Terminal Branch of maxillary artery
Maxillary and mandibular division of trigemenial (V)
Derived from arch cartilages (originating from neural crest):
From maxillary cartilages:
Mackel’s cartilage, malleus
Upper portion of external ear (auricle) is derived from dorsal aspect of 1st pharyngeal arch.
Derived by direct ossification from arch dermal mesenchyme:
Maxilla, zygomatic, squamous portion of temporal bone, mandible
Muscles of mastication (temporalis, masseter, and pterygoids), mylohyoid, anterior belly of digastric, tensor tympani, tensor veli palatini (originate from cranial somitomere 4)
Stapedius artery (embryologic) and cortiotympanic artery (adult)
Facial nerve (VII)
Stapes, styloid process, stylohyoid ligament, lesser horns and upper rim of hyoid (derived from the second arch cartilage; originate from neural crest).
Lower portion of external ear (auricle) is derived from 2nd pharyngeal arch.
Muscles of facial expression (orbicularis oculi, orbicularis oris, auricularis, platysma, fronto-ooccipitalis, buccinator), posterior belly of digastric, stylohyoid, stapedius (originate from cranial somitomere 6)
Common carotid artery, most of internal carotid
Lower rim and greater horn of hyoid (derived from the third arch cartilage; originate from neural crest cells)
Sytlopharyngeus (originate from cranial somitomere 7)
Left: Arch of aorta;
Right: Right subclavian artery;
Original sprouts of pulmonary arteries
Superior laryngeal branch of vagus (X)
Laryngeal cartilages (Derived from the 4th arch cartilage, originate from lateral plate mesoderm)
Constrictors of pharynx, cricothyroid, levator veli palatine (originate from occipital somites 2-4)
Ductus arteriosus; roots of definitive pulmonary arteries
Recurrent laryngeal branch of vagus (X)
Laryngeal cartilages (derived from the 6th-arch cartilage; originate from lateral plate mesoderm)
Intrinsic muscles of larynx (originate from occipital somites 1 and 2)
Respiratory system plays important role in maintaining homeostasis . Other than its major function , which is supplying the cells with needed oxygen to produce energy and getting rid of carbon dioxide , it has other functions :
1 Vocalization , or sound production.
2 Participation in acid base balance .
3 Participation in fluid balance by insensible water elimination (vapors ).
4 Facilitating venous return .
5 Participation in blood pressure regulation : Lungs produce Angiotensin converting enzyme ( ACE ) .
6 Immune function : Lungs produce mucous that trap foreign particles , and have ciliae that move foreign particles away from the lung. They also produce alpha 1 antitrepsin that protect the lungs themselves from the effect of elastase and other proteolytic enzymes
Agonist, Antagonist, and Partial Agonists
Agonists: molecules that activate receptors. A drug that mimics the body's own regulatory processes.
Antagonists: produce their effects by preventing receptors activation by endogenous regulatory molecules and drugs. Block activation of receptors by agonists.
Noncompetive Antagonist: Bind irreversibly to receptors, and reduce the maximal response that an agonist can elicit.
Competitive Antagonist: Bind reversibly to receptors, competing with agonists for binding sites.
Partial Agonists: Have moderate intrinsic activity, the maximal effect that a partial agonist can produce is lower than that of a full agonist. Act as antagonists as well as agonists.
HISTOLOGIC CHANGES OF THE PULP
Pulp decreases in size by the deposition of dentin.
This can be caused by age, attrition, abrasion, operative procedures, etc.
Cellular organelles decrease in number.
They are more obvious in injury rather than aging. Occasionally, scarring may also be apparent.
Pulpal stones or denticles
They can be: a)free, b)attached and/or c)embedded. Also they are devided in two groups: true or false. The true stones (denticles) contain dentinal tubules. The false predominate over the the true and are characterized by concentric layers of calcified material.
Calcified deposits along the collagen fiber bundles or blood vessels may be observed. They are more often in the root canal portion than the coronal area.
Histology of the Cementum
Cementum is a hard connective tissue that derives from ectomesenchyme.
Embryologically, there are two types of cementum:
Primary cementum: It is acellular and develops slowly as the tooth erupts. It covers the coronal 2/3 of the root and consists of intrinsic and extrinsic fibers (PDL).
Secondary cementum: It is formed after the tooth is in occlusion and consists of extrinsic and intrinsic (they derive from cementoblasts) fibers. It covers mainly the root surface.
Functions of Cementum
It protects the dentin (occludes the dentinal tubules)
It provides attachment of the periodontal fibers
It reverses tooth resorption
Cementum is composed of 90% collagen I and III and ground substance.
50% of cementum is mineralized with hydroxyapatite. Thin at the CE junction, thicker apically.
Classification of Dental amalgam
1. By powder particle shape .
2. By total amount of copper
3.By presence of zinc
Autopsy is examination of the dead body to identify the cause of death. This can be for forensic or clinical purposes.
Constitutes the pelvic girdle
United with the vertebral column
Union of three parts that is marked by a cup shaped cavity (acetabulum) Ilium
• Prominence of the hip
• Superior border is the crest
• Anterosuperior spine-projection at the anterior tip of the crest
• Corresponding projections on the posterior part are the posterosuperior and posteroinferior iliac spines
• Greater sciatic notch-located beneath the posterior part
• Most is a smooth concavity (iliac fossa)
• Posteriorly it is rough and articulates with the sacrum in the formation of the sacroiliac joint
Anterior part of the innominate bone
Symphysis pubic-joining of the two pubic bones at the midline
Body and two rami
• Body forms one fifth of the acetabulum
• Superior ramis extends from the body to the median plane: superior border forms the pubic crest
• Inferior ramus extends downward and meets with the ischium
• Pubic arch is formed by the inferior rami of both pubic hones
Forms the lower and back part of the innominate bone
• Forms two fifths of the accrabulum
• Ischial tuberosiry-supports the body in a sitting position
• Ramus-passes upward to join the inferior ramus of rhe pubis; known as rhe obturator foramen
Fanned by the right and left hip bones, sacrum, and coccyx
o Bounded by the ilia and lower lumbar vertebrae
o Gives support to the abdominal viscera
o Brim of the pelvis corresponds to the sacral promontory
o Inferior outlet is bounded by the tip of the coccyx, ischial tuberosities, and inferior rami of the pubic bones
o Shows adaptations related to functions as a birth canal Wide outlet
o Angle of the pubic arch is obtuse
o Shows adaptations that contribute to power and speed
o Heart-shaped outlet
o Angle of the pubic arch is acute
Femur-longest and strongest bone of the body
Proximal end has a rounded head that articulates with the acetabulum
Constricted portion-the neck
Greater and lesser trochanters
Slightly arched shaft; is concave posteriorly
o Linea aspera-strengthened by this prominent ridge
o Site of attachment for several muscles
Distal end has two condyles separated on the posterior side by the intercondyloid notch
Embedded in the tendon of the quadriceps muscle
Articulates with the femur
o Proximal end has two condyles that articulate with the femur
o Triangular shaft
Distal-medial malleolus that articulates with the latus to form the ankle joint
o Articulates with the lateral condyle of the tibia but does not enter the knee joint
o Distal end projects as the lateral malleolus
Ankle, foot, and toes
Adapted for supporting weight but similar in structure to the hand
o Occupies the uppennost and central position in the tarsus
o Distributes the body weight from the tibia above to the other tarsal bones
Calcaneus (heel)-Iocated beneath the talus
Navicular-located in front of the talus on the medial side; articulates with three cuneifonn bones distally
Cuboid-lies along the lateral border of the navicular bone
o First, second, and third p1etatarsals lie in front of the three cuneifonn bones
o (2) Fourth and fifth metatarsals lie in front of the cuboid bone
o Distal to the metatarsals
o (2) Two in the great toe; three in each of the other four toes .
Longitudinal arches in the foot (2)
o Lateral-fonned by the calcaneus, talus, cuboid, and fourth and fifth metatarsal bones
o Medial-fonned by the calcaneus, talus, navicular, cuneifonn, and first, second, and third metatarsal bones
Transverse arches-formed by the tarsal and metatarsal bones
The Transition from the Deciduous to the Permanent Dentition.
1. The transition begins with the eruption of the four first permanent molars, and replacement of the lower deciduous central incisors by the permanent lower central incisors.
2. Complete resorption of the deciduous tooth roots permits exfoliation of that tooth and replacement by the permanent (successional) teeth
3. The mixed dentition exists from approximately age 6 years to approximately age 12 years. In contrast, the intact deciduous dentition is functional from age 2 - 2 /2 years of age to 6 years of age.
4. The enamel organ of each permanent anterior tooth is connected to the oral epithelium via a fibrous cord, the gubernaculum. The foramina through which it passes can be seen in youthful skulls
The deciduous second molars are particularly important. It is imperative that the deciduous second molars be preserved until their normal time of exfoliation. This prevent mesial migration of the first permanent molars.
Use a space maintainer in the event that a second deciduous molar is lost prematurely