++
OBJECTIVES
This chapter should help the student to:
Name the parts of the digestive tract and the primary function of each.
Describe the structure of the tongue, teeth, and gingiva.
Describe the development of the teeth.
Compare the digestive tract organs in terms of the four layers comprising their walls and relate any structural variations to differences in organ function.
Describe the distinguishing regional structure of each digestive tract component.
Name the secretory product(s), the distinguishing structural features, and (where appropriate) the staining properties of each secretory cell type in the digestive tract mucosa.
List the features of the small intestine that promote nutrient absorption and trace the steps in this process.
Identify the organ, region, cell types present, and type of section (i.e., transverse or longitudinal) in a micrograph of any part of the digestive tract.
+++
MAX-Yield™ STUDY QUESTIONS
++
List the digestive tract organs in the order food passes them (I.A1). What happens to the food in each (I.C.1–3)?
Sketch a cross-section of a generalized tubular organ of the digestive tract that shows the layered structure of its walls (Fig. 15–1 B; I.B.1–4) and indicate the location of the following:
Lumen
Mucosa
Submucosa
Muscularis externa
Serosa
Epithelium
Lamina propria
Muscularis mucosae
Submucosal (Meissner’s) plexus
Myenteric (Auerbach’s) plexus
Mesothelium
Attachment of the mesentery
Describe the oral cavity in terms of its epithelial lining, the muscle type in its walls, and the structural difference between the hard and soft palates (II.A).
Describe the tongue in terms of its predominant tissue and the epithelium that covers it (II.C).
Name the four types of lingual papillae and compare them in terms of their characteristic shape, taste bud distribution, and relative abundance (II.C.1–4).
List the four types of teeth (by shape) found in humans (III.A).
Compare the “dental formula” for permanent and deciduous teeth (III.B).
Sketch a tooth and its surrounding structures in sagittal (midline longitudinal) section (Fig. 15–2) and label the following:
Gingiva
Alveolar bone
Crown
Neck
Root
Apical foramen
Enamel
Cementum
Dentin
Pulp
Periodontal ligament
Epithelial attachment (of Gottlieb; III.D.3)
Compare dentin, enamel, and cementum (III.C.5–7) in terms of:
Hardness
Porosity
Collagen content
Cell responsible for synthesis
Capacity for replacement
Describe tooth pulp in terms of its predominant tissue, major cell types, blood supply, and innervation (III.C.4 and 5.b; Fig. 15–2).
Describe the periodontal ligament in terms of its composition, location, functions, attachments, and the effects of dietary vitamin C and protein deficiency (III.D.1; Fig. 15–2).
Compare ameloblasts, odontoblasts, and cementoblasts in terms of their embryonic origin (III.E), the layer of tooth structure formed by each (III.E), and their survival into adulthood (III.C.5.c, 6.c, and 7).
Beginning with the dental laminae, name, in order, the stages of crown development (Fig. 15–3; III.E.1).
Sketch a developing tooth in the bell stage (Fig. 15–3) and label the following:
Ameloblasts
Odontoblasts
Enamel organ
Inner enamel epithelium
Outer enamel epithelium
Stellate ...