Integument

Question 1

___ is the largest organ of the body and constitutes ___ - ___ % of the total body mass

Answer 1

skin; 15-20

Question 2

What are the functions of skin?

Answer 2

protection, sensation, thermoregulation, and immune response

Question 3

this component of the skin is composed of the keratinized stratified scams epithelium that grows continuously and desquamates from the surface. It is derived from the ectoderm.

Answer 3

epidermis

Question 4

this component of the skin is composed of CT that provides support for the skin and hosts blood vessels and nerves. It is derived from the mesoderm.

Answer 4

dermis

Question 5

this component of the skin contains a variable amount of adipose tissue. It is equivalent to the subcutaneous fascia described in gross anatomy. Its main function is insulation.

Answer 5

hypodermis

Question 6

Principal cells of the epidermis are called ____

Answer 6

keratinocytes

Question 7

The least differentiated cells of the epidermis are found within the ___ layer

Answer 7

basal

note: keratinocytes go through a maturation process as they move up within the epidermis

Question 8

As the cells reach the apical layer in the epidermis, they undergo ___ and are sloughed off

Answer 8

apoptosis

Question 9

this is the deepest layer of epidermis represented by a single layer of cuboidal or columnar cells resting on the basement membrane, which separates the epidermis from the dermis

Answer 9

stratum basale

Question 10

____ linke the keratinocytes of the stratum basal to the basal lamina

Answer 10

hemidesmosomes

Question 11

Autoimmune reaction to hemidesmosomes result in what?

Answer 11

blistering diseases (bullous pemphigoid)

Question 12

this layer of the epidermis is typically several cells thick. Keratinocytes here are larger than in the stratum basal and connected to each other by numerous desmosomes that look like “spines” . cells in this layer are more or less spherical in shape

Answer 12

stratum spinosum

Question 13

cells in the ___ _____ contain conspicuous keratohyalin granules that stain intensely. Cells in this layer are flattened and squamous in appearance

Answer 13

stratum granulosum

Question 14

This layer of the epidermis is usually visible only in the thick skin. It is a highly refractive layer that contains cells that have gone through apoptosis and their nucleus and organelles became disrupted. This layer stains very lightly with H and E

Answer 14

stratum lucidum

Question 15

This layer of the epidermis contains most differentiated cells. These cells have lost their nucleus and cytoplasmic organelles and become filled entirely with keratin filaments. This layer stains rather dark with H and E

Answer 15

stratum cornuem

Question 16

The spaces between cells in the stratum corneum are filled with ___ which makes this layer impermeable to water

Answer 16

lipid

Question 17

What are the two major functions of keratinocytes?

Answer 17

production of keratin and formation of epidermal water barrier

Question 18

The cytoplasm of keratinoycytes contains numerous free ___ and ___ ___

Answer 18

ribosomes; intermediate filaments

Question 19

___ ____ start appearing in the upper layers of the epidermis (stratum granulosum). They contain two major proteins associated with intermediate filaments: flagrant and trichohyalin.

Answer 19

keratohyalin granules

Question 20

As keratohyalin granules are released into the cytoplasm of keratinocytes, they promote what?

Answer 20

keratinizaiton

Question 21

Keratohyalin granules are aggregates of protein and are not surrounded by a membrane. True or false?

Answer 21

true

Question 22

In regards to cellular structure of keratinocytes, ___ bodies are membrane-bound vesicles that contain a mixture of lipids which play a key role in making the epidermis a water-impermeable layer.

Answer 22

lamellar

Question 23

Lipids from lamellar bodies coat the keratinocytes and form an ___ ____ barrier which extends between the cells

Answer 23

extracellular hydrophobic

Question 24

Squamos cell carcinoma is a malignant tumor that is derived form the keratinocytes of the ___ ____

Answer 24

stratum spinosum

Question 25

___ ____ carcinoma is the most common type of skin cancer and is derived from the keratinocytes within the stratum basale

Answer 25

basal cell

Question 26

____ are derived from the neural crest cells and are mostly found within the stratum basal. They form a unique functional association with keratinocytes

Answer 26

melanocytes

Question 27

What is the function of melanin?

Answer 27

protects the organism against damaging effects of UV irradiation

Question 28

Melanocytes have a rounded cell body and numerous long processes that extend between the keratinocytes into the ____ ____

Answer 28

stratum spinosum

Question 29

Melanocytes are bound to other cells by desmosomes. True or false?

Answer 29

false; they are not

Question 30

Because of the processes, melanocytes are called ____ cells

Answer 30

dendritic note: DO NOT CONFUSE THESE WITH THE DC'S OF THE IMMUNE SYSTEM

Question 31

Melanocytes contain ____, which are granules containing melanin. They are mostly found near the ends of cellular processes of melanocytes.

Answer 31

melanosomes

Question 32

How do melanosomes enter neighboring keratinocytes?

Answer 32

tips of processes containing melanosomes are phagocytosed by the neighboring keratinocytes and the granules enter this cell

Question 33

Langerhan's cells are monocyte-derived dendritic-appearing cells of the immune system present where?

Answer 33

the epidermis

Question 34

What is the function of langerhan's cells

Answer 34

APCs, generate skin immune response

Question 35

After accumulating antigens within epidermis, langerhan's cells migrate where?

Answer 35

lymph nodes for antigen presentation

Question 36

Langerhans' cells are dendritic cells with long branching processes and a nucleus that is indented in multiple places. The cytoplasm contains racquet-shaped endosomes called ____ granules

Answer 36

Birbeck

Question 37

Langerhans' cells are not bound to other cells by desmosomes. True or false?

Answer 37

true

Question 38

These cells are epidermal cells responsible for cutaneous sensation and are abundant in fingertips

Answer 38

merkel's cells

Question 39

The main function of Merkel's cells is ____

Answer 39

mechanoreception - they make synaptic contacts with sensory nerve fibers

Question 40

Merkel's cells are modified epidermal cells and are bound to adjacent keratinocytes by desmosomes. True or false?

Answer 40

true

Question 41

Merkel's cells are located in the ___ ___ layer of the epidermis

Answer 41

stratum basale

Question 42

The cytoplasm of Merkel's cells contains numerous __-___ granules that are released into the synaptic cleft and act as NT to excite the afferent myelinated nerve fibers

Answer 42

dense-core

Question 43

Merkel's cell carcinoma is a rare skin cancer that proves fatal in roughly ____ of patients

Answer 43

1/3

Question 44

attachment of the epidermis to the dermis is enhanced by the increased surface between the two tissues. For this purpose, the epidermis forms numerous ridges called ___ ridges and the dermis forms numerous projects called the ___ ____

Answer 44

rete; dermal papillae

Question 45

Cells of the dermis are the same cells that are found where?

Answer 45

CT proper

Question 46

There are two layers of the dermis. What are they?

Answer 46

papillary layer: consists of loose CT and is immediately beneath epidermis, delicate network of collagen fibers - not large bundles reticular layer: considerably thicker and less cellular than the papillary layer. It is composed of very dense irregular CT and has large bundles of type I collagen

Question 47

The two most important components of the skin blood supply are ___ ____ and ____ ____

Answer 47

vascular plexuses; capillary loops

Question 48

____ ___ extend into the dermal papillae and bring blood towards the surface of the skin. The pink skin color results from the blood present in these structures

Answer 48

capillary loops

Question 49

This vascular plexus of blood vessels is found at the junction between papillary and reticular layers of the dermis. Capillary loops are supplied by this plexus

Answer 49

superficial vascular plexus

Question 50

this vascular plexus is located at the cutaneous/subcutaneous junction

Answer 50

the deep vascular plexus

Question 51

____ capillaries are usually found in the dermal papillae

Answer 51

lymphatic

Question 52

_____ apparatus includes hair follicles and their product, hair and sebaceous glands

Answer 52

pilosebaceous

Question 53

the ___ ____ is responsible for production and growth of the hair

Answer 53

hair follicle

Question 54

The part of the hair located within the follicle is called the ___; the part that projects above the surface of the epidermis is called the ____

Answer 54

roof; shaft

Question 55

The innermost layer of the hair is the ___ which contains large vacuolated cells

Answer 55

medulla

Question 56

Surrounding the medulla of the hair is the ____ which contains live cells accumulating keratin

Answer 56

cortex

Question 57

The outermost layer of the hair is formed of dead squamous cells and is called the _____

Answer 57

cuticle

Question 58

Sebaceous glands develop as outgrowths of the ___ wall

Answer 58

follicular

Question 59

The sebum is produced via ___ secretion

Answer 59

holocrine

Question 60

In regards to sebaceous glands, the proliferating immature cells are located adjacent to the ___ ___. As more cells are produced, some of the cells are "pushed" out of this layer and begin to ___

Answer 60

basal lamina; mature

Question 61

In regards to sebaceous glands, the maturing cells enlarge, have abundant ___ and accumulate ___ ___

Answer 61

SER; lipid droplets

Question 62

In regards to sebaceous glands, mature cells are large, terminally differentiated cells, filled with large lipid droplets and undergo ____

Answer 62

apoptosis note: the nucleus become pyknotic and these cells break apart as they are released into hair follicle

Question 63

____ ____ muscle connects the deeper part of the follicle to the superficial dermis. It is composed of smooth muscle.

Answer 63

Arrector pili

Question 64

Innervation of the arrector pili is by what branch of autonomic nervous system?

Answer 64

sympathetic

Question 65

These sweat glands are distributed over the entire body expect the lips and parts of the genitalia. Their main function is thermoregulation via the production of sweat.

Answer 65

eccrine sweat glands

Question 66

Eccrine sweat glands are ___ ___ ___ glands that are not associate with the hair follicle

Answer 66

simple coiled tubular

Question 67

The duct of eccrine sweat glands is lined with ___ ___ epithelium

Answer 67

stratified cuboidal

Question 68

The secretory portion of the eccrine sweat gland is lined with ___ epithelium that contains three main cell types: clear cells, dark cells, and myopeithelial cells

Answer 68

stratified

Question 69

In regards to the secretory portion of the eccrine sweat gland, ___ cells produce the watery component of sweat

Answer 69

clear

Question 70

In regards to the secretory portion of the eccrine sweat gland, ___ cells are characterized by abundant RER and glycoprotein granules. They secrete the proteinaceous component of the sweet via merocrine secretion

Answer 70

dark

Question 71

In regards to the secretory portion of the eccrine sweat gland, ____ cells produce contractions that help discharge the sweat into the duct

Answer 71

myoepithelial

Question 72

These sweat glands are large-lumen tubular glands associated with hair follicles and are structurally similar to eccrine sweat glands

Answer 72

apocrine

Question 73

Why do apocrine glands have a more dilated secretory segment?

Answer 73

they store the secretion within their lumen

Question 74

The secretory part of the apocrine sweat glands contains a single type of secretory cell. True or false?

Answer 74

true

Question 75

Apocrine glands secrete a protein-rich secretion containing ____ via merocrine secretion

Answer 75

pheromones

Question 76

The human apocrine glands are found where?

Answer 76

lips, axilla, areola of breasts, perineal regions

Question 77

When do apocrine glands become active?

Answer 77

puberty - they increase in size in response to steroid hormones

Question 78

These glands can be considered modified apocrine sweat glands and develop under the influence of sex hormones

Answer 78

mammary

Question 79

In females, mammary glands enlarge in response to steroid hormones. The actual secretion is initiated by ____, screwed by the adenohypophysis

Answer 79

prolactin

Question 80

The ejection of milk from the breast is stimulated by ___, released by neurohypophysis and is due to the action of ___ cells located between secretory cells and the basal lamina

Answer 80

oxytocin; myoepithelial

Question 81

Mammary gland is composed of ___ to __ irregular lobules.

Answer 81

15 - 20

Question 82

Each lobule in the mammary gland is a ____ ___ gland embedded into loose CT

Answer 82

branched tubular

Question 83

near the nipple the ducts of the tubuloalveolar glands dilate to form _____ sinuses, lined with _____ ____ epithelium

Answer 83

lactiferous; stratified cuboidal

Question 84

In regards to mammary glands, the terminal parts of the ducts are called lactiferous ducts and open within the mammary papilla or nipple. They are lined with _____ _____ epithelium

Answer 84

stratified squamous

Question 85

Do the tubuloalveolar glands within the inactive mammary gland contain secretory end-pieces?

Answer 85

no - contain large amounts of CT

Question 86

During pregnancy, the mammary glands undergo dramatic proliferation an development as they start actively secreting milk and become active or ___ ____ glands

Answer 86

lactating mammary

Question 87

Under the influence of ___ the compound tubuloalveolar glands quickly develop secretory end-pieces that proliferate at a significant rate.

Answer 87

progesterone

Question 88

Both ___ and ____ secretion are involved in the production of milk

Answer 88

merocrine; apocrine

Question 89

The proteinaceous component of milk is synthesized in the RER, packed in the golgi, and secreted via ___ secretion

Answer 89

merocrine

Question 90

The fatty component of milk is formed within the ____. The large droplets coalesce and migrate towards the apical portion of the cell, where they project into the lumen of the acinus. The droplets are then invested into the envelope formed by the plasma membrane and released from the cell via ____ secretion

Answer 90

cytoplasm; apocrine