Anatomy and physiology Lab quiz 4

Arrector pili

Thin ribbons of smooth muscle, extending from the hair follicle to the formal papillae.

Keratinization

This process begins within the stratum Granulosum, where the keratinocytes fill up with the protein keratin, and in so doing, cause both the cell's nucleus and organelles to disintegrate and the cells dies. The process is not complete until the cells reach the superficial epidermal layers.

Sweat glands duct

Transports the secretions to the surface of the epidermis( in a merocrine sweat gland) or into a hair follicle( in an apocrine sweat gland).

Stratum spinosum or spiny layer

Formed by sveral layers of polygonal keratinocytes

Thick skin

Is found on the palms of the hands, and the soles of the feet. All five epidermal strata occur in _____ skin. The epidermis of ____ skin ranges between 0.4 mm and 0.6 mm thick. It houses sweat glands but has no hair follicles or sebaceous( oil) glands.

The Integument

Is the skin that covers your body

Shaft

Is the third portion of he hair that extends beyond the skin surface. Consists of dead epithelial cells.

Root

Is the zone of the hair extending from the bulb to the skin surface. Consists of dead epithelial cells.

Stimulation of the arrector pili

Is usually a result of an emotional state, such as fear or rage, or as a response to exposure to cold temperatures. Upon stimulation, the arrector pili contracts, pulling on the hair follicle and elevating the hair producing "goosebumps."

Terminal hair

Is usually coarser, pigmented, and longer than vellus. it grows on the scalp, and it is also the hair of eyebrows and eyelashes. At puberty, ______hair replaces vellus hair in the Dillard and pubic regions, and it forms the beard on the faces of males.

Epidermis

It is keratinized ,stratified squamous epithelium

lines of cleavage

(tension lines) in the skin identify the predominant orientation of collagen fiber bundles.

The cells of the Stratum corneum contain large amounts of the protein ________ ?

Keratin

Three types of cells occupy the stratum basale

Keratinocytes, Melanocytes, Tactile cells

The stratum basale is dominated by ?

Large keratinocytes stem cells, which divide to generate new cells that replace dead keratinocytes shed from the surface.

Apocrine sweat glands

Location: axilla, areola of the breast, pubic, and anal regions Description: coiled tubular glands located next to hair follicles. Ducts open into the hair follicle. Mode of secretion: Merocrine- exocytosis of vesicles containing product into the duct of the gland Function: produce a thick, slightly oily sweat that may have pheromone-like properties Word orgin: apo-,away from, + krino, to separate o secrete

Merocrine( eccrine) sweat glands

Location: most of the surface of the body Description: coiled tubular glands whose main secretory portions are found deep within the reticular layer of the dermis. Mode of secretion: Merocrine- exocytosis of vesicles containing product into the duct of the gland Function: Produce the thin, watery sweat that cools the body Word origin: meros, share,+ krino, to separate or secrete

Nervous tissue detects and monitors ?

Sensory stimuli in the skin, which provides information about touch, pressure, temperature, and pain.

Thick vs. thin

Skin is classified as either thick or thin based on the number of epidermal strata and the relative thickness of the epidermis, rather than the thickness of the entire integument.

Which 3 specific layers, or strata are composed of living keratinocytes?

Stratum basale, stratum spinosum, stratum granulosum

Sebum

An oily , waxy secretion, that is usually discharged into the hair follicle and onto the hair itself. produced by sebaceous glands that are holocrine glands. Acts as lubricant to keep the skin and hair from becoming dry, brittle, and cracked. Also has some bactericidal (bacteria-killing) properties.

The cells of the follicle walls are organized into two principal concentric layers:

An outer connective tissue root shear and an inner epithelial tissue root sheath

Apocrine glands

Are coiled, tubular glands that release their secretions into the hair follicles in the axillae , around the nipples , in the pubic region, and in the anal region. Produce their secretions by exocytosis. The secretions they produce is viscous and cloudy, and it contains both proteins and lipids that are acted upon by bacteria to produce a distinct, noticeable order. These sweat glands become active and produce secretions beginning around puberty.

Sebaceous glands

Are holocrine glands that'll office an oily, waxy secretion called sebum. The secretion of sebum in both sexes is stimulated by hormones, especially androgens( male sex hormones). Sebaceous glands are relatively inactive during childhood; however, they are activated during puberty in both sexes, when the production of sex hormones increases

Epidermal dendritic cells

Are immune cells that help fight infection in the epidermis. These immune cells are often present in the stratum spinosum and stratum granulosum, but they are not identifiable in standard histologic preparations. Their phagocytize activity initiates an immune response to protect the body against pathogens that have penetrated the superficial epidermal layers as well as epidermal cancer cells.

Ceruminous glands

Are modified apocrine sweat glands located in the external acoustic meatus( ear canal), where their secretion forms a waterproof earwax called cerumen. Both cerumen and the tiny hairs in the meatus help trap foreign particles or small insects and keeps them from the reaching the eardrum. Cerumen also helps lubricate the external acoustic meatus and eardrum.

Merocrine glands

Are the most numerous and widely distributed sweat glands. The adult integument contains between 3 and 4 million merocrine sweat glands. They are simply coiled tubular glands that discharge their secretions directly onto the surface of the skin. The clear secretion they release by exocytosis is called sweat. _______ sweat glands major function is thermoregulation, which is the regulation of the body temperature by evaporation of fluid from the skin. ___ sweat glands provide a means for the loss of both. Water and electrolytes. The secretions also help eliminate a number of ingested drugs. And provide some protection from environmental hazards both by diluting harmful chemicals and by preventing the growth of microorganisms ( antibacterial and antigen goal activity.)

Vellus

At birth , most of the lanugo has been replaced with similarly fin unpigmneted or lightly pigmented hair called _____. it is the primary human hair and is found on the upper and lower limbs.

Nail matrix

At the nail root and the proximal end of the nail body, the nail bed thickens to form the _______ _________ , which is actively growing part of the nail.

The deepest epidermal layer is the ?

Stratum basale, this single layer of cuboidal to low columnar cells is tightly attached to an underlying basement membrane that separates the epidermis from the connective tissue of the adjacent dermis.

Layer Epidermis contains which specific layers:

Stratum corneum, Stratum lucidum, Stratum granulosum, Stratum spinosum, Stratum basale

The most superficial two strata that contain dead cells ?

Stratum corneum, stratum lucidum

The connective tissue that underlies the epithelium provides ?

Strength and resilience to the skin

Their name is derived from their synthesis of keratin , a protein that ?

Strengthens the epidermis considerably.

Dermis contains which specific layers:

Superficial Papillary layer and deeper Reticular layer

Hair papilla

Surrounded by the epithelium at the base of the bulb, which is composed of a small amount of connective tissue containing tiny blood vessels and nerves.

Nail folds

along the lateral and proximal borders of the nail, folds of skin called_____ ________ overlap the nail.

Cavernous Hmangiomas

also known as port-wine stains, involve larger dermal blood vessels and may last a life time.

Eponychium (epi= upon , onyx= nail)

also known as the cuticle, is a narrow band of epidermis extending from the margin in the nail wall onto the nail body.

dermal papillae(top part) and epidermal ridges(bottom part)

interdigitate much like two sets of egg crate foam stacked on top of one another. Together they increase the area of contact between the two layers and interlock them.

Hyponychium (hypo= below)

is a region of the thickened stratum corneum over which the free nail edge projects.

functions of the intergument

protection,prevention of water loss and water gain, metabolic regulation (vitamin D) , secretion and absorption, immune function, temperature regulation and sensory reception

Stratum spinosum

several layers of keratinocytes attached to neigors by desmosomes: epidermal dendrite cells present

Which specific layers , or strata of the epidermis can only be found in THICK skin?

stratum lucidum

Papillary layer

superficial layer of dermis; composed of areolar connective tissue; forms dermal papillae

Nail bed

the nail body covers a layer of epidermis called _______. Which contains only the deeper, living cell layers of the epidermis.

Melanocyte activity and the color of the melanin produced by these cells varies among individuals and race, resulting in different skin color tones? true or false?

true

Does everyone have the same amount of melanocytes ?

yes

This connective tissue also contains smooth muscle associated with hair follicles (arrector pili) that ?

Alters hair position

Sweat pore

An indented region located in the opening of the sweat gland duct on the epidermal surface

Nail plate

formed by the nail body, nail root and nail plate

Differences in hair density are due primarily to ?

Differences in the texture and pigmentation of the hair

Keratinized cell

Is dead( because it has neither a nucleus nor organelles), but it is structurally strong because of the keratin it contains.

Hair

Is found almost everywhere on the body except the palms of the hands and Palmer surface of the fingers, the sides and soles of the feet and toes, the lips.

Cortex

Relatively hard,Formed by several layers of flattened cells closer to the outer surface of the developing hair

Stratum lucidum

2-3 layers of anucleate, dead keratinocytes; seen only in thick skin (e.g., palms of hands, soles of feet). This layer helps protect the skin from ultraviolet light.

Stratum granulosum

3-5 layers of keratinocytes with distinct grandules of cytoplasm; keratinization begins in this layer

Eleidin

A translucent protein that fills the flattened keratinocytes within the stratum lucidum. It is an intermediate product in the process of keratin maturation.

Melanin pigment( which includes the colors black, brown, tan, or yellow-brown)

Accumulates around the nucleus of the keratinocytes and shields the nuclear DNA from ultraviolet radiation. The darker tones of the skin result from melanin produced by the melanocytes.

Tactile cells

Also called Merkel cells, are few in number and found scattered song the cells within the stratum basale. Their sensitive to touch and, when compressed, they release chemicals that stimulate sensory nerve endings, providing information about objects touching the skin.

Merocrine and apocrine sweat glands

Both have a coiled, tubular secretory portion that is located In the reticular layer of the dermis.

Hair bulb

Consists of epithelial cells and is a swelling at the base where the hair originates in the dermis. Consists of living epithelial cells.

The integumentary system

Consists of the skin and its derivatives: nails, hair, sweat glands, and sebaceous (oil) glands.

Thin skin

Covers most of the body. it lacks a stratum lucidum, so it only has four specific layers in the epidermis. ____ skin contains the following structures: hair follicles, sebaceous glands, sweat glands. The epidermis of thin skin ranges from 0.075 mm to 0.150 mm thick.

Skin is also known as the _____ _______.

Cutaneous membrane

The keratin a found in epidermal cells of the skin are called ?

Cytokeratins, their structure in these cells gives skin its strength and makes the epidermis almost waterproof.

Reticular layer

Deeper layer of dermis; composed of dense irregular connective tissue surrounding hair follicles, sebaceous glands and sweat glands, nerves, and blood vessels

Stratum basale

Deepest, single layer of cuboidal to low columnar keratinocytes in contact with basement membrane; cell division occurs here; also contains melanocytes and tactile cells

Hair matrix

Hair production involves a specialized type of keratinization that occurs here. A structure immediately adjacent to the hair papilla in the hair bulb.

Melanocytes

Have long, branching processes and are scattered among the keratinocytes of the stratum basale.

It's surface is an epithelium that protects ?

Internal body structures

Lanugo

Is a fine, unpigmented, downy hair that first appears o the fetus in the last trimester of development.

Melanin

Is a pigment produced and stored in melanocytes. This pigment that gives human skin, hair, and eyes their color. Dark-skinned people have more melanin in their skin than light-skinned people have.

Hair follicle

Is an oblique tube that surrounds the hair root. It always extends into the dermis and sometimes into the subcutaneous layer.

Hemoglobin

Is an oxygen-binding protein present in red blood cells. It exhibits a bright red color upon binding oxygen, thus giving blood vessels in the dermis a reddish tint that is seen most easily in lightly pigmented individuals.

Melanocytes cytoplasmic processes transfer melanin pigment within ?

Melanosomes, to the keratinocytes within the basal layer and sometimes in more superficial layers.

Stratum corneum

Most superficial layer of epidermis; 20-30 layers of dead, flattened, anucleate, keratin-filled keratinocytes. The dead cells are anucleate( lacking a nucleus) and are tightly packed together.

Medulla

Not found in all hair types, is a remnant of the soft core of the matrix. It is composed of loosely arranged cells and air spaces, and contains flexible, soft keratin.

Mammary glands

Of the beats are modified Aphrodite sweat glands. Both males and females have mammary glands, but these glands become functional only functional in pregnant and lactating females, when they produce milk, a secretion that nourishes offspring. The development of the glands and its secretions are controlled by a complex interaction between gonadal and pituitary hormones.

Melanin ( pigment )

Produced and stored by the Melanocytes in response to ultraviolet light exposure.

Functions of hair

Protection, facial expression, heat retention, sensory reception , visual identification, chemical signal dispersal

Tanning is the result of ?

The melanocytes attempting to block UV light from causing mutations in the DNA of your skin cells!

Dermatology

The scientific study and treatment of the integumentary system.

friction ridges

are another type of skin marking. These ridge patterns along the contours of the skin, varying from small conical pegs (in thin skin) to the complex arches and whorls. Are found on the fingers(fingerprints), palms, soles, and toes of both dermis and epidermis. They help increase the friction on contact, so that our hands can firmly grasp items and our feet do not slip when we walk barefoot.

Why does the nail body appear pink ?

because of the blood flowing in the underlying capillaries; the free edge of the nail appears white because there are no underlying capillaries.

the amount of melanin in the skin is determined by ?

both heredity and light exposure

Free edge

distal whitish on nail

Carotene

is a yellow-orange pigment that is acquired from various yellow-orange vegetables, such as carrots,corn, and squashes. Normally, it accumulates inside keratinocytes of the stratum corneum and in the subcutaneous fat. Within the body, ________ is converted into vitamin A, which plays an important role in normal vision. Vitamin A has also been though to reduce potentially dangerous molecules called free radicals that form during normal metabolic activity in the body.

Hemangioma

is an anomaly(ABNORMALITY) that results in skin discoloration due to blood vessels that proliferate to from a benign tumor.

Albinism

is an inherited recessive condition where the enzyme needed to produce melanin is nonfunctional. As a result, melanocytes are unable to produce melanin. Individuals who have ________ typically have white hair, pale skin, and pink irises.

Nail root

is the proximal part embedded in the skin

Lunula (Luna=moon)

is the whitish semilunar are of the proximal end of the nail body. It has a whitish appearance because a thickened stratum basale obscures the underlying blood vessels.

Dermis

is to the epidermis and ranges in the thickness from 0.5 mm to 3.0mm. This layer of the integument is composed of connective tissue proper and contains primarily collagen fibers, although elastic and reticular fibers also are found within the dermis. Other structures within the dermis are blood vessels, sweat glands, sebaceous glands, hair follicles, nail roots, sensory nerve endings, and arrector pilli.

Subcutaneous layer (hypodermis)

it not considered a part of the integument. This layer consists of areolar connective tissue and adipose conncetive tissue. The _____ layer pads and protects the body, acts as an energy reservoir, and provides thermal insulation.

Capillary hemangiomas

or strawberry-colored birthmarks, appear in the skin as bright red to deep purple nodules that are usually present at birth and disappear in childhood. However, their development may occur in adults.

Outer connective tissue sheath

originates from the dermis

Inner epithelial tissue root sheath

originates from the epidermis

Nail body

pinkish part of nail

Dermis layer

primarily dense irregular connective tissue

Dark-skinned individuals have melanocytes that

produce relatively more and darker melanin than lighter-skinned individuals