Are you familiar with fight or flight syndrome? Everyone has experienced it. This is our physiological response to a stressful or terrifying experience. Doesn’t it make you wonder how we react in stressful situations? This fight-or-flight syndrome is mediated by our body’s adrenergic receptors. Adrenergic receptors are proteins that are sensitive to our body’s neurotransmitters: norepinephrine and epinephrine. Adrenergic receptors help regulate our responses to certain stimuli. There are two main types of these receptors: alpha receptors and beta receptors.
We can locate alpha receptors in the postsynaptic region of sympathetic effector junctions in our organs. There are two main types of alpha receptors: alpha1 and alpha2. These alpha receptors play a very important role. Generally, alpha receptors have a big impact on our body’s systems. Regarding our blood vessels, smooth muscles, alpha receptors can constrict the blood vessels of our skin and skeletal muscles. In addition to this, alpha receptors are also responsible for splanchnic vasoconstriction. Since it mediates vasoconstriction, it can help regulate our blood pressure.
Alpha receptors also control myenteric plexus inhibition in the gastrointestinal system. As for our genitourinary system, it regulates uterine contractions in pregnant women. It is also one of the factors that regulate ejaculation in the male penis and seminal vesicles. As for our skin, alpha receptors regulate our motor smooth muscle contractions and apocrine gland contractions. Regarding our metabolic processes, alpha receptors are responsible for gluconeogenesis and glycogenolysis. In other words, alpha receptors act as mediators of the body in the stimulation of several effector cells.
Like alpha receptors, beta receptors are located at postsynaptic organ sympathetic effector junctions. Specifically, beta receptors are found under smooth, involuntary muscles, including our hearts, airways, blood vessels, uterus, and even fat tissue. If alpha receptors are used to stimulate effector cells, beta receptors are used to relax effector cells. There are three main types of beta receptors: beta1, beta2, and beta3. When beta receptors are activated, muscles relax. However, when it comes to our heart, beta receptors stimulate it to beat faster. If alpha receptors cause a pregnant woman’s uterus to contract, beta receptors dilate the blood vessels around the uterus and dilate the airways; thus relaxing the uterine wall.
Most importantly, beta receptors work in the opposite way to alpha receptors. Alpha receptors cause stimulation and contraction; while beta receptors cause relaxation and expansion. When we face the fight-and-flight phenomenon, these bodily processes become our local responses to specific stressors.
Summary:
There are two main types of adrenergic receptors, alpha and beta receptors. Both of these receptors help regulate our fight-and-flight response when we’re exposed to certain stressors.
Both alpha and beta receptors are located postsynapically at sympathetic junctions in several organs. You can find these receptors in the heart, blood vessels, airways, uterus, adipose tissue and many other areas.
There are two main types of alpha receptors: alpha1 and alpha2. There are three main types of beta receptors: beta1, beta2 and beta3.
Alpha receptors are mainly involved in the stimulation of effector cells and the constriction of blood vessels. On the other hand, beta receptors are mainly involved in the relaxation and vasodilation of effector cells.
Although beta receptors regulate our body’s relaxing function, when it comes to the heart organ, they make our heart beat faster and more forcefully.
