Muscular System - Upper Flashcards
How are head and neck muscles organized?
based on location and/or function
Muscles of the Scalp
What is the muscle of the scalp?
occipitofrontalis muscle
Muscles of the Scalp
What forms the occipitofrontalis muscle?
frontal belly + occipital belly connected by epicranial aponeurosis
Muscles of the Scalp
What does the frontal belly do?
wrinkles forehead skin, raises eyebrows
Muscles of the Scalp
What is the epicranial aponeurosis?
flat tendon – sheet of connective tissue
Muscles of Facial Expression
- origin
- insertion
- nerve/innervation
O: skull bones
I: skin of face
N: CN VII
Muscles of Facial Expression
What does contraction of muscle cause?
different facial expressions
Muscles of Facial Expression
How are muscles classified? (3)
- muscles around orbital cavity
- muscles around nasal cavity
- muscles around oral cavity
Muscles of Facial Expression
What is the muscle around the orbital cavity? What does it do?
orbicularis oculi – completely surrounds orbit and closes eyelids
Muscles of Facial Expression
What is the muscle around the nasal cavity? What does it do?
nasalis muscle – bridges over nose and flares the nostrils
Muscles of Facial Expression
What is the muscle around the oral cavity? What does it do?
orbicularis oris – completely surrounds oral fissure, and closes/purses lips
Muscles of Mastication
What are the 4 muscles?
masseter
temporalis
medial pterygoid
lateral pterygoid
Muscles of Mastication
What are all muscles innervated by?
mandibular branch/division of CN V
Muscles of Mastication
Masseter
- origin
- insertion
- function
O: zygomatic arch
I: ramus of mandible (lateral surface)
F:
- elevates mandible
- clenches teeth
Muscles of Mastication
Temporalis
- origin
- insertion
- function
O: temporal fossa of skull
I: coronoid process of mandible
F: elevates mandible
Muscles of Mastication
Medial Pterygoid
- origin
- insertion
- function
O: sphenoid bone
I: medial surface of ramus of mandible
F:
- elevates mandible, and moves it side to side
- contralateral deviation (deviates mandible to opposite side)
Muscles of Mastication
Lateral Pterygoid
- origin
- insertion
- function
O: sphenoid bone
I: condyle of mandible, and articular disc of TMJ
F:
- protrudes mandible, and moves it side to side
- contralateral deviation (deviates mandible to opposite side)
Extraocular Muscles
How many muscles are there? What do they do?
7 muscles that either move eyeball in different directions, OR elevate upper eyelid
Extraocular Muscles
What does the levator palpebrae superioris do?
attaches to upper eyelid
elevates superior eyelid
innervated by CN III, IV, VI
Extraocular Muscles
What are the muscles innervated by?
CN III, IV, VI
Pharyngeal Muscles
What are the 2 types of muscles?
longitudinal muscles
circular muscles
Pharyngeal Muscles
What do longitudinal muscles do?
shorten pharynx, and elevate larynx (laryngeal elevators)
Pharyngeal Muscles
What do circular muscles do?
constrict pharynx (pharyngeal constrictor muscles)
Pharyngeal Muscles
What are the muscles innervated by?
CN X (except stylopharyngeus)
Muscles of Soft Palate
- origin (2)
- insertion (2)
first group
O: base of cranium
I: soft palate
or
second group
O: soft palate
I: tongue or pharynx
Muscles of Soft Palate
What does the first group of muscles do?
elevates or stretches soft palate
Muscles of Soft Palate
What does the second group of muscles do?
depresses soft palate
Muscles of Soft Palate
What are the muscles innervated by?
CN X (except tensor veli palatini)
Muscles of Tongue
What are the 2 types of muscles?
intrinsic muscles
extrinsic muscles
Muscles of Tongue
Intrinsic Muscles
- origin
- insertion
O: inside tongue
I: inside tongue
Muscles of Tongue
Extrinsic Muscles
- origin
- insertion
O: soft palate, mandible, styloid process, or hyoid bone
I: tongue
Muscles of Tongue
What are the muscles innervated by?
CN XII (except palatoglossus)
Muscles of Larynx
What are the 2 types of muscles?
intrinsic muscles
extrinsic muscles
Muscles of Larynx
Intrinsic Muscles
- location
- function
stretched between laryngeal cartilages
change length or tension of vocal cords during phonation and respiration
Muscles of Larynx
Extrinsic Muscles
- types (2)
- function
suprahyoid muscle of the neck: elevate neck
infrahyoid muscle of the neck: depress neck
Muscles of Larynx
What are the muscles innervated by?
CN X
Muscles of Neck
What are the 2 groups of muscles in the neck?
superficial
deep
Muscles of Neck - Superficial
What are the 3 superficial muscles?
sternocleidomastoid (SCM)
infrahyoid
suprahyoid
Muscles of Neck - Superficial
Sternocleidomastoid (SCM)
- origin
- insertion
- function
- nerve/innervation
O: sternum and clavicle
I: mastoid process of temporal bone
F: unilaterally bends neck towards shoulder, and rotates head contralaterally
N: by CN XI
Muscles of Neck - Superficial
Infrahyoid
- origin
- insertion
- function
- nerve/innervation
O: sternum
I: thyroid cartilage OR hyoid bone
F: depress hyoid bones and larynx
N: by ansa cervicalis of cervical plexus
Muscles of Neck - Superficial
Suprahyoid
- origin
- insertion
- function
- nerve/innervation
O: temporal bone OR mandible
I: hyoid bone
F: elevate hyoid bone and larynx OR depress mandible
N: by mandibular division of CN V or CN VII
Muscles of Neck - Deep
What are the 2 deep muscles?
- scalene (anterior, middle, and posterior)
- prevertebral
Muscles of Neck - Deep
Scalene (anterior, middle, and posterior)
dont need to know origins
- origin
- insertion
- function
- nerve/innervation
O: transverse processes of cervical vertebrae (except CI)
I: first or second ribs
F: elevate first two ribs OR laterally flex neck
N: by anterior rami of some cervical spinal nerves
Muscles of Neck - Deep
Prevertebral
- function
- nerve/innervation
F: lateral flex head and neck
N: by anterior rami of some cervical spinal nerves
What are the 4 types of trunk muscles?
back, thoracic, abdominal, and pelvic musculatures
Muscles of Back
How are muscles classified?
into 3 distinct layers (superficial, intermediate, and deep)
Muscles of Back
What are the extrinsic back muscles?
superficial and intermediate layers
Muscles of Back
What are the intrinsic back muscles?
deep layer
Muscles of Back - Superficial
What do superficial muscles do?
connect upper limbs to trunk, and position pectoral girdle and upper limb
Muscles of Back - Superficial
What are superficial muscles innervated by?
anterior rami of spinal nerves
Muscles of Back - Superficial
What are the 5 muscles?
trapezius latissimus dorsi levator scapulae rhomboid major rhomboid minor
Muscles of Back - Superficial
Trapezius
- main action(s)
- nerve/innervation
MA: upward rotation, elevation, depression, and retraction (adduction) of scapula
N: CN XI
Muscles of Back - Superficial
Latissimus Dorsi
- insertion
- main action(s)
- nerve/innervation
I: intertubercular groove of humerus
MA: extension, adduction, and medial rotation of shoulder joint
N: thoracodorsal nerve
Muscles of Back - Superficial
Levator Scapulae
- main action(s)
- nerve/innervation
MA: elevation of scapula
N: dorsal scapular nerve (C5), and C3, C4 spinal nerves
Muscles of Back - Superficial
Rhomboid Major
- main action(s)
- nerve/innervation
MA: retraction (adduction), and elevation of scapula
N: dorsal scapular nerve
Muscles of Back - Superficial
Rhomboid Minor
- main action(s)
- nerve/innervation
MA: retraction (adduction) and elevation of scapula
N: dorsal scapular nerve
Muscles of Back - Intermediate
What are the intermediate back muscles?
accessory respiratory muscles
Muscles of Back - Intermediate
What are the intermediate back muscles innervated by?
anterior rami of spinal nerves
Muscles of Back - Intermediate
What are the 2 muscles?
serratus posterior superior
serratus posterior inferior
Muscles of Back - Intermediate
Serratus Posterior Superior
- main action(s)
- nerve/innervation
MA: elevation of ribs II-V
N: anterior rami of T2-T5
Muscles of Back - Intermediate
Serratus Posterior Inferior
- main action(s)
- nerve/innervation
MA: depression of ribs IX-XII
N: anterior rami of T9-T11
Muscles of Back - Deep
What are the 3 groups that deep muscles divide into?
erector spinae
transversospinalis
segmental
Muscles of Back - Deep
What does the erector spinae group do?
maintain erect position of trunk and neck, and extend and rotate vertebral column
Muscles of Back - Deep
What does the transversospinalis group do?
maintain erect position of trunk and neck, and extend and rotate vertebral column
Muscles of Back - Deep
What does the segmental group do?
extends or laterally flexes vertebral column, or elevates ribs
Muscles of Back - Deep
What are muscles innervated by?
posterior rami of spinal nerves
Muscles of Back - Deep
What are the 3 muscles in the neck?
splenius capitis
splenius cervicis
Muscles of Back - Deep
Splenius Capitis
- main action(s)
- nerve/innervation
MA: extension and rotation of head
N: posterior rami of cervical spinal nerves
Muscles of Back - Deep
Splenius Cervicis
- main action(s)
- nerve/innervation
MA: extension and rotation of neck
N: posterior rami of cervical spinal nerves
Muscles of Back - Deep, Erector Spinae
What are the 3 muscles of the erector spinae group?
iliocostalis
longissimus
spinalis
Muscles of Back - Deep, Erector Spinae
Iliocostalis
- main action(s)
- nerve/innervation
MA: extension and lateral flexion of vertebral column
N: posterior rami of corresponding spinal nerves
Muscles of Back - Deep, Erector Spinae
Longissimus
- main action(s)
- nerve/innervation
MA: extension and lateral flexion of vertebral column and head
N: posterior rami of corresponding spinal nerves
Muscles of Back - Deep, Erector Spinae
Spinalis
- main action(s)
- nerve/innervation
MA: extension of vertebral column and head
N: posterior rami of corresponding spinal nerves
Muscles of Back - Deep
What are the 3 muscles of the transversospinalis group?
semispinalis
multifidus
rotatores
Muscles of Back - Deep, Segmental
What are the 3 muscles of the segmental group?
levator costarum
intertransversarii
interspinales
Muscles of Back - Deep, Segmental
Levator Costarum
- main action
- nerve/innervation
MA: elevation of ribs
N: posterior rami of corresponding spinal nerves
Muscles of Back - Deep, Segmental
Intertransversarii
- main action
- nerve/innervation
MA: lateral flexion of vertebral column
N: posterior rami of corresponding spinal nerves
Muscles of Back - Deep, Segmental
Interspinales
- main action
- nerve/innervation
MA: extension of vertebral column
N: posterior rami of corresponding spinal nerves
Muscles of Thorax
What are the 2 types of muscles?
Where do they originate and insert?
extrinsic muscles: originate from thorax, and insert to upper limb
intrinsic muscles: originate and insert in thorax
Muscles of Thorax
What are the 4 types of extrinsic muscles?
pectoralis major
pectoralis minor
serratus anterior
subclavius
Muscles of Thorax - Extrinsic
Pectoralis Major
- origin
- insertion
- main acation(s)
- nerve/innervation
O: medial half of clavicle and sternum
I: lateral lip of intertubercular groove of humerus
MA: horizontal adduction and medial rotation of shoulder joint
N: medial and lateral pectoral nerves
Muscles of Thorax - Extrinsic
Pectoralis Minor
- insertion
- main acation(s)
- nerve/innervation
I: coracoid process of scapula
MA: protraction (abduction) of scapula
N: medial and lateral pectoral nerves
Muscles of Thorax - Extrinsic
Serratus Anterior
- origin
- insertion
- main acation(s)
- nerve/innervation
O: ribs I-IX
I: medial border of scapula
MA: protraction (abduction) and upward rotation of scapula
N: long thoracic nerve (roots of C5-C7)
Muscles of Thorax - Intrinsic
What do intercostal muscles do?
mainly involved in respiration by increasing/decreasing thoracic cavity volume during inhalation/exhalation
Muscles of Thorax - Intrinsic
What are the 3 main openings of the diaphragm?
What are they passages for?
aortic opening: for passage of aorta, at level of TXII
esophageal hiatus: for passage of esophagus, at level of TX
inferior vena cava opening: for passage of inferior vena cava, at level of TVIII
Muscles of Thorax - Intrinsic
What are the 3 intrinsic muscles?
external intercostal
internal intercostal
diaphragm
Muscles of Thorax - Intrinsic
External Intercostal
- origin
- insertion
- main action(s)
- nerve/innervation
O: inferior border of rib above
I: superior border of rib below
MA: elevation of rib above
N: intercostal nerves (anterior rami of TI-T11)
Muscles of Thorax - Intrinsic
Internal Intercostal
- origin
- insertion
- main action(s)
- nerve/innervation
O: superior border of rib below
I: inferior border of rib above
MA: depression of rib above
N: intercostal nerves (anterior rami of TI-T11)
Muscles of Thorax - Intrinsic
Diaphragm
- origin
- insertion
- main action(s)
- nerve/innervation
O: xiphoid process of sternum, lower 6 ribs, and upper 3 lumbar vertebrae
I: central tendon of diaphragm
MA: increases volume of (expands) thoracic cavity
N: phrenic nerve
Muscles of Abdomen
What are the 2 types of muscles?
anterolateral wall musculatures
posterior abdominal wall musculatures
Muscles of Abdomen
What do anterolateral wall musculatures do?
flexes and rotates trunk, and increase abdominal cavity pressure
Muscles of Abdomen
What do posterior abdominal wall musculatures do?
extends and laterally flexes trunk, or flexes and laterally rotates hip joint
Muscles of Abdomen - Anterolateral Abdominal Wall Muscles
What are the 4 muscles?
rectus abdominis
external abdominal oblique
internal abdominal oblique
transversus abdominis
Muscles of Abdomen - Anterolateral Abdominal Wall Muscles
Rectus Abdominis
- origin
- insertion
- main action(s)
- nerve/innervation
O: pubic bone and pubic symphysis
I: xiphoid process and costal cartilages V-VII
MA: compression of abdominal viscera, and flexion of trunk
N: anterior rami of T7-T12
Muscles of Abdomen - Anterolateral Abdominal Wall Muscles
External Abdominal Oblique
- origin
- insertion
- main action(s)
- nerve/innervation
O: lower 8 ribs
I: iliac crest, pubic bone, and linea alba
MA: compression of abdominal viscera, flexion, and contralateral rotation of trunk
N: anterior rami of T7-T12
Muscles of Abdomen - Anterolateral Abdominal Wall Muscles
Internal Abdominal Oblique
- origin
- insertion
- main action(s)
- nerve/innervation
O: iliac crest and inguinal ligament
I: lower 4 ribs and linea alba
MA: compression of abdominal viscera, flexion and ipsilateral rotation of trunk
N: anterior rami of T7-L1
Muscles of Abdomen - Anterolateral Abdominal Wall Muscles
Transversus Abdominus
- origin
- insertion
- main action(s)
- nerve/innervation
O: iliac crest, inguinal ligament, and lower 6 ribs
I: linea alba
MA: compression of abdominal viscera
N: anterior rami of T7-L1
Muscles of Abdomen - Anterolateral Abdominal Wall Muscles
What is aponeurosis?
sheet-like tendon that attaches anterolateral abdominal muscles (except rectus abdominis) to their insertion
Muscles of Abdomen - Anterolateral Abdominal Wall Muscles
What is the inguinal ligament?
inferior free border of aponeurosis of external abdominal oblique muscle stretched between anterior superior iliac spine (ASIS) and pubic tubercle
Muscles of Abdomen - Anterolateral Abdominal Wall Muscles
What is the rectus sheath formed by?
fibrous sheath formed by aponeuroses of external, internal, and transversus abdominis muscle
almost complete invests rectus abdominis muscle
Muscles of Abdomen - Anterolateral Abdominal Wall Muscles
What is the linea alba?
What is it formed by?
Where it it located?
band of dense connective tissue formed by union of aponeuroses of anterolateral abdominal muscles in midline
extends from xiphoid process to pubic symphysis
Muscles of Abdomen - Anterolateral Abdominal Wall Muscles
What is the inguinal canal?
What is it formed by?
What are the 2 openings?
What does it contain?
short oblique canal located parallel and a little above medial half of inguinal ligament
formed by and between external, internal and transversus abdominis muscles
2 openings: deep inguinal ring and superficial inguinal ring
contains spermatic cord in male, and round ligament of uterus in female
Muscles of Abdomen - Posterior Abdominal Wall Muscles
What are the 3 muscles?
psoas major
iliacus
quadratus lumborum
Muscles of Abdomen - Posterior Abdominal Wall Muscles
Psoas Major
- origin
- insertion
- main action(s)
- nerve/innervation
O: transverse processes and bodies of lumbar vertebrae and intervening discs
I: lesser trochanter of femur
MA: flexion and lateral rotation of hip joint
N: anterior rami of L1-L3
Muscles of Abdomen - Posterior Abdominal Wall Muscles
Iliacus
- origin
- insertion
- main action(s)
- nerve/innervation
O: iliac fossa
I: lesser trochanter of femur
MA: flexion and lateral rotation of hip joint
N: femoral nerve
Muscles of Abdomen - Posterior Abdominal Wall Muscles
Quadratus Lumborum
- origin
- insertion
- main action(s)
- nerve/innervation
O: transverse process of LV and iliac crest
I: transverse processes of LI-LIV and rib XII
MA: extension and lateral flexion of trunk, and fixation of rib XII
N: anterior rami of T12-L4
Muscles of Pelvis
What are the 2 pelvic wall muscles?
Where do they originate and insert?
piriformis muscle
obturator internus muscle
O: pelvic cavity
I: femur
Muscles of Pelvis
Where are perineal muscles?
contained within perineum
Muscles of Pelvis - Pelvic Diaphragm
What do muscles join to form?
these muscles from left and right sides join together to form muscular funnel-shaped membrane located between true pelvis and perineum
Muscles of Pelvis - Pelvic Diaphragm
What do levator ani muscles arise from?
What do its anterior fibers do?
What do its posterior fibers do?
- arises from inner surface of hip bone
- anterior fibers merge with fibers of opposite side levator ani
- posterior fibers insert to sacrum and coccyx
Muscles of Pelvis - Pelvic Diaphragm
Where does the coccygeus muscle originate and insert?
O: ischial spine
I: coccyx and sacrum
Muscles of Pelvis - Pelvic Diaphragm
What does the muscle support?
supports pelvic viscera
Muscles of Pelvis - Pelvic Diaphragm
What are the 2 muscles?
levator ani muscle
coccygeus muscle
Muscles of Pelvis - Pelvic Diaphragm
What is the muscle innervated by?
branches from sacral plexus
Muscles of Pelvis
What is the perineum?
diamond-shaped area located inferior to pelvic diaphragm between thighs
Muscles of Pelvis
What are the boundaries of the perineum?
same as inferior pelvic aperture (outlet) – coccyx (posteriorly), pubic symphysis (anteriorly), and ischial tuberosities (laterally)
Muscles of Pelvis
What is the perineum subdivided into?
anterior urogenital triangle and posterior anal traingle by horizontal line between ischial tuberosities
Muscles of Pelvis
What does the urogenital triangle contain?
distal part of urethra, external genitalia, and perineal muscles (except external and anal sphincter)
Muscles of Pelvis - Urogenital Triangle
What do the main muscles do?
cover root of external genitalia
Muscles of Pelvis - Urogenital Triangle
What are the 2 main muscles?
bulbospongiosus
ischiocavernosus
Muscles of Pelvis - Urogenital Triangle
What does bulbospongiosus do?
help in draining last drops of urine (in males), and acts as sphincter for vaginal opening (in females)
Muscles of Pelvis - Urogenital Triangle
What does ischiocavernosus do?
assist in maintaining erection of penis or clitoris
Muscles of Pelvis
What does the anal triangle contain?
anal canal surrounded by external anal sphincter muscle
Muscles of Pelvis - Anal Triangle
What is the muscle?
What is it innervated by?
perineal muscle
innervated by pudendal nerve