LEC 1 Flashcards
What do you mean by prenatal?
“before birth”
What are the 3 Periods:
- Period of Ovum (fertilization - 14th day)
- Period of Embryo (14th-56th day)
- Period of Fetus (56th day 270th/birth)
What period: fertilization - 14th day
Period of Ovum
What period: (14th-56th day)
Period of Embryo
What period: 56th day-270th/birth
Period of Fetus
An attachment to the uterine wall
Cleavage of the ovum
By the end of this period - 1.5 mm in length is observed.
Period of the Ovum
By the end of Period of the Ovum, how much length is observed?
1.5mm
When the sperm meets the egg, and they develop
together, a cleavage of ovum forms and attaches
itself to the uterine wall.
Period of the Ovum
21 days after conception
Period of the Embryo
3 mm in length and head begins to take shape.
Period of the Embryo
Head is made up of prosencephalon.
Period of the Embryo
On the Period of the Embryo, the head is made up of ____?
Prosencephalon
At that time, before connection exists between
oral cavity and foregut, the head is primarily made
up of prosencephalon.
Period of the Embryo
It is the most rostral part of the CNS, this is during Period of the Embryo.
Prosencephalon
Inferior portion of prosencephalon frontal prominence which overhangs the developing oral groove.
Period of the Embryo
Many facial components: ears, parts of nose, jaw, teeth, salivary glands arise from the pharyngeal portions of the foregut among others.
Period of the Embryo
Face develops from tissues surrounding the oral pit.
Facial Development at 4-7th week
Covering the brain, from which develops
the forehead
Frontal Process
Development of the lateral to the oral pit (LR) - cheeks
Maxillary processes
Development below the oral pit to lower jaw
Mandibular arch
Also the 2nd pharyngeal arch
Hyoid arch
Lying inferior to mandibular arch, its muscle
expands into and contribute to the face.
Hyoid arch
It also forms the external & middle ear.
Hyoid arch
Evident below the pit and on the sides
of the neck
Pharyngeal Arches (4th week)
Processes of the brain bulge forward & laterally to
dominate the facial area.
Frontal Process (4th week)
Below the frontal processes are 2 small wedge-shaped tissues termed as:
Maxillary Process
It lies lateral to the oral pit.
Maxillary Process
It is beneath maxillary processes
Mandibular Arch
Divided or constricted in the middle
Mandibular Arch
Heart begins to grow fast and is beginning to pump blood throughout the body.
Period of Embryo
It begins to grow fast and is beginning to pump blood throughout the body.
Heart
Fastest growing organ
Heart
4th week: pumps blood
Heart (Period of the Embryo)
Environmental factors play an important role in facial and palatal malformations. The period before the fifth week is the critical time during which these factors can affect facial development.
A. 1st Statement is true, and 2nd Statement is false.
B. 2nd Statement is false, and 1st Statement is true.
C. Both statements are True
D. Both Statements are False
E. Neither
C. Both statements are True
During the fifth week, the bilateral nasal placodes, or thickened areas of epithelium appear in the upper border of the lip. As the tissues around those placodes grow - resulting into 2 slits opening into the oral pit.
A. 1st Statement is true, and 2nd Statement is false.
B. 2nd Statement is false, and 1st Statement is true.
C. Both statements are True
D. Both Statements are False
E. Neither
C. Both statements are True
What period when frontal area becomes known as “frontal-nasal processes”
Period of Embryo (5th week)
During the Period of Embryo at 5th week, What area becomes known as frontonasal processes.
Frontal area
During the Period of Embryo at 5th week, deepened as the area around them continue to
grow anteriorly.
Nostrils
The distance between nostrils
Internasal Area
It is the width of the face
Internasal Area
Frontal prominence diminishes, and the face
broadens.
Period of Embryo (5th week)
This become prominent as well on the sides of head.
Eyes
Loses its midline constriction.
Mandibular Arch
Lateral parts of the face expand, broadening face - caused by the lateral growth of the brain.
Period of the Embryo (6th Week)
Lateral parts of the face expand, broadening face - caused by the ____.
Lateral growth of the brain
front of the face
Eyes and maxillary processes
To the point that which the maxillary & your mandibular tissues emerge.
Mouth slit widens (6th Week)
The nasal processes are limited to the middle of the upper lip = face looks more human
Period of the Embryo (6th Week)
Are limited to the middle of the upper lip = face looks more human
The nasal processes
Nasal processes and two maxillary segments
Upper Lip
lateral to pit
Lateral nasal process
Philtrum
Upperlip/Medial nasal process
Medial to pits
Medial nasal process
two maxillary processes and the medial third
is the medial nasal
Border of Lip
failure of fusion of medial nasal and max process.
Cleft Lip
This period is important during pregnancy.
Cleft lip (6th week)
zone of fusion
Nasal Fin
It continue behind the nasal fin to open into the roof of the mouth at 6 weeks.
The Nasal Pits
It grows around the oral pit
Orbicularis Oris Muscle
Oblique groove from the nostrils to the eyes
Oronasal optic groove
This is the tissue beneath the oronasal optic groove
Nasolacrimal duct develops
auditory tube
1st pharyngeal groove
More human appearance
Period of the Embryo (7th Week)
A third of the face added lateral to reach nostril.
Period of the Embryo (7th Week)
philtrum
Upper lip (Period of the Embryo (7th Week)
The upper lip has fused, producing a ____.
Medially located philtrum (Period of the Embryo (7th Week)
Ears are formed
Period of the Embryo (7th Week)
Eyelids develop
Period of the Embryo (7th Week)
A third of the face has been added lateral to each nostril.
Period of the Embryo (7th Week)
The mouth is limited in size with the change in facial proportions.
Period of the Embryo (7th Week)
The danger of cleft lip has passed.
Period of the Embryo (7th Week)
The medial & nasal processes have emerged in this
period.
Period of the Embryo (7th Week)
Auricles of the ear have developed as well.
Period of the Embryo (7th Week)
The ear hillocks have fused and grown to form the ears (auricles).
Period of the Embryo (7th Week)
The ridges around the eyes will soon develop
into eyelids
Period of the Embryo (7th Week)
Because the face develops on the surface of the brain, defects of the anterior brain may result in developmental alteration of the facial form.
Period of the Embryo (7th Week)
8th - 12th week fetus triples its length, from 20 to 60 mm
Period of Fetus
Eyelids and nostrils form and close
Period of Fetus
Relatively increase in Mandibular size
Period of Fetus
Anteroposterior maxillomandibular relationship -
aprons that of newborn infant
Period of Fetus
aprons that of newborn infant
Anteroposterior maxillomandibular relationship
Increase in size and change in proportions.
Period of Fetus
Great changes have taken place in the facial structures
Period of Fetus
But the changes seen in the last 2 trimester of intrauterine life are largely just increase in size & change in proportions.
Period of Fetus
