Dorothy FarrarMechanoreceptors
The mechanoreceptors register mechanical forces and convert these forces into nerve impulses. There are mechanoreceptors in both the skin and internal organs. Misperceptions of the mechanoreceptors can result in faulty organ regulation.
Definition
A group of sensory cells is called mechanoreceptors. These receptors are capable of converting mechanical forces into nerve impulses. Mechanical stimuli from the environment are converted into nerve impulses by mechanoreceptors and thus reach the central nervous system via the nerve tracts , where they are processed.
Anatomy
In a total of five human sensory systems, signal transduction takes place partially or largely via mechanoreceptors. In addition to the sense of touch, the mechanoreceptors play a role in the vestibular system, the perception of body movements, the digestive system and hearing. The structure and anatomy of the receptors differs with the particular sensory system to which they are linked.
Some of the receptors originated from epithelial cells. The other part has developed from ganglion cells. The epithelial form descends from cells on the surface of the body. The conversion of mechanical stimulus into nerve impulses takes place in epithelial mechanoreceptors in the cilia . These cell appendages are connected to the cytoskeleton of the receptors via microtubules . The deformation of the cell appendages thus opens or closes the ion channels through the microtubules. The receptor is thereby either inhibited or excited.
After excitation of the receptor, an action potential is generated at the axon hillock in primary sensory cells. In contrast, a neurotransmitter is released in secondary sensory cells. Unlike epithelial mechanoreceptors, ganglionic mechanoreceptors are embedded in tissue. They have wide branches and nearly a thousand terminals. The transformation of mechanical stimuli takes place in the endings of these terminals. Each terminal can be excited independently of the others. The sum of all terminal excitations is formed in the control center.
Function
Mechanoreceptors are responsible for sensing pressure, touch, and vibration. They accept this reception not only on the outer skin, but also in the mucous membranes of the organs and in the vascular system. The so-called Merkel cells on the border between the epidermis and subcutaneous tissue , for example, perceive sustained pressure. They therefore play a role in the sense of touch.
The same applies to the Meissner probes. They perceive surface sensibilities and register changes in pressure. Thanks to the tactile corpuscles, people register when an object moves on their skin, for example. Hair follicle receptors react to touching the hair and play a role in hearing and the vestibular system.
Father Paccinian bodies, on the other hand, are in the hands and feet. Additionally, they are found in muscles , ligaments , and bones . Thanks to them, man can regulate his strength. They also provide depth sensitivity and respond to vibrations.
In the urinary bladder , on the other hand, mechanoreceptors are responsible for registering stretching and triggering the urge to urinate. Stretch receptors and baroreceptors are also present in the heart . Here they measure the stretching of the aortic arches and transmit the data to the central nervous system, where a blood pressure-regulating response is initiated if necessary.
In the stomach , the stretch receptors register the filling level and ensure a feeling of fullness. In the rectum , the urge to defecate is also controlled by mechanoreceptors. In the auditory and vestibular systems, the hair cells are the mechanoreceptors.
Diseases
- bladder disorders
In most cases, the faulty perceptions of the mechanoreceptors are not caused by diseases of the receptors themselves, but by damage to the nerve tracts that transmit the stimulus. Such damage can occur, for example, in the context of inflammation .
In this context, the inflammatory autoimmune disease multiple sclerosis should be mentioned in particular. In the course of this disease, nerve tissue is destroyed by immunological reactions. For example, sensory disorders of the skin can occur. Tumors of the central nervous system can also be responsible for faulty perceptions of the mechanoreceptors.
Only in rare cases are the receptors themselves affected by diseases. When the mechanoreceptors of the heart or internal organs are affected by disease, they report false perceptions. This can have life-threatening consequences. The regulation of the internal processes can no longer be controlled via the nervous system and misregulations occur. The various organ functions can no longer be coordinated with one another. Thus, the disease of a receptor system can lead to a multi-organ disease.
Primary receptor diseases are, for example, bronchial asthma, bladder disorders, cardiac arrhythmias and gastrointestinal disorders, but also many blood pressure and circulatory disorders. Actual receptor diseases can be caused, among other things, by poisoning.
Hello and welcome to my Health Guide & Encyclopedia! My name is Dorothy Farrar, and I'm the founder and main author of this platform.
My passion for health and wellness started at a young age when I became interested in the connection between the food we eat and the way we feel. This fascination led me to study nutrition and dietetics in college, where I learned about the importance of a balanced diet and the impact of various nutrients on the body.