Anatomy Chapter 6: Skin and Membranes

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Questions and Answers

What is a membrane and what are the two major categories of body membranes?

A membrane is a thin sheet-like structure. The two major categories are epithelial membranes and connective tissue membranes.

Describe the structure and function of the cutaneous membrane.

The cutaneous membrane, or skin, has a superficial layer of epithelial cells and an underlying layer of connective tissue. It provides protection, regulates temperature, and acts as a sense organ.

Explain the structure and function of a serous membrane.

The serous membrane consists of a thin layer of simple squamous epithelium and a connective tissue layer. It lines body cavities and covers organs.

What is a mucous membrane and what is the mucocutaneous junction?

Mucous membranes line body surfaces opening to the exterior and contain both epithelial and connective tissue layers. The mucocutaneous junction is where skin and mucous membranes meet. Signup and view all the answers

What is the structure of a synovial membrane and its function?

The synovial membrane is a connective tissue membrane that lines joint capsules. It secretes synovial fluid to reduce friction between bones. Signup and view all the answers

Name and describe the layers of the epidermis.

The epidermis has five layers: stratum germinativum (innermost), stratum corneum (outermost), and several others that provide protection and waterproofing. Signup and view all the answers

Explain the structure of the dermis.

The dermis is the deeper skin layer, composed of connective tissue with collagen and elastic fibers. It contains nerves, hair follicles, and glands. Signup and view all the answers

Differentiate between the hair papilla, hair root, and hair shaft.

Hair papilla is where hair growth begins, hair root lies hidden in the follicle, and hair shaft is the visible part of the hair. Signup and view all the answers

What occurs when the arrector pili contract?

The contraction of arrector pili pulls hair upright and causes goosebumps. Signup and view all the answers

Name the four receptors of the skin and their stimuli.

Lamellar corpuscle (detects pressure) and Tactile corpuscle (detects light touch). Signup and view all the answers

What are eccrine glands and what do they produce?

Eccrine glands are sweat glands located all over the body and produce a transparent watery liquid called perspiration. Signup and view all the answers

What are apocrine glands and where are they located?

Apocrine glands are larger sweat glands found mainly in the armpits and around the genitals, producing a thicker secretion. Signup and view all the answers

What are sebaceous glands and what do they secrete?

Sebaceous glands secrete oil called sebum for the hair and skin. Signup and view all the answers

What are the five primary functions of the skin?

Protection, vitamin D synthesis, temperature regulation, sense organ activity, and excretion. Signup and view all the answers

Explain the difference between second-degree and third-degree burns.

Second-degree burns injure the epidermis and upper dermis, causing pain and blisters; third-degree burns destroy the epidermis and dermis completely, leading to tissue death. Signup and view all the answers

What protective function does melanin provide?

Melanin absorbs harmful UV radiation, protecting the skin. Signup and view all the answers

How does the skin regulate temperature?

The skin releases body heat through sweat secretion and by adjusting blood flow close to the surface. Signup and view all the answers

What type of skin cancer is described as a small lesion with center erosion?

Basal cell carcinoma. Signup and view all the answers

The ____, _, and _______ are the three types of epithelial membranes.

Cutaneous, serous, mucous Signup and view all the answers

Epithelial membranes usually consist of two layers: the epithelial layer and a supportive connective tissue layer called the _________________.

Basement membrane Signup and view all the answers

The membrane lining the interior of the chest wall is called the _________________.

Parietal pleura Signup and view all the answers

The membrane covering the organs of the abdomen is called the _________________.

Visceral peritoneum Signup and view all the answers

The connective tissue membrane that lines the space between the bone and the joints is called _________________.

The synovial membrane Signup and view all the answers

The main layers of the epidermis are the....?

Stratum corneum, stratum germinativum Signup and view all the answers

As new skin cells approach the surface of the skin, their cytoplasm is replaced by a unique waterproof protein called........?

Keratin Signup and view all the answers

The upper region of the dermis has projections called ____________ that form unique fingerprints.

Dermal papillae Signup and view all the answers

The _________ are sweat glands that can be found all over the body and produce a transparent watery liquid.

Eccrine Signup and view all the answers

The ____________ are sweat glands that can be found in the armpits and produce a thicker secretion.

Apocrine Signup and view all the answers

The sebaceous glands secrete an oil called ___________.

Sebum Signup and view all the answers

_, , and ______ are the three functions of the skin.

Protection, excretion, vitamin D synthesis, sensation, temperature regulation. Signup and view all the answers

The receptors in the skin that respond to deep pressure in the dermis are called ______________.

Lamellar Pacinian corpuscle Signup and view all the answers

Which of the following is not a warning sign of melanoma?

Density Signup and view all the answers

The receptors in the skin that respond to light touch are called ______________.

Tactile Meissner's corpuscle Signup and view all the answers

Which burn extends below the subcutaneous tissue to reach muscle or bone?

Fourth-degree burn Signup and view all the answers

What is the growth of the epidermal cells into the dermis forming a small tube called?

Hair follicle Signup and view all the answers

What is a cuplike cluster of cells where hair growth begins?

Hair papilla Signup and view all the answers

What part of the hair is hidden in the follicle?

Hair root Signup and view all the answers

What part of the hair is visible and extends from the follicle?

Hair shaft Signup and view all the answers

Study Notes

Body Membranes

Membrane: A thin sheet-like structure in the body.
Two major categories: Epithelial membranes (including cutaneous, serous, and mucous membranes) and connective tissue membranes (synovial membranes).

Cutaneous Membrane (Skin)

Largest organ, composed of an epithelial layer (epidermis) and supportive connective tissue (dermis).
Epidermis has five layers; the innermost is the stratum germinativum (cell division), and the outermost is the stratum corneum (keratinized, protective layer).
Functions: Protection against microbes, regulation of temperature through sweat, sense organ activity (touch, pressure), excretion, and synthesis of vitamin D.

Serous Membrane

Composed of two tissue layers: simple squamous epithelium and a thin connective tissue layer.
Parietal layer lines body cavities; visceral layer covers organ surfaces.
Examples include pleura (lungs), pericardium (heart), and peritoneum (abdominal cavity).

Mucous Membrane

Lines body surfaces open to the exterior (respiratory, digestive, urinary, reproductive tracts).
Contains epithelial and connective tissue layers; produces mucus for moisture and protection.
Mucocutaneous junction: Area where skin meets mucous membranes, lacking accessory organs.

Synovial Membrane

Connective tissue membrane lining joint capsules and bursae, without epithelial components.
Secretes synovial fluid (thick, lubricating) to reduce friction between moving bone surfaces.

Epidermis Layers

Five layers: stratum germinativum (melanin production), stratum corneum (keratin), and others, all contributing to skin protection.

Dermis Structure

Deeper skin layer, made of connective tissue with collagen and elastic fibers.
Contains nerves, blood vessels, hair follicles, sweat and oil glands.
Papillary layer features dermal papillae, contributing to fingerprints; reticular layer provides toughness through collagen.

Hair Structure

Hair papilla: Nourishing base of hair growth.
Hair root: Portion contained in the follicle.
Hair shaft: Visible part extending from the follicle.

Arrector Pili Muscle

Contracts in response to cold or fright, causing hairs to stand upright and skin to form goosebumps.

Skin Receptors

Lamellar (Pacinian) corpuscle: Detects deep pressure.
Tactile (Meissner's) corpuscle: Senses light touch.

Eccrine and Apocrine Glands

Eccrine glands: Widely distributed, producing sweat to regulate body temperature and excrete waste.
Apocrine glands: Located in armpits and genital areas, producing thicker secretion starting at puberty.

Sebaceous Glands

Secrete sebum, an oil that lubricates skin and hair; active during adolescence due to hormonal changes.

Functions of Skin

Protection against environmental damage and microbes.
Vitamin D synthesis.
Temperature regulation through sweat and blood flow adjustments.
Sensory functions detecting touch, pressure, pain, and temperature.
Excretion of waste substances.

Burns

Second-degree burns: Affect deep epidermal layers, causing pain and blisters (partial thickness).
Third-degree burns: Full thickness burns involving destruction of epidermis and dermis; insensitivity to pain immediately after injury.
Fourth-degree burns extend to muscle or bone, considered full thickness.

Melanin

Absorbs UV radiation to protect skin; increased melanin production results in darker skin during prolonged sun exposure.

Temperature Regulation

Skin regulates temperature via sweat evaporation and changes in blood flow near surface.

Skin Cancer

Basal cell carcinoma: Common, less likely to metastasize, presents as a small lesion with central erosion on the face.

Epithelial Membrane Types

Three types: Cutaneous, serous, and mucous membranes.

Basement Membrane

Supportive connective tissue layer under epithelial membranes.

Specific Membranes

Parietal pleura: Lines the chest wall.
Visceral peritoneum: Covers abdominal organs.
Synovial membrane: Lines joint spaces.

Skin Layers to Remember

Main layers: Stratum corneum and stratum germinativum.
Key proteins: Keratin (provides waterproof protection).

Unique Skin Features

Dermal papillae: Contribute to unique fingerprints.
Eccrine glands: Produce clear sweat; found all over body.
Apocrine glands: Produce thicker secretion; found in specific regions like armpits.

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Description

Test your knowledge of membranes in Chapter 6, focusing on the two major categories: epithelial membranes and connective tissue membranes. This quiz will help you define key terms and understand the different types of body membranes. Perfect for students studying anatomy!