Test 1 review

Question 1

There are 4 muscles of mastication:

Answer 1

1. Masseter
2. Temporalis
3. Medial pterygoid
4. Lateral pterygoid

Question 2

Masseter

Answer 2

Most superficial and strongest. Thick flat rectangular muscle on each side of the face, anterior to the parotid gland.

2 heads (superficial and deep)

Origin- Both heads originate from the zygomatic arch. Superficial =angle of the mandible. Deep = ramus

When the patient clenches their teeth is when the elevation of the mandible is taking place (closing of the jaws)

Innervated by the Masseteric nerve (V3)

Question 3

Temporalis

Answer 3

broad fan-shaped muscle of mastication on each side of the head that fills the temporal fossa, superior to the zygomatic arch.

Temporal space is formed by the temporal fascia covering the temporalis muscle. Infratemporal space is bordered laterally by the medial surface of the mandible and the temporalis muscle.

originates from the temporal fossa – a shallow depression on the lateral aspect of the skull

Action- retraction of mandible, elevating the mandible. Also allows freeway space at its physiologic rest position

Innervated by 5^th cranial or trigeminal nerve.

Question 4

Medial pterygoid

Answer 4

Rectangular form has 2 heads due to differing depth (deep and superficial, smaller head).

The superficial head originates from the maxillary tuberosity and the pyramidal process of palatine bone. The deep head originates from the lateral pterygoid plate of the sphenoid bone. Both parts attach to the ramus of the mandible, near the angle of mandible.

DEEPEST MUSCLE OF MASTICATION

Elevates the mandible during the closing of the jaws

Innervated by 5^th cranial or trigeminal nerve

Question 5

Lateral pterygoid

The superior head originates from the greater wing of the sphenoid. The inferior head originates from the lateral pterygoid plate of the sphenoid. The two heads converge into a tendon, which attaches to the neck of the mandible.

Answer 5

short thick almost conical muscle of mastication superior to the medial pterygoid. Two separate heads (superior an inferior). They are separated anteriorly by a slight interval but fuse together posteriorly.

The entire muscle lies within the infratemporal fossa deep to the temporalis muscle.

The only muscle of mastication that ASSISTS in depressing the mandible, lowering the lower jaw! Depression of the mandible occurs during the opening of the jaws. Protrusion also occurs when the jaws are opened

The muscle is innervated by the lateral pterygoid nerve, a branch of the mandibular nerve (V3)

Pterygomandibular space is formed by the lateral pterygoid muscle (roof), medial pterygoid muscle (medial wall), and the mandibular ramus (lateral wall). It is the injection site for the inferior alveolar block.

Question 6

Free gingiva

Answer 6

closely adapted around each tooth but not attached
keratinized

Question 7

Parts of free gingiva

Answer 7

Gingival margin
gingival sulcus
junctional epithelium
free gingival groove

Question 8

Gingival margin

.

Answer 8

the edge of the gingiva nearest to the incised surface of the tooth

Question 9

Gingival sulcus

Answer 9

The crevice between the free gingiva and the tooth.

Question 10

Junctional epithelium

Answer 10

the epithelial attachment provides a seal at the base of the sulcus
non keratinized separates the periodontal ligament from the oral environment

Question 11

Free gingival groove

Answer 11

a shallow linear demarcation between free gingiva and attached gingiva

Question 12

Interdental papillae

Answer 12

Extensions of unattached gingiva between adjacent teeth
keratinized fills embrasure spaces

Question 13

Attached gingiva

Answer 13

Part of the gingiva that is tightly connected to the cementum on the root (cervical third) and to the connective tissue cover of the alveolar bone

Question 14

Mucogingival junction

Answer 14

The line that marks the connection between the attached gingiva and the alveolar mucosa on the facial surfaces of all quadrants and the lingual surfaces of the mandibular arch

Question 15

Alveolar mucosa

Answer 15

The thin, moveable, loosely attached tissue covering the alveolar bone.
non keratinized

Question 16

Anesthesia Landmarks

ASA

Answer 16

Nerve: Anterior superior alveolar

Teeth: maxillary anterior teeth

Landmarks:

maxillary mucobuccal fold

canine eminence

maxillary canine

Question 17

Anesthesia Landmarks

MSA

Answer 17

Nerve: Middle superior alveolar

Teeth: maxillary molars

Landmarks:

maxillary mucobuccal fold

maxillary 2nd premolar

Question 18

Anesthesia Landmarks

PSA

Answer 18

Teeth: Maxillary molars

Nerve: Posterior superior alveolar

Landmarks:

Maxillary tuberosity

PSA foramina

maxillary mucobuccal fold

maxillary second molar

Question 19

Anesthesia Landmarks

IA

Answer 19

Teeth: Mandibular teeth to the midline (molar - central incisor)

Nerve: Inferior alveolar, mental, incisive nerve, lingual

Landmarks:

Medial surface of Ramus

mandibular foramen

pterygomandibular fold overlying raphe

Question 20

Ectoderm

Answer 20

layer in trilaminar embryonic disc derived from epiblast layer and lining stomodeum. Gives rise to the skin epidermis the CNS

Question 21

Endoderm

Answer 21

layer in trilaminar embryonic disc derived from hypoblast layer

Question 22

Mesoderm

Answer 22

embryonic layer located between ectoderm and endoderm. Gives rise to CT such as skin dermis, cartilage, bone, blood, muscle, and associated other tissue

Question 23

Neuroectoderm

Answer 23

specialized group of cells that differentiates from ectoderm. Gives rise to the respiratory epithelium and cells of glands

Question 24

When does the primitive streak form (“when do things form??”)

Answer 24

During the beginning of the third week of prenatal development within the embryonic period, the primitive streak forms within the bilaminar disc. This furrowed, rod-shaped thickening in the middle of the disc results from increased proliferation of cells in the midline area.

Question 25

Epiblast

Answer 25

superior layer from the bilaminar embryonic disc composed of high columnar cells.

Question 26

Hypoblast

Answer 26

inferior layer from the bilaminar embryonic disc composed of small cuboidal cells.

Question 27

Neuroectorderm

Answer 27

a specialized group of cells that differentiates from the ectoderm. Eventually develops the neural tube

Question 28

Endoderm

Answer 28

cells that locate in the middle with mesoderm between the epiblast and hypoblast layers and embryonic CT

Question 29

Bilateral symmetry

Answer 29

Bilateral symmetry is when each half of an embryo mirrors the other half.

Question 30

Fusion (what does it mean?)

Answer 30

Fusion is the joining of embryonic tissue of two separate surfaces, elimination of a furrow between two adjacent tooth germs unite to form large tooth.

Question 31

What’s the neural tube?

Answer 31

As further growth of the neuroectoderm occurs, the neural tube is formed during the fourth week by the neural folds undergoing fusion at the most superior part. The neural tube forms the future spinal cord as well as other neural tissue of the CNS.

Question 32

Where do the neural crest cells migrate from?

Answer 32

These cells migrate from the crests of the neural folds and then join the mesoderm to form mesenchyme.

Question 33

What is cleavage and when does it occur?

Cleavage – the process during prenatal development when mitosis converts a zygote to a blastocyst

Answer 33

After fertilization, the zygote then undergoes mitosis, or individual cell division, that splits it into more and more cells due to cleavage. After initial cleavage, the solid ball of cells becomes a morula. Because of the ongoing process of mitosis and secretion of fluid by the cells within the morula, the zygote now becomes a blastocyst (or blastula). The rest of the first week is characterized by further mitotic cleavage, in which the blastocyst splits into smaller and more numerous cells as it undergoes successive cell division by mitosis.

Question 34

When does implantation occur and how does it occur?

Answer 34

As the blastocyst grows by cleavage, it travels from the site where fertilization took place to the uterus.

By the end of the first week, the blastocyst stops traveling and undergoes implantation and thus becomes embedded in the prepared endometrium, the innermost lining of the uterus on its back wall.

Question 35

How does the mandibular arch form (basically)?

Answer 35

After formation of the stomodeum but still within the fourth week, two bulges of tissue appear inferior to the primitive mouth: the two mandibular processes. These processes consist of a core mesenchyme formed in part by NCC’s that migrated to the facial region to join with the mesoderm; they are covered externally by ectoderm and internally by endoderm. These paired mandibular processes then fuse at the midline to form the mandibular arch.

Question 36

Anesthesia Landmarks

Mental

Answer 36

Teeth: None

Nerve: Mental

Landmarks:

Mandibular premolars

mental foramen

mandibular mandibular fold

Question 37

What does the maxillary process form from?

Answer 37

The mandibular arch (During the fourth week of prenatal development, within the embryonic period, an adjacent swelling forms from increased growth of the mandibular arch on each side of the stomodeum, the maxillary process.)

Question 38

Embryonic layers (germ layers)

Answer 38

increased number of embryonic cells within the blastocyst.

Question 39

What are the 3 stages of pregnancy?

Answer 39

Preimplantation period – first week (zygote, blastocyst)

Embryonic period – weeks 2-8 (disc, embryo, folded embryo)

Fetal period – months 3-9 (embryo, fetus)

Question 40

What’s the diff b/w meiosis and mitosis

Answer 40

Meiosis – The process of reproductive cell production that ensures the correct number of chromosomes; meiosis that takes place during fertilization.

Mitosis – cell division that occurs in phases and results in two daughter cells; Mitosis is a process that takes place during tissue growth or regeneration

Question 41

How does cleft lip form?

Answer 41

Failure of fusion of the maxillary process

with the medial nasal process

Question 42

When does the medial nasal and the maxillary processes form?

What happens when they form incorrectly?

Answer 42

The upper lip is formed from the fusion of the maxillary process with the medial nasal process.

This process starts at the beginning of the sixth week and is completed during the end of the seventh week of pregnancy.

When they form incorrectly, a cleft lip can occur.

Question 43

When does the facial development start, what week?

Answer 43

4^th week (within the embryonic period)

Question 44

What happens in the second branchial arch - what forms from it?

Answer 44

The first branchial arch, which is also known as the mandibular arch, and its associated tissue were described earlier and include Meckel cartilage.

Forming within the second branchial arch, which is also known as the hyoid arch, is cartilage similar to that of the mandibular arch, Reichert cartilage. Most of it disappears during development; however, parts of it are responsible for a middle ear bone, a process of the temporal bone, and parts of the hyoid bone.

Question 45

What does the mandibular arch form from?

Answer 45

The fusion of the two mandibular processes

Question 46

When do the maxillary and nasal processes form?

Answer 46

Maxillary process – 4^th week

Nasal processes:

Frontonasal process – 4^th week

Medial nasal processes – weeks 4-7

Lateral nasal processes – week 4

Question 47

When do the paranasal sinuses form?

Answer 47

Some of the paranasal sinuses develop later during the fetal period, and others develop after birth.

All form as outgrowths of the walls of the nasal cavities and become air-filled extensions of the nasal cavities in the adjacent bones, such as in the maxilla and the frontal bone.’ 4^th week and also after?

Question 48

What is Reichert cartilage?

Answer 48

Reichert cartilage is cartilage in the second branchial arch that eventually disappears.

Question 49

How many processes are included in facial development?

Answer 49

Facial development depends on the five major facial processes that form during the fourth week and surround the primitive mouth of the embryo:

1. frontonasal process.

2/3. mandibular arch (paired)

4/5. maxillary process (paired)

Question 50

In week 1 (preimplantation), name the events that occur within the organism as it develops (in order):

Answer 50

1. ) fertilization w/ sperm and ovum
2. ) zygote undergoes mitosis (cleavage), to form a morula
3. ) morula forms a blastocyst
4. ) Blastocyst implants in the endometrium. 2 layers now (trophoblast, embryoblast)
5. ) trophoblast layer gives rise to prenatal support tissue, embryoblast layer gives rise to the embryo.

Question 51

In week 2 (embryonic period), name the events that occur within the organism as it develops (in order):

Answer 51

1. ) implanted blastocyst grows via proliferation + morphogenesis.
2. ) leads to the formation of bilaminar embryonic disc (epiblast EB layer

[high columnar cells], and hypoblast HB layer [small cuboidal cells]).

3. ) suspension of the disc in endometrium between amniotic cavity (EB) and the yolk sac (HB) (embryo sac).
4. ) Placenta joins embryo, allowing oxygen, CO2, nutritional, and hormonal substances to exchange.

Question 52

in week 3 (embryonic period), name the events that occur within the organism as it develops (in order):

Answer 52

1. ) development of primitive streak w/in the disc (creating bilateral symmetry)
2. ) epiblast layer cells migrate toward hypoblast layer to become mesoderm and embryonic endoderm.
3. ) formation of trilaminar embryonic disk (mesoderm, endoderm, ectoderm)
4. ) CNS development (brain, spinal cord begin)

A.) ectoderm creates neuroectoderm, within neural plate, that thickens to form neural groove.

B.) Neural groove deepens to become surrounded by neural folds

C.) neural folds meet and fuse to form neural tube.

5.) Formation of somites (38-paired cuboidal segments of mesoderm)

Question 53

in week 3 (embryonic period), the ectoderm develops into what?

Answer 53

1. ) skin epidermis
2. ) CNS
3. )NCC’s
4. ) mammary & cutaneous glands
5. ) Histologic feature-Columnar
6. ) Origin- Epiblast layer

Question 54

in week 3 (embryonic period), the endoderm develops into what?

Answer 54

1. ) respiratory/digestive system linings
2. ) glandular cells
3. ) liver/pancreatic cells
4. ) Histologic features- Cuboidal
5. ) Origin- Migrating cells from epiblast layer

Question 55

in week 4 (embryonic period), name the events that occur within the organism as it develops (in order):

(Hint/trick to remember-fold, feed, face)

Answer 55

1. ) trilaminar embryonic disk undergoes anterior (cephalic) and lateral embryonic folding (endoderm inside ecto+meso)
2. ) formation of tube that becomes future digestive tract from cephalic (oropharyngeal membrane) to caudal (cloacal membrane) end. (Foregut [anterior], Midgut [posterior], Hindgut[posterior])
3. ) Development of face and neck (primitive eyes, ears, nose, oral cavity, and jaw areas)

Question 56

in week 3 (embryonic period), the trilaminar embryonic disc develops two ends called?

Answer 56

1. ) Cephalic end (Head end)
2. ) Caudal end (Tail end)

Question 57

in week 3 (embryonic period), the mesoderm develops into what?

Answer 57

1. ) connective tissue (such as skin dermis, cartilage, bone, blood, muscle).
2. ) excretory and reproductive organs
3. ) histologic features- varies
4. ) origins- migrating cells from epiblast layer

Question 58

in week 3 (embryonic period), the Neural Crest Cells develop into what?

Answer 58

1. ) components of nervous system pigment cells, connective tissue proper, cartilage, bone, certain dental tissue
2. ) Histologic Features- Varies
3. ) Origin- Migrating neuroectoderm