Lab 14 Muscles Overview. Muscle Labs Most of the labs for the next two weeks will consist of looking...
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Transcript of Lab 14 Muscles Overview. Muscle Labs Most of the labs for the next two weeks will consist of looking...
Lab 14
Muscles Overview
Muscle Labs
• Most of the labs for the next two weeks will consist of looking at models and diagrams to learn the muscles.
• The models will be the same models used on the practical quizzes
• I will post these lectures on the website
Muscle Practical
• Tuesday 11/20• 50 points• Covers all the muscles on the Muscle List
(available on the website and in the syllabus:– head and face; neck; chest; abdominal; and back and
shoulder , upper arm; lower arm; hip and thigh; upper leg; and lower leg
– You need to know origins and insertions for the ones listed in bold only
– Know general functions• Uses about half models (little men, torsos, hand,
foot, arms, legs) and half B&W book pictures
Muscle exam
• The muscle exam will include some muscle labeling from the first half of the muscles
Divisions of the Muscular System
1. Axial muscles:– position head and spinal column– move rib cage– 60% of skeletal muscles
2. Appendicular muscles:– support pectoral and pelvic girdles– support limbs– 40% of skeletal muscles
Origins and Insertions
• Muscles have 1 fixed point of attachment (origin) and 1 moving point of attachment (insertion)
• Most muscles originate or insert on the skeleton
• Origin is usually proximal to insertion
Origin and Insetaions
• Fixed end in (b) below is the origin, while moving end is the insertion
Figure 10–13
Actions
• Movements produced by muscle contraction
• Body movements – e.g., flexion, extension, adduction, etc.
• Described in terms of bone, joint, or region
Muscle Interactions
• Muscles work in groups to maximize efficiency
• Smaller muscles reach maximum tension first, followed by larger, primary muscles
Muscle Terminology Based on Function
• Agonist (prime mover):– produces a particular movement
• Antagonist:– opposes movement of a particular agonist
Muscle Terminology Based on Function
• Synergist:– a smaller muscle that assists a larger agonist– helps start motion or stabilize origin of agonist
(fixator)
Muscle Opposition
• Agonists and antagonists work in pairs:– when 1 contracts, the other stretches– i.e., flexors–extensors, abductors–adductors,
etc.
How does the name of a muscle help identify its location, appearance, or
function?
Names of Skeletal Muscles
• Correct names of muscles include the term muscle
• Exceptions: – platysma– diaphragm
Descriptive Names for Skeletal Muscles
1. Location in the body
2. Origin and insertion
3. Fascicle organization
4. Relative position
5. Structural characteristics
6. Action
Location in the Body
• Identifies body regions:– e.g., temporalis muscle
Origin and Insertion
• First part of name indicates origin
• Second part of name indicates insertion:– e.g., genioglossus muscle
Fascicle Organization
• Describes fascicle orientation within muscle:– rectus (straight) = parallel to body or limb– transversus = perpendicular to the midline– oblique
Relative Position
• Externus (superficialis):– visible at body surface
• Internus (profundus):– deep muscles
• Extrinsic:– muscles outside an organ
• Intrinsic:– muscles inside an organ
Structural Characteristics
• Number of tendons (or heads):– bi = 2, tri = 3
• Shape: – trapezius, deltoid, rhomboid
• Size…
Names for Muscle Size (1 of 2)
• Longus = long
• Longissimus = longest
• Teres = long and round
• Brevis = short
• Magnus = large
Names For Muscle Size (2 of 2)
• Major = larger
• Maximus = largest
• Minor = small
• Minimus = smallest
Action
• Movements: – e.g., flexor, extensor, retractor
• Occupations or habits: – e.g., risor = laughter
Naming Skeletal Muscles
Table 11–1 (1 of 2)
Naming Skeletal Muscles – contiuned
Table 11–1 (2 of 2)
Lab 14
• Examine muscle structure
• Look at and draw NMJ slide
• Drawing and Reviews Sheet due next week
• Due next Thursday