Muscles can be classified in four functional groups. Please list a definition of each of the following terms: – agonist (prime mover) -antagonist -synergist -fixator 2 The names of muscles often make a lot of sense. For each of the following categories, name one of the muscles off of our list of 17 muscles that fits the criteria. – named for a nearby bone – named for the number of origins – named for the location of the attachments – named for the muscle size 3. Let’s say your neighbor went to the eye doctor yesterday and they told her that her vision was 20/40. What exactly do they mean by this? In addition, define the terms: myopia, hyperopia, and presbyopia. Which one of these terms would relate to your neighbor’s eye condition?
The Correct Answer and Explanation is:
1. Muscle Functional Groups Definitions:
- Agonist (Prime Mover): A muscle primarily responsible for producing a specific movement. It contracts to initiate and execute the desired action.
- Antagonist: A muscle that opposes the action of the agonist. It relaxes while the agonist contracts, helping to control the movement and prevent injury.
- Synergist: A muscle that assists the agonist by adding extra force or reducing unnecessary movement, thereby ensuring smooth motion.
- Fixator: A muscle that stabilizes the origin of the agonist or a joint during movement. It prevents unwanted movement in other parts of the body.
2. Muscle Names Based on Characteristics:
- Named for a nearby bone: Temporalis — located near the temporal bone.
- Named for the number of origins: Biceps brachii — “bi-” indicates two origins.
- Named for the location of the attachments: Sternocleidomastoid — attaches to the sternum, clavicle, and mastoid process.
- Named for muscle size: Gluteus maximus — “maximus” denotes it as the largest of the gluteal muscles.
3. Understanding 20/40 Vision and Eye Conditions:
A vision measurement of 20/40 means that the individual sees at 20 feet what a person with normal vision can see at 40 feet. This indicates reduced visual acuity, suggesting a need for corrective lenses or further evaluation.
Myopia is nearsightedness, where distant objects appear blurry because light focuses in front of the retina.
Hyperopia is farsightedness, where close objects are blurry because light focuses behind the retina.
Presbyopia is an age-related condition where the lens becomes less flexible, making it hard to focus on close objects.
For a person with 20/40 vision, the likely condition is myopia, especially if distant vision is the primary issue. This is common and can usually be corrected with glasses, contact lenses, or refractive surgery.
