hair and scalp

• Hair Shaft

     The visible part of the hair that sticks out of the skin. It consists of three layers
• Cuticle: The outermost layer, made up of overlapping cells that protect the inner layers.
• Cortex: The thickest layer containing melanin, which gives hair its color, and keratin, which gives hair its strength.
• Medulla: The innermost layer, which may be present or absent in fine hair. It is a soft, spongy core.
• Hair Root:

  The part of the hair located below the skin surface.
• Hair Follicle: The structure in the skin from which the hair grows. It surrounds the hair root
• Hair Bulb: The rounded, lower part of the hair root. It contains living cells that divide to grow the hair.
• Dermal Papilla: A structure at the base of the hair bulb that supplies nutrients to the growing hair and is critical for hair growth
• Sebaceous Gland:

  A small gland attached to the hair follicle that secretes sebum (oil) to lubricate and waterproof the hair and skin
• Arrector Pili Muscle:

  A tiny muscle attached to the hair follicle that contracts when you’re cold or scared, causing the hair to stand up (goosebumps).
• Blood Vessels - The scalp is richly supplied with blood vessels that nourish the hair follicles and skin.
• Nerves - The scalp contains sensory nerves that detect touch, pain, and temperature changes.
• Protection - Shields the Scalp: Scalp hair protects your head from the sun's harmful rays and reduces the risk of sunburn.
• Temperature Control - Keeps Your Head Warm: Scalp hair helps keep your head warm in cold weather by trapping heat.
• Sensation - Feels Touch: Scalp hair can sense when something touches your head, like a light breeze or an insect, because it's connected to nerve endings
• Alopecia: The medical term for hair loss, which can occur on the scalp or other parts of the body.
• Common types include Alopecia Areata (patchy hair loss) and Androgenic Alopecia (pattern baldness).
• Folliculitis: Inflammation of the hair follicles, often resulting in small, red bumps or pustules on the scalp.
• Seborrheic Dermatitis: A common inflammatory condition that causes flaky, white to yellowish scales to form on oily areas such as the scalp. It is associated with dandruff.
• Telogen Effluvium: A temporary condition where a significant number of hair follicles enter the telogen (resting) phase, leading to diffuse hair shedding.
• Trichorrhexis Nodosa: A condition where the hair shaft develops weak points, causing it to break easily.
• Tinea Capitis: A fungal infection of the scalp, also known as ringworm of the scalp, which can cause hair loss, scaling, and itching.
• Traction Alopecia: Hair loss caused by constant pulling or tension on the hair, often due to certain hairstyles
• Psoriasis: A chronic autoimmune condition that causes rapid skin cell turnover, leading to thick, scaly patches on the scalp.
• . Trichoscopy: A non-invasive diagnostic method using a dermatoscope to examine hair and scalp conditions.
• Scalp Biopsy: A procedure in which a small sample of scalp tissue is removed and examined to diagnose conditions like alopecia or psoriasis.
• Hair Transplantation: A surgical procedure to move hair follicles from one part of the body to the scalp, often used to treat androgenic alopecia
• It's normal to lose about 50 / 100 hairs per day as part of the natural growth cycle.
• Arrector Pili Muscle - goosebumps
• cortex -  gives hair its strength.
• Dermal Papilla: supplies nutrients to the growing
• Dandruff and Flaking - Dry scalp, fungal infections
• General Hair Thinning - Stress, nutritional deficiencies, hormonal changes