anatomy exam part 2
There are 3 subgroups (state the subgroups) that make up the superficial muscles and help with maintaining posture. These subgroups are known collectively as the erector spinae
3 subgroups iliocostalis longissimus spinalis Don't forget the quadratus lumborum; it connects from the twelfth rib to the iliac crest and also extends the spine
Most parts of the sarcomere shorten during contraction, but what part of the sarcomere stays the same size during contraction?
A Band
What is the I band of the sarcomere?
Actin filaments, Z discs, and connectin - but no overlap with thick filaments.
Of the three systems that make energy for muscle cells, which one uses oxygen and makes the most ATP?
Aerobic cellular respiration
levator ani
+ coccygeus = pelvic diaphragm consists of iliococcygeus and pubococcygeus inferior to coccygeus support abdominal organs inferiorly, forming muscular wall that prevents organs from slipping through opening in pelvis
coccygeus
+ levator ani = pelvic diaphragm superior to levator ani support abdominal organs inferiorly, forming muscular wall that prevents organs from slipping through opening in pelvis
Put the steps of cross-bridge cycling in the order they occur, starting with formation of cross-bridges between myosin and actin.
Cross-bridge formation (myosin binds to actin) Myosin head pulls and slides actin filament, myosin releases ADP and Pi Myosin head binds ATP and releases from actin. Myosin head resets as it breaks down ATP into ADP and Pi.
What is the 'neuro' part of the neuromuscular junction?
It's the axon terminal of a motor neuron that contacts the muscle cell.
Pterygoids
Origin: Pterygoid plate, greater wing of sphenoid (L), maxilla (M) .Insertion: Mandible.Action: Moves jaw from side to side, protracts, "excursions"
temporalis
Origin: Temporal fossa. Insertion: Mandible. Action: Closes jaw, retracts mandible.
Masseter
Origin: Zygomatic arch. Insertion: lateral side of mandible. Action: Primer mover of jaw-moving muscle group; elevates and protracts jaw.
Thoracic muscles and breathing
Scalenes, intercostals, and diaphragm. Understand that these muscles are synergists; be able to state the prime mover of the group.
Why is skeletal muscle rich in blood vessels and innervation?
Skeletal muscles need to bring in a lot of oxygen and nutrients and quickly remove wastes to function properly. Nerves allow us to control contraction consciously.
What does the sarcoplasmic reticulum do in muscle cells?
Stores calcium and releases it when the action potential travels into the T tubule.
Two sets of trunk muscles are responsible for moving the vertebral column and keeping us upright.
The deep group (intertransversarii, rotatores, multifidus, and interspinales muscles) connect from one vertebrae to the next, and allow the spine to extend, rotate, land laterally flex. Deep group: from vertebra to vertebra - Superficial group extend from vertebrae to ribs
The muscle fibers arranged in the orbicularis oculi have a circular arrangement -- what does this mean?
They are arranged in a ring around an opening.
What do you know to be true for "slow oxidative fibers"?
They use aerobic respiration to make ATP, are a darker red color because they have myoglobin, and usually have slower contractions than fast fibers.
The occipitofrontalis muscle has its origin on the occipital bone and inserts into the skin of the eyebrows and nose. What would you expect its action to be?
To wrinkle the forehead, as it moves the scalp and eyebrows.
lateral compartment muscles
abducts thigh
medial compartment muscles
adduct thigh
The muscle whose action is opposite that to the action of the agonist is the _____.
antagonist
tibialis anterior
anterior compartment dorsiflex, invert
extensor digitorum longus
anterior compartment extend toes
rectus abdominis
anterior most; deep to rectus sheath muscle more medial
Where is the rectus abdominus located?
anterior-most part of the abdominal wall, under the rectus sheath.
The erector spinae muscles (spinalis, longissimus, and iliocostalis)
are the superficial trunk muscles that maintain posture and keep the spine erect.
dorsiflex
bend foot toward upper surface (point toes up)
mastication
chewing. Involves elevation/depression of the mandible and excursion to grind the teeth together, TMJ• Act with the muscles of hyoid in movement of the mandible • Muscles of the cheek and tongue aid mastication by pushing the food under the teeth• Masseter, temporalis, lateral and medial pterygoids
pelvic diaphragm
coccygeus+levator ani support abdominal organs inferiorly, forming muscular wall that prevents organs from slipping through opening in pelvis
internal obliques
deep to external oblique and rectus abdominis, between external oblique and transversus more lateral when unilaterally contracted, laterally flex vertebral column rotates vertebral column to opposite side of contracting muscles
transversus abdominis
deepest abdominal muscle more lateral when unilaterally contracted, laterally flex vertebral column rotates vertebral column to opposite side of contracting muscles
Which one of the following muscles is most likely to be involved in a frown?
depressor anguli oris
The following muscles are all used in breathing. Which one is the prime mover?
diaphragm
prime mover
diaphragm
Intrinsic muscles:
entirely within the tongue and allow change in shape•
lateral compartment
evertors with some plantar flexion
quadriceps
extend
anterior compartment muscles
extend knee/flex thigh
As part of the posterior compartment muscles of the thigh, the hamstrings
extend the hip
triceps brachii
extends elbow and shoulder, adducts arm
general actions of posterior group
extension of wrist, hand, fingers
gracilis
flex
hamstrings
flex
posterior compartment
flex
sartorius
flex
posterior compartment muscles
flex knee or extend thigh
Generally speaking, the anterior arm muscles (ie, biceps brachii)
flex the elbow
brachialis
flexes elbow
brachioradialis
flexes elbow
biceps brachii
flexes shoulder and elbow, supinates forearm and hand
general actions of anterior group of muscles in forearm
flexion, abduction adduction little pronation
plantar flex
foot moves downward away from body (point toes down)
Which set of muscles moves the tongue?
genioglossus, palatoglossus, styloglossus
retinacula of forearm
help hold tendons close to bone
Extrinsic muscles:
insert in tongue and allow change in shape and movement
The _____ is the more mobile end of the muscle.
insertion
anterior compartment
invertors
rotation and abduction
lateral and posterior groups
fibularis longus
lateral compartment evertors with some plantar flexion
gastrocnemius
lateral compartment evertors with some plantar flexion
prime mover
masseter
Due to its size and locations of its origin and insertion, the trapezius muscle has multiple actions. One of those actions is
moves/stabilizes the scapula.
flexion
musclmuscles deep within neck along anterior/lateral margins of vertebral bodies
What protein will you find in thick filaments?
myosin
tensor fasciae latae
origin - anterior superior iliac spine insertion - lateral condole of tibia abducts, medial rotation
hyoglossus
origin - hyoid bone depresses/retract tongue
iliopsoas
origin - iliac fossa of pelvis insertion - lesser trochanter of femur adduct and flex
gluteus maximus
origin - ilium and sacrum insertion - femur and iliotibial tract extend, rotate
sartorius
origin - immediately below anterior superior iliac spine insertion - upper medial of shaft of tibia flex thigh and flex knee
palatoglossus
origin - inferior surface of palatine aponeurosis lifts back of tongue
biceps femoris (hamstring)
origin - is hail tuberosity of os coxa insertion - lateral side of head of fibula extend thigh, move knee
semitendinosus (hamstring)
origin - ischial tuberosity insertion - proximal end of tibia extend thigh, move knee
genioglossus
origin - mandible sticks tongue out
pectineus
origin - pectineal line of pubis insertion - pectineal line of femur adduct and flex
adductor magnus
origin - pubis insertion - lines aspera and adductor tubercle of femur extends and laterally rotates
gracilis
origin - pubis insertion - tibia adduct and flex
styloglossus
origin - styloid process of temporal bone retraction/elevation of tongue
semimembranosus (hamstring)
origin - superior lateral quadran of ischial tuberosity insertion - posterior surface of medial tibial condyle extend thigh, move knee
sternocleidomastoid
pair lateral neck laterally flex/rotate head if both contract, flex neck
Muscles that move the arm and rotator cuff:
pectoralis major latissimus dorsi deltoid(***) subscapularis infraspinatus supraspinatus teres minor
Muscles in the posterior compartment of the leg, like the gastrocnemius muscle,
plantar flex (push down) the foot.
semispinalis capitis
posterior neck extends neck
trapezius
posterior neck extends neck (somewhat), mostly move scapula, supports arm
splenius capitis
posterior neck (superficial to semispinalis capitis) extends, rotates, laterally flexes neck
extension
posterior neck muscles attach to occipital bone
The masseter is the prime mover of the muscles involved in chewing (mastication). It
pulls the jaw up and forward.
invert
soles of feet face inward side (medially)
evert
soles of feet face outward side (laterally)
soleus
superficial posterior compartment flex
external obliques
superficial to rectus abdominis more lateral when unilaterally contracted, laterally flex vertebral column rotates vertebral column to opposite side of contracting muscles
The sternocleidomastoid has its origins on the manubrium and clavicle and inserts onto the mastoid process. When both contract equally,
the neck flexes.
Muscles that act on the scapula
trapezius levator scapulae rhomboid major and rhomboid minor pectoralis minor serratus anterior