Chapter 10 Flashcards
Functions of muscle?
Movement, stability, control body openings, heat production, glycemic control
What does “muscular system” refer to?
Skeletal muscles
What is the study of skeletal muscles?
Myology
What is the endomysium?
Thin sleeve of connective tissue around each muscle fiber
What is the perimysium?
Thicker sheath of connective tissue that wraps multiple muscle fibers into a bundle called a fascicle
What is the epimysium?
Fibrous sheath around an entire muscle, or multiple fascicles
What is the fascia?
Sheet of connective tissue that separates neighboring muscles from one another
So, order of skeletal muscle components from smallest and deepest to largest and most superficial?
Endomysium, perimysium, epimysium, fascia
What are fusiform muscles?
Thick in the middle, tapered at the end. Relatively strong
What are parallel muscles?
Fairly uniform width and parallel, like a column. Can span long distances, not as forceful
What are triangular muscles?
Fan-shaped, relatively strong
What are pennate muscles?
Feather shaped, 3 types
What are unipennate muscles?
They look like a quill, and all fascicles approach tendon from one side
What are bipennate muscles?
Looks like a full feather, and fascicles approach tendon from both sides
What are multipennate muscles?
Looks like a leaf of lettuce, converges at a single point
What are circular muscles?
Form rings around body opening and contract to prevent passage. Can also be made up of smooth muscle
What are muscle compartments?
Groups of functionally related muscles
What are direct attachments?
So little separation from muscle and bone that they appear to be attached. In reality, muscles stop short and collagen fibers bridge the gap
What are indirect attachments?
Muscle ends noticeably short of the bone, and this is bridged by a tendon, which has collagen fibers extend into the bone
What is aponeurosis?
A broad sheet-looking tendon
What is retinaculum?
A band of connective tissue, under which groups of tendons pass under
What is the origin?
The bony attachment at the stationary end of the muscle
What is the belly?
Thicker, middle region between origin and insertion
What is the insertion?
The bony attachment at the moving end of the muscle
What is an intrinsic muscle?
A muscle contained entirely within a region of interest
What is an extrinsic muscle?
A muscle that acts upon a designated organ or region, but arises from another region
What is a prime mover/agonist?
The muscle that produces most of the force during a particular joint action
What is a synergist?
A muscle that aids the prime mover
What is an antagonist?
A muscle that opposes the prime mover
What is a fixator?
A muscle that prevents a bone from moving
What is an innervation?
The nerve that supplies a given muscle
What does brevis mean?
Short
What does major mean?
Large
What is the frontalis?
Wrinkles forehead, raises eyebrows
What is the occipitalis?
Draws scalp posteriorly
Where is the frontalis?
Two bands above each eyebrow
Where is the occipitalis?
In the middle of the back of the head
What is the orbicularis oculi?
Closes eyelids for sleeping, blinking, helps tears flow
Where is the orbicularis oculi?
Ring around each eyeball
What is the nasalis?
Widens nostrils
Where is the nasalis?
Bridge of nose
What is the orbicularis oris?
Encircles mouth to close lips, kiss
Where is the orbicularis oris?
Around the lips
What is the zygomaticus major and minor?
Elevates corner of mouth for smiling, laughing, sneering, exposes teeth
Where is the zygomaticus major?
Inferior and lateral to the zygomaticus minor; kind of along the cheekbone attaching to the mouth
Where is the zygomaticus minor?
Superior and medial to the zygomaticus major; kind of along the cheekbone attaching to the mouth
What is the mentalis?
Elevates and protrudes lip in drinking, pouting
Where is the mentalis?
Chin
What is the buccinator?
Compresses cheek, directs food between molars, puckers cheeks
Where is the buccinator?
Deeper than the zygomaticus, like diagonal from lip corner to ear
What is the platysma?
Draws lip and mouth downward for horror and surprise, may aid in opening mouth
Where is the platysma?
Very top of the neck, on the left and right of the front
What is a depression of the mouth?
Opening it
What is an elevation of the mouth?
Biting and grinding
What is a protraction of the mouth?
Incisors can cut
What is a retraction of the mouth?
Make rear teeth meet
What are lateral and medial excursions of the mouth?
Grinding food
What is the temporalis?
Closes mandible
Where is the temporalis?
Overlying temporal bones
What is the masseter?
Originates on zygomatic arch, inserts on the angle of the mandible
Where is the masseter?
On the angle of the jaw
What is the digastric muscle?
Opens mouth widely (depresses mandible)
Where is the digastric muscle?
Under the chin, above the hyoid, vertical-ish
What is the mylohyoid?
Elevates floor of mouth at beginning of swallowing
Where is the mylohyoid?
Deeper than the hyoid bone and the digastric muscle, running horizontally
What is the stylohyoid?
Elevates hyoid bone
Where is the stylohyoid?
Attaching to the hyoid bone, running diagonal from jaw to meet it
What is the sternohyoid?
Depresses hyoid after elevation
Where is the sternohyoid?
Running down the neck, attached to the hyoid
What are the neck flexors?
Sternocleidomastoid and scalenes
What are the neck extensors?
Trapezius, splenius capitis, and semispinalis capitis
Muscles of normal breathing?
Diaphragm, external intercostal
What is the diaphragm?
Muscular dome between thoracic and abdominal cavities
Muscles of forced inhalation?
Sternocleidomastoid, scalenes of neck, pectoralis major, serratus anterior of chest, latissimus dorsi of back
Muscles of forced exhalation?
Internal and external obliques, transverse abdominus
What happens during inspiration?
Contraction flattens diaphragm, enlarges thoracic cavity
What do the external intercostals do?
Elevate ribs, move sternum anteriorly. Expands thoracic cavity. Air flows in
What do the internal intercostals do?
Depress and retract ribs. Compress thoracic cavity. Air flows out
3 layers of the anterior abdominal wall, from superficial to deep?
External abdominal oblique, internal abdominal oblique, transverse abdominus
What does the external abdominal oblique do?
Support viscera, aid in breathing and contralateral rotation of waist
What does the internal abdominal oblique do?
Rotates waist, contains aponeuroses
What does the transverse abdominus do?
Compress abdominal contents
What does the rectus abdominis do?
Produces forward bending at waist
Where is the rectus abdominis?
From the sternum to pubic. Enclosed by a rectus sheath.
What divides the rectus abdominis?
3 transverse tendinous intersections. Makes 6-pack
What are some muscles of the back?
Latissimus dorsi, trapezius, erector spinae
What is the perineum?
The diamond-shaped region between the thighs
What is the perineum bordered by?
Pubic symphysis (anterior), coccyx (posterior), 2 ischial tuberosities (lateral)
What is the urogenital triangle?
The anterior half of the perineum