Autonomic Nervous System Overview

Hearing loss caused by damage to the auditory nerve or structures in the inner ear, including the cochlea and hair cells. This affects the ability to process sound signals and transmit them to the brain.

Six muscles that control eye movement. These muscles attach to the outer surface of the eyeball and are responsible for rotating the eye in different directions.

A small pit in the center of the macula lutea, responsible for sharp central vision. It contains a high concentration of cones, which are light-sensitive cells that allow us to see color and detail.

The area where the optic nerve leaves the back of the eye. It lacks photoreceptor cells, making it insensitive to light, resulting in a blind spot in our visual field.

A thin layer of tissue at the back of the eye that converts light signals into electrical impulses. It contains photoreceptor cells (rods and cones) which detect light and send signals to the brain via the optic nerve.

A hormone that, alongside Epinephrine, enhances the body's stress response, boosting alertness, senses, and muscle function.

This division of the autonomic nervous system is responsible for preparing the body for 'fight or flight' responses by releasing norepinephrine and epinephrine.

The anatomical location of the sympathetic nervous system's origin, starting in the thoracic and lumbar regions of the spinal cord.

A chain of ganglia along the spinal cord where many sympathetic preganglionic neurons synapse with postganglionic neurons.

The division of the autonomic nervous system that promotes rest and digestion, counteracting the effects of the sympathetic division.

The anatomical location of the parasympathetic nervous system's origin, starting in the brain and sacral region of the spinal cord.

The inner core of the adrenal gland that acts as a sympathetic ganglion, releasing epinephrine and norepinephrine into the bloodstream.

Sensory receptors that detect changes in temperature, specifically heat and cold. They are found in the skin.

Sensory receptors located in the eyes that are responsible for detecting light. They allow us to see.

Nociceptors are pain receptors that detect tissue damage or potential tissue damage. They are found throughout the body, including skin, muscles, and internal organs.

Chemoreceptors detect chemicals, including odors, tastes, and the composition of body fluids. They are found in the nose, tongue, and blood vessels.

These receptors detect physical deformation or changes in pressure, touch, stretch, or tension within tissues. They are found throughout the body.

Sensory receptors that detect stimuli from the external environment, such as light, sound, touch, and temperature.

Interoceptors detect stimuli from within the body, such as changes in blood pressure, blood oxygen levels, and digestive processes.

These receptors detect position and movements of the body and limbs. They are found in muscles, tendons, and joints.

These senses are distributed throughout the body and are found in skin, muscles, tendons, joints, and internal organs. They include touch, pressure, temperature, pain, and proprioception.

These senses are limited to the head, innervated by cranial nerves, and are associated with specialized sensory organs. They include vision, hearing, smell, taste, and balance.

The autonomic nervous system, specifically the sympathetic and parasympathetic branches, regulates the movement and secretions of the digestive system. This includes controlling the esophagus, stomach, and intestines, as well as the release of digestive enzymes and acids.

The neurotransmitter released by sympathetic preganglionic fibers is acetylcholine (ACh).

The neurotransmitter released by most sympathetic postganglionic fibers is norepinephrine (NE).

The neurotransmitter released by parasympathetic preganglionic fibers is acetylcholine (ACh).

The neurotransmitter released by parasympathetic postganglionic fibers is acetylcholine (ACh).

Muscarinic receptors are activated by acetylcholine (ACh) and are found in the heart, smooth muscles, and glands. They are named after muscarine, a toxin found in mushrooms.

Nicotinic receptors are also activated by ACh, but they're found primarily in autonomic ganglia, where preganglionic fibers stimulate postganglionic cells. They are named after nicotine. Their effect is always excitatory.

Alpha-1 adrenergic receptors are activated by norepinephrine (NE) and have excitatory effects. They are involved in processes like labor contractions, piloerection (hair standing up), constricting blood vessels, and inhibiting intestinal motility.

Alpha-2 adrenergic receptors are activated by norepinephrine (NE) and generally have inhibitory effects. They work by inhibiting the production of cyclic AMP (cAMP) which is a chemical messenger involved in many cellular processes.

Specialized proteins on cells that bind to neurotransmitters like norepinephrine (NE) and epinephrine (adrenaline), triggering specific physiological responses.

Primarily found in the heart, kidneys, and fat tissue. Activation increases heart rate and strength of contraction, and stimulates renin secretion by the kidneys, ultimately contributing to blood pressure regulation.

Located in the lungs, blood vessels serving the heart, liver, and skeletal muscles. Their activation generally relaxes smooth muscle, dilating blood vessels and bronchioles, promoting easier breathing and blood flow.

Found primarily in fat tissue. Their activation stimulates lipolysis, the breakdown of fat for energy release.

Located in various blood vessels, visceral organs, salivary glands, and the sympathetic nervous system. Their activation constricts blood vessels and sphincters, constricts pupils, and is involved in various responses like vasoconstriction and pupil dilation.

Found on adrenergic nerve terminals, pancreas, and blood platelets. Their activation inhibits the release of norepinephrine, reduces insulin secretion, and promotes blood clotting.

A substance that binds to a receptor and activates it, mimicking the effects of the natural neurotransmitter.

A substance that binds to a receptor but blocks its activation, preventing the natural neurotransmitter from exerting its effect.

The outer layer of the brain involved in complex thought, emotions, and voluntary movement. It influences autonomic function by generating emotions like anger, fear, and excitement, which in turn affect physiological responses.

A small but crucial brain region located below the thalamus, playing a major role in regulating essential bodily functions like hunger, thirst, temperature, and emotional responses. It is the central control center for the autonomic nervous system.