Nervous System and Endocrine System Homeostasis

Vocabulary flashcards covering the nervous system, endocrine system, feedback mechanisms, metabolic disorders, thermoregulation, cellular structure of neurons, reflex arcs, sensory receptors, and osmoregulation.

Nervous System

A system used in homeostasis by sending electrical signals between parts of the body via neurons, acting rapidly on specific parts of the body.

Endocrine System

A system used in homeostasis by sending chemical signals from glands between parts of the body via the circulatory and lymphatic system, which is slow and generally has effects throughout the body.

Homeostasis

The process by which the body can respond to changes internally and externally to return to a baseline.

Negative Feedback Loops

Feedback loops that oppose a stimulus by counteracting it, serving as the mechanism behind homeostasis.

Positive Feedback

Feedback loops that amplify a stimulus by repeating it until an objective is complete.

Synapses

The junctions between neurons where neurotransmitters such as acetylcholine allow for the transmission of nerve signals.

Central Nervous System (CNS)

The organisational part of the nervous system comprised of interneurons, including the brain and spine.

Peripheral Nervous System (PNS)

The response part of the nervous system comprised of sensory and motor neurons.

Thyroid

An organ controlled by the Pituitary gland that controls the body's metabolism.

Hypothyroidism

A condition where the body's metabolism is too low due to lower thyroxine, resulting in lethargy and weight gain.

Hyperthyroidism

A condition where the body's metabolism is too high due to excess thyroxine, resulting in irritability and weight loss.

Insulin

A hormone produced by the pancreas when blood glucose is high (hyperglycaemia) that signals the liver and muscle cells to produce glycogen from glucose.

Glucagon

A hormone produced by the pancreas when blood glucose is low (hypoglycaemia) that signals the liver and muscle cells to break down glycogen back into glucose.

Type 1 Diabetes

Diabetes caused by the body being unable to produce insulin, which is unrelated to lifestyle, influenced by genetics, and presents symptoms including light-headedness, fainting, weight fluctuation, and frequent urination.

Type 2 Diabetes

Diabetes caused by the body being insensitive to insulin, which cannot be treated with injections, is influenced by lifestyle and genetics, and presents symptoms including weight gain, increased thirst, and frequent urination.

Thermoregulation

The homeostatic regulation of body temperature to $37\,^{\circ}\text{C}$ using negative feedback, controlled by the hypothalamus and thermoreceptors in the skin.

Axon

Carries the electrical signal from one end of the nerve cell to the other.

Dendrite

Receives a signal from another nerve cell.

Myelin Sheath

Insulates the electrical signal for faster travel along the neuron.

Soma (Cell Body)

Carries out cellular functions in a neuron.

Axon Terminal

Passes the signal to another nerve cell or cells.

Sensory Neuron

Takes the signal from a receptor to the Central Nervous System (CNS).

Interneuron

Relays the signal through the Central Nervous System (CNS) to a motor neuron.

Motor Neuron

Sends a signal to an effector to carry out a response.

Reflex Arc

The pathway of a reflex response: $\text{Stimulus} \rightarrow \text{Receptor} \rightarrow \text{Sensory Neuron} \rightarrow \text{Interneuron} \rightarrow \text{Motor Neuron} \rightarrow \text{Effector} \rightarrow \text{Response}$.

Adrenaline (epinephrine)

A hormone released by the adrenal glands above the kidneys during stress, fear, or exercise.

Photoreceptor

A type of receptor that receives light signals for the CNS, such as an image.

Chemoreceptor

A type of receptor that receives chemical signals, such as flavour.

Thermoreceptor

A type of receptor that receives heat-based signals, such as cold.

Mechanoreceptor

A type of receptor that receives movement-based signals, such as sound.

Osmoregulation

The process by which ADH from the pituitary gland controls the amount of water and salt filtered from the blood by the kidney to reach homeostasis.

Collecting Duct

The site in the kidney where water is absorbed via osmosis.

Dialysis

A treatment that uses machines to filter waste from the blood like a mechanical kidney when the kidneys fail.