Physiological functions of the skin
The skin is permeated with nerve endings and acts as a primary analyzer, transmitting information to the central nervous system.
Main functions of the skin:
- Barrier — protects against mechanical damage, aggressive chemicals, and bacterial penetration.
- Excretory — eliminates excess heat and metabolites from the body via sweat.
- Respiratory — participates in gas exchange.
- Bactericidal — destroys pathogens owing to the acidic surface environment.
- Vitamin-synthesizing — produces vitamin D upon moderate ultraviolet exposure.
Sebum (sebaceous gland secretion) maintains skin elasticity, protects against desiccation and damage, and prevents excessive softening of the stratum corneum by sweat.
Consequences of skin contamination
The skin is constantly contaminated by products of its own metabolism, as well as dust and dirt from the external environment.
If the skin is not cleansed, a pathological cascade is triggered:
- A layer of dirt clogs the ducts of the skin glands.
- Bacteria proliferate within the blocked sebaceous glands, causing inflammation (folliculitis).
- Microorganisms decompose organic contaminants, releasing fatty acids, which leads to malodor and irritation.
- Against the background of these changes, dermatitis, pyoderma, and fungal infections develop.
Cleansing rules and bath procedures
The baseline care method is regular washing with hot water, soap, and a washcloth. However, excessive use of hot water and harsh soaps (with a high free alkali content) leads to defatting of the skin, decreased resistance to cold, and loss of tone. Showering is optimal.
It is recommended to take bath procedures once a week.
| Bath type | Temperature | Humidity | Features |
|---|---|---|---|
| Russian steam room | 45–60 °C | 90–100% | Exerts therapeutic and prophylactic effects |
| Finnish (sauna) | 80–90 °C | 5–15% | Better tolerated due to dry air, accelerates recovery after exertion |
Hygiene of specific body areas
- Hands: require frequent washing. Since the vast majority of bacteria accumulate under the nails, a brush is necessary for thorough cleansing. After washing, hands must be dried with an individual towel or electric hand dryer. Medical personnel must pay special attention to hand hygiene.
- Face and neck: washing twice a day is sufficient. Very hot water and frequent use of soap or alcohol-based products should be avoided to prevent skin dehydration.
- Hair: washing is recommended no more than once a week. Head massage and brushing are useful for stimulating growth, as they improve blood circulation and nutrition of the hair follicles.
- Feet: require frequent washing due to increased sweating and rapid contamination.
Prevention of epidermophytosis
Public baths, swimming pools, and showers are frequent sites of infection with foot fungus (Epidermophyton). The disease is transmitted by contact and domestic routes through shared footwear, basins, or washcloths. The lesion begins in the interdigital folds (scaling, vesicles, fissures, pruritus) and can spread to the nails, making them dull and crumbly. Without treatment, the infection becomes chronic.
For prevention, it is essential to strictly use individual footwear (rubber slippers) and hygiene items in public places, as well as to promptly treat hyperhidrosis of the feet.
Briefly: answers to topical questions
What nosological forms of pustular infections (pyoderma) develop when skin glands are occluded?
Mechanical occlusion of skin glands and bacterial invasion lead to inflammation and pustular skin diseases.
The main nosological forms include:
- Folliculitis — inflammation of occluded sebaceous glands.
- Furuncle — acute purulent-necrotic inflammation of a hair follicle, sebaceous gland, and surrounding tissue.
- Carbuncle — a conglomerate of inflamed follicles.
- Hidradenitis — inflammation of apocrine sweat glands.
What is the algorithm for surgical hand scrubbing by medical personnel?
The algorithm for surgical hand antisepsis by medical personnel includes preliminary washing followed by antiseptic treatment.
Procedure stages:
- Hand washing — performed before applying antiseptics.
- Antiseptic treatment — performed with a 0.5% alcohol solution of chlorhexidine, iodine, lysanin, or other preparations for 2–3 minutes.
- Donning gloves — after treatment, sterile surgical rubber gloves must be worn for aseptic performance of the surgery.
Through what physiological mechanisms does the skin dissipate heat?
The skin dissipates heat via physical thermoregulation mechanisms, including changes in vascular tone and sweat gland activity.
Main heat dissipation pathways:
- Radiation — infrared heat radiation, accounting for 45% of heat loss at rest.
- Convection — heat transfer by moving currents of air or water (30%).
- Perspiration (evaporation) — the physiological process of sweating and moisture evaporation from the skin surface (25%).
- Conduction (heat conduction) is the contact transfer of heat upon touching cold surfaces.
At high temperatures, vasodilation (widening of skin blood vessels) occurs, which increases radiation and convection heat loss, and sweating also sharply increases.
Class and exam questions
Why should laundry soap not be used for daily washing?
Laundry soap contains up to 2% free alkali (toilet soap contains no more than 0.05%). This leads to severe degreasing of the skin, dryness, and loss of protective properties.
How to properly clean subungual spaces?
Up to 95% of the microflora of the hands accumulates under the nails. These microorganisms can only be removed using a special brush.
Why is a Finnish sauna tolerated easier than a Russian bath?
Despite the higher temperature (80–90 °C), the sauna has very low humidity (5–15%), which facilitates sweat evaporation and thermoregulation processes.
What else to study on this topic
- Pathogenesis and consequences of hypokinesia
- Specific and non-specific effects of physical exercise
- Mechanisms of cardiovascular system adaptation to exercise
- The role of physical activity in mental labor
- Clinical stages of tinea pedis
Master the entire topic in the "Hygiene" course
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Other topics in "Chapter 9. Personal Hygiene and Healthy Lifestyle"
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