Part 3: Axial musculature Flashcards
Axial musculature is associated with _____
the axial skeleton (skull, vertebral column, & thoracic cage)
Appendicular musculature is associated with _____
the appendicular skeleton (limbs & girdles)
Main characteristics of the axial musculature
1) Innervation by cranial nerves (CNs) or spinal nerves
2) Attachments on the axial skeleton, associated organs (e.g., eyeball), and/or soft tissue (skin of face)
Major functions of the axial musculature
1) Vision, hearing, mastication, facial expression, & swallowing
2) Upright posture & movement of the back
3) Support of abdominal & pelvic viscera
4) Respiration
5) Urination, defecation, & parturition
Four major groups of axial muscles
1) Muscles of the head & neck
2) Muscles of the back
3) Muscles of the thorax & abdomen
4)Muscles of the pelvis & perineum
Muscles of facial expression: innervated by _____
facial nerve (CN VII)
Extra-ocular muscles: innervated by _____
oculomotor (CN III), trochlear (CN IV), & abducens nerves (CN VI)
Muscles of mastication: innervated by _____
mandibular branch of trigeminal nerve (CN V3)
Tongue muscles: innervated by _____
hypoglossal nerve (CN XII)
Pharyngeal muscles: innervated by ____
vagus nerve (CN X)
Neck muscles: innervated by ____
cranial & cervical nerves
muscles of facial expression + action
(left) Procerus: Moves nose; draws medial side of eyebrow inferiorly
Orbicularis oculi: Closes eyelids
Orbicularis oris: Purses lips; kissing
Platysma: Tenses skin of neck
(right) Occipitofrontalis (frontal belly): Raises eyebrows; wrinkles forehead
Zygomaticus major: Elevates corner of mouth; smiling
Buccinator: Tenses cheeks; helps with chewing
Label eye
- Levator palpebrae superioris (CN III) : Elevates the eyelid
- Superior rectus (CN III): Eye looks up*
- Inferior rectus (CN III): Eye looks down*
- Medial rectus (CN III): Eye looks medially
- Lateral rectus (CN VI): Eye looks laterally
- Inferior oblique (CN III): Eye rolls up & laterally
- Superior oblique (CN IV): Eye rolls down & laterally
TMJ is a ____ joint - _____ (_____)
Ellipsoid joint – bicondylar (rotation & translation)
Opening of mouth involves (TMJ) ______
1) Rotation of condyle (inferior compartment)
2) Translation of condyle (superior compartment)
Label, both are ____
Temporalis :Temporal bone to coronoid process of mandible
Masseter : Zygomatic arch to lateral side of ramus of mandible
elevators of mandible when chewing on food & closing mouth
Pterygoid plate = part of the ____
sphenoid bone
Label, both muscles come from ____
- MEDIAL pterygoid plate BUT one has a medial origin, the other a lateral origin
Lateral pterygoid: Lateral side of medial pterygoid plate to mandibular condyle; Depressor of mandible to open mouth; can also move mandible side-to-side
Medial pterygoid: Medial side of pterygoid plate to medial side of mandibular ramus; Elevator of mandible when chewing on food & closing mouth
depression of mandible & mouth opening - also side to side motion muscle
Lateral pterygoid muscle
elevation of mandible & mouth closing
Temporalis muscle
Medial pterygoid muscle
Masseter muscle
tongue itself is ____
a muscle
label tongue muscles
Palatoglossus (palate to tongue)
Styloglossus (styloid process to tongue)
Hyoglossus (hyoid bone to tongue)
Genioglossus (chin to tongue)
Label pharyngeal muscles
Tensor & levator veli palatini: tenses & elevates soft palate
Superior pharyngeal constrictor: constriction of pharynx first
Middle pharyngeal constrictor: constriction of pharynx next
Inferior pharyngeal constrictor: constriction of pharynx last
Label superficial neck muscles
Mylohyoid muscle: Mandible to hyoid
(floor of mouth) -> Tenses floor of mouth during swallowing
Digastric muscle (2 bellies) Styloid process – hyoid – mandible -> Assists in depression of mandible to open mouth wide
Suprahyoid muscles -Skull to hyoid (above hyoid) –> Elevate hyoid (& larynx)
Biomechanics of swallowing
1) Contraction of mylohyoid & all tongue muscles (push food posteriorly)
2) Contraction of tensor & levator veli palatini muscles (blocks nasal cavity)
3) Elevation of larynx by suprahyoid muscles (blocks trachea)
4) Sequential contraction from the top of constrictor muscles to esophagus
Label superficial neck muscles
Infrahyoid muscles: Below hyoid bone; Pull down hyoid bone (& larynx)
Sternocleidomastoid muscle :Sternum – clavicle – mastoid process ; Turns head to opposite side of contraction (slight elevation)
Together = head flexion
Label deep anterior neck muscles
1) Longus capitis (head) muscle
2) Longus colli (neck) muscle:
both are Transverse processes to anterior surface of cervical vertebrae & occipital bone - Flexors of neck (colli) & head (capitis)
3) Scalene muscles: Transverse processes to rib 1 & 2; Lateral flexors of neck; Elevators of ribs 1 & 2
Label back muscles
Longissimus (transverse to transverse processes)
Spinalis (spinous to spinous processes)
Iliocostalis (ribs to ribs – from ilium)
Erector spinae (3 groups of muscle)
—>Extensors of back (vital to maintain upright posture)
Quadratus lumborum (transverse processes & ribs – ilium) –> Lateral flexor of trunk & helps with respiration
Intercostal muscles are where? ___different layers: _______
All innervated by ___
rib to rib
3
external, internal, innermost
spinal thoracic nerves
External intercostal muscles are _____ during respiration (inhalation phase)
Forced exhalation: ______intercostal muscles will assist
Innermost layer are ____
elevators of ribs
internal
fixators
Diaphragm separates ______ cavities. It is the ______– expand thoracic cavity.
Innervated by _____
thoracic & abdominal
chief muscle of respiration
phrenic nerve (C3-C5 levels of spinal cord)
diaphragm is connected to ____
Sternum (xiphoid process), ribs 7-12 & associated coastal cartilage, lumbar vertebrae to central tendon
label holes in diaphragm and diaphragm itself
Inferior vena cava (1)
Esophagus (2)
Aorta (3)
muscle fibers
Central tendon
Crura (legs on lumbar vertebrae)
diaphragm inhalation & exhalation
inhalation: contraction - increase volume of thoracic cavity
exhalation: relaxation
Label abdominal muscles
rectus abdominis: Ribs & sternum to pubis; Flexor of trunk & can help with respiration
abdominal muscles (3 different layers); ribs to os coxae:
2 obliques (external oblique & internal oblique); Lateral flexors & rotators of trunk
1 transverse (transversus abdominis: deepest)
Label abdominal muscles
Rectus abdominis
External abdominal oblique
Internal abdominal oblique
Transversus abdominis
Label pelvic muscles
green -levator ani pubococcygeus,ischiococcygeus (orange), puborectalis (pink)
yellow- Coccygeus (ischial spine to coccyx)
pelvic muscles provide support to _____. They are innervated by ____
pelvic viscera such as urinary bladder, rectum, uterus (female), prostate gland (male) by tensing
pudendal nerve (S2-S4)
perineal muscles are innervated by ____
pudendal nerve (S2-S4)
Label perineal muscles
External urethral sphincter (Regulates urethral opening (urinary continence); more developed in males)
External anal sphincter (Regulates anal opening (fecal continence))
Label perineal muscles
green: ischiocavernosus
orange: bulbospongiosus
contraction of these muscles increases blood flow into erectile tissues of genitalia
