Labs 17 + 18
Muscles
Bone Practical
•
•
•
•
Wed 7/11 @ 8am
40 – 50 stations
About half axial, half appendicular bones
Disarticulated bones: Skulls, partial skulls,
vertebrae, ribs, skeletons, arm bones, leg
bones, hand, foot, os coxa, sternum,
clavicle, scapula
• Know names and locations of all bones
and bone parts on the list
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
Final Practical
• Covers head and face; neck; chest;
abdominal; and back and shoulder, upper
arm; lower arm; hip and thigh; upper leg;
and lower leg
• Brain and cranial nerves
Quiz format
• 40+ stations, about half with models and
half with B/W photocopies of figures
straight out of your book.
• 50 pts, plus bonuses
• Know locations, origins and insertions
(for the ones in bold on the muscle list)
and general functions
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.
2.
3.
4.
5.
6.
Location in the body
Origin and insertion
Fascicle organization
Relative position
Structural characteristics
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 17
• Do the three activities, which include:
– Draw the sarcomere (use space at bottom of
page 239
• Due next week in lab
Lab #18
Muscles of the Head and Neck
Quiz 8 – Muscles I
• Next week: on head and face; neck; chest;
abdominal; and back and shoulder (20 pts)
Quiz format
• 20+ stations, about half with models and
half with B/W photocopies of figures
straight out of your book.
• 20 pts, plus bonuses
• Know locations, origins and insertions (for
the ones in bold on the muscle list) and
general functions (though you will need
to know functions mostly for the exam).
What are the principle
axial muscles of the body,
their origins, insertions,
actions, and innervation?
The Axial Muscles
• Divisions based on location and function:
– muscles of head and neck
– muscles of vertebral column
– oblique and rectus muscles
– muscles of pelvic floor
6 Muscle Groups of
the Head and Neck
• 1. Muscles of facial expression:
– originate on skull
• 2. Extrinsic (outside) eye muscles:
(don’t need to know)
6 Muscle Groups of
the Head and Neck
• 3. Muscles of mastication:
– move the mandible
• 4. Muscles of the tongue:
– names end in glossus (FYI)
• 5. Muscles of the pharynx:
– begin swallowing process (FYI)
6 Muscle Groups of
the Head and Neck
• 6. Anterior muscles of the neck:
– control position of larynx
– depress the mandible
– support tongue and pharynx
Muscles of Facial Expression
• Orbicularis oris:
– constricts the mouth opening
• Buccinator:
– moves food around the cheeks
• Corrugator supercilli – wrinkles forehead
• Orbicularis oculi – sphincter of eye
Others
• Zygomaticus – pull skin of mouth up and
out when smiling
• Levator labii superiorus – raises upper
lip
• Depressor labii inferiorus – “pouting”
muscle
Muscles of the
Epicranium (Scalp)
• Temporoparietalis
• Occipitofrontalis:
– frontal and occipital bellies
– separated by epicranial aponeurosis
• Platysma:
– covers anterior surface of neck
Muscles of Facial Expression
Figure 11–4a
Muscles of Facial Expression
Figure 11–4b
Summary: Muscles of
Facial Expression
Table 11–2 (1 of 2)
Summary: Muscles of
Facial Expression
Table 11–2 (2 of 2)
3 Muscles of Mastication
• Masseter:
– the strongest jaw muscle
• Temporalis:
– helps lift the mandible
• Pterygoid muscles (FYI):
– position mandible for chewing
Muscles of Mastication
Figure 11–6
Summary: Muscles of
Mastication
Table 11–4
Muscles of the Tongue
Don’t need to
know any of
these
Figure 11–7
Muscles of the Neck
• Digastric:
– from chin to hyoid
– also hyoid to mastoid
• Platysma:
– covers anterior surface of neck
• Sternocleidomastoid:
– from clavicle and sternum to mastoid
Anterior Muscles of the Neck
Figure 11–9
Summary:
Anterior Muscles of the Neck
Table 11–7
Today: Lab #18
• Examine the relevant muscles of the
head, jaw, and neck
• Remember: if it’s not on the list, you don’t
have to locate it or write about it in the lab
report
• Lab report for #18 due next week