Human Anatomy: Hair and Skin Structures

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Questions and Answers

Which layer of the epidermis is primarily composed of dead, fat keratinocytes?

Stratum Granulosum

Stratum Corneum (correct)

Stratum Basale

Stratum Spinosum

What is the main function of melanocytes found in the epidermis?

To produce melanin (correct)

To produce keratin

To provide touch sensation

To ingest foreign debris

How does the Stratum Granulosum contribute to the skin's properties?

By enabling touch sensation

By forming new cells through mitosis

By providing a waterproof barrier via lipid secretion (correct)

By producing melanin

Which of the following skin conditions results from the absence of melanin production?

Albinism Signup and view all the answers

What type of cells are responsible for the sensation of touch in the epidermis?

Merkel Cells Signup and view all the answers

What is considered a critical burn condition?

More than 25% of the body has 2nd degree burns Signup and view all the answers

Which layer of the epidermis is involved in the production of new keratinocytes?

Stratum Basale Signup and view all the answers

Which of the following fungal infections is commonly known as jock's itch?

Tinea cruris Signup and view all the answers

Which of the following is NOT a consequence associated with burns?

Nutrient deficiency Signup and view all the answers

Which pigment produced by melanocytes helps protect the skin against UV radiation?

Melanin Signup and view all the answers

What causes cold sores?

Viral infection Signup and view all the answers

What is the role of Langerhans Cells in the skin?

To ingest bacteria and foreign debris Signup and view all the answers

What is the primary process occurring in the nail matrix for growth?

Mitosis Signup and view all the answers

Which of the following tissues primarily serve as a depot for fat storage in the body?

Adipose tissue Signup and view all the answers

What is the primary composition of each hair?

Keratinized epidermal cells Signup and view all the answers

During which phase of the hair cycle does the hair shed?

Shedding phase Signup and view all the answers

What type of connective tissue primarily makes up the papillary region of the dermis?

Areolar connective tissue Signup and view all the answers

Which glands are classified as exocrine glands in the integumentary system?

Sweat glands and sebaceous glands Signup and view all the answers

Which part of the hair is located beneath the skin's surface?

Hair root Signup and view all the answers

What differentiates the cuticle of the hair from other layers?

It is the outermost and most keratinized layer Signup and view all the answers

What is the primary function of sebum secreted by sebaceous glands?

To lubricate hair and skin Signup and view all the answers

Which structure causes 'goose bumps' in the skin?

Arrector pili muscle Signup and view all the answers

Which component is NOT found in the reticular region of the dermis?

Meissner corpuscles Signup and view all the answers

What is the visible portion of the nail called?

Nail body Signup and view all the answers

What is the combined secretion of the ceruminous and sebaceous glands called?

Cerumen Signup and view all the answers

Which type of sweat gland produces a secretion that evaporates and cools the body?

Merocrine sweat glands Signup and view all the answers

Which of the following parts of nails secures it to the fingertip?

Hyponychium Signup and view all the answers

Which layer of skin is primarily composed of fatty tissues?

Hypodermis Signup and view all the answers

Where are apocrine sweat glands predominantly found in the body?

Armpits and pubic regions Signup and view all the answers

In adults, what percentage of the body surface area is attributed to the legs according to the Rule of 9's?

18% Signup and view all the answers

Which type of burn involves damage to both the epidermis and upper dermis?

Second Degree Burn Signup and view all the answers

Which type of skin cancer is most deadly and known to metastasize rapidly?

Malignant Melanoma Signup and view all the answers

What does the 'A' in the ABCD rule for detecting skin cancer signify?

Asymmetry Signup and view all the answers

How is a first-degree burn typically characterized?

Only epidermis is damaged Signup and view all the answers

Which statement about malignant skin cancers is true?

They can spread to other parts of the body. Signup and view all the answers

What is the correct percentage of the total body surface area attributed to the head in children?

18% Signup and view all the answers

What does a mole with a border irregularity indicate according to the ABCD rule?

It may be cancerous. Signup and view all the answers

Study Notes

Thermal Insulation, Energy Storage, and Shock Absorption

The layer comprises areolar and adipose tissues.
Connective fibers attach to the underlying fascia around muscles and bones.
Acts as a fat storage depot and contains large blood vessels supplying the skin.
Houses nerve endings sensitive to pressure.

Hair Anatomy

Hair is found on almost all skin surfaces except palms, fingertips, soles, and plantar surfaces.
Comprised of dead, keratinized epidermal cells bonded with extracellular proteins.

Parts of the Hair

Hair Shaft: The visible part above the skin.
Hair Root: Extends into the dermis and sometimes the subcutaneous layer.
Hair Follicle: Surrounds the hair root.
Hair Bulb: Base of the hair follicle.

Accessory Structures

Arrector Pili Muscle: Causes "goose bumps" by elevating the skin around hair shafts.
Sebaceous Gland: Oil-producing gland.
Sweat Gland: Regulates body temperature.

Hair Structure

Medulla: Inner center of the hair.
Cortex: Middle layer surrounding the medulla.
Cuticle: Outermost layer, most keratinized.

Hair Cycle

Phases are rest, growth, rest, and shedding.

Nails

Composed of tightly packed, hard, dead, keratinized cells forming a solid cover on the distal digits.

Parts of the Nails

Nail Body (Plate): Visible part of the nail.
Free Edge: Whitish ends.
Nail Root: Embedded in skin folds.
Lunula: Whitish crescent-shaped area.
Hyponychium/Nail Bed: Attaches the nail to the fingertip.
Eponychium/Cuticle: Margin of the nail wall.

Epidermis

Composed of keratinized stratified squamous epithelium, providing protection.
Contains five layers from superficial to deep: Stratum Corneum, Lucidum, Granulosum, Spinosum, Basale.

Epidermal Layers

Stratum Corneum: 25-30 rows of dead keratinocytes.
Stratum Lucidum: Found only in specific areas; 3-5 rows of fat, dead keratinocytes.
Stratum Granulosum: 3-5 rows of flattened keratinocytes; cells starting to degenerate.
Stratum Spinosum: 8-10 rows of keratinocytes with connections to melanocytes and Langerhans cells.
Stratum Basale: Deepest layer with a single row of cuboidal or columnar keratinocytes.

Cell Types in the Epidermis

Keratinocytes: Main cells forming keratin.
Melanocytes: Produce melanin for UV protection and skin pigmentation.
Merkel Cells: Function as touch receptors.
Langerhans Cells: Immune cells that ingest foreign material.

Skin Pigments

Melanin: Yellow to brown-black pigment produced by melanocytes.
Carotene: Yellow-orange pigment derived from Vitamin A.
Hemoglobin: Oxygen-carrying pigment in red blood cells, responsible for red coloring.

Skin Pigment Conditions

Albinism: Lack of melanin production affecting hair, eyes, and skin.
Vitiligo: Partial loss of melanocytes causing irregular white spots.

Dermis

Composed of areolar and dense irregular connective tissue.
Contains collagen and elastic fibers providing strength and elasticity.

Dermis Regions

Papillary Region: Superficial area with areolar connective tissue, containing capillaries and nerve endings.
Reticular Region: Deeper area with dense irregular tissue housing glands, hair follicles, and nerves.

Cutaneous Glands

Exocrine glands in the skin:
- Sebaceous Glands: Secrete sebum, keeping hair hydrated.
- Sweat Glands: Regulate body temperature; different types include merocrine and apocrine.
- Ceruminous Glands: Produce earwax, providing protection.

Hypodermis

Deepest layer of skin, composed of fatty tissue, also known as the subcutaneous layer.

Homeostatic Imbalances of the Skin

Fungal Infections: Includes tinea pedis (athlete's foot), tinea corporis (ringworm), etc.
Bacterial Infections: Problems include boils, carbuncles, and impetigo.
Viral Infections: Includes cold sores.
Burns: Classified based on depth and severity.

Burn Classification

First Degree: Affects only the epidermis; skin is red and swollen.
Second Degree: Affects epidermis and upper dermis; red with blisters.
Third Degree: Destroys entire skin layer; skin appears gray-white or black.

Skin Cancer

Basal Cell Carcinoma: Least malignant and most common.
Squamous Cell Carcinoma: Can metastasize but is highly curable if caught early.
Malignant Melanoma: Most dangerous skin cancer; rapid metastasis, check via ABCD rule.

ABCD Rule for Skin Cancer Detection

A – Asymmetry: Uneven sides.
B – Border Irregularity: Notched edges.
C – Color Variation: Multiple colors in the mole.
D – Diameter: Larger than 6 mm.

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Description

Explore the fascinating details of hair anatomy and associated skin structures in this quiz. Learn about components like hair follicles, sebaceous glands, and the role of connective tissues in thermal insulation. Test your knowledge on how the body regulates temperature and the importance of nerve endings in skin sensitivity.