Skin and Body Membrane

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What type of skin cancer arises from the cells of stratum spinosum?

Basal cell carcinoma

Malignant melanoma

Keratoacanthoma

Squamous cell carcinoma (correct)

Which of the following is NOT one of the ABCDE rules for detecting malignant melanoma?

Color

Asymmetry

Bleeding (correct)

Diameter

Why is early removal of squamous cell carcinoma important?

It has a good chance of cure if removed early (correct)

It is a benign tumor

It can only be treated with chemotherapy

It has a high chance of metastasizing

What percentage of skin cancers does malignant melanoma account for?

5 percent Signup and view all the answers

What characteristic of malignant melanoma involves changes in the mole's features?

Evolution Signup and view all the answers

Which skin condition is commonly observed at birth and typically disappears by the third week?

Milia Signup and view all the answers

How does malignant melanoma primarily spread in the body?

Through the lymphatic system Signup and view all the answers

What typically covers the body of a fetus by the fifth or sixth month and disappears by birth?

Lanugo Signup and view all the answers

What primarily determines the extent of red coloring in blood?

Hemoglobin oxygen content Signup and view all the answers

Which condition is characterized by a yellow cast to the skin?

Jaundice Signup and view all the answers

What stimulates sebaceous glands to become activated?

Increased levels of androgens Signup and view all the answers

Which type of gland is responsible for body temperature regulation through sweat production?

Eccrine glands Signup and view all the answers

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

Moisten skin and hair Signup and view all the answers

Which of the following is NOT a reason for the skin to appear pale (blanching)?

Increased blood flow Signup and view all the answers

What component is included in the sweat produced by eccrine glands?

Water, salts, and vitamin C Signup and view all the answers

Which type of glands are cutaneous glands classified as?

Exocrine glands Signup and view all the answers

What is the primary function of melanocytes in the skin?

Generate melanin pigment Signup and view all the answers

Which layer of the dermis is responsible for containing blood vessels and sweat glands?

Reticular layer Signup and view all the answers

What type of connective tissue is found in the papillary layer of the dermis?

Areolar connective tissue Signup and view all the answers

Which cells in the epidermis are primarily involved in alerting the immune system to infections?

Epidermal dendritic cells Signup and view all the answers

What characteristic feature do dermal papillae provide to the skin on palms and soles?

Enhanced friction and gripping ability Signup and view all the answers

What pigment is responsible for the orange-yellow coloration found in the skin?

Carotene Signup and view all the answers

Which of the following is NOT a feature of the reticular layer of the dermis?

Sensory nerve endings Signup and view all the answers

What role do Merkel cells play in the epidermis?

Touch sensation Signup and view all the answers

What part of the nail is responsible for its growth?

Nail matrix Signup and view all the answers

Which condition is characterized by an itchy, red peeling skin between the toes?

Athlete's foot Signup and view all the answers

What is the visible attached portion of the nail called?

Nail body Signup and view all the answers

What kind of lesions does impetigo primarily cause?

Fluid-filled raised lesions Signup and view all the answers

Which of the following is NOT a characteristic feature of nails?

Presence of pigment making them colorful Signup and view all the answers

Which skin condition is often triggered by hormonal changes, stress, or trauma?

Psoriasis Signup and view all the answers

How are carbuncles related to boils?

They are clusters of boils caused by bacteria. Signup and view all the answers

The cuticle is described as which part of the nail?

The skin fold overlapping the nail edges Signup and view all the answers

What is the primary role of keratinocytes in the epidermis?

To produce a fibrous protein called keratin Signup and view all the answers

Which layer of the skin is primarily responsible for anchoring the skin to underlying organs?

Subcutaneous tissue (hypodermis) Signup and view all the answers

What is the deepest layer of the epidermis that lies next to the dermis called?

Stratum basale Signup and view all the answers

Which layer of the epidermis is comprised of dead cells and is found only in thick, hairless skin?

Stratum lucidum Signup and view all the answers

What type of epithelium makes up the majority of the epidermis?

Stratified squamous epithelium Signup and view all the answers

What characteristic of the stratum corneum helps to prevent water loss from the skin?

It consists of cells filled with keratin Signup and view all the answers

Which layer of the epidermis contains cells that begin the process of keratinization?

Stratum spinosum Signup and view all the answers

What is a key characteristic of the epidermis that distinguishes it from the dermis?

It is avascular Signup and view all the answers

Study Notes

Vitamin D Synthesis

Modified cholesterol molecules in skin convert to vitamin D when exposed to sunlight.

Structure of the Skin

Skin comprises two main tissue types: epidermis and dermis, with subcutaneous tissue (hypodermis) anchoring it to underlying organs.
Hypodermis consists mostly of adipose tissue, acting as a shock absorber and insulator, but is not part of the integumentary system.

Epidermis

The outer layer of skin made of stratified squamous epithelium.
Predominantly consists of keratinocytes, which produce the fibrous protein keratin, contributing to skin toughness through keratinization.
Lacks blood vessels (avascular) and is organized into five strata from deepest to most superficial: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum (found in thick skin), and stratum corneum.

Stratum Details

Stratum Basale: Deepest layer, adjacent to the dermis, where mitosis occurs.
Stratum Spinosum: Cells flatten and become more keratinized.
Stratum Granulosum: Contains cells transitioning to the next layer.
Stratum Lucidum: Dead cells present only in thick skin (e.g., palms, soles).
Stratum Corneum: Outermost layer made of dead, keratin-filled cells that protect against water loss.

Skin Pigments

Melanin: Produced by melanocytes primarily in the stratum basale; ranges in color from yellow to black.
Carotene: An orange-yellow pigment found in certain vegetables.
Hemoglobin: Gives red coloring from blood cells; oxygen levels affect its intensity.

Dermis

Comprised of connective tissue located under the epidermis, divided into two regions: papillary and reticular layers.
Papillary Layer: Contains dermal papillae that indent the epidermis, comprising areolar connective tissue, capillary loops, and receptors for pain and touch.
Reticular Layer: The deeper layer, formed by dense irregular connective tissue, containing blood vessels, glands, and pressure receptors.

Skin Appendages

Sebaceous Glands: Produce sebum to soften/moisturize skin and hair, active during puberty, and are generally found around hair follicles.
Sweat Glands: Include eccrine (regulate body temperature, acidic sweat) and apocrine glands.
Nails: Composed of keratinized cells; growth occurs from the stratum basale under the nail bed.

Skin Color and Conditions

Erythema: Redness due to embarrassment, inflammation, or fever.
Pallor: Paleness from stress, anemia, or low blood flow.
Jaundice: Yellowing indicating liver disorders.
Bruises: Result from blood pooling in tissues after trauma.

Homeostatic Imbalances

Infections: Include conditions like athlete's foot (fungal), boils (inflammation of hair follicles), and cold sores (herpes).
Contact Dermatitis: Allergic reactions to chemicals causing skin irritation.
Skin Cancers:
- Squamous Cell Carcinoma: UV-induced, arises from stratum spinosum; early removal increases cure chances.
- Malignant Melanoma: Most deadly form of skin cancer, rapid metastasis; identified via ABCDE rule (Asymmetry, Border, Color, Diameter, Evolution).

Developmental Aspects

Fetal Development: Lanugo (downy hair) appears by the fifth month and disappears by birth.
Birth Conditions: Vernix caseosa (oily cover) and milia (small white spots) typically present at birth.
Aging Skin: More prone to acne, scales, and dermatitis.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge on the structure and functions of the skin, including the synthesis of vitamin D and the roles of different skin layers. This quiz covers key concepts related to epidermis, dermis, and subcutaneous tissue. Perfect for those studying anatomy and physiology.