Podcast
Questions and Answers
What type of gland is characterized by having a narrow lumen and opens directly onto the skin surface?
What type of gland is characterized by having a narrow lumen and opens directly onto the skin surface?
What component of hair follicles is responsible for the growth in length of hair?
What component of hair follicles is responsible for the growth in length of hair?
Where do the ducts of sweat glands typically open?
Where do the ducts of sweat glands typically open?
What type of secretion is produced by sebaceous glands?
What type of secretion is produced by sebaceous glands?
Signup and view all the answers
What feature distinguishes thick skin from thin skin concerning sweat glands?
What feature distinguishes thick skin from thin skin concerning sweat glands?
Signup and view all the answers
What structure forms a hole for hair roots and is lined with a specific type of epithelium?
What structure forms a hole for hair roots and is lined with a specific type of epithelium?
Signup and view all the answers
Which of the following components is NOT part of the hair follicle structure?
Which of the following components is NOT part of the hair follicle structure?
Signup and view all the answers
What type of keratin is found in the hair shaft?
What type of keratin is found in the hair shaft?
Signup and view all the answers
Which characteristic distinguishes the apical section of secretory cells in sweat glands from their basal portion?
Which characteristic distinguishes the apical section of secretory cells in sweat glands from their basal portion?
Signup and view all the answers
Which statement is true regarding the secretory parts of sweat glands?
Which statement is true regarding the secretory parts of sweat glands?
Signup and view all the answers
What role do male and female sex hormones play in sweat gland function?
What role do male and female sex hormones play in sweat gland function?
Signup and view all the answers
How are sebaceous glands characterized in terms of their secretion method?
How are sebaceous glands characterized in terms of their secretion method?
Signup and view all the answers
What is a defining structural feature of the hair follicle's wall?
What is a defining structural feature of the hair follicle's wall?
Signup and view all the answers
What structural element helps provide the hair with color?
What structural element helps provide the hair with color?
Signup and view all the answers
Which of the following regions is NOT densely populated with sweat glands?
Which of the following regions is NOT densely populated with sweat glands?
Signup and view all the answers
What type of keratin is found in the root of hair follicles?
What type of keratin is found in the root of hair follicles?
Signup and view all the answers
Study Notes
Skin Related Structures
- Skin includes sweat glands, hair, hair follicles, sebaceous glands, and arrector pili muscles.
Sweat Glands
- Location: Deep in the dermis or hypodermis.
- Density: More numerous in thick skin than thin skin.
- Type: Simple coiled tubular gland.
- Structure:
- Secretory parts (acini): These produce sweat.
- Excretory parts (ducts): Collect sweat secretion from the acini. - Merocrine glands: Duct ascends in a spiral to the epidermis, opening on the skin's surface. - Apocrine glands: Duct opens into a hair follicle.
Types of Sweat Glands
- Merocrine (Eccrine):
- Location: Nearly all over the body.
- Number: Very numerous.
- Secretion Mode: Secretory cells remain intact after secretion.
- Function: Secretion of "sweat."
- Secretory Part: Narrow lumen.
- Excretory Part: Opens on the skin surface.
- Apocrine:
- Location: Axilla, areola of the breast, pubic region, perianal region.
- Number: Less numerous.
- Secretion Mode: Apical part of cytoplasm detaches during secretion (artifact).
- Function: Secretion of a "characteristic sweat" after puberty, influenced by sex hormones.
- Secretory Part: Wide lumen.
- Excretory Part: Opens into a hair follicle.
Hair
- Structure (by Naked Eye):
- Shaft: Projects above the skin surface.
- Root: Embedded or implanted in the skin.
- Internal Structure:
- Medulla: Polyhedral cells, containing soft keratin.
- Cortex: Elongated cells containing hard keratin and melanin (hair color). Flat scales.
- Cuticle: Contains hard keratin.
-
Hair Bulb: Expanded lower end of the hair, where hair matrix (cellular mass) proliferation leads to hair growth.
- Consists of hair matrix —a cellular mass.
- Its proliferation leads to hair growth in length
Hair Follicle
- Definition: Hole formed by epidermal down-growth, containing the hair root.
- Structure (Root Sheath):
- Inner root sheath
- Outer root sheath
- Connective tissue (CT) sheath: Condensed part of the dermis. The outer root sheath is continuous with the epidermis's malpighian layer.
- It is identical with the Malpighian layer of the epidermis.
- It acts as condensed part of the dermis C.T
Sebaceous Glands
- Location: Opens into the upper 1/3 of the hair follicle, at an obtuse angle to the follicle surface.
- Secretion Mode: Holocrine (central cells disintegrate to secrete sebum).
- Structure:
- Sac-like structure.
- Secretory part (alveoli): Form a common duct.
- Excretory duct: Short, wide, opening into the upper 1/3 of the hair follicle. Lined with stratified squamous epithelium.
Arrector Pili Muscle
- Definition: Smooth muscle band at the bottom of the sebaceous gland.
- Function: Contraction leads to:
- Hair shaft erection.
- Sebaceous secretion squeezing into the duct.
- Goosebumps (appearance of goose skin).
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
