ap chpt 5

melanocytes of dark skin people

produce more and darker melansomes and retain keratinocytes longer

melanon made of

tyrosine amino acids

nails are hard becomes

contain hard keratin

basal cell carcinoma

80% of skin cancers, statum basale cells proliferate, invading dermis and hypodermis

he composition of the secretions of the eccrine glands is ________.

99% water, sodium chloride, trace amounts of wastes, and vitamin C

Which of the following cells and their functions are correctly matched?

Dendritic cells activate the immune system

Select the most correct statement concerning skin cancer.

Melanomas are rare but must be removed quickly to prevent them from metastasizing.

skin secretes natural antibiotics called

defensins

second degree burn

epidermis and upper layer of dermis

epidermis made of

epithelial cells

What is the most common cell type in the epidermis?

eratinocytes

hirustism

excesssive hairiness. may be from adrenal or ovarian gland that secrete abnormally large amounts of androgen

The dermis is a strong, flexible connective tissue layer. Which of the following cell types are likely to be found in the dermis?

fibroblasts, macrophages, and mast cells

ceruminous glands

found in external ear canal produces earwax, keeps bugs out and foreign substance

substances that penetrate skin in limited amounts

lipid soluble substances- oxygen, fat soluble vitamins.. k, a. and steroids oleorosins- like poinson ivy organic solvents- acetone, paint thinner salts of heavy metals - like mercury, lead

hair pigment made by

melanocytes at base of hair follicle and transferred to cortical cells

The most dangerous type of skin cancer is __________

melanoma

The skin is NOT a __________ barrier.

metabolic

Melanocytes and keratinocytes work together in protecting the skin from UV damage when keratinocytes ______

accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment layer

In a woman that has hirsutism, ________.

androgens stimulate vellus hair to become terminal hair Correct Androgens are group of chemically-related male sex hormones that induce male-specific body changes. Normally they are produced in females at very low levels. But when their levels rise, they can cause changes like hair growth on the body and face.

Which skin function is NOT correctly matched with the structure that accounts for that function? eccrine glands: excretion tactile corpuscles: cutaneous sensation apocrine gland: thermoregulation keratinocytes: physical barrier

apocrine gland: thermoregulation

squamous cell melanoma

arise from keratinocytes of stratum spinosum can grow fast and metastisize if not removed

hair consists of mostly

dead keratinized cells or 3 layers; medulla, central area of large cells and air sacs, and soft keratin cortex, layer around medulla of flattened cells cuticle, single layer of cells overlapping each other, most heavily keratinized part. helps give hair stength

pallor or blanching

during certain emotions, fear or anger, some peoples skin becomes pale

third degreee burn

enitre thickness of skin, nerve endings dead. not painful because nerves gone. severe fluid loss and infection. can lead to electrolyte imbalance, renal failure, fluid loss, circulatory shock

alopecia

hair thining due to hair follicles falling out faster than they are replaced

epidermal cells

keratinocytes; in stratum basale, most popular cells melanocytes spider chaped cells synthesize melanin dendritic cells are activators of immune system, ingest foreign substances tactile cells function as sensory receptor

bronzing

metalic appearance of skin, signifies addisons disease

melanoma

most dangerous, can occur anywhere where there is pigment and can metastasize quickly invade important organs like lymph nodes

sebaceous glands

oil glands that are branched alveolar glands .secrete sebum on hair follicle, occasionally on pore. lubricates hair and skin and slows water loss when humidity is low

fist degree burn

only epidermis injured

eccrine/ merocrine sweat glands

palms, soles of feet, forehead. secretory part lie in dermis. prevents body from overheating contains vitamin c, salts, water, microbe killing peptide dermicidin, and metabolic waste

dermis layers

papillary- with aeolar connective tissue of elastic fibers allows cells to search and clean out bacteria - contain dermal papillae with touch receptors recticular- coarse dense irregular tissue. contain blood vessels, adipose tissues, collagen fibers. give skin strength and resiliency

treating severe burns

put on iv to replenish fluids and food calories. need thousands of calories to replace lost tissue and protein loss. skin graft quickly needed to avoid infection

The dermis has two major layers. Which layer constitutes 80% of the dermis and is responsible for the tension lines in the skin?

recticular layer

erethyma

redness or blushing of skin,

nails appear pink due to

rich bed of capillaries in underlying dermis

mammary glands

secrete milk

layers of epidermis

stratum basale- deepest cell layer, continuously renews cell population stratum spinosum- prickly cells, use desmosomes to hold cells tight statum granulosum- layers of flattened cells, contan granules that release lipids and form keratin stratum licidum- consists of dead keratinocytes stratum corneum- 30 layers, keratin, dead cells, glycolipids in extrcellular space

carotene found in

straum corneum, orange color. can be converted to vitamin A which is good for vision and epidermal health

Which of the following terms describes layer D?

subcutaneous

hypodermis also known as and comprised as

subcutaneous gland, made up dense connective tissue vascularized; nutrients diffuse through epidermis in dermis

Which of the following correctly describes a common feature of all structures labeled A through D in the figure?

Structures A, B, C, and D are located in the dermis

1. ? The most abundant cells of the epidermis. 2. ? The protein found in the epidermis that is responsible for toughening the skin. 3. ? Cells plus a disc-like sensory nerve ending that functions as a sensory receptor for touch. 4. ? Skin macrophages that help activate the immune system. 5. ? Cell remnants of the stratum corneum.

1. Keratinocytes The most abundant cells of the epidermis. 2. Keratin The protein found in the epidermis that is responsible for toughening the skin. 3. Merkel disc Cells plus a disc-like sensory nerve ending that functions as a sensory receptor for touch. 4. Dendritic cells Skin macrophages that help activate the immune system. 5. Cornified keratinocytes Cell remnants of the stratum corneum.

Earwax is made by __________.

Ceruminous glands are modified apocrine sweat glands found in the lining of the external ear canal. Their secretion mixes with sebum produced by nearby sebaceous glands to form a sticky, bitter substance called cerumen, or earwax, which is thought to deter insects and block entry of foreign material.

apocrine sweat glands

axillary, and anogenital areas. release by exocytosis like eccrine glands have everything eccrine sweat does plus fatty substances and protein exact function not known but activated during pain and stress

bruises

black and blue marks where blood escaped circulation..hematomas

Which structure is a type of sweat gland?

c

Which of the following represents a difference between eccrine sweat glands and apocrine sweat glands? Which of the following represents a difference between eccrine sweat glands and apocrine sweat glands?

the secretions of apocrine sweat glands contain more fat and protein than do the secretions of eccrine sweat glands.

William has a cut that is superficial, painful but not bleeding. Based on this information you would predict that the cut has penetrated to ________

the stratum basale but not the dermal layers

If a person were born without eccrine glands, what skin function would he or she have a hard time completing?

thermoregulation

jaundice

yellow skin, normally signifies liver disorder