Physiology & Histology of the Skin

Question 1

Which term refers to the STUDY of the FUNCTIONS and ACTIVITIES perfromed by the BODY structures, including PHYSICAL and CHEMICAL processes?

Answer 1

Physiology

Question 2

Which term refers to the STUDY of the STRUCTURE and COMPOSITION of TISSUE?

Answer 2

Histology

Question 3

Why do estheticians need to have a thorough understanding of PHYSIOLOGY and HISTOLOGY?

Answer 3

The complexity of human skin has many LAYERS, COMPONENTS, and FUNCTIONS that all work TOGETHER to PROTECT and REGULATE the SKIN and other parts of the BODY.
Understanding PHYSIOLOGY and HISTOLOGY helps the esthetician use to the best of their knowledge how to help their client BEST maintain their skin’s HEALTH and LONGEVITY.

Question 4

What is the LARGEST ORGAN of the BODY?

Answer 4

Skin

TIP: Strong barrier designed to PROTECT us from outside elements

Question 5

What ASPECTS CONTROL the SKIN’S intricate functions?

Answer 5

HORMONES, GROWTH FACTORS, and OTHER BIOCHEMICALS

Question 6

What is the basic MATERIAL and BUILDING BLOCK for our BODY’S TISSUES?

Answer 6

Protein

TIP: AMINO ACIDS are the BUILDING BLOCKS for our BODY’S TISSUES

Question 7

List the APPENDAGES of the SKIN

Answer 7

HAIR, NAILS, SWEAT GLANDS, and OIL GLANDS

Question 8

List CHARACTERISTICS of HEALTHY SKIN

Answer 8

Healthy skin is SLIGHTLY MOIST, SOFT, SMOOTH, and somewhat ACIDIC

Question 9

What are the SIX (6) PRIMARY FUNCTIONS of the SKIN?

Answer 9

SENSATION, PROTECTION, HEAT REGULATION, EXCRETION, SECRETION, and ABSORPTION

Question 10

Describe the 6 PRIMARY FUNCTIONS of the SKIN

Answer 10

1) Sensation: Touch is one of the FIRST SENSES to DEVELOP. Sensations felt on our SKIN cause us to FEEL, REACT, or MOVE. Different NERVE sensations help us to DETECT and PERCIEVE changes in our ENVIRONMENT, such as HEAT, COLD, TOUCH, PAIN, and PRESSURE. Sensory NERVE FIBERS are the MOST ABUNDANT in the FINGERTIPS and is ONE of the MOST SENSITIVE PARTS of the BODY
2) Protection: SKIN has many DEFENSE MECHANISMS to PROTECT the body from INJURY and INVASION. SEBUM on the EPIDERMIS gives the skin PROTECTION from EXTERNAL FACTORS such as from CERTAIN BACTERIA. The hydrolipidic film on our SKIN also PROTECTS it from DRYING OUT and from EXPOSURE to DAMAGING EXTERNAL FACTORS. The BALANCED pH of the SKIN (4.5-5.5) is IMPORTANT to PROTECT the BODY from PATHOGENS which is why its BARRIER FUNCTION also PROTECTS us from TEWL, SENSITIVITIES, AGING, and DEHYDRATION.
3) Heat Regulation: Our BODY maintains THERMOregulation through EVAPORATION, PERSPIRATION, RADIATION, and INSULATION. Millions of SWEAT GLANDS RELEASE HEAT to keep us from OVERHEATING. Constricting BLOOD VESSELS and DECREASED blood FLOW help to PROTECT ourselves from the COLD, including our BODY FAT. HAIR FOLLICLES also play a big role to PROTECT us from heat loss as our ARRECTOR PILI MUSCLES cause GOOSEBUMPS to WARM UP the SKIN when they CONTRACT from the COLD.
4) Excretion: The SKIN’S SUDORIFEROUS GLANDS excrete PERSPIRATION. They SERVE to PREVENT the body from OVERHEATING. Our LIVER and KIDNEYS help to DETOXIFY any IMPURITIES from our BODY. Heavy SWEATING can cause a LOSS of FLUIDS, DEHYDRATION, and the LOSS of MINERAL BALANCE needed to keep the BODY FUNCTIONING OPTIMALLY. SWEAT is also part of the ACID MANTLE.
5) Secretion: SEBUM PROTECTS the SURFACE of the SKIN and LUBRICATES BOTH the SKIN and HAIR. Our SEBACEOUS GLANDS are APPENDAGES attached to FOLLICLES that PRODUCE SEBUM. These OILS help KEEP the SKIN SOFT and PROTECTED from OUTSIDE ELEMENTS. SEBUM coating the SURFACE of the SKIN SLOWS DOWN the EVAPORATION of WATER (TEWL). EMOTIONAL STRESS and HORMONE IMBALANCES can STIMULATE OIL GLANDS to INCREASE the flow of SEBUM, which can cause ACNEIC BREAKOUTS.
6) Absorption: Absorbing CHEMICALS, HORMONES, MOISTURE, and OXYGEN is NECESSARY for our SKIN’S HEALTH. VITAMIN D is a great example of a VITAMIN that is SYNTHESIZED and PRODUCED in the SKIN upon EXPOSURE to the SUN. ABSORPTION of select TOPICAL PRODUCTS helps KEEP the SKIN MOISTURIZED, NOURISHED, and PROTECTED. Many skin care INGREDIENTS can PENETRATE the SKIN’S DEEPER LAYERS. This EFFECT can be EITHER HARMFUL or BENEFICIAL, depending on the elements in the TOPICAL APPLICATION.

Question 11

The SKIN comprises of THREE (3) MAIN components. Briefly DESCRIBE and LIST those 3 components.

Answer 11

1) Hypodermis/Subcutaneous Layer: LOOSE, CONNECTIVE TISSUE (also known as ADIPOSE TISSUE). This LAYER is composed of 80% FAT, creates a PROTECTIVE CUSHION that gives CONTOUR and SMOOTHNESS to the BODY, and a SOURCE of ENERGY for the BODY. DECREASES and THINS with AGE. Contains VESSELS, NERVES, FIBERS, ADIPOSE CELLS, and FIBROBLASTS
2) Dermis: SUPPORT LAYER of CONNECTIVE TISSUES ABOVE the HYPODERMIS (also known as the DERMA / CORIUM). 25x THICKER than the EPIDERMIS and consists of the RETICULAR and PAPILLARY LAYER. SUPPLIES the SKIN with OXYGEN and NUTRIENTS through a NETWORK of BLOOD VESSELS and LYMPHATIC CHANNELS.
3) Epidermis: The OUTERMOST LAYER of the SKIN and EPITHELIAL TISSUE that COVERS our BODY. A THIN, PROTECTIVE COVERING with MANY NERVE ENDINGS. COMPOSED OF the Stratum Germinativum, Stratum Spinosum, Stratum Granulosum, Stratum Lucidum, Stratum Corneum. MOST IMPORTANT LAYER as estheticians WORK on this layer THE MOST and is within the SCOPE of their PRACTICE.

Question 12

Which term refers to a CELL COMPOSED of KERATIN and comprises 95% of the EPIDERMIS?

Answer 12

Keratinocyte

TIP: Contains BOTH PROTEIN and LIPIDS

Question 13

Which term refers to a FIBROUS PROTEIN that PROVIDES RESILIENCY and PROTECTION?

Answer 13

Keratin

TIP: Found in ALL LAYERS of the EPIDERMIS, including HAIR and NAILS

Question 14

List OTHER CELLS found in the EPIDERMIS

Answer 14

MELANOCYTES, IMMUNE CELLS, LAMELLAR GRANULES, and Merkel CELLS (Nerve Receptors)