Maintaining homeostasis in the human body involves the coordination of various physiological processes, and receptors play a crucial role in sensing and responding to changes in the internal and external environment. The measurement of the performance of these receptors is the time to return to homeostasis, for example skin elasticity with age.

Thermoreceptors:

Location: Skin, hypothalamus

Function: Monitor body temperature and initiate responses to maintain thermal equilibrium.

Baroreceptors:

Location: Arteries (especially in the carotid sinus and aortic arch)

Function: Monitor blood pressure and regulate it by influencing heart rate and blood vessel diameter.

Osmoreceptors:

Location: Hypothalamus

Function: Sense changes in osmotic pressure of the blood and regulate water balance and thirst.

Glucose Receptors:

Location: Pancreas (specifically in the islets of Langerhans)

Function: Monitor blood glucose levels and regulate insulin and glucagon release to maintain glucose homeostasis.

Chemoreceptors:

Location: Peripheral chemoreceptors in the carotid bodies and aortic bodies, central chemoreceptors in the medulla oblongata

Function: Detect changes in the concentration of oxygen, carbon dioxide, and pH in the blood and cerebrospinal fluid, regulating respiratory rate and depth.

Ion-Specific Receptors (e.g., Sodium and Potassium Receptors):

Location: Various tissues, especially in the kidneys

Function: Monitor ion concentrations in the blood and extracellular fluid, influencing electrolyte balance and blood pressure.

Stretch Receptors:

Location: Various tissues, including the walls of organs like the stomach and bladder

Function: Monitor the stretching of tissues and contribute to reflexes that regulate organ function.

Hormone Receptors:

Location: Various tissues, depending on the specific hormone

Function: Bind to hormones and initiate cellular responses, contributing to the regulation of various physiological processes.

Pain Receptors (Nociceptors):

Location: Throughout the body, especially in the skin, muscles, and internal organs

Function: Detect tissue damage or potential harm and trigger pain sensations to protect the body.

Light Receptors:

Location: Retina of the eye (rods and cones)

Function: Detect light stimuli and initiate visual responses to maintain visual perception.

Calcium Receptors:

Location: Parathyroid glands and thyroid glands

Function: Monitor blood calcium levels and regulate the secretion of parathyroid hormone (PTH) and calcitonin to maintain calcium homeostasis.

Red Blood Cell Receptors (Oxygen Sensors):

Location: Kidneys and tissues

Function: Monitor oxygen levels in the blood and tissues, regulating erythropoietin release to stimulate red blood cell production.

Aldosterone Receptors:

Location: Kidneys

Function: Monitor sodium and potassium levels in the blood and regulate aldosterone release to maintain electrolyte and fluid balance.

Leptin Receptors:

Location: Hypothalamus and other tissues

Function: Monitor fat stores and regulate appetite and energy expenditure to maintain body weight and adipose tissue homeostasis.

Prostaglandin Receptors:

Location: Various tissues, including the kidneys, blood vessels, and gastrointestinal tract

Function: Respond to prostaglandins, influencing inflammation, blood flow, and other physiological processes.

Volume Receptors:

Location: Heart and major blood vessels

Function: Monitor blood volume and influence the release of antidiuretic hormone (ADH) to regulate water reabsorption in the kidneys.

Cholecystokinin Receptors:

Location: Gastrointestinal tract

Function: Respond to cholecystokinin, regulating the release of bile and pancreatic enzymes to aid in digestion and nutrient absorption.

Stretch Receptors in the Lungs:

Location: Bronchi and bronchioles

Function: Monitor lung expansion and initiate reflexes that regulate respiratory rate to maintain proper oxygen and carbon dioxide levels.

Adenosine Receptors:

Location: Various tissues, including the brain and blood vessels

Function: Respond to adenosine, influencing blood flow, neurotransmitter release, and other processes to maintain cellular energy balance.

Gastrin Receptors:

Location: Stomach lining

Function: Respond to gastrin, regulating the secretion of gastric acid and promoting digestive processes in the stomach.

Vitamin D Receptors:

Location: Various tissues, including the intestines, bones, and immune cells

Function: Monitor vitamin D levels and regulate calcium absorption in the intestines and calcium mobilization from bones.

Cortisol Receptors (Glucocorticoid Receptors):

Location: Various tissues, including the liver, immune cells, and adipose tissue

Function: Respond to cortisol, influencing metabolism, immune response, and stress adaptation.

Taste Receptors:

Location: Taste buds on the tongue and oral mucosa

Function: Detect various tastes (sweet, salty, sour, bitter, umami) and influence dietary choices to maintain nutritional homeostasis.

Pressure Receptors in the Bladder:

Location: Bladder walls

Function: Monitor bladder distension and initiate reflexes to regulate urinary function and maintain bladder homeostasis.

Cannabinoid Receptors:

Location: Brain, immune cells, and various tissues

Function: Respond to endocannabinoids and influence processes such as appetite, pain perception, and immune function.

Vestibular Receptors:

Location: Inner ear (vestibular system)

Function: Monitor head movements and spatial orientation, contributing to balance and postural control.

Stretch Receptors in the Liver:

Location: Liver

Function: Monitor liver distension and contribute to the regulation of blood glucose levels and other metabolic processes.

Melatonin Receptors:

Location: Brain (pineal gland) and various tissues

Function: Respond to melatonin, influencing circadian rhythms, sleep-wake cycles, and seasonal adaptation.

Pressure Receptors in the Digestive Tract:

Location: Stomach and intestines

Function: Monitor stretch and pressure in the digestive organs, regulating digestive processes and the movement of food.

Neurotrophin Receptors:

Location: Nervous system

Function: Respond to neurotrophins, influencing the survival, development, and function of neurons in the central and peripheral nervous systems.