Integumentary System Flashcards
The first hairs-__- are fine, soft and lightly pigmented
Lanugo
Some capillaries acquire muscular coats through the differentiation of ___ developing int he surrounding mesenchyme, and they become what
Myoblasts
Arterioles, arteries, venues, and veins
Permanent third molar
13-25 years
Lanugo begins to appear toward the end of the _ week and is plentiful by _ to _ weeks
12
17-20
Eccrine gland secretions begin when? Apocrine sweat gland secretions begin when?
Shortly after birth
Puberty
The central core of loosely arranged cells between he layers of the enamel epithelium is the __ __(__ __)
Enamel retinaculum (stellate retinaculum0
Deciduous canine:
Erupt 16-20 mo
She’d 10-12 yrs
Deciduous:second molar
Erupt 20-24 mo
Shed-10-12 yrs
Congenital absence of one or more teeth is often a __ trait
Familial
During the late fetal period, the epidermis at the site of origin of the primordial mammary gland becomes depressed, forming a shallow __ ___
Mammary pit
The melanin produced by melanocytes is transferred tot he hair forming cells int he __ ___ several weeks before birth
Germinal matrix
Molecular studies indicate that melanocyte-stimulating hormone cell surface receptor and melanosomal _-protein determining the degree of pigmentation by regulating __ ___ levels and activity
P
Tyrosine kinase
The ___ is a superficial epithelial tissue that is derived from __ __ ___
Epidermis
Surface embryonic ectoderm
Permanent canine
Erupt 1-12 yrs
The arrector msucles are poorly developed int he hairs of the __ and certain parts of the __
Axilla
Face
Deciduous:lateral incisor
Erupt 8-10 mo
She’d 7-8 yrs
Later the melanoblasts migrate to the dermoepidermal junction and differentiate into ____
Melanocytes
Capillary loops develop in some of the dermal ridges and do what
Provide nourishment for the epidermis
The hemolysis associated with hemolytic disease of the neonate may produce- to _ discoloration of the teeth
Blue
Black
Polymastia
Extra breast
The periodontal ligament is derived from ___
NCC
At first, the developing nail is covered by superficial layers of epidermis, the ___
Eponychium
As each tooth bud is invaginated by mesenchyme, the primordium of the dental __ and dental __-the bud becomes cap chapped
Papilla
Follicle
The ectodermal part of the developing tooth, the __ organ, eventually produces __
Enamel
Enamel
Proliferation of cells in the stratum germinativum also produces __ __, which extend into the developing dermis
Epidermal ridges
True angiomas as _ tumors of endothelial cells, usually composed of solid or hollow cords; hollow cords contain blood
Benign
Sebaceous glands , independent of hair follicles, develop in a similar manner as buds of the ___ that invade the ___
Epidermis
Dermis
As the dentin increases, it reduces the pulp cavity to a narrow __ __ through which the vessels and nerve pass
Root canal
Teeth develop from the oral ___, ___ and ___
Ectoderm
Mesenchyme
NCC
The thickening, U shaped bands -___ __- follow the curves of the primordial jaws
Dental laminae
The blood vessels int he dermis differentiate from mesenchyme by ___
Vasculogenesis
In enamel hypoplasia, various factors may injure ameloblasts such as what
Nutritional defiencies, tetracycline therapy, and infectious disease
Macrodontia
Condition caused by the union of two adjacent tooth germs
Crowns of the two teeth can be partially of completely fused
Same applies to roots
The permanent teeth develop in a manner similar to that described for the deciduous teeth. As a permanent tooth grows, the root of the corresponding deciduous tooth is gradually resorted by ___
Osteoclasts
Glands are derived from the __ and grow into the __
Epidermis
Dermis
At puberts in females, Growth of the duct and lobe systems also occurs because ofthe increased level of circulating __ and ___
Estrogen
Progesterone
In the axillary and pubic regions, the lanugo is replaced at ___ by even courser __ __
Puberty
Terminal hairs
As the root of the tooth grows its crown gradually erupts through the oral epithelium
The part of the oral mucosa around the erupted crown becomes the gingiva
Dermatoglyphics
Looking at finger prints
The central cells of the alveoli break down , forming an oily secretion ___
Sebum
The outer cell layer of the enamel organ is the ___ enamel epithelium, whereas the inner cell layer lining the cap is the __ enamel epithelium
Outer
Inner
Hair begins to develop during the _ to _ weeks, but become recognizable in the _ week
9, 12
20
The hair grows through the epidermis on the eyebrows and the upper lip by the end of the _ week
12
Why does albinism occur
Melanocytes do not produce melanin because of a lack of the enzyme, tyrosinase
The dermis develops from __ underlying the surface ectoderm
Mesenchyme
Dentinogenesis imperfecta
Common in Caucasian’s
Teeth are brown to gray blue, with an opalescent sheen
Deciduous:medial incisor
Erupt 6-8 mo
She’d 6-7 yrs
Odontogenesis is initiated by the inductive influence of the what
Neural crest-induced mesenchyme int he overlying ectoderm
In males, where do they also get terminal hairs at puberty
Face and chest
In females the mammary glands enlarge rapidly during __. Why
Puberty
Fat and other CT development int he breasts under the influence of estrodiol
The mammary crests appear during the _ week but normally persist only int he pectoral area where the breasts develop
4
The tooth buds for the permanent teeth appear at _ weeks fromt he deep continuations of the dental laminae
10
What is the periodontal ligament
Specialized vascular CT that surrounds the root of the tooth, separating it from and attaching it to the alveolar bone
The pattern of epidermal ridges that develop on the surface of palms and hands and soles of the feet is __ determined, and constitutes the basis for examining fingerprints (_)
Genetically
Dermtoglyphics
As enamel increases, the ameloblasts regress toward the __ enamel epithelium
Outer
At the end of the _ year, all 20 deciduous teeth are usually present
2
The relative contents of melanin in the melanocytes accounts for the different colors of skin
Yup
The buds for the second and third permanent molars develop __ birth
After
The mandibular medial incisors-or _ incisors-usually erupt 6-8 months after birth, but maybe not until 12-13 months in some
Central incisors
What causes amelogenesis imperfecta
Mutational defects of genes that encode for enamel, dentin, and mineralization
What is the first indication fo toothe development
Thickening of the oral epithelium , a derivative of the surface ectoderm seen during the sixth week
A child’s dentition contain _ deciduous teeth
20
Later, the predentin calcified and becomes __
Dentin
Angioma
Vascular anomalies in which transitory and/our surplus blood or lymphatic vessels persist
Approximately 90% of males with __ syndrome have gynecomastia
Klinefelter
The peripheral cells of the developing hair follicle form the __ __ __ and the surrounding mesenchymal cells differentiate into the __ ___ _
Epidermal root sheath
Dermal root sheath
Toenails and fingernails begin to develop at the tips of the digits at approximately _ weeks
10
The mammary bud grows down into the mesenchyme as a response to an __ influence of the mesenchyme
Inductive
After birth, increased amounts of melanin are produced in response to _ light
UV
Permanent lateral incisor
Erupt 8-9 yrs
The epidermal ridges begin to appear in embryos at _ weeks are are permanently established at __ weeks
10
17
The basal layer of the epidermis becomes the __ __, which produces new cells that are displaced into the more superficial layers
Stratum germinativum
Each dental lamina develops _ centers of proliferation from which tooth buds grow into underlying ___
10
Mesenchyme
The primordium of the epidermis is the __ ___
Surface ectoderm
Cells of the inner enamel epithelium differentiate into ___, which produce enamel in the form of prisms over the dentin
Ameloblasts
As skin grows, new capillaries grow out from the primordial vessels (_)
Angiogenesis
What are neonate nipples like
Poorly formed and depressed
In amelogenesis the teeth are covered with only a thin layer of abnormally formed enamel through which the color of the underlying dentin is visible, giving the teeth a darkened appearance
Rare AD condition
Inheritance of dentinogenesis imperfecta
AD
What causes enamel hypoplasia
Temporary disturbances of enamel formation
Herlequin ichthyosis
Rare AR Mutation in ABCA12 Skin thickened, ridged, and cracked 70% die early
The periodontal ligament is located between what
Cement or the root and the bony alveolus
Amelogenesis imperfecta
Tooth enamel is soft and friable bc of hypocalcifciation and the teeth are yellow to brown in color
Supernumerary nipples may be mistaken for __
Moles
All ___ are extensively incorporated into the teeth
Tetracyclines
Canalizations of the mammary buds is induced by what
Maternal sex hormones entering the fetal circulation
Together, the dental papillla and enamel organ form the __ __
Tooth germ
The inner cells of the dental sac differentiate into ____, which produce cement that is restricted to the root
Cementoblasts
What is sebum
Substances released into hair follicle and passes to the surface of the skin. It mixes with desquamated peridermal cells to form the vernix caseosa
The hair bulb is soon __ by a small mesenchymal hair papilla
Invaginated
The cells in the surface ectoderm proliferate and form a layer of ___ epithelium, the __ and a __ layer
Squamous
Periderm
Basal
Generalized albinism
AR
Sin hair and retina lack pigment
The permanent molars have no deciduous predecessors;they develop as buds from posterior extensions of the __ __
Dental laminae
When do secretions from apocrine glands start
Puberty
What forms enamel pearls
Aberrant groups of emaloblasts
The mesenchymal cells in the dental papilla adjacent to the inner enamel epithelium differentiate into ___, which produce ___ and deposit it adjacent to the epithelium
Odontoblasts
Predentin
The epithelial root sheath grows into the mesenchyme and initiates __ formation
Root
The peripheral cells of the secretory part of the sweat gland differentiate into ___ and ___ cells
Myoepithelial
Secretory
The root of the tooth begins to develop after dentin and enamel formation is well __
Advanced
As a result, the ducts of apocrine sweat glands open into the upper part of the hair follicles, superficial to the openings of the __ __
Sebaceous glands
Permanent :medial incisor
Erupt 7-8 yrs
The skin is characterized by __ and ___ , in ichthyosis
Dryness and scaling
The buds grow into the surrounding CT and branch to form the primordia of the ___ and their associated ducts
Alveoli
__/__ signaling also regulated many’s tage of tooth development
Wnt/B catenin
Enamel hypoplasia
Defective enamel formation causes pits, fissures, or both in the enamel of the teeth
The epithelial attachment of the developing sweat gland tot he epidermis forms the primordium of the __ __
Sweat duct
The enamel is completely formed on all but the third molars by _ years of age
8
Mammary buds begin to develop during the _ week as solid downgrowths of the epidermis into the underlying mesenchyme
6
Abnormally shaped teeth common?
Yup
Enamel overlies the yellowing dentin and does what
Protects it from being fractured
In macrodontia, occasionally a tooth bud divides or two buds partially fuse to form fused teeth
Commonly observed int he mandibular incisors of the primary dentition, but it can also occur in the permanent dentition
What does the integumentary system insist of
Skin and its appendages (nail, hair, sebaceous glands, and arrector msucles of hairs)
Mammary glands and teeth
Tooth development occurs for __ after birth
Years
Tooth buds develop into the __ teeth, which are shed during childhood
Deciduous
Tetracyclines produce brownish-yellow discoloration (mottling) and enamel hypoplasia bc they interfere with the metabolic processes of the ____
Ameloblasts
Cystic lymphangioma
Cystic hygromas
Angioma of lymphatics
Lanugo is replaced during the perinatal period by coarser hairs that persist over __ of the body
Most
The mammary glands develop similarly and are of the same structure in both sects
Ok
Permanent Second premolar
11-12 yrs
Permanent second molar
Erupt 12 yrs
The internal part of each cap-shaped tooth, the dental ___, is the primordium of the dental pulp
Papilla
As the deciduous teeth develop, they begin a continuous slow movement toward the oral cavity.
Ok
Where are supernumerary teeth usually
Int he area of the maxillary incisors and may disrupt the position and eruption of normal teeth
Usually erupt posterior to normal teeth
The hairs forming the eyebrows and eyelashes(cilia) have what kind of arrector msucles
NO ARRECTOR MSUCLES
The exfoliated peridermal cells form part of a white, greasy substance-__ __-that covers the fetal skin
Vernix caseosa
The primordia of the nails appear as thickened areas, or fields, of the epidermis at the tip of each digit
Later these nail fields migrate onto the dorsal surface carrying their innervation from the ventral surface.
As the cellular bud elongates, its ends coil to form the primordium of the __ part of the gland
Secretory
Enamel pearls
Spherical masses of enamel attached to the tooth
Replacement of the peridermal cells continues until approximately the 21st week;thereafter, the periderm __ and the stratum corneum forms the __ __
Disappears
Stratum Lucidum
The skin under the free margin of the nail is the _____
Hyponychium
Arrector msucles of hairs, small bundles of smooth muscle fibers, differentiate from the mesenchyme surrounding the hair follicle and attach to the dermal root sheath and the papillary layer of the dermis
Ok
The mammary buds develop from ___ ___, which are thickened strips of ____ extending fromt he axillary to the inguinal regions
Mammary crests
Ectoderm
Foreign substance discolor teeth if they are incorporated into he developing enamel and dentin.
Discolored teeth
What is the embryonic skin at 4-5 weeks
Single layer of surface ectoderm overlying mesoderm
As the enamel organ differentiates, the developing tooth becomes _ shaped
Bell
Each primary mammary bud soon gives rise to several secondary mammary buds that develop into the __ __ and their branches
Lactiferous ducts
What is total anodontia associated with
Congenital ectodermal dysplasia
Cells from the proximal nail fold grow over the nail field and __ to form the nail plate
Keratinize
The lanugo help holds the __ on the skin
Vernix
Ichthyosis
General term for a group of skin disorders resulting from excessive keratinization
What is cement
Bone like, rigid CT covering the root of the tooth.
The melanocytes begin producing __ before birth and distribute it to the epidermal cells
Melanin
The mammary glands are modified and highly specialized types of _ glands
Sweat
Development of _nails precedes _nails by 4 weeks
Finger
Toe
The mandibular teeth usually erupt before the maxillary teeth. And __ teeth usually erupt sooner
Female
The fibrous CT and fat of the mammary gland develop from the surrounding ____
Mesenchyme
Usually, eruption of the deciduous teeth occurs between _ and _ months after birth
6
24
Some fibers of the periodontal ligament are embedded int he _ of the root;other fibers are embedded int he __ __ of the alveolus
Cement
Bony wall
When he deciduous tooth is shed, it consists only of the crown and the cervical, or uppermost part of the root
The permanent teeth usually begin to erupt during the 6th year and continue to appear until early adulthood
Normal gynecomastiA
IN NEONATES bc of stimulation of the mammary glands by maternal sex hormones
Disappears in a few weeks
Polythelia associated with what
Congenital defects, including renal and urinary tract anomalies
The tooth is held in its ___ by the strong periodontal ligament, a derivative of the __ ___
Alveolus
Dental sac
The dental sac is the primordium of what
Cement and periodontal ligament
The nail fields are surrounded laterally and proximally by folds of the epidermis -___ __
Nail folds
As the teeth develop and the jaws ossify, the outer cells of the dental sac also become active in bone formation
Each tooth soon becomes surrounded by bone, except over its crown
Sensory nerve endings form in other ridges. The developing afferent nerve fibers apparently play an important role in what
Spatial and temporal sequence of dermal ridge formation
The fingernails reach the fingertips at _ weeks;the toenails reach the tips of the toe at _ weeks
32 36
Soon after birth, the nipples usually rise from the __ ___. Why
Mammary pits
Proliferation of the surrounding CT of the areola
Maxillary lateral incisor teeth may have a slender , tapered shape
Peg shaped teeth
For tooth discoloration(tetracycline), The critical period of risk is from approximately _ weeks of fetal life to the _ postnatal month for deciduous teeth and from _ weeks of fetal like to _ postnatal year for permanent teeth
14 10
14 16
Angiomas of blood vessels ma be:
Arterial
Venous
Cavernous
During puberty, approximately 2/3 of males have varying degrees of __ of breasts
Hyperplasia
Partial anodontia
On or more teeth absent
As the epidermal ridges form, the dermis projects into the epidermis, forming __ __
Dermal papillae
Who should not be administered tetracycline
Pregnant women
Children younger than 8
There are _ tooth buds in each jaw, one for each deciduous tooth
10
As cells in the germinal matrix proliferate, they are pushed toward the surface, where they ___ to form __ __
Keratinization
Hair shafts
This process continues until late gestation and by term, how many lactiferous ducts have formed
15-20
Total anodontia
No teeth
Rare
By 11 weeks, cells from the stratum germinativum have formed an ___ layer
Intermediate
Apocrine sweat glands develop from downgrowths of the __ __ or the epidermis that give rise to the hair follicles
Stratum germinativum
What causes dentinogenesis imperfecta
Failure of the odontoblasts to differentiate normally producing poorly calcified dentin
Expression of what in the migrating NCC and ectoderm and mesenchyme is essential for the initiation of tooth development
MSX and Dlh(these two are HOX)
BMP, Tnf, Wnt, Shh, and FgF
The enamel is derived from ___ and the oral cavity; all other tissue differentiate fromt he surrounding mesenchyme and NCC
Ectoderm
The odontoblasts adjacent to the epithelial root sheath form dentin that is continuous with that of the __
Crown
Polythelia
Extra nipple
In dentinogenesis imperfecta both deciduous and permanent teeth are usually involved.
The enamel tends to wear down rapidly, exposing the dentin . A
The myoepithelial cells are believed to be specialized smooth muscle cells that assist in expelling sweat from glands
Eccrine sweat glands begin to function shortly after birth
The relative amounts of melanin accounts for different _ colors
Hair
As the enamel organ and dental papilla develop, the mesenchyme surrounding the developing tooth condenses to form the __ __, a vascularized capsular structure
Dental sac
The glands of skin include __ and ___ sweat glands, __ glands, and __ glands
Eccrine
Apocrine
Sebaceous
Mammary
___ __ affects the differentiation fo the permanent teeth, resulting in incisors with central notches
Congenital syphilis
Permanent first molar
Erupt 6-7 yrs
__ arising during the critical period of permanent tooth development is the most common cause of enamel hypoplasia
Rickets
Rickets is a disease in children who are deficient in vitamin _. It is characterized by disturbances of ossification of the epiphyseal cartilages and disorientation of cells at the metaphysis-section of bone between epiphysis and diaphysis
Metaphysics
A hair follicle begins as a proliferation fo the __ __ of the epidermis and extends into the underlying ___
Stratum germinativum
Dermis
Localized albinism/piebaldism
AD
Lack of melanin in patches of skin, hair or both
Most of the mesenchyme that differentiates into the CT of the dermis originates from the __ layer of the ___ ___
Somatic
Lateral mesoderm
The __, underlying the epidermis, is a deep layer composed of dense, irregular arranged CT that is derived from ___
Dermis
Mesenchyme
Gynecomastia
Excessive development of male mammary tissue
The eponychium ___, exposing the nail, except at its base ,where it persists as the ___
Degenerates
Cuticle
__ is the hardest tissue in the body
Enamel
Two sets of teeth normally develop
Deciduous teeeth
Permanent teeth
What is the second hardest tissue int he body
Dentin
Menaloblasts migrate into the __ __ and differentiate into ___
Hair bulbs
Melanocytes
Collodion neonate
Covered by a thick, taut membrane that resembles collodion or parchment
Membrane cracks with first respiratory movement and falls off in large sheets
Shedding takes several weeks and normal appearing skin after
Abnormal chromosome complements affect the development of the ridge patterns..example?
50% of neonates with downs have distinctive ridge patterns on their hands and feet that are of diagnostic value
Polymastia or polythelia appear in what regions in females
Axillary or abdominal regions
Permanent first premolar
Erupt 10-11 yrs
Most sebaceous glands develop as buds from the sides of the developing __ ___ ___ of the hair follicles
Epidermal root sheaths
By the end of the __ __, the blood supply of the fetal dermis is well established
First trimester
The epithelial cells of the hair bulb constitute the __ _, which later produces the hair
Germinal matrix
The inner and outer enamel epithelial come together in the neck of the tooth, where they form a fold, the __ ___ __-
Epithelial root sheath
The central cells of the primordial ducts ___, forming a __
Degenerate lumen
As the dentin thickens, the odontoblasts regress toward the center of the dental papilla;however their cytoplasmic processes-__ __-remain embedded in the dentin
Odontoblastic process
Late in the embryonic period, ____ migrate into the mesenchyme in the developing dermis and differentiate into _____
NCC
Melanoblasts
The first tooth buds appear iwhere. Later toothe development occurs where
Anterior mandibular region
Anterior maxillary region and progresses posteriorly in both jaws
Eccrine sweat glands develop as epidermal downgrowths-__ __-underlying mesenchyme
Cellular buds
The __ __ soon becomes a club shaped hair bulb
Hair bud
By _ weeks, the mesenchymal cells have begun to produce collagenous and elastic CT fibers
11
What does the vernix do
Protects the developing skin from constant exposure to amniotic fluid containing urine, bile salts, and sloughed cells
What percent of the female population has polymastia or polythelia
.2-5.6
Cement is deposited over the dentin of the root and meets the __ at the neck of the tooth
Enamel
Hairs are first recognizable where
Eyebrows, upper lip, chin
Th apocrine sweat glands are mostly confined to the __, ___ and __ regions and the __
Axillary, pubic, perineal, areolae around nipple
Extra nipples of breasts develop alon the __ __
Mammary crest
The cells of the periderm continually undergo ____ and ____ and are replaced by cells arising from the __ layer
Keratinization
Desquamtion
Int erneralized albinism, what shows pigmentation
The iris
Deciduous first molar
Erupt 12-16 mo
Shed-9-11 yrs
The tooth buds for the permanent teeth appear at different dimes, mostly during the _ period
Fetal
