Exam 2 Study Guide

Question 1

What are the four primary human tissues?

Answer 1

nervous tissue, muscle tissue, epithelial tissue, and connective tissue

Question 2

Name and describe the various types of epithelia

Answer 2

Squamous: flat and scale like
Cuboidal: cube shaped
Columnar: tall and column shaped

Question 3

What is the difference between stratified and simple?

Answer 3

Stratified: two or more layers of cells stacked
Simple: single layer of cells

Question 4

Why is collagen important in connective tissue?

Answer 4

-strongest and most abundant type
-tough; provides high tensile strength
-the more collagen, the stronger it is

Question 5

What is the major difference between skeletal and cardiac and smooth muscle?

Answer 5

skeletal: attached to the bones of the skeleton; cells are striated
cardiac: only found in the wall of the heart; does not regenerate; cells are striated
smooth muscle: cells have no visible striations; within walls or hollow organs

Question 6

Indicate the general characteristics of nervous tissue.

Answer 6

main component of nervous system; internal communication; contains neurons and supporting cells

Question 7

What are neurons?

Answer 7

specialized nerve cells that generate and conduct nerve impulses; respond to stimuli and transmit electrical impulses

Question 8

What are the three embryonic germ layers?

Answer 8

Ectoderm: nervous tissue
Mesoderm:
Endoderm:

Question 9

Stratum basale

Answer 9

deepest epidermal layer; one row of actively mitotic stem cells

Question 10

Stratum spinosum

Answer 10

several layers of keratinocytes unified by desmosomes; cells contain thick bundles of intermediate filaments made of pre keratin

Question 11

Stratum granulosum

Answer 11

1-5 layers of flattened cells, organelles deteriorating; cytoplasm full of lamellar granules and keratohyaline granules

Question 12

Stratum corneum

Answer 12

most superficial layer; 20-30 layers of dead cells, essentially flat membranous sacs filled with keratin. l

Question 13

Basal cell carcinoma

Answer 13

least malignant; most common
-stratum basale cells proliferate and slowly invade dermis and hypodermis
-cured by surgical excision in 99% of cases

Question 14

Squamous cell carcinoma

Answer 14

second most common type; involves keratinocytes of stratum spinosum; usually scaly reddened papule; does metastasize; good prognosis if treated by radiation therapy or removed surgically

Question 15

Melanoma

Answer 15

cancer of melanocytes; most dangerous; highly metastatic and resistant to therapy; ABCD rule
Asymmetry: two sides of pigmented area do not match
Border: exhibit indentations
Color: various colors
Diameter: spot is larger than 6mm

Question 16

What tissue types compose the epidermis and dermis?

Answer 16

The epidermis is composed of epithelial tissue
The dermis is composed mostly of fibrous connective tissue

Question 17

What are the layers of the epidermis?

Answer 17

Stratum basale
Stratum spinosum
Stratum granulosum
Stratum lucidum
Stratum corneum

Question 18

What are the layers of the dermis?

Answer 18

papillary and reticular

Question 19

Is the dermis or epidermis composed largely of dead cells?

Answer 19

epidermis

Question 20

Why are stem cells important in the epidermis?

Answer 20

aid in the repair of the dermis after injuries

Question 21

What are the cells of the epidermis?

Answer 21

Keratinocytes
Melanocytes
Dendritic Cells
Tactile Epithelial Cells

Question 22

Describe keratinocytes

Answer 22

-produce keratin
-most cells of epidermis
-tightly connected by desmosomes

Question 23

Describe melanocytes

Answer 23

-10-25% of cells in deepest epidermis
-produce pigment melanin(protect keratinocyte nucleus from UV damage)

Question 24

Describe dendritic(Langerhans) cells

Answer 24

-arise from bone marrow and migrate to epidermis
-macrophages, ingest foreign substances and are key activators of immune system

Question 25

Describe tactile(Merkel) cells

Answer 25

-present at epidermal/dermal junction -sensory receptor for touch

Question 26

Which cells are actively in the cell cycle, versus differentiated?

Answer 26

osteoprogenitor cells differentiate into osteoblasts or bone lining cells

Question 27

Why are serious burns life threatening?

Answer 27

dehydration and electrolyte imbalance(loss) can lead to renal shutdown and circulatory shock

Question 28

How do you determine the extent of a burn

Answer 28

rule of nines; method divides the body into 11 areas, each accounting for 9% of total body area plus 1% for genitals on body surface

Question 29

Describe first degree burns

Answer 29

First: only the epidermis is damaged; localized redness, swelling, and pain; tend to heal in 2-3 days; ex: sunburn; considered partial degree burn

Question 30

Describe second degree burns

Answer 30

injure the epidermis and the upper region of the dermis; redness, swelling, pain, and blisters; skin regeneration occurs w little to no scarring within 2-3 weeks; considered partial thickness burn

Question 31

Describe third degree burn

Answer 31

full thickness burn; involving entire thickness of skin; burned area appears grey, white cherry red, or blackened; not painful; skin grafting is advised to prevent fluid loss and infection

Question 32

When are burns considered critical?

Answer 32

-over 25% of the body has second degree burns -over 10% of the body has third degree burns -third degree burns on face(possibly mean burned respiratory passageways), hands, or feet

Question 33

Bone is a source of what crucial nutrient? Why does the body need it?

Answer 33

calcium; functions in nerve impulse transmission, muscle contraction and blood coagulation

Question 34

Parathyroid hormone(PTH)

Answer 34

produced by the parathyroid glands; when blood levels of Ca decline, PTH is released, which stimulates osteoclasts to resorb bone, releasing calcium into the blood; removes calcium from bone regardless of bone integrity

Question 35

Describe the histology of compact bone

Answer 35

also called lamellar bone; has osteons or Haversian system; hollow tubes of bone matrix called lamellae; perforating(volkmann's) canals; lacunae: small cavities that contain osteocytes; canaliculi: hairlike structures

Question 36

Describe the histology of spongy bone

Answer 36

mesh of bony spines called trabeculae which: align along lines of stress; no osteons; irregularly arranged lamellae and osteocytes interconnected by canaliculi; capillaries in endosperm supply nutrients

Question 37

Chemical composition of bone(ORGANIC components)

Answer 37

includes cells and osteoid; osteogenic cells; osteoblasts, osteocytes, bone lining cells, and osteoclasts; osteoid: 1/3 of organic bone matrix secreted by osteoblasts; provides tensile strength and flexibility

Question 38

Chemical composition of bone(INORGANIC composition)

Answer 38

hydroxyapatites(mineral salts); 65% of bone by mass; mainly of tiny calcium phosphate crystals in and around collagen fibers; responsible for hardness and resistance to compression

Question 39

What calcium compound is important to bone hardness?

Answer 39

calcium hydroxyapatite`

Question 40

Osteoblasts

Answer 40

produce matrix

Question 41

Osteocytes

Answer 41

maintain matrix

Question 42

Osteoclasts

Answer 42

degrade bone

Question 43

Explain how hormones regulate bone remodeling

Answer 43

negative feedback hormonal loop for Ca homeostasis; controls blood Ca levels not bone integrity

Question 44

Explain how physical stress regulates bone remodeling

Answer 44

remodel in response to demands placed on it; ex: tennis player's arm

Question 45

Describe the disorder of bone remodeling in osteoporosis.

Answer 45

bone resorption outpaces deposit