A&P1 Chapter 7 Short Answer, Anatomy Chp 5 &6

On an outline diagram of the human body, mark off various regions according to the rule of nines. What percentage of the total body surface is affected if the skin over the following body parts is burned? (a) The entire posterior trunk and buttocks (b) An entire lower limb (c) The entire front of the left upper limb

(a) 36% (b) 9% (c) 2.25% Total percentage: 47.25%

Explain each of these familiar phenomena in terms of what you learned in this chapter: (a) pimples (b) dandruff (c) greasy hair and "shiny nose" (d) stretch marks from gaining weight (e) freckles

(a) Accumulated sebum blocks a sebaceous gland duct, a white head appears. If the material oxidizes and dries, it darkens to form a blackhead. (b) Shingle-like cell remnants of the stratum corneum (cornified cells). (c) The arrector pili muscle contracts to force sebum out of the hair follicles on to the skins surface (shiny nose), and the sebum directly on the hair shaft results in greasy hair. (d) Silvery white scars (striae). (e) Local accumulations of melanin.

Count Dracula, the most famous vampire, rumored to have killed at least 200,000 people, was based on a real person who lived in eastern Europe about 600 years ago. He was indeed a "monster" although he was not a real vampire. The historical Count Dracula may have suffered from which of the following? (a) porphyria (b) EB (c) Halitosis (d) vitilgo. Explain your answer.

(a) Porphyria- Certain enzymes needed to form the heme of hemoglobin of blood are lacking. Without the enzymes, metabolic intermediates of the heme pathway called porphyrins build up, spill into the circulation, and eventually cause lesions throughout the body, especially when exposed to sunlight. The fingers, toes, and nose are disfigured, gums degenerate and teeth become prominent.

Count Dracula, the most famous vampire, rumored to have killed at least 200,000 people, was based on a real person who lived in eastern Europe about 600 years ago. He was indeed a "monster," although he was not a vampire. The historical Count Dracula may have suffered from which of the following? (a) porphyria (b) EB (c) halitosis, (d) vitiligo. Explain your answer.

(a) Porphyria. Porphyria victims lack the ability to form the heme of Hb. Buildup of intermediate by-products (porphyrins) in the blood cause lesions in sun-exposed skin. Dracula was said to have drunk blood and to have shunned the daylight. (p. 156)

While walking barefoot in a barn, Jeremy stepped on a rusty nail that penetrated the epidermis on the sole of his foot. Name the layers the nail pierced from the superficial skin surface to the junction with the dermis.

-Stratum corneum -Stratum lucidum -Stratum granulosum -Stratum spinosum -Stratum basale

The appendectomy incision ran parallel to the less dense "lines of cleavage" that separate bundles of collagen fiber in the dermis. The gallbladder incision cut across them.

A model is concerned about a new scar on her abdomen. She tells her surgeon that there is practically no scar from the appendix operation done when she was 16, but this new gallbladder scar is "gross." Her appendectomy scar is small and obliquely located on the inferior abdominal surface—it is very indistinct. By contrast, the gallbladder scar is large and lumpy and runs at right angles to the central axis of the body trunk. Can you explain why the scars are so different?

Osteomalacia, a condition of soft bones, is prevalent in Muslim countries that decree that their women wear the burka, a garment that covers all but their eyes. What is the cause and effect here?

A woman such as this, even though she lives in a climate with ample direct sunlight, has her entire body shielded from the sun nearly all the time. The lack of UV radiation on her skin would prevent normal UV directed conversion of vitamin D in the skin, which could compromise her ability to absorb calcium. (p. 163)

The product of this type of sweat gland includes protein and lipid substances that become odoriferous as a result of bacterial action:

Apocrine gland

How do the relative proportions of the cranium and face of a fetus compare with those of an adult skull?

At birth, the skull is huge relative to the facial skeleton. During childhood and adolescence, the face grows out from the skull. By adulthood, the cranial and facial skeletons are the appropriate proportional size.

Which type of skin cancer develops from the youngest epidermal cells?

Basal cell carcinoma develops from the youngest epidermal cells.

Why are there no skin cancers that originate from stratum corneum cells?

Because the cells in the stratum corneum are dead.

Why is the lunule of a nail white instead of pink like the rest of the nail?

Because the thick nail matrix that underlies it blocks the rosy color of the dermal blood supply from showing through

You have just gotten a paper cut. It is very painful, but it doesn't bleed. Has the cut penetrated into the dermis or just the epidermis?

Because there is no bleeding, the cut has penetrated into the avascular epidermis only.

A man got his finger caught in a machine at the factory. The damage was less serious than expected, but the entire nail was torn off his right index finger. The parts lost were the body, root, bed, matrix, and eponychium of the nail. First, define each of these parts. Then, tell if this nail is likely to grow back.

Body- visible attached portion Root- embedded in the skin Bed- extends beneath the nail Matrix- thickened proximal portion of the nail bed Eponychium- proximal nail fold projects onto the nail body No, the nail is not likely to grow back because the matrix was lost.

Briefly describe the anatomical characteristic impairment of function seen in cleft palate and hip dysplasia.

Both cleft palate and hip dysplasia are congenital abnormalities affecting skeletal formation. A cleft palate occurs if the fusion of the midline of the maxilla fails to occur. Problems may range from simple cosmetic abnormality to a complete lack of separation of the nasal and oral cavities. In such a case, the infant will have difficulty taking in food, and may even aspirate it, due to a lack of a palate to regulate breathing and swallowing. Hip dysplasia occurs if the acetabulum fails to form a complete socket around the head of the femur correctly, or if the ligaments securing the femur at the hip are too loose. The femur may easily slip out of its socket, creating difficulty walking.

Although the anterior head and face represent only a small percentage of the body surface, burns to this area are often more serious than those to the body trunk. Why?

Burns to the face are serious because damage to the respiratory passageways can occur in such burns.

An arrector pili muscle

Can cause a hair to stand straight up

Which epidermal cells are also called prickle cells? Which contain keratohyaline and lamellar granules?

Cells of the stratum spinosum are called prickle cells because of their spiky shape in fixed tissues; granules of keratohyalin and lamellar granules appear in the cells of the stratum granulosum. (p. 152)

List at least two specific anatomical characteristic each for typical cervical, thoracic, and lumbar vertebrae that allow anyone to identify each type correctly.

Cervical vertebrae possess transverse foramina, have small bodies and bifurcate spinous processes; Thoracic vertebrae possess facets for the ribs and have circular vertebral foramina; Lumbar vertebrae have massive bodies and blunt spines.

You go to the beach to swim on an extremely hot, sunny summer afternoon. Describe two ways in which your integumentary system acts to preserve homeostasis during your outing.

Chemical barriers of protection: Melanin provides a chemical pigment shield to prevent UV damage to skin cells. Body temperature regulation: The body releases sweat (body heat) and as that evaporates off the skin it cools the body.

Thelma, a 30-year-old resident of a mental hospital, has an abnormal growth of hair on the dorsum of her right index finger. The orderly comments that she gnaws on that finger continuously. What do you think is the relationship between Thelma's gnawing activity and her hairy finger?

Chronic physical irritation or inflammation can lead to excessive hair growth in the region affected due to an increase in blood flow to the area. (p. 159)

Name the cranial and facial bones and compare and contrast the functions of the cranial and facial skeletons.

Cranial bones: parietal, temporal, frontal, occipital, sphenoid, and ethmoid. Facial bones: mandible, vomer, maxillae, zygomatics, nasals, lacrimals, palatines, and inferior conchae. Cranial bones provide sites for attachment and enclose and protect the brain. The facial bones form the framework of the face, hold eyes in position, provide cavities for organs of taste and smell, secure the teeth, and anchor facial muscles.

What is cyanosis and what does it indicate?

Cyanosis is a bluish cast of the skin that indicates tha hemoglobin in the red blood cells in the dermal capillaries is poorly oxygenated.

The two most important problems encountered clinically with a victim of third-degree burns are a loss of body fluids resulting in dehydration and an electrolyte imbalance, and the risk of infection. Intact skin effectively blocks not only the diffusion of water and water-soluble substances out of the body, but acts as a barrier limiting the invasion of various microorganisms.

Dean, a 40-year-old aging beach boy, is complaining to you that although his suntan made him popular when he was young, now his face is all wrinkled, and he has several darkly pigmented moles that are growing rapidly and are as big as large coins. He shows you the moles, and immediately you think "ABCD." What does that mean and why should he be concerned?

Which cell functions as a part of the immune system?

Dendritic cell

Describe the process of hair formation, and list several factors that may influence (a) growth cycles and (b) hair texture.

Each follicle goes through growth cycles. In the regressive phase, the hair matrix cells die and the follicle base and hair bulb shrivel somewhat, dragging the hair papilla upward to abut the region of the follicle that does not regress. The follicle enters a resting phase for one to three months. The cycling part of the follicle regenerates and the matrix proliferates again and forms a new hair to replace the old one that has fallen out or will be pushed out by the new hair.

The rule of nines is helpful clinically in

Estimating the extent of a burn

Which tissue of the hypodermis makes it a good shock absorber?

Fatty tissue in the hypodermis gives it insulating and shock-absorbing properties.

The healing of burns and epidermal regeneration is usually uneventful unless the burn is a third-degree burn. What accounts for this difference?

First- and second-degree burns can heal uneventfully by regeneration of epidermal cells as long as infection does not occur. Third-degree burns destroy the entire depth of skin and regeneration is not possible. Infection and loss of body fluid and proteins are problematic.

Distinguish clearly between first-, second-, and third-degree burns.

First- only the epidermis is damaged. Second- injure the epidermis and the upper regions of the dermis. (first and second are partial-thickness burns) Third- involve the entire thickness of the skin.

Distinguish clearly between first-, second-, and third-degreeburns.

First-degree burns affect only the epidermis; second-degree burns affect down to the dermis; and third-degree burns affect down to the subcutaneous tissue and muscle. (p. 166)

Skin surface markings that reflect points of tight dermal attachment to underlying tissues are called

Flexure lines

Is a bald man really hairless? explain

Generally not. Most "bald" men have fine vellus hairs that look like peach fuzz in the "bald" areas. (p. 159)

Describe the process of hair formation, and list several factors that may influence (a) growth cycles and (b) hair texture.

Hair formation begins with an active growth phase, followed by a resting phase. After the resting phase a new hair forms to replace the old one. Factors that affect growth cycles include nutrition, hormones, local dermal blood flow, body region, gender, age, genetic factors, physical or emotional trauma, excessive radiation, and certain drugs. Factors that affect hair texture include hormones, body region, genetic factors, and age. (p. 159)

A common belief is that having your hair cut makes is become thicker. Explain why this belief is not true.

Hair is composed of dead keratinized cells. The growth occurs at the hair follicle and is influenced by nutrition and hormones. Cutting the dead hair does not influence the growth at the follicle. (pp. 157-158)

What is the difference between heat-induced sweating and a "cold sweat" and which variety of sweat gland is involved?

Heat induced sweating occurs all over the body when we are overheated. A cold sweat is emotionally induced sweating that begins on the palms, soles and armpits and then spreads to other body areas. Both types of sweating are produced by the eccrine sweat glands, but activity of apocrine sweat glands is also likely during a cold sweat.

Dean, a 40-year-old aging beach boy, is complaining to you that although his suntan made him popular when he was young, now his face is all wrinkled, and he has several darkly pigmented moles that are growing rapidly and are as big as large coins. He shows you the moles, and immediately you think "ABCD." What does that mean and why should he be concerned?

His long-term overexposure to ultraviolet radiation in sunlight is considered a risk factor for the development of skin cancer. The ABCD rule is a set of diagnostic criteria used to assess moles or pigmented areas of the skin for cancer. Moles or pigmented spots that show asymmetry (A), border irregularity (B), color variation (C), and a diameter greater than 6 mm (D) all exhibit signs of a possible malignant melanoma. He should seek immediate medical attention. If it is a malignant melanoma, the chance for survival is not high, but early detection increases the survival rate. (p. 165)

When Anthony returned home from a run in 85 degree F weather, his face was dripping in sweat. Why?

His sympathetic nervous system activated his eccrine sweat glands and caused heat-induced sweating in order to cool the body.

Compare a young adult skeleton to that of an extremely aged person relative to bone mass in general and the bony structure of the skull, thorax, and vertebral column particular.

In a young adult skeleton, the bone mass is dense, water content is normal in discs, the vertebral column is strong. In old age, the discs decline in water content and become thinner and less elastic, the spine shortens and becomes an arc, and all the bones lose mass. The thorax becomes more rigid with increasing age, mainly due to the ossification of costal cartilage. The cranial bones lose less mass with age than most bones, but the facial contours of the aged change.

Which is not a true statement about the papillary layer of the dermis?

It is most responsible for the toughness of the skin.

What color does carotene impart to the skin?

It is the yellow to orange pigment most obvious in the palms and soles, where the stratum corneum is thickest, and most intense when large amounts of carotene-rich foods are eaten.

Which alteration in skin color may indicate a liver disorder?

Jaundice or a yellow cast to the skin due to the deposit of yellow bile pigments in body tissues may indicate a liver disorder.

The epidermis provides a physical barrier due largely to the presence of _____.

Keratin

Which epidermal cell type is most numerous?

Keratinocyte

Which epidermal cells are also called prickle cells? Which contain keratohyaline and lamellar granules?

Keratinocytes. Keratinocytes in the stratum granulosum.

What change in the skin leads to cold intolerance in the elderly?

Loss of subcutaneous fat, common in the elderly, leads to cold intolerance seen in this group of people.

Sebum

Lubricates the surface of the skin and hair, consists of cell fragments and fatty substances, and in excess may cause seborrhea

She was probably told that regeneration would occur, and grafts would not be needed if infection was avoided.

Mrs. Gaucher received second-degree burns on her abdomen when she dropped a kettle of boiling water. She asked her doctor (worriedly) if she would need to have a skin graft. What do you think he told her?

A man got a finger caught in a machine at the factory. The damage was less serious than expected, but the entire nail was torn off his right index finger. The parts lost were the body, root, bed, matrix, and eponychium of the nail. First define each of these parts. Then, tell if this nail is likely to grow back.

Nail body: the visible attached portion of the nail. Nail root: the embedded portion of the nail. Nail bed: the epidermis that extends beneath the nail. Nail matrix: the proximal, thickened portion of the nail bed responsible for nail growth. Eponychium: the cuticle. If the matrix is damaged the nail may not grow back or may grow back distorted. In this case the nail probably will not grow back because everything including the matrix was lost. (p. 160; Fig. 5.6)

Is a bald man really hairless? Explain.

No, the follicular growth cycles become so short that many hairs never even emerge from their follicles before shedding.

Name and diagram the normal vertebral curvatures. which are primary and which are secondary curvatures?

Normal curves are: cervical, thoracic, lumbar, and sacral. The thoracic and sacral are primary and exist at birth; the cervical and lumbar are secondary and develop as an upright posture is attained.

You go to the beach to swim on an extremely hot, sunny summer afternoon. Describe two ways in which you integumentary system acts to preserve homeostasis during your outing.

On an extremely hot, sunny summer day your integumentary system will function to maintain homeostasis in several ways. First, your skin will sweat. Sweating is a form of thermoregulation that helps prevent you from overheating by increasing blood flow to the skin and allowing it to dump heat into the environment. Second, your melanocytes will begin to produce more melanin. The melanin granules will then be taken into keratinocytes where they will protect the keratinocyte nucleus from the damaging UV rays of the sun. (pp. 162-163)

Skin's exposure to sunlight (Ultraviolet Rays in particular) causes the production of Vitamin D. Vitamin D helps with the retaining of calcium in the bones. Calcium is what makes the bones healthy and strong. The Burka drastically reduces the amount of sunlight exposure Muslim women get, therefore decreasing their vitamin D levels and making it difficult for their bones to acquire calcium.

Osteomalacia, a condition of soft bones, is prevalent in Muslim countries that decree that their women wear the burka, a garment that covers all but their eyes. What is the cause and effect here?

Peter Howell, a teaching assistant in anatomy class, picked up a hip bone and pretended it was a telephone. Held the big hole in this bone right up to his ear and said " Hello obturator, obturator (operator, operator)." Name the structure he was helping the student to learn.

Peter was having a little fun with the obturator foramen, the large opening in the hip bone through which pass some blood vessels and nerves.

Which cutaneous glands are associated with hair follicles?

Sebaceous glands and apocrine glands are associated with the hair follicles.

Mrs. Gaucher received second-degree burns on her abdomen when she dropped a kettle of boiling water. She asked her doctor (worriedly) if she would need to have a skin graft. What do you think he told her?

Second-degree burns are regenerative, and do not normally require skin grafts, unless the area of coverage is extensive enough to make it unlikely that the skin could regenerate quickly enough to cover the large burn area. If the skin loss was extensive, the risk of fluid loss and infection would be too great, and grafting would be required. (p. 166)

On an outline diagram of the human body, mark off various regions according to the rule of nines. What percentage of the total body surface is affected if the skin over the following body parts burned? (a) the entire posterior trunk and buttocks, (b) an entire lower limb, (c) the entire front of the left upper limb.

See Figure 5.9 (p. 165). a. 18% posterior trunk + 4.5% right buttock + 4.5% left buttock = 27% b. one entire lower limb = 18% c. entire front (anterior) left upper limb = 4.5%

Which of the following is not an epidermal derivative?

Sensory receptor

Given that epithelia are avascular, which layer would you expect to have the best-nourished cells?

Stratum basale.

Why are there no skin cancers that originate from stratum corneum cells?

Stratum corneum cells are dead. By definition, cancer cells are rapidly dividing cells. (pp. 154, 164)

How is sunlight important to bone health?

Sunlight causes the skin to produce a precursor of vitamin D from cholesterol. Vitamin D is essential for bone synthesis.

What name is given to the rule for recognizing the signs of melanoma?

The ABCD rule helps one to recognize signs of melanoma.

Skin color is determined by

The amount of blood, pigments, and oxygenation level of the blood.

Distinguish between the anulus fibrosus and nucleus pulposus region of a disc. Which provides durability and strength? Which provides resilience? Which part is involved in a supplied discs?

The annulus fibrosis, composed of fibrocartilage, is more external and contains the nucleus pulposus. The nucleus is the semifluid substance enclosed by the annulus. The annulus provides strength and durability. The nucleus provides resilience. Disc herniation involves protrusion of the nucleus pulposus through a break in the annulus

A model is concerned about a new scar on her abdomen. She tells her surgeon that there is practically no scar from the appendix operation done when she was 16, but this new gallbladder scar is "gross." Her appendectomy scar is small and obliquely located on the inferior abdominal surface—it is very indistinct. By contrast, the gallbladder scar is large and lumpy and runs at right angles to the central axis of the body trunk. Can you explain why the scars are so different?

The appendectomy incision ran parallel to the less dense "lines of cleavage" that separate bundles of collagen fiber in the dermis. The gallbladder incision cut across them. (p. 155)

What is the role of an arrector pili muscle?

The arrector pili muscles pull the hair to the upright position (when cold or scared)

Why does skin wrinkle and what factors accelerate the wrinkling process?

The decreasing elasticity of the skin, along with the loss of subcutaneous tissue, inevitably leads to wrinkling. Old age, UVA and UVB rays.

The sensations of touch and pressure are picked up by receptors located in

The dermis

What is the function of the intervertebral discs?

The discs act as shock absorbers and allow the spine to flex and extend (provide flexibility).

Which epidermal cells play a role in body immunity?

The epidermal dendritic cells

List three important differences between male and female pelvises.

The female pelvis inlet and outlet are wider; the pelvis is shallower, lighter, and rounder than that of the male; and the ischial tuberosities are farther apart.

What is the function of the hair papilla?

The hair papilla contains a knot of capillaries that supply nutrients to cells of the hair bulb.

A common belief is that having your hair cut makes it become thicker. Explain why this belief is not true.

The hair that gets cut is already dead. Cutting the hair does not change the color or shape of the hair follicle.

Why are nails so hard?

The keratin they contain is the hard keratin variety.

What chemicals produced in the skin help provide barriers to bacteria? List at least three and explain how the chemicals are protective.

The low pH of skin secretions (acid mantle) inhibits division of bacteria, and many bacteria are killed by bactericidal substances in sebum or by natural antibiotics called defensins. Damaged skin secretes cathelicidins that are effective against a certain strain of strep bacteria.

Sebaceous glands are not found in thick skin. Why is their absence in those body regions desirable?

The palms of the hands and the soles of the feet are thick skin areas. It would be dangerous to have oily soles and oily palms would decrease the ability of the hands to hang onto things.

Which layer of the dermis is responsible for producing fingerprint patterns?

The papillary layer of the dermis gives rise to fingerprint patterns.

The major function of the shoulder girdle is flexibility. What is the major function of the pelvic girdle? Relate these functional deference to anatomical difference in these girdles.

The pelvic girdle functions to attach and transfer the weight of the body to the lower limbs. The bones are large, strong, and securely attach the bones of the thigh to the axial skeleton. The pectoral girdle bones are light and quite mobile to provide flexibility at the expense of strength and stability.

What are the concentric regions of a hair shaft, from the outside in?

The regions of a hair from outside in are the cuticle, cortex, and medulla.

How does the skin contribute to body metabolism?

The skin carries out chemical conversions that supplement some of the protective conversions carried out by the liver, convert some chemicals into carcinogens, activate some steroid hormones, and synthesize the vitamin D precursor.

Why are the desmosomes connecting the keratinocytes so important?

The skin is subjected to a lot of abrasion. Desmosomes, which are connecting junctions, help hold the cells together during stress.

The stratum basale is also called the stratum germinativium, a name that refers to its major function. What is that function?

The stratum basale undergoes almost continuous mitosis to replace cells lost by abrasion.

Melanin and carotene are two pigments that contribute to skin color. What is the third and where is it found?

The third pigment contained in red blood cells found in blood vessels of the dermis.

Victims of third-degree burns demonstrate the loss of vital functions performed by the skin. What are the two most important problems encountered clinically with such patients? Explain each in terms of the absence of skin.

The two most important problems encountered clinically with a victim of third-degree burns are a loss of body fluids resulting in dehydration and an electrolyte imbalance, and the risk of infection. Intact skin effectively blocks not only the diffusion of water and water-soluble substances out of the body, but acts as a barrier limiting the invasion of various microorganisms. (pp. 165-166)

Chronic physical irritation or inflammation can lead to excessive hair growth in the region affected due to an increase in blood flow to the area.

Thelma, a 30-year-old resident of a mental hospital, has an abnormal growth of hair on the dorsum of her right index finger. The orderly comments that she gnaws on that finger continuously. What do you think is the relationship between Thelma's gnawing activity and her hairy finger?

Why is having your hair cut painless?

There are no nerves in a hair

How does UV radiation contribute to skin wrinkles?

UV radiation degrades collagen and leads to loss of skin elasticity and water-holding capacity.

What is the source of vernix caseosa that covers the skin of the newborn baby?

Vernix caseosa is a product of the sebaceous glands.

The two most important problems encountered clinically with a victim of third-degree burns are a loss of body fluids resulting in dehydration and an electrolyte imbalance, and the risk of infection. Intact skin effectively blocks not only the diffusion of water and water-soluble substances out of the body, but acts as a barrier limiting the invasion of various microorganisms.

Victims of third-degree burns demonstrate the loss of vital functions performed by the skin. What are the two most important problems encountered clinically with such patients? Explain each in terms of the absence of skin.

___________ appear when dermis elasticity declines from age or excessive sun exposure.

Wrinkles

Why does skin wrinkle and what factors accelerate the wrinkling process?

Wrinkling is due to the loss of elasticity of the skin, along with the loss of the subcutaneous tissue, and is hastened by prolonged exposure to wind and sun. (p. 167)

What color does carotene impart to the skin?

Yellow to orange color in stratum corneum and in fatty tissue of hypodermis. (p. 156)

The most superficial cells of the epidermis become less viable and ultimately die. What two factors account for this natural demise of the epidermal cells?

a. They are increasingly farther from the blood supply in the dermis b. They are increasingly laden with water-insoluble keratin and surrounded by glycolipids, which hinder their ability to receive nutrients by diffusion

What is a true rib? A false rib?

a. True ribs attach to the vertebral column and sternum directly at both ends; false ribs attach at vertebral column directly, but indirectly anteriorly by having the cartilage attach to the cartilage of the lowest true rib. b. A floating rib is a false rib.

Explain each of the familiar phenomenon in terms of what you learned in this chapter: (a) pimples, (b) dandruff, (c) greasy hair and "shiny nose," (d)stretch marks from gaining weight, (e) freckles

a. When a blocked sebaceous gland becomes infected, it produces a pimple. (p. 162) b. Noninfectious dandruff is the normal shedding of the stratum corneum of the scalp. (p. 154) c. Greasy hair and a shiny nose both result from the secretion of sebum onto the skin. (p. 162) d. Stretch marks represent small tears in the dermis, as the skin is stretched by obesity or pregnancy. (p. 156) e. A freckle is a small area of pigmentation in the epidermis, caused by an accumulation of melanin. (p. 157)

Name the tissue type composing the dermis.

dense irregular connective tissue

Skin markings that occur where the dermis is secured to deeper structures are called _______.

flexure lines

Skin cuts that run parallel to_______________ gape less than cuts running across these skin markings.

lines of cleavage

Name the tissue type composing the epidermis

stratified squamous epithelium

A more scientific term for 'stretch marks' is _________.

striae