In: Anatomy and Physiology
1. The respiratory diaphragm is a
a. hypaxial muscle
b. expaxial mucle
c. smooth muscle
d. spinchter muscle
2. The pharyngeal constrictor muscles are derived from which arch?
a. arch 3
b. arch 4-6
c. arch 2
d. arch 1
3. The brain develops from the folding and expansion of the notochord
a. true
b. false
Question 1:
Answer: Option a
Explanation: The muscle which is located in the ventral aspect of the horizontal septum of vertebrae is called as Hypaxial muscle. Diaphragm is located ventral to the horizontal septum so it is Hypaxial.
Question 2:
Answer: Option b
Explanation: There are three Pharyngeal constrictors they are superior, middle and inferior Pharyngeal constrictors. There are 5 pharyngeal arches present in the embryo. In that arch 4 derives the Pharyngeal constrictors. The main function of this muscles are contraction of pharynx for the peristaltic movement.Arch 5 does not derive anything and arch 6 derives the laryngeal muscles.
Question 3:
Answer: False
Explanation: The brain get develops from the neural tube not from notochord. The process of formation of neural tube is called Neurulation. In that process the vertebral embryo get fold and the neural plate is transformed into neural tube and it leads to formation of central nervous system such as brain and spinal cord.