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Flashcards in Axial Muscles Deck (58):

Which part of axial muscles lie on the axial skeleton?

BOTH their origins and insertions


This (1) contributes to facial expressions and consists of a muscle (2) and a thin, flattened tendonous sheet (3).

1. Epicranius
2. occipitofrontalis muscle
3. galea aponeurotica (a broad epicranial aponeurosis)


This muscle (1) has two "bellies", separated by the galea aponeurotica; the first overlays the fronal bone (2), and the second covers the posterior of the head (3).

1. occipitofrontalis muscle
2. frontal belly
3. occipital belly


The first sphincter of the alimentary canal (digestive tract)

orbicularis oris


If you stand in front of a mirror and tense the skin of your neck, you can see the broad sheets of this thin muscle bulging out.

the platysma


This may be sore in a novice trumpeter if they do not have much practice in sucking and blowing.

the buccinator muscle


Which term refers to what process that is accomplished by muscles that move the mandible at the temporomandibular joint (TMJ)?

mastication refers to the process of chewing


What do the temporalis, masseter, medial and lateral pterygoid, tongue, and buccinator all have in common?

they are the muscles of mastication


What do the occipitofrontalis muscle, orbicularis oris, platysma, and buccinator have in common?

they are the muscles of facial expression


You can palpate this muscle by placing your fingers along your temple and clenching your teeth together.

the temporalis


You can feel the contraction of this muscle near the angle of the mandible when you clench your teeth together.

the masseter


What might you use to your advantage while masticating the various foods at your Aunt Gretta's Thanksgiving dinner?

the medial and lateral pterygoid. (they help maximize efficiency of teeth while chewing or grinding foods of various consistencies)


Deadly toxins that can alter the function of human muscles (excessive contraction or paralysis) are produced by _________, only under _______ conditions, and are often found in soil or feces.

produced by bacterium Clostridium tetani, only under anaerobic conditions


What toxigenic disease follows a dirty puncture wound and results in involuntary contraction of the muscles that move the mandible (or "_____")?

Tetanus disease results in "lockjaw"


Eliot the electrician stumbles to work after a long night at the bar and finds himself making a rookie mistake which proceeds to send several volts of electricity through his body. His coworker Eileen runs to his aid after hearing his initial yelp in pain, however finds herself frozen at the unnatural sight of his posture. What is Eliot doing that has caused Eileen to go into "shock" (hehe) and why does this occur during electrocution?

Eliot has an extremely arched back. The erector spinae muscles are stronger than the rectus abdominus muscles, so when all your muscles contract (such as in electrocution), your spine is hyperextended.


What does tetanus and electrocution have in common?

both cause all muscles to lock-up, resulting in an arched back due to the erector spinae muscles being stronger than the rectus abdominus muscles.


During inhalation, ___1__ of several muscles ___2__ the dimensions of the thoracic cavity, creating ___3___ pressure, which ___4__ the lungs.

During inhalation, CONTRACTION of several muscles INCREASES the dimensions of the thoracic cavity, creating NEGATIVE pressure, which PULLS AIR INTO the lungs.


During exhalation, ___1__ of lung tissue pulls the chest wall ___2__ and the diaphragm ___3____, collectively ___4___the dimensions of the thoracic cavity, creating ___5___ pressure, which ___6__ of the lungs.

During exhalation, ELASTIC RECOIL of lung tissue pulls the chest was INWARD and the diaphragm UPWARD, collectively DECREASING the dimensions of the thoracic cavity, creating POSITIVE pressure, which FORCES AIR OUT of the lungs.


these muscles are used to maintain posture and to help us stand erect and are found along the entire vertebral column.

the erector spinae


when they contract together, the vertebral column extends. when they contract separately, the vertebral column flexes laterally toward that side.

the erector spinae AND the transversospinalis muscles both have this action


these muscle connect and stabilize the vertebrae, deep to the other group of muscles associated with the spine.

transversospinalis muscles


how do the muscles of respiration compare to the muscles of the thoracic wall in terms of position?

the muscles of respiration are DEEP to the more superficial muscles of the thoracic wall.


the muscles used for restful breathing

external intercostal muscles


lift ribs like a "bucket handle" during inhalation

external intercostal muscles


the muscles used during forceful exhalation

internal intercostal muscles ("internal" intercostals for "intense" breathing)


Although not listed with the muscles of respiration, these muscles may also contract during forced exhalation, thereby increasing pressure within their cavity and forcing the diaphragm superiorly.

the abdominal muscles


the most important muscle associated with breathing.

the diaphragm


internally placed, dome-shaped skeletal muscle that forms the partition between the thoracic and abdominal cavities.

the diaphragm


Contraction during inhalation causes _____ of the diaphragm (moves ____), thereby ______ the thoracic cavity and _____ the abdominopelvic cavity.

Contraction during inhalation causes FLATTENING of the diaphragm (moves INFERIORLY), thereby EXPANDING the thoracic cavity and COMPRESSING the abdominopelvic cavity.


What 4 purposes do the 4 pairs of muscles on the anteriolateral wall of the abdomen collectively serve?

1. compress and hold abdominal organs in place
2. assis in defecation
3. aid in forceful exhalation
4. flex and stabilize vertebral column


This essential, muscular organ is attached to the superior surface of the most important muscle for breathing, and moves with it. What two muscles are being described?

The heart is attached to the superior surface of the diaphragm


What do the muscles of the abdominal wall, the erector spinae muscles, and the transversospinalis muscles have in common?

When they flex unilaterally, they laterally flex the vertebral column.


These three pairs of muscles (1) form an aponeurosis (2) which surrounds and enfolds the central superficial muscle (3).

1. the external oblique, internal oblique, and transverse abdominis
2. the "rectus sheath"
3. the "rectus abdominis"


Latin for a "line that is curved like a half moon"

the "linea semilunaris"


Where the aponeuroses of these three pairs of lateral muscles join with the anterior rectus sheath (which surrounds the rectus abdominis) there is a cutaneous depression formed just lateral to the rectus abdominis called the "_______".

"linea semilunaris"


The rectus abdominis is partitioned horizontally into four segments by what?

three fibrous "tendinous intersections"


What is synonymous with "tendinous intersections"

tendinous inscriptions


Why is everyone so obsessed with tendinous intersections?

they form the traditional "six-pack" of a muscular, toned abdominal wall.


The rectus abdominis is partitioned vertically into left and right halves by what?

a vertical fibrous strip termed the "linea alba"


What is Latin for "white line"?

"linea alba"


This muscle forms an aponeurosis that contributes to the rectus sheath, then extends inferiorly to form a strong, cordlike what?

The "external oblique" muscle forms an aponeurosis that contributes to the rectus sheath, then extends inferiorly to form a strong, cordlike "inguinal ligament".


What extends from the anterior superior iliac spine to the pubic tubercle?

the inguinal ligament


What muscle is immediately deep to the external oblique and also forms an aponeurosis that contributes to the rectus sheath?

the "internal oblique"


What is the deepest muscle, whose fibers project transversely across the abdomen?

the "transversus abdominis"


What long, strap-like muscle extends vertically the entire length of the anteriomedial wall between the sternum and the pubic symphysis?

the "rectus abdominis"


The floor of the pelvic cavity is formed by three layers of muscles and associated fasciae, and is collectively known as what?

the "pelvic diaphragm"


What term refers to a muscle or group of muscles that covers or partitions an opening?



What extends from the ischium and pubis of the ossa coxae across to the sacrum and coccyx?

the pelvic diaphragm


What is the "perineum"?

the diamond-shaped region between the lower appendages


What does the pubic symphysis (anteriorly), coccyx (posteriorly), and both ischial tuberosities (laterally) have in common?

they are the four significant bony landmarks of the perineum


What is significant about a transverse line drawn between the ischial tuberosities?

It partitions the perineum into an anterior "urogenital triangle" and a posterior "anal triangle"


The portion of the perineum that contains the external genitalia and urethra.

the "urogenital triangle" (anterior)


The portion of the perineum that contains the anus.

the "anal triangle" (posterior)


What is the largest and most important group of muscles that contribute to the pelvic diaphragm?

the "levator ani" group


Why is the "levator ani" group of muscles significant in anatomy? Where is it located?

It contributes to the pelvic diaphragm (location). It supports the pelvic viscera and functions as a sphincter at the anorectal junction , urethra, and vagina (significance).


What prevents a uterine prolapse from happening regularly?

The "levator ani" group


Name one muscle that contributes to the levator ani group.

the "pubococcygeus"


What does the pubococcygeus have anything to do with jellyfish?

Kegel exercises specifically target and strengthen the pubococcygeus muscle to help with incontinence and sexual pleasure during coitus. These exercises are often described as similar to "jellyfish pulsing" the muscle.