Assignment 6

Indicate Two Mechanisms Used By the Integumentary System To Help Maintain Body Temperature. Indicate two mechanisms used by the integumentary system to help maintain body temperature.

Alter production of sweat Alter diameter of dermal blood vessels Alter secretions from sebaceous glands Alter melanin production (all)

Anchoring the epidermis to the superficial dermis is a thin layer called the __________.

basement membrane

Nails consist of __________.

keratinized epithelial cells

The epidermal cells called __________ are responsible for producing the pigment found in the skin.

melanocytes

Merocrine (eccrine) sweat glands are located __________ and function to __________.

almost everywhere in the body; cool the skin

Within the epidermis, cell division and growth occurs in the stratum __________.

basale

Complete the sentences about the causes of different skin tones.

1. A pale skin tone can occur with constriction of dermal blood vessels . 2. A yellow tint to the skin is associated with jaundice . 3. Flushed or red skin will occur with dilation of dermal blood vessels . 4. A bluish tint to the skin is called cyanosis .

How do apocrine glands differ from other skin glands?

Apocrine glands secrete in response to emotional stimuli.

Function of Integumentary Components Match the component of the integumentary system with its primary function.

Prevents water loss and entry of microorganisms Epidermal layer Provides input about environment and environmental conditions Sensory receptors Maintenance of body temperature Dermal blood supply Production of pigment Melanocytes

Nutrient and oxygen supply for the epidermis comes from blood vessels located in the __________ layer of the skin.

dermal

The surface area of contact between the epidermis and the dermis is increased by structures called __________. This increased surface area allows for improved gas and nutrient exchange and waste removal by dermal blood vessels.

dermal papillae

The dermis extends upward between ridges of epidermis. These dermal extensions are called dermal __________.

papillae

Burns classified as __________ burns heal quickly with no scarring.

superficial partial-thickness

As body temperature increases, the blood vessels of the dermis will __________.

vasodilate

homeostasis /hypothalamus /vasodilation /merocrine sweat/vasoconstriction/shivering

As a part of maintaining homeostasis, body temperature is closely regulated. A change in body temperature is detected by receptors in the hypothalamus of the brain, which then sends signals to effectors in the skin. An increase in body temperature results in vasodilation of blood vessels in the dermis of the skin, allowing heat carried by the blood to dissipate. An increase in body temperature also causes the nervous system to stimulate merocrine sweat glands to increase their activity. A drop in body temperature triggers vasoconstriction, reducing blood flow and, therefore, heat loss from the skin. If a drop in body temperature is great enough, skeletal muscles are stimulated to begin shivering, a mechanism that generates body heat.

The skin has a role in the production of vitamin __________ by the body.

D

What type of burn involves the destruction of some of the epidermis and some of the underlying dermis?

Deep partial-thickness burn

What variation in melanin accounts for the differences in skin tone between individuals?

Differences in the amount of melanin produced

What type of dead cells make up a hair?

Epithelial cells

Healing of Burns Match the description of burn healing with the correct type of burn.

Growth of epidermis from edges of burn; may require skin graft Full-thickness burn Division of stem cells within accessory structures to replace tissue Deep partial-thickness burn Inflammation, then healing without scarring Superficial partial-thickness burn

List the accessory structures that are missing from the skin of the soles of the feet and the palms of the hands, but found elsewhere in the skin of the body. Check all that apply.

Hair

Name the area where growth of a hair occurs.

Hair bulb

What is keratinization and where does it occur?

Hardening of cells; occurs in epidermis

What type of burn involves injury to only the epidermis?

Superficial partial-thickness burn

Skin Pigmentation Complete the following sentences describing pigmentation of the skin.

Melanocytes are epidermal cells that produce the pigment called melanin. These cells are located in the stratum basale of the epidermis, with cellular extensions reaching into more superficial layers. As the melanocytes produce their pigment, the pigment granules migrate along cellular extensions and are transferred to neighboring epidermal cells. As pigment is transferred to other skin cells, the pigment granules position themselves superficial to the nucleus of the skin cell. This protects the nucleus from harmful radiation. The variation in skin color among races is due to differences in the amount of pigment produced, not in the number of melanocytes.

In the dermis of the skin, name the more superficial layer.

Papillary layer

Define the term erythema.

Reddened skin

Complete the sentences describing skin tones.

The condition of the blood and the amount of blood flow can influence skin tone. If someone has a low blood oxygen content, their blood is described as deoxygenated. This individual will have a bluish tint to their skin and mucous membranes. This condition is called cyanosis. If an individual has an increased rate of blood flow to the skin, such as would happen with emotion (such as embarassment) or alcohol consumption, their skin takes on a reddish tint. When someone is cold, the blood flow to the skin is decreased. As a result, this person will have a pale skin tone.

Cells of the Epidermis Complete the sentences describing the cells and layers of the epidermis.

The epidermis consists of multiple layers of epidermal cells called keratinocytes. These cells produce a tough, fibrous, waterproof protein called keratin which, over time, hardens in a process called keratinization. The cells of the epidermis are produced by the process of mitosis in the deepest layer of the epidermis. This layer is called the stratum basale. As new cells are formed, they push older cells further away from the dermis and the blood supply available there. Consequently, the cells die. The dead, hardened outermost cells of the epidermis form the layer called the stratum corneum. These cells eventually are sloughed off.

Why do cells of the epidermis die as they are pushed toward the surface of the skin?

They are too far from their nutrient supply.

To shift position of hair follicles

What is the function of the arrector pili?

Epidermis

When healing a shallow cut in the skin, the rate of mitosis increases in what layer?

Complete the sentences describing the integumentary system.

Recall from earlier chapters that cells are organized into tissues which are organized into organs which, in turn, are organized into organ systems. This chapter looks at the largest organ (by weight) in the body, called the skin. It is part of the organ system called the integumentary system. Also part of this system are structures including nails, hair, sweat glands, and oil glands. These structures are referred to as the accessory structures of the skin.

Altered Skin Tones Complete these sentences describing factors that change skin tone or color.

Skin can take on a yellow tint due to liver malfunction. This yellowish tone is called jaundice When blood oxygen is low, hemoglobin (the blood pigment) is dark red, and the skin will have a bluish tint. This is called cyanosis

During wound healing, granulations may form. What are granulations?

Small masses consisting of a blood vessel and associated fibroblasts.

Arrector pili are located in the dermis of the skin. What are they?

Smooth muscles

Description of Different Types of Glands Match the description with the correct type of secretory gland.

Specialized structures formed of epithelial cells located near or connected to hair follicles (not in palms or soles) Sebaceous glands Function by secreting in response to pain, fear, emotional upset, and sexual arousal Apocrine glands Secrete ear wax into external ear canal Ceruminous glands Function to lower body temperature Merocrine glands Near hair follicles in armpit and groin Apocrine glands Modified sweat glands located in breast tissue Mammary glands Function to keep hair soft, pliable, and waterproof Sebaceous glands Open onto skin surface of forehead, neck, and back Merocrine glands

Name the epidermal layer that is found in thick skin, but is absent from thin skin.

Stratum lucidum