Is Hair Made of Tissue

[theLovelyStyle]

If so please please provide sources.

I had an argument with a friend about what hair is made of. Mind you, this friend is male and his only source of information was his biology book and his mother. He is convinced that hair is made up of tissue, but I was trying to explain how hair was made up of keratin protein and dead cells.
Also this friend believes that hair growth is determined by length erplexed and grows thicker if cut (We all know this is an illusion, right?)

Anywho, if I'm wrong so be it. If he is right please explain and cite sources.

Thank you.

 

[westNDNbeauty]

tis·sue
   /ˈtɪʃu or, especially Brit., ˈtɪsyu/ Show Spelled [tish-oo or, especially Brit., tis-yoo] Show IPA noun, verb, -sued, -su·ing.
–noun
1.
Biology . an aggregate of similar cells and cell products forming a definite kind of structural material with a specific function, in a multicellular organism.

Technically, you friend may be right. Keratin is created some kind of way in the body right? Would those cells be similar? Probably. Are they structural with a specific function? I would say so.

 

[Tiye]

Does he have a computa and internet service? Tell him to make friends with Google. He'll find plenty of material about hair if he puts some time into searching.

For example ...
hair - definition of hair in the Medical dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia.

 

[theLovelyStyle]

Does he have a computa and internet service? Tell him to make friends with Google. He'll find plenty of material about hair if he puts some time into searching.

For example ...
hair - definition of hair in the Medical dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia.

Yes he does, but I doubt he'll say its even worth looking up. He is just going off what he thought he heard his professor said in class.

 

[theLovelyStyle]

Technically, you friend may be right. Keratin is created some kind of way in the body right? Would those cells be similar? Probably. Are they structural with a specific function? I would say so.

Can you elaborate? I looked up tissue and saw four types of tissue in the human body and none of them seemed to point back to hair directly. They mentioned skin, joints, and bones, etc but no instances or references to hair.

 

[topnotch1010]

Hair is made up of karatinized (change shape & dry out) protein.

If I'm not mistaken, I think tissue needs blood (in humans) to survive.

 

[westNDNbeauty]

Keratin refers to a family of fibrous structural proteins. Keratin is the key structural material making up the outer layer of human skin. It is also the key structural component of hair and nails. Keratin monomers assemble into bundles to form intermediate filaments, which are tough and insoluble and form strong unmineralized tissues found in reptiles, birds, amphibians, and mammals. The only other biological matter known to approximate the toughness of keratinized tissue is chitin

-wikipedia
Keratin - Wikipedia, the free encyclopedia

 

[tHENATuRALhAiRpRoJEcT]

summons Nonie

 

[Bnster]

summons Nonie

That is so cute, I was thinking the same thing.

 

[baglady215]

I think technically it is a tissue, since hair is composed of epithelial cells. A tissue is a group of cells. But you are right as well, because the cells are keratinized.

 

[Nonie]

Technically, you friend may be right. Keratin is created some kind of way in the body right? Would those cells be similar? Probably. Are they structural with a specific function? I would say so.

I agree with @westNDNbeauty. Cells combine to form tissues and inside the follicle hair cells are alive and multiplying and combining to form a pole of cells (tissue), but as they are pushed up and out of the scalp/skin by new cells forming below, their blood supply is cut off and they also form a hard protein and die becoming dead tissue we call hair. To be sure, I checked what the definition of fiber is (since muscle tissue is sometimes referred to as muscle fiber and hair is usually referred to as fiber than tissue)... I wondered if they might mean different things. I found the following definition for fiber:

3. Anatomy a. Any of the filaments constituting the extracellular matrix of connective tissue.
b. Any of various elongated cells or threadlike structures , especially a muscle fiber or a nerve fiber.

(Source)
Here's a class assignment and the answers list hair and fur as tissue:
Comparing Cells, Tissues, and Organs

 

[Nonie]

Oooh theLovelyStyle, I found an article that spells it out

Hair Basics

The hair on our heads isn't just there for looks. It keeps us warm by preserving heat. The hair in the nose, ears, and around the eyes protects these sensitive areas from dust and other small particles. Eyebrows and eyelashes protect eyes by decreasing the amount of light and particles that go into them. The fine hair that covers the body provides warmth and protects the skin. Hair also cushions the body against injury.

Human hair consists of the hair shaft, which projects from the skin's surface, and the root, a soft thickened bulb at the base of the hair embedded in the skin. The root ends in the hair bulb, which sits in a sac-like pit in the skin called the follicle, from which the hair grows.

At the bottom of the follicle is the papilla, where hair growth actually takes place. The papilla contains an artery that nourishes the root of the hair. As cells multiply and produce keratin to harden the structure, they're pushed up the follicle and through the skin's surface as a shaft of hair. Each hair has three layers: the medulla at the center, which is soft; the cortex, which surrounds the medulla and is the main part of the hair; and the cuticle, the hard outer layer that protects the shaft.

Hair grows by forming new cells at the base of the root. These cells multiply to form a rod of tissue in the skin. The rods of cells move upward through the skin as new cells form beneath them. As they move up, they're cut off from their supply of nourishment and start to form a hard protein called keratin in a process called keratinization. As this process occurs, the hair cells die. The dead cells and keratin form the shaft of the hair.

Each hair grows about ¼ inch (about 6 millimeters) every month and keeps on growing for up to 6 years. The hair then falls out and another grows in its place. The length of a person's hair depends on the length of the growing phase of the follicle. Follicles are active for 2 to 6 years; they rest for about 3 months after that. A person becomes bald if the scalp follicles become inactive and no longer produce new hair. Thick hair grows out of large follicles; narrow follicles produce thin hair.

The color of a person's hair is determined by the amount and distribution of melanin in the cortex of each hair (the same melanin that's found in the epidermis). Hair also contains a yellow-red pigment; people who have blonde or red hair have only a small amount of melanin in their hair. Hair becomes gray when people age because pigment no longer forms.

Source: Skin, Hair, and Nails

 

[GraceV]

If so please please provide sources.

I had an argument with a friend about what hair is made of. Mind you, this friend is male and his only source of information was his biology book and his mother. He is convinced that hair is made up of tissue, but I was trying to explain how hair was made up of keratin protein and dead cells.
Also this friend believes that hair growth is determined by length erplexed and grows thicker if cut (We all know this is an illusion, right?)

Anywho, if I'm wrong so be it. If he is right please explain and cite sources.

Thank you.

@ the bolded: You both are on the right track but...

A tissue is a group of similar cells. Bio 101.

Hair is made up of keratinocytes, the suffix -cyte refers to cells Cyte | Define Cyte at Dictionary.com literally "Keratin cells," that is, epithelial cells ( think "surface cells" that make up the skin, hair, nails and the lining of your intestines for example) that undergo Keratinization (keratinization - definition of keratinization in the Medical dictionary - by the Free Online Medical Dictionary, Thesaurus and Encyclopedia. ) to form horny cells a.k.a dead keratin cells. I think it's pretty established on this board that hair is basically dead keratin cells.

Here's an excerpt from Principles of Anatomy and Physiology:

Each hair is composed of columns of dead keratinized cells bonded together by extracellular proteins [....] The shaft and root of the hair both consist of three concentric layers of cells: medulla, cortex, and cuticle of the hair. Hairs are growths of epidermis composed of dead keratinized cells. (Tortorra & Derrickson, 2006, pp. 152-153).

Now if hair was going to be classified under the 4 types of tissues, it would most likely fall under epithelial tissues (remember the "surface" cells/tissues). The problem is: epithelial tissues have their "own nerve supply but [lack their own] Blood supply" (Tortorra & Derrickson, 2006, p. 111). Also Anatomy & Physiology: Epithelial Tissue - CliffsNotes . Hair would not fall smoothly into this classification-- our hair doesn't hurt when you cut it since it has no nerves.


So if your friend is going strictly on the very basic stuff: Similar cells make up a tissue, then dead keratinized cells (which we established as the component of hair) would make keratinized tissue. Looking at the anatomy side of things-- what it's made of.

BUT since hair does not fall into the classification for tissues and does not function as epithelial tissues function (Epithelial tissue bottom of page) it's not exactly tissue material. The physiology side-- how it functions.

Basically hair (and nails) are extensions of your skin (a type of epithelial tissue) that have undergone some changes so that they have differentiated (changed into something else) from what they originally were.

With all this said. I CANNOT believe how much time I invested in finding this information. I'm one of those "curiosity killed the cat" type people who just can't walk away from trivia like this. I'm so mad at myself!

 

[Bnster]

And this why I like LHCF, this place is so informative and inquisitive from members questions and contributions!

ETA: Thanks Nonie and GraceV and all the other ladies on your input.

 

[Aireen]

summons Nonie

Love this!

 

[theLovelyStyle]

And this why I like LHCF, this place is so informative and inquisitive from members questions and contributions!

ETA: Thanks Nonie and GraceV and all the other ladies on your input.

Cosign!

Thanks everybody.

So essentially we were both right I guess. I gather that tissue is live and present inside the follicle during "birth", then pushed up as others grow in, and finally the hair we see on our heads is the result of keratinization.