The Muscular System Flashcards
List the histological features of muscle tissue?
- Each muscle fibre = is a long cylindrical cell with multiple oval nuclei arranged just
beneath its sarcolemma. - Sarcoplasm = is similar to cytoplasm
of cells and contains myoglobin - Myoglobin = is a red pigment that stores oxygen in the
muscle. - Myofibrils = densely packed where mitochondria and other organelles are squeezed between
them. - Within the myofibril = are striations, repeating dark A and light I bands.
- Each A band has a light stripe = H zone, within H zone
= is the M line. - I lines = are dissected by a Z disk.
- Sarcomere = between two Z disks, is a contractile unit, made up of filaments or myofilaments.
(Thick filaments= myosin, thin filaments= actin.) - SR = smooth ER, interconnecting tubules surround each myofibril like a sleeve on the arm.
- T tubules = at each A-I band junction, sarcolemma of the muscle cell penetrates into the cell interior to form elongated tubes whose lumen is continuous with the EC space.
Briefly describe and identify the histological features of skeletal muscle tissue?
SKELETAL:
- single, cylindrical, multi-nucleated cells
- myofibrils present (myofibrils)
- sarcomere = single cell unit; contractile
- SR present (around each myofibril)
- T tubules present
- epi-, peri- and endomysium present
Briefly describe and identify the histological features of cardiac muscle tissue?
CARDIAC:
- branching cells that bi- or uninucleate with striation
- myofibrils are at different thickness
- SR present
- T tubules present (not as much as skeletal)
- only endomysium present
Briefly describe and identify the histological features of smooth muscle tissue?
- single, fusiform, uninucleate cells
- no sarcomeres
- no T tubules
- SR equivalent to cardiac muscle
- only endomysium
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
Muscles of the head: muscle of mastication
(1) Masseter
(2) main jaw mover, elevates mandible
(3) Trigeminal
(1) Temporal
(2) closes jaw, retracts mandible and keeps it at rest
(3) Trigeminal
(1) Medial pterygoid
(2) elevates mandible, grinding movements
(3) Trigeminal nerve
(1) Lateral pterygoid
(2) protrudes jaw, side to side grinding movements
(3) Trigeminal nerve
(1) Buccinator
(2) trampoline action, keeps food within the grinding surfaces of the teeth
(3) facial nerve
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
Muscles of the anterior neck and throat: SUPRAHYOID MUSCLES
Suprahyoid muscles = superior to hyoid bone. Muscles that form the floor of the oral cavity, anchor tongue, elevate hyoid, move larynx superiorly,
(1) Digastric
(2) elevate and steady hyoid bone during swallowing and speech. Opens mouth and depresses mandible
(3) Mandibular branch of the Trigeminal branch (anterior belly) and Facial nerve (posterior belly)
(1) Stylohoid
(2) elevates and retracts the hyoid therefore elongating the floor of the mouth during swallowing
(3) facial nerve
(1) Mylohoid
(2) elevates the hyoid bone and floor of the mouth, allowing the tongue to exert upwards and backwards pressure to push food into the pharynx
(3) Mandibular branch of the Trigeminal nerve
(1) Geniohyoid
(2) pulls the hyoid bone superiorly and anteriorly, shortening the floor of the mouth and widening to the pharunx to receive food.
(3) First cervical spinal nerve via the hypoglossal
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
Muscles of the anterior neck and throat: INFRAHYOID MUSCLES
INFRAHYOID MUSCLES = straplike muscles that depress the hyoid and larynx during swallowing and speech
(1) Sternohyoid
(2) depress the hyoid bone and larynx when mandible is fixed
(3) cervical spinal nerves C1 - C3
(1) Sternothyroid
(2) pulls the hyoid bone and larynx inferiorly (thyroid cartilage)
(3) cervical spinal nerves C1 - C3
(1) Omohyoid
(2) depresses and retract the hyoid bone
(3) cervial spinal nerves C1 - C3
(1) Thyrohyoid
(2) depresses the hyoid or elevates the larynx if the hyoid bone is fixed
(3) first cervical nerve via the hypoglossal
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
Muscles of the anterior neck and throat: ANTEROLATERAL MUSCLES
(1) Sternocleidomastoid
(2) head flexion as when lying down and lifting your head
(3) accessory nerve
(1) Scalene
(2) elevates the first 2 ribs, flexes and rotates the neck
(3) Cervical spinal nerves
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
Muscles of the VERTEBRAL COLUMN
(1) Erector
(2) Back extension and forwards bending
(3) spinal nerves
(1) iliocostalis
(2) extending vertebral column, maintain erect posture
(3) spinal nerves
(1) Longissimus
(2) Extends vertebral column and turns the face
(3) spinal nerves
(1) Spinalis
(2) Extends the vertebral column
(3) spinal nerves
(1) Semispinalis
(2) Extends vertebral column and head and rotates them
(3) spinal nerves
(1) Quadratus Lumborum
(2) flexes vertebral column laterally when acting separately
(3) T12 and upper lumbar spinal nerves
(1) Splenius
(2) Extend or hyperextend the head
(3) cervical spinal nerves
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
Muscles of the thorax; EXTERNAL and INTERNAL INTERCOSTAL
(1) External intercostal
(2) pulls ribs close together to elevate the ribcage, aid in inspiration
(3) intercostal nerves
(1) Internal intercostal
(2) draws ribs together to depress the ribcage
(3) intercostal nerves
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
Muscles of the thorax; superficial muscles of the ANTERIOR THORAX
(1) Pectoralis minor
(2) Draws the scapula forwards and down
(3) Pectoral nerve C6 - C8
(1) Serratus anterior
(2) Protracts and holds the scapula against the chest wall, rotates the scapula, resp. in abduction, lifting arm upwards, horizontal movement of arm (boxing)
(3) Long thoracic nerves C5 - C7
(1) Subclavius
(2) Stabilizes and depresses pectoral girdle
(3) Nerves to the subclavius C5 - C6
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
Muscles of the thorax; superficial muscles of the POSTERIOR THORAX
(1) Trapezius
(2) stabilizes, raises, retracts and rotates the scapula
(3) cervical spinal nerves C3 - C4
(1) Levator scapulae
(2) elevates/adducts the scapula
(3) cervical spinal nerves and dorsal scapular nerves
(1) Rhomboids
(2) stabilizes scapula and rotates glenoid cavity of the scapula downwards
(3) dorsal scapular nerves
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
DIAPHRAGM
(1) Diaphragm
(2) Main mover of inspiration, flattens on contraction and increase dimensions of the thorax
(3) Phrenic nerves
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
muscles of the ABDOMINAL WALL
(1) Rectus abdominis
(2) Flexes and rotates the lumber region of the vertebrae, fix and depresses ribs and stabilizes pelvis when walking
(3) Intercostal nerves (T7 - T12)
(1) External oblique
(2) Flexes vertebral column, compresses abdominal wall, turn rotation and lateral flexion
(3) Intercostal nerves
(1) Internal oblique
(2) Flexing vertebral column and compresses abdominal wall, turn rotation and lateral flexion
(3) Intercostal nerves and L1
(1) Transverse abdominis
(2) Compresses abdominal contents
(3) Intercostals and L1
Name the muscles (1) of the following regions giving the action (2) and nerve (3) supply of each:
Muscles of the pelvic floor and perineum: muscles of the PELVIC and UROGENITAL DIAPHRAGMS
Two paired muscles (below) form the funnel-shaped pelvic floor (pelvic diaphragm):
PELVIC DIAPHRAGM:
(1) Levator ani
(2) Supports and maintain the position of the pelvic viscera, forms sphincter at the anorectal area and vagina. Lifts the anal canal during defecation.
(3) S4 and inferior rectal nerves
(1) Coccygeus
(2) Supports the pelvic viscera, pushes coccyx forwards when reflected during defecation and child birth.
(3) S4
UROGENITAL DIAPHRAGM:
(1) Deep transverse perineal
(2) supports the pelvic organs
(3) pudendal nerve
(1) External urethral sphincter
(2) Constricts the urethra, allows voluntary inhibition of urination and support pelvic organs
(3) pudendal nerve
