Gustation

Describe the process of swallowing? Indicate the phases and which phases are voluntary and involuntary?

1. Voluntary Phase: Bolus of food is pushed by tongue against hard palate and then moves toward oropharynx. 2. Pharyngeal Phase (involuntary): As bolus moves into oropharynx, the soft palate closes off nasopharynx, the epiglottis closes over laryngeal opening. 3. Esophageal phase (involuntary): Esophageal muscle contractions push bolus toward the stomach, soft palate and epiglottis return to their pre-swallowing positions.

What percent of the volume of saliva is water?

99% Volume of saliva secreted daily ranges between 1 and 1.5L

Which type of papillae are distributed on the anterior two‐thirds of the tongue surface and does not house taste buds and has no sensory role in gustation? A. Filiform B. Fungiform papillae C. Vallate (circumvallate) papillae D. Foliate

A. Filiform

Describe the tongue?

An accessory digestive organ that is formed from skeletal muscle and covered with lightly keratinized stratified squamous epithelium Manipulates and mixes ingested materials during chewing and Helps compress the partially digested materials against the palate to turn these materials into a bolus, which is a globular mass of partially digested material. It Performs important functions in swallowing The Inferior surface of the tongue attaches to the floor of the oral cavity by a thin vertical mucous membrane, the lingual frenulum Numerous small projections (papillae) cover the superior (dorsal) surface The Posterior surface contains lingual tonsils

The palate is composed of an anterior part and a posterior part. What is the difference between the two?

Anterior two‐thirds of the palate is hard and bony (hard palate) Posterior one‐third is soft and primarily composed of skeletal muscle (soft palate)

Which type of papillae are primarily located on the tip and sides of the tongue and contain only a few taste buds each? A. Filiform B. Fungiform papillae C. Vallate (circumvallate) papillae D. Foliate

B. Fungiform papillae

Which type of papillae are least numerous yet the largest and are arranged in an inverted V shape on the posterior dorsal surface of the tongue? Each of this type of papillae is surrounded by a deep, narrow depression and most of our taste buds are housed within the walls of papillae. A. Filiform B. Fungiform papillae C. Vallate (circumvallate) papillae D. Foliate

C. Vallate (circumvallate) papillae

Which type of papillae are not well developed on the human tongue, extend as ridges on the posterior lateral sides, and house only a few taste buds during infancy and early childhood? A. Filiform B. Fungiform papillae C. Vallate (circumvallate) papillae D. Foliate

D. Foliate

The more posteriorly placed permanent teeth tend to appear first, followed by the anteriorly placed teeth in development. True or False?

False. The opposite is true.

What is the function of Saliva?

Moistens ingested food and helps turn it into a semisolid bolus that is more easily swallowed Moistens and cleanses the oral cavity structures First step in chemical digestion occurs when amylase in saliva begins to break down carbohydrates. Contains antibodies and an antibacterial element called lysozyme that helps inhibit bacterial growth in the oral cavity Watery medium into which food molecules are dissolved so taste receptors can be stimulated

What nerves that serve the salivary glands?

Parasympathetic axons in CN IX stimulate parotid salivary gland secretions. Parasympathetic axons in CN VII stimulate submandibular and sublingual salivary gland secretions Sympathetic stimulation from cervical ganglia stimulates mucus secretion

Which salivary gland only secretes serous secretions and not mucous?

Parotid gland. Submandibular and Sublingual have both mucous and serous secretions.

Bolus is mixed and moved down the GI tract by?

Peristalsis and Segmentation

Which salivary gland produces the least amount of saliva?

Sublingual Glands

What role do supporting cells and basal cells play in olfaction or the sense of smell?

Supporting cells sandwich the olfactory nerves and sustain and maintain the receptors Basal cells function as stem cells to replace olfactory epithelium components

Which salivary gland is the largest?

The parotid gland

What are olfactory neurons?

They are also called olfactory receptor cells. These cells detect odors.

Skeletal muscles move the tongue. True or False?

True.

In an infant, 20 ___________, also called ________, erupt between 6 months and 30 months after birth.

deciduous teeth; milk teeth

Roots of the teeth fit tightly into __________, which are sockets within the alveolar processes of both the maxillae and the mandible

dental alveoli

When swallowing, the soft palate and the uvula _________ to close off the opening of the nasopharynx

elevate

What anchors a tooth to the jaw?

exposed crown, a constricted neck, and one or more roots

List the 4 types of lingual papillae (papillae of the tongue)?

filiform; fungiform; vallate; foliate

Fauces are bounded by paired muscular folds: What are the folds?

glossopalatine arch (anterior fold) pharyngopalatine arch (posterior fold)

Collectively, the roots, the dental alveoli, and the periodontal ligament that binds the roots to the alveolar processes form a ______________.

gomphosis joint

What are the three pairs of large, multicellular salivary glands?

parotid glands submandibular glands sublingual glands

The tongue detects five basic taste sensations. List them?

salty - Limited in concentrated forms in nature, so important to detect, preference may be learned in humans sweet - response to glucose, inverse relationship between sensitivity and body size (doesn't apply to humans). Maybe related to gut size. Smaller the gut, greater sensitivity to sweetness. sour - Response to acidity, works closely with sweetness to assess ripeness. bitter - Response to alkalinity, typically avoided due to the association with toxic secondary compounds, yet secondarily sought after by humans for other side effects. umami - Or savoriness, a response to glutamic acid. Least understood, MSG used as a flavor enhancer.

Which salivary gland provides the most saliva?

submandibular gland

Describe the oral cavity or mouth?

• Entrance to the GI tract • Initial site of mechanical digestion (via mastication) and chemical digestion (via enzymes in saliva) • Bounded anteriorly by the teeth and lips and posteriorly by the oropharynx • Superior boundary is formed by the hard and soft palates • Floor, or inferior surface, of the oral cavity contains the tongue as well as the mylohyoid muscle covered with mucosa • Vestibule is the space between the cheeks or lips and the gums • The lateral walls are formed by the cheeks (buccinator muscle) • Lips (labia) • Gingivae, or gums • Labial frenulum