chemical stimuli.

Thermoreceptors

Sensory receptors that respond to changes in temperature.

Hearing

The ability to detect pressure waves in a fluid and perceive them as sound.

Auditory Canal

Channel that directs sound waves to the tympanic membrane.

Cochlea

The main structure of the inner ear, a spiral fluid-filled tube where sound waves are detected.

Hair Cells

Mechanoreceptors in the cochlea that transduce mechanical vibrations into electrical signals.

Auditory Cortex

Area of the brain responsible for auditory processing.

Olfaction

The sense of smell, involving olfactory receptor neurons in the nasal cavity.

Taste receptors

Chemicals that transmit taste information to the brain.

Gustation

The sense of taste, involving taste buds that detect different flavors.

Muscle Spindles

Sensory neurons located in muscles and tendons that provide information about body position and movement.

Proprioception

The ability to sense the position, location, orientation, and movement of the body and its parts.

Nociceptors

Specialized neurons that respond to painful stimuli, triggering defensive behaviors.

Pain Perception

The perception of pain, mediated by nociceptors.

Endorphins

Compounds that modulate pain perception by blocking substance P.