Muscular System 2 Flashcards
What is the primary focus of Module 2 in Anatomy & Physiology?
The muscular system
This module covers the functional groups of muscles.
What are the learning outcomes for topic 2.2a?
Identify selected muscles of the head, face, and neck; Describe the actions of the muscles moving the head, face, and neck
What are the muscles involved in facial expression called?
Muscles of facial expression
What is unique about the insertion of muscles of facial expression?
They insert into the skin rather than onto bones
What is the function of orbicularis oculi?
Closes the eye, assists with blinking and squinting
Which cranial nerve innervates orbicularis oculi?
Facial nerve - cranial nerve number 7
What action is performed by zygomaticus major?
Raises the corners of the mouth to smile
What muscle assists with smiling by drawing the corner of the lip laterally?
Risorius
What is the role of orbicularis oris?
Closes the lips and allows for puckering
What muscle compresses the cheek during sucking or whistling?
Buccinator
What is the main function of the temporalis muscle?
Closes the jaw and maintains jaw position at rest
What muscle is considered the prime mover for closing the jaw?
Masseter
What distinguishes a Duchenne smile from a non-Duchenne smile?
Duchenne smile involves contraction of orbicularis oculi, indicating genuine happiness
Which muscle is responsible for head flexion?
Sternocleidomastoid
What are the origins of the sternocleidomastoid muscle?
Sternal and clavicular
What do the scalene muscles assist with?
Lateral flexion of the neck and elevating the first and second rib during breathing
What is the action of the splenius capitis muscles when contracted bilaterally?
Extends or hyperextends the head
What is the relationship between sternocleidomastoid and splenius capitis?
They are antagonists to each other
What general rule applies to muscles crossing joints?
Anterior side produces flexion; posterior side produces extension
In the upper limb, where are flexors typically located?
Anterior compartment
Which muscles produce knee extension?
Quadriceps muscles
Which muscles produce knee flexion?
Hamstrings
What is the exception to the rule regarding anterior and posterior compartments in the lower limb?
Lower limb extensors are located in the anterior compartment and flexors in the posterior compartment
What muscles work synergistically to create a smile?
Risorius and zygomaticus major
How many key muscles are involved in mastication and facial expression?
7 key muscles
What is the role of splenius muscles in head movement?
Antagonists to sternocleidomastoid in head flexion but prime movers for head extension
What is the general rule regarding functional groups and regional compartments?
Anterior compartment = flexors; posterior compartment = extensors, with exceptions at the hip
