Enteric Nervous System Quiz

The physiological process that maintains internal systems at equilibrium despite external changes.

The autonomic nervous system (ANS) is a part of the peripheral nervous system that controls involuntary bodily functions like heart rate, digestion, and breathing.

The sympathetic nervous system activates the 'fight or flight' response, preparing the body for stressful situations.

The parasympathetic nervous system is responsible for 'rest and digest' functions, promoting relaxation and recovery.

The enteric nervous system (ENS) is a part of the autonomic nervous system that controls the gastrointestinal tract.

The sympathetic nervous system uses a two-neuron relay system: preganglionic and postganglionic neurons.

The preganglionic neuron is located in the spinal cord and releases acetylcholine (Ach) as a neurotransmitter.

The postganglionic neuron is located outside the spinal cord and is responsible for releasing neurotransmitters to target organs.

The majority (90%) of postganglionic neurons in the sympathetic nervous system release this neurotransmitter, which prepares the body for 'fight or flight' responses.

These neurons represent a smaller portion (10%) of the postganglionic sympathetic nervous system and primarily target sweat glands and piloerector muscles.

These muscles attach to the hairs in our skin and when they contract, they cause the hair to stand on end.

The majority of parasympathetic preganglionic neurons are located in the visceral efferent motor nuclei of these specific cranial nerves.

These preganglionic neurons are located in the lateral grey matter of the sacral spinal cord.

They are long and lightly myelinated, allowing for faster transmission of signals to target organs.

They release acetylcholine as a neurotransmitter, promoting the 'rest and digest' response.

The sympathetic nervous system uses these pathways to connect the spinal cord to the ganglia where preganglionic neurons synapse.

The sympathetic chain is a series of interconnected ganglia located along the vertebral column, from the cervical region to the coccyx.

The splanchnic nerves are bundles of preganglionic sympathetic axons that originate from the thoracic and lumbar spinal cord and project to the prevertebral ganglia.

The prevertebral ganglia are located in the abdominal cavity and innervate organs in the abdomen and pelvis. Examples include the celiac, superior mesenteric, and inferior mesenteric ganglia.

The sympathetic chain extends beyond the lumbar region, even though preganglionic neurons are only found in the thoracic and upper lumbar levels.

The white ramus is a short myelinated fiber tract that carries preganglionic sympathetic axons from the spinal nerve to the sympathetic chain ganglia.

The grey ramus carries postganglionic sympathetic axons from the sympathetic chain ganglia back to the spinal nerve, allowing them to reach their target organs.

Sympathetic activity can cause pupil dilation in the eye and eyelid retraction, allowing more light into the eye during a 'fight or flight' response.

Postganglionic sympathetic neurons increase the viscosity of saliva, but don't change the volume of saliva production.

The myenteric plexus is located between the circular and longitudinal smooth muscle layers of the gut, and is involved in regulating peristalsis by coordinating the contraction and relaxation of the smooth muscles.

The submucosal plexus is found within the submucosa of the gut wall and plays a role in regulating the chemical composition of the lumen, including secretion of mucus and other digestive juices

Sensory neurons in the myenteric plexus monitor the degree of stretch in the longitudinal and circular smooth muscles, providing information about the distention of the gut wall.

Sensory neurons in the submucosal plexus detect the chemical composition of the lumen, providing information about the contents of the gut and triggering appropriate responses.

The enteric nervous system is capable of functioning largely independently of the brain, but it also receives regulatory input from the parasympathetic and sympathetic nervous systems.

A part of the adrenal gland that releases adrenaline and noradrenaline into the bloodstream, primarily in response to stress or 'fight or flight' situations.

The sympathetic nervous system primarily uses acetylcholine (ACh) as a neurotransmitter at the preganglionic synapse and noradrenaline (NA) at the postganglionic synapse.

A type of G-protein coupled receptor (GPCR) that binds to adrenaline and noradrenaline, triggering a cascade of intracellular signaling pathways in target cells.

A specific type of adrenergic receptor (α1) that activates phospholipase C, leading to an increase in intracellular calcium levels and smooth muscle contraction.

A specific type of adrenergic receptor (β2) that binds to adrenaline and noradrenaline, leading to relaxation of smooth muscle in bronchioles, increasing airway diameter.

Adrenaline/noradrenaline binding to β1 adrenergic receptors increases heart rate and contractility, resulting in increased blood flow throughout the body.

Adrenaline/noradrenaline binding to α2 adrenergic receptors inhibits the release of neurotransmitters from presynaptic nerve terminals, decreasing sympathetic activity.

The specific enzyme involved in the breakdown of lipids (fats) stored in adipose tissue, a process known as lipolysis.

Visceral sensory neurons are specialized nerve cells that transmit information about the internal organs and systems to the central nervous system.

The dorsal root ganglia (DRG) are clusters of nerve cell bodies located in the spinal cord and contain visceral sensory neurons that relay information about the internal organs.

Afferent neurons, also known as sensory neurons, carry signals from the periphery towards the central nervous system.

The nucleus of the solitary tract (NST) is a group of neurons in the brainstem that receives and processes information from the internal organs, including taste, blood pressure, and heart rate.

The NST receives information from visceral sensory neurons in the medulla, where it processes and relays this information to other parts of the brain and nervous system.

The autonomic nervous system is responsible for controlling involuntary bodily functions like heart rate, digestion, and breathing. Visceral sensory information plays a crucial role in regulating this system.

Visceral sensory information is processed by the NST, which sends signals to the autonomic nervous system, influencing the activity of preganglionic neurons in the brainstem and spinal cord.

The preganglionic neurons are located in the brainstem and spinal cord and send signals to the autonomic ganglia, which are clusters of nerve cells located outside the central nervous system.