Oropharyngeal anatomy

Questions reviewed by:

David Bainbridge VetMB MA PhD MRCVS
David Kilroy MVB CVMA MRCVS
Kirstie Pickles BVMS MSc Cert EM (Int Med) PhD Dip ECEIM MRCVS Lecturer in Equine Practice

1

Which of the following is not a primary muscle of mastication?

	Masseter muscle
	Temporal muscle
	Pterygoid muscle
	Zygomaticus muscle
	Digastricus muscle
Please select an option Incorrect. The masseter muscles are jaw closing muscles and so are important in mastication. They are derived from the first visceral arch and are innervated by the mandibular branch of the trigeminal nerve. They originate from the maxillary region of the skull and zygomatic arch and insert on the caudal side of the mandible. WikiVet Article: Mastication Incorrect. The temporal muscles are jaw closing muscles and so are important in mastication. They are derived from the first visceral arch and are innervated by the mandibular branch of the trigeminal nerve. They originate from the lateral surface of the cranium and insert on the coronoid process. WikiVet Article: Mastication Incorrect. The lateral and medial pterygoid muscles are jaw closing muscles and so are important in mastication. They are derived from the first visceral arch and are innervated by the mandibular branch of the trigeminal nerve. The lateral pterygoid muscle originates from the pterygopalantine region of the skull and inserts on the lateral aspect of the mandible. The medial pterygoid muscle originates from the pterygopalantine region of the skull and inserts on the medial aspect of the mandible. WikiVet Article: Mastication Correct! The zygomaticus muscles purse the lips and are primarily muscles of facial expression. WikiVet Article: Mastication Incorrect. The digastricus muscles are jaw opening muscles and so are important in mastication. There are two muscle bellies; the cranial muscle belly is derived from the first visceral arch and is innervated by the mandibular branch of the trigeminal nerve and the caudal muscle belly is derived from the second visceral arch and is innervated by the facial nerve. They originate from the paracondylar process of the occipital bone and insert on the angle of the mandible. WikiVet Article: Mastication

2

Which tongue papillae are particularly well developed in the cat and give the tongue its rough texture?

	Vallate
	Foliate
	Filiform
	Conical
	Fungiform
Please select an option Incorrect. Vallate (or circumvallate) papillae are large papillae found in a row forming in inverted 'V' towards the base of the tongue, taste buds are found on the side of these papillae. They are no more developed in cats than in other species. The correct answer is filiform papillae. WikiVet Article: Tongue Incorrect. Foliate papillae are found on the caudal third of the tongue, either side of the midline and they are covered in taste buds. They are no more developed in cats than in other species. The correct answer is filiform papillae. WikiVet Article: Tongue Correct! Filiform papillae form backward-facing hooks which help hold food and in the cat they are very well developed to provide the abrasiveness needed for self-grooming. These papillae do not have taste buds. WikiVet Article: Tongue Incorrect. Conical papillae are found on the caudal third of the tongue interspersed between filiform papillae and they do not have taste buds. They are no more developed in cats than in other species. The correct answer is filiform papillae. WikiVet Article: Tongue Incorrect. Fungiform papillae are the red dots seen on the rostral two thirds of the tongue and they are covered in taste buds. They are no more developed in cats than in other species. The correct answer is filiform papillae. WikiVet Article: Tongue

3

Which two muscles shorten the oropharynx?

	Cricopharyngeal and stylopharyngeal muscles
	Pterygopharyngeal and palatopharyngeal muscles
	Thyropharyngeal and palatopharyngeal muscles
	Hyopharyngeal and cricopharyngeal muscle
	Stylopharyngeal and pterygopharyngeal muscles
Please select an option Incorrect. The cricopharyngeal muscle constricts the propharynx and the stylopharyngeal muscle dilates the oropharynx. The pterygopharyngeal and palatopharyngeal muscles shorten the oropharynx. WikiVet Article: Oropharynx Correct! The pterygopharyngeal and palatopharyngeal muscles shorten the oropharynx. WikiVet Article: Oropharynx Incorrect. Although the palatopharyngeal muscle does shorten the oropharynx, the thyropharyngeal muscle constricts the propharynx. The additional muscle that shortens the oropharynx is the pterygopharyngeal muscle. WikiVet Article: Oropharynx Incorrect. The hyopharyngeal muscle constricts the propharynx and the cricopharyngeal muscle constricts the propharynx. The pterygopharyngeal and palatopharyngeal muscles shorten the oropharynx. WikiVet Article: Oropharynx Incorrect. Although the pterygopharyngeal muscle does shorten the oropharynx, the stylopharyngeal muscle dilates the oropharynx. The additional muscle which shortens the oropharynx is the palatopharyngeal muscle. WikiVet Article: Oropharynx

4

Which part of the domestic mammalian hyoid apparatus articulates with the larynx?

5

Which hyoid bone has a lingual process in horses, ruminants and pigs?

	Epihyoid bone
	Keratohyoid bone
	Thyrohyoid bone
	Stylohyoid bone
	Basihyoid bone
Please select an option Incorrect. The epihyoid bone does not have a lingual process. The basihyoid bone has a lingual process which protrudes into the roof of the tongue in horses, ruminants and pigs. It is particularly small in pigs. WikiVet Article: Hyoid apparatus. Incorrect. The keratohyoid bone does not have a lingual process. The basihyoid bone has a lingual process which protrudes into the roof of the tongue in horses, ruminants and pigs. It is particularly small in pigs. WikiVet Article: Hyoid apparatus. Incorrect. The thyrohyoid bone does not have a lingual process. The basihyoid bone has a lingual process which protrudes into the roof of the tongue in horses, ruminants and pigs. It is particularly small in pigs. WikiVet Article: Hyoid apparatus. Incorrect. The stylohyoid bone does not have a lingual process. The basihyoid bone has a lingual process which protrudes into the roof of the tongue in horses, ruminants and pigs. It is particularly small in pigs. WikiVet Article: Hyoid apparatus. Correct! The basihyoid bone has a lingual process which protrudes into the roof of the tongue in horses, ruminants and pigs. It is particularly small in pigs. WikiVet Article: Hyoid apparatus.

6

Which laryngeal muscle is the principle abductor of the arytenoids?

	Cricothyroid muscle
	Lateral cricoarytenoid muscle
	Transverse arytenoid muscle
	Thyroarytenoid muscle
	Dorsal cricoarytenoid muscle
Please select an option Incorrect. The cricothyroid muscle moves cricoid and arytenoid cartilages caudally thereby tensing the vocal folds. Contraction of the dorsal cricoarytenoid muscle dilates the larynx by abducting the arytenoid cartilage and therefore the vocal cords. WikiVet Article: Larynx Incorrect. The lateral cricoarytenoid muscle adducts the vocal processes thereby narrowing the glottis. Contraction of the dorsal cricoarytenoid muscle dilates the larynx by abducting the arytenoid cartilage and therefore the vocal cords. WikiVet Article: Larynx Incorrect. The transverse arytenoid muscle passes between the two arytenoid cartilages and it narrows the glottis. Contraction of the dorsal cricoarytenoid muscle dilates the larynx by abducting the arytenoid cartilage and therefore the vocal cords. WikiVet Article: Larynx Incorrect. The thyroarytenoid muscle alters the tension of the vocal and vestibular folds. Contraction of the dorsal cricoarytenoid muscle dilates the larynx by abducting the arytenoid cartilage and therefore the vocal cords. WikiVet Article: Larynx Correct! Contraction of the dorsal cricoarytenoid muscle dilates the larynx by abducting the arytenoid cartilage and therefore the vocal cords. WikiVet Article: Larynx

7

Which laryngeal cartilage is ring-shaped?

	Interarytenoid cartilage
	Epiglottic cartilage
	Cricoid cartilage
	Arytenoid cartilage
	Thyroid cartilage
Please select an option Incorrect. The interarytenoid cartilage is a nodule of hyaline cartilage found between the arytenoid cartilages dorsally. It is the cricoid cartilage which is ring-shaped. WikiVet Article: Larynx Incorrect. The epiglottic cartilage is leaf-shaped and is the most rostral cartilage of the larynx. It is the cricoid cartilage which is ring-shaped. WikiVet Article: Larynx Correct! The cricoid cartilage is ring-shaped. WikiVet Article: Larynx Incorrect. The arytenoid cartilages are a pair of triangular shaped cartilages which articulate with the rostral part of the ring-shaped cricoid cartilage. WikiVet Article: Larynx Incorrect. The thyroid cartilage forms most of the floor of the larynx. It is the cricoid cartilage which is ring-shaped. WikiVet Article: Larynx

8

What is the permanent dental formula of a dog?

	2 (I3/3 C1/1 P3/3 M3/2)
	2 (I3/3 C1/1 P3/3 M2/3)
	2 (I3/3 C1/1 P4/4 M3/3)
	2 (I3/3 C1/1 P4/4 M2/3)
	2 (I3/3 C1/1 P4/4 M3/2)
Please select an option Incorrect. The incisors and canines are correct but dogs have four upper and four lower premolars and two upper and three lower molars in each half of their mouth. The dental formula should read 2 (I3/3 C1/1 P4/4 M2/3). WikiVet Article: Dental Formula - Dog Incorrect. The incisors, canines and molars are correct but dogs have four upper and four lower premolars in each half of their mouth. The dental formula should read 2 (I3/3 C1/1 P4/4 M2/3). WikiVet Article: Dental Formula - Dog Incorrect. The incisors, canines and premolars are correct but dogs have two upper and three lower molars in each half of their mouth. The dental formula should read 2 (I3/3 C1/1 P4/4 M2/3). WikiVet Article:Dental Formula - Dog Correct! Dogs have three upper and three lower incisors, one upper and one lower canine, four upper and four lower premolars and two upper and three lower molars in each half of their mouth. WikiVet Article: Dental Formula - Dog Incorrect. The incisors, canines and premolars are correct but dogs have two upper and three lower molars in each half of their mouth. The dental formula should read 2 (I3/3 C1/1 P4/4 M2/3). WikiVet Article: Dental Formula - Dog

9

What is the permanent dental formula of a cat?

	2 (I 3/3, C 1/1, P 2/2, M 1/1)
	2 ( I 3/3, C 1/1, P 3/3, M 1/1)
	2 ( I 3/3, C 1/1, P 3/2, M 1/1)
	2 ( I 3/3, C 1/1, P 3/2, M 2/2
	2 ( I 3/3, C 1/1, P 2/3, M 1/1)
Please select an option Incorrect. The incisors, canines and molars are correct but cats have three upper and two lower premolars in each half of their mouth. The dental formula should read 2 (I3/3 C1/1 P3/2 M1/1). WikiVet Article: Dental Formula - Cat Incorrect. The incisors, canines and molars are correct but cats have three upper and two lower premolars in each half of their mouth. The dental formula should read 2 (I3/3 C1/1 P3/2 M1/1). WikiVet Article: Dental Formula - Cat Correct! Cats have three upper and three lower incisors, one upper and one lower canine, three upper and two lower premolars and one upper and one lower molar in each half of their mouth. WikiVet Article: Dental Formula - Cat Incorrect. The incisors, canines and premolars are correct but cats have one upper and one lower molar in each half of their mouth. The dental formula should read 2 (I3/3 C1/1 P3/2 M1/1). WikiVet Article: Dental Formula - Cat Incorrect. The incisors, canines and molars are correct but cats have three upper and two lower premolars in each half of their mouth. The dental formula should read 2 (I3/3 C1/1 P3/2 M1/1). WikiVet Article: Dental Formula - Cat

10

You are performing a dental on an eight year old dog in your practice and you decide to extract the dog's upper right second premolar. How would you identify this tooth using the modified Triadan system?

	206
	106
	407
	307
	506
Please select an option Incorrect. This is the upper left second premolar. The correct answer is 106. Link to Veterinary Dentistry Correct! This digit 1 denotes the quadrant i.e. the right upper permanent quadrant. Digits 0 and 6 denote the tooth position within the quadrant and the second premolar is the sixth tooth along from the midline. Link to Veterinary Dentistry Incorrect. This is the lower right second premolar. The correct answer is 106. Link to Veterinary Dentistry Incorrect. This is the lower left second premolar. The correct answer is 106. Link to Veterinary Dentistry Incorrect. This number correctly identifies the upper right second premolar, but the digit 5 denotes the right upper deciduous quadrant and since this is an eight year old dog it will have permanent teeth. The correct answer is 106. Link to Veterinary Dentistry

11

What is the permanent dental formula of a horse?

	2 (I 3/ 3, C 1/ 1, P 3-4/ 3, M 3/ 3)
	2 ( I 3/ 3, C 1/ 1, P 4/ 4 M 3/ 3)
	2 ( I 3/ 3, C 1/ 1, P 3/ 3-4, M 4/ 4)
	2 (I 3/ 3, C 1/ 1, P 3/ 3, M 3/ 3)
	2 ( I 3/ 3, C 1/ 1, P 3-4/ 3, M 4/ 4)
Please select an option Correct! In the horse, upper premolar one, or the wolf tooth, is often lacking, hence the upper dental formula of P 3-4. Horses have three upper and three lower molar teeth on each side, which work in a unit along with their premolars. Females usually don't have canines so the formula is often written 1(0)/ 1(0) for mares. WikiVet Article: Dental Formula - Horse Incorrect. The horse only has three lower premolars but usually has an extra upper premolar i.e. premolar one or the wolf tooth. The dental formula should read 2 (I 3/ 3, C 1/ 1, P 3-4/ 3, M 3/ 3).Females usually don't have canines so the formula is often written 1(0)/ 1(0) for mares. WikiVet Article: Dental Formula - Horse Incorrect. The horse only has three lower premolars but usually has an extra upper premolar i.e. premolar one, or the wolf tooth. Also horses have three lower and three upper premolars so thedental formula should read 2 (I 3/ 3, C 1/ 1, P 3-4/ 3, M 3/ 3). Females usually don't have canines so the formula is often written 1(0)/ 1(0) for mares. WikiVet Article: Dental Formula - Horse Incorrect. Although this dental formula may be correct for many horses, most horses have an extra upper premolar i.e. premolar one, or the wolf tooth. The dental formula should read 2 (I 3/ 3, C 1/ 1, P 3-4/ 3, M 3/ 3). Females usually don't have canines so the formula is often written 1(0)/ 1(0) for mares. WikiVet Article: Dental Formula - Horse Incorrect. Horses have three lower and three upper molars. The dental formula should read 2 (I 3/ 3, C 1/ 1, P 3-4/ 3, M 3/ 3). Females usually don't have canines so the formula is often written 1(0)/ 1(0) for mares. WikiVet Article: Dental Formula - Horse