The Integumentary System

What id terminal hair? Vellus hair?

Terminal hair stops growing at one point (eyebrow hair). Vellus hair is fine and temporary (baby hair).

Describe the structure of a strand of hair and the function of the different components.

The structure of a strand of hair contains 3 parts. The medulla is the centermost layer and it is lighter in color. It is made up of soft keratin. The middle layer is the cortex and it is thicker depending on the thickness of the hair. This is controlled by genetics and there are multiple layers of this present. The outermost layer is the cuticle and it is a single layer of cells that serves a protective function and it is heavily keratinized.

What are apocrine gland, where are they found and what is their general function?

Apocrine glands are found in the armpit and anal-genital regions. They release fatty substances and the odor is bacteria. These glands attach to the hair follicle for release. They are activated at puberty. Areolar glands are the nipples. Mammary glands excrete milk and the ceremonious gland (ear wax).

What is carotene and what important role does it play in our bodies? How does it contribute to skin color?

Carotene is found in vegetables we eat and it plays a role in the health of the epidermis. It gives our skin a yellow tint.

What are cleavage lines and why are they important from a medical perspective?

Cleavage lines are ridges in the reticular layer that are parallel to the skin. These are important from a medical perspective when it comes to injuries and surgeries because if that is where a cut is placed, it will speed up the recovery time since there are less fibers there.

What are the layers of the skin and briefly, what unique thing is happening in each?

Corneum, Granulosum, spinosum, basale

How are we able to utilize the appearance of fingernails in diagnosis?

Dubbed or protruding nails: sign on iron deficiency. Yellow tint: thyroid or respiratory disorder Beau's lines: side to side and can be a sign of an eating disorder Longitudinal likes and pitting: radiation therapy Onycholysis: nails detaching from the skin, sickle cell anemia Mee's/Muchikie's lines: horizontal bands, many diseases

What are eccrine gland, where are they found and what is their function?

Eccrine glands are in the dermis and open up as sweat pores of the skin. They are common and we do not control them. They release sweat and vitamins/salts/nitrogenous waste. Dermadin is also found here and it is an antibacterial substance.

Where do fingerprints come from?

Fingerprints come from the friction ridges of the fingertips. The ridges are seen due to oil/sweat given off.

What are flexure lines?

Flexure lines are dermal folds at or near joints.

What contributes to hair color?

Hair color pigment is tied to skin color. the more pheomelanin a hair has the darker it will be and the more eumelanin a hair has the blonder/redder it will be.

What is hemoglobin and what important role does it play in our bodies? How does it contribute to skin color?

Hemoglobin is in the blood and gives our skin a pink tint when it is oxygenated. It can bind with up to 4 oxygen and the more oxygen it binds to the brighter the pink it will be. It will give the skin a bluish tint when it is not oxygenated.

What are the cell types found in the epidermis and be able to explain the importance of their function in the maintenance and function of the epidermis.

Keratinocytes make the barrier from the inside to the outside of the body so it protects from viruses/ bacteria. Also, this barrier prevents uncontrolled water loss because the cells are tightly connected. Melanocytes produce melanin and therefore protect against UV radiation. They are oxidized from tyrosine. Dendritic Cells look like star fish and are a continuous network that are first responders and stimulate an immune response. The ingest foreign substances. they originate in the bone marrow and are also known as longerham cells. Tactile cells aid in the sense of touch

What are our nails composed of? What is their general function?

Our nails are composed of hard carotene and disulfide bridges. The nails protect the fingertips and allows for more precise movement.

What are the general functions of the integumentary system?

Protection: the skin covers the body and it is acidic, dry, and dead making it difficult for bacteria to live on. Body Temperature Regulation: sweat cools the body Cutaneous: sense of touch and pressure (blinking in response to wind) Metabolic Functions: synthesis of Vitamin D and production of keratin from pharagnocytes Blood Reservoir: holds 5% of the body's blood Excretion: nitrogenous waste, salts, etc

What are sebaceous glands, where are they found and what is their function?

Sebaceous glands are everywhere except the palms of the hands and the soles of the feet. They are attached to the hair follicle and the secretion is one by the shaft so the skin is lubricated. It serves a protective function since it kills bacteria.

Explain how and why skin cells die as they move from the intersection of the dermis/epidermis to the outermost part of the skin.

Skin cells die as they move from the intersection of the dermis/ epidermis to the outermost part of the skin because the veins are lower down in the layers. The top layers are not vascularized therefore the cells do not receive nutrients an they eventually flatten out and die.

What are the functions of the reticularly layer and what important structures are found here?

The reticular layer is made up of adipose cells and collagen fibers that make it very compact. The layer cushions the body and binds to water to hydrate the skin. this layer also contains elastic fibers that help "snap" the skin back in place after movement.

How does the epidermis differ from the dermis?

The dermis differs from the epidermis because it is vascularized and contains nerve endings. It also contains the sweat glands, hair follicles, and is made up of connective tissue.

What is the difference between "cyte" and "blast"?

The difference between "cyte" and "blast" is that "cyte" is a mature specialized cell where as "blast" is still maturing.

What is the difference between think skin and thin skin and where are each located?

The difference between thick skin and thin skin id that thick skin has an extra layer in the epidermis called stratum luadom. Thick skin is located in the hands and feet due to the extra friction that is caused there. Thin skin is located everywhere else in the body.

Describe the structure of a hair follicle and the function of the different components.

The hair follicle folds down into the dermis and hypodermis. The bulb anchors the hair and is surrounded by nerve receptors. The hair papilla is vascularized. There is active cell division in the matrix. There is a protective sheath made up of keratinized tissue. The root is where there is living hair and DNA.

What important functions does hair serve us and other mammals?

The hair serves as a source of heat and as a sensory function to sense wind and air pressures. The hair also protects and filters air.

What is the hypodermis and where is it in relation to the layers of the skin? What is important about the hypodermis?

The hypodermis is below the dermis and is a superficial fascia that anchors tissue and muscle. It also works as a shock absorber and stores fat that builds up as we age.

What are the three layers of the skin and what is their location?

The layers of the skin are the dermis, epidermis, and subcutaneous layers. The epidermis is the top layer which is followed by the dermis then the subcutaneous layer.

What are the functions of the papillary layer and what important structures are found here?

The papillary layer is thin and made up of loose areole connective tissue and collagen fibers. It is vascularized and innervated. this layer also aids in the regulation of the body's temperature.

Discuss the different types of skin cancer, being sure to include aggressiveness and the likelihood of recover for each type.

The two types of skin cancer are Melanoma and non-melanoma. Melanoma can spread throughout the body and is therefore more aggressive but it only accounts for about 4% of the cases. It can start in moles or because of an excess of melanin from melanocytes. Non-melanoma accounts for 80% of cases and is not as serious. It comes from keratinocytes. There are two types: 1. Basal Cells (BSC) and it is slow growing and not aggressive. 2. Squamous Cell (SSC) ad it is rare but more aggressive.

What three factors contribute to skin color?

Three factors that contribute to skin color are melanin, carotene, and hemoglobin.

How do UVA and UVB differ? Which is more commonly linked with skin cancer?

UVA gives our skin a tan appearance while UVB burns our skin. UVB is linked with cancer.

Where do we get melanin? What important function does it serve?

We get melanin from the melanocytes in the epidermis and it gives our skin its tone. Melanin is converted from tyrosine and protects DNA from UV radiation by targeting specific locations. UV radiation causes thymine diners (mutation in DNA) that build up over time.