chapter 10 muscles

  1. how many muscles are there?
    about 600
  2. how much of our body weight are our muscles?
    about half
  3. what are the three kinds of muscle tissue?
    skeletal, cardiac, smooth
  4. what are muscles specialized to do?
    converting the chemical energy in ATP into the mechanical energy of motion
  5. what is the study of the muscular system?
  6. what are the functions of the muscles?
    movement, stability, control of openings and passageways, heat production by skeletal muscles
  7. Muscles and movement:
    • –move from place to place, movement of body parts and body contents in breathing, circulation, feeding and digestion, defecation, urination, and childbirth–role in communication
    • –speech, writing, and nonverbal communications
  8. Muscles and stability:
    • –maintain posture by preventing unwanted movements
    • –antigravity muscles
    • –resist the pull of gravity and prevent us from falling or slumping over
    • –stabilize joints
  9. Muscles and control over openings and passageways:
    –sphincters-internal muscular rings that control the movement of food, bile, blood, and other materials
  10. Muscles and heating the body:
    as much as 85% of our body heat
  11. endomysium
    • –thin sleeve of loose connective tissue surrounding each muscle fiber
    • –allows room for capillaries and nerve fibers to reach each muscle fiber
  12. perimysium
    • –slightly thicker layer of connective tissue
    • –fascicles–bundles of muscle fibers wrapped in perimysium
    • –carry larger nerves and blood vessels, and stretch receptors
  13. Epimysium
    • –fibrous sheath surrounding the entire muscle
    • –outer surface grades into the fascia
    • –inner surface sends projections between fascicles to form perimysium
  14. fascia
    sheet of connective tissue that separates neighboring muscles or muscle groups from each other and the subcutaneous tissueConnective
  15. –the effects produced by a muscle
    –to produce or prevent movement
  16. muscle that produces most of force during a joint action
    prime mover (agonist)
  17. muscle that aids the prime mover–stabilizes the nearby joint–modifies the direction of movement
  18. opposes the prime mover
    –relaxes to give prime mover control over an action
    –preventing excessive movement and injury
    –antagonistic pairs-muscles that act on opposite sides of a joint
  19. muscle that prevents movement of bone
  20. intrinsic muscle
    • entirely contained within a region, such as the hand
    • –both its origin and insertion there
  21. extrinsic muscle
    act on a designated region, but has its origin elsewhere–fingers –extrinsic muscles in the forearm
  22. suprahyoid group
    digastric, geniohyoid, mylohyoid, stylohyoid
  23. opens mouth widely
  24. depresses mandible
  25. elevates floor of mouth at beginning of swallowing
  26. elevates hyoid
  27. infrahyoid group
    omohyoid, sternohyoid, thyrohyoid, sternothyroid
  28. depresses hyoid after elevation
    omohyoid, sternohyoid
  29. depresses hyoid and elevates larynx
  30. depresses larynx after elevation
  31. –encircle pharynx forming a muscular funnel
    –during swallowing drive food into the esophagus
    the three pairs of pharyngeal constrictors
  32. the three functional groups for muscles in the trunk
    • –muscles of respiration
    • –muscles that support abdominal wall and pelvic floor
    • –movement of vertebral column
  33. External intercostals
    • –elevates ribs
    • –expand thoracic cavity
    • –create partial vacuum causing inflow of air
  34. internal intercostals, Innermost intercostals
    • –depresses and retracts ribs
    • –compresses thoracic cavity
    • –expelling air
  35. external abdominal oblique
    • •Most superficial of lateral abdominal muscles
    • •Supports abdominal viscera against pull of gravity
    • •Stabilizes vertebral column during heavy lifting
    • •Maintains posture
    • •Compresses abdominal organs
    • •Aids in forced expiration•Rotation at waist
  36. internal abdominal oblique
    • •Intermediate layer of lateral abdominal muscles
    • •Unilateral contraction causes ipsilateralrotation of waist
    • •Aponeurosis–tendons of oblique and transverse muscles
    • –broad, fibrous sheets
  37. transverse abdominal
    • •Deepest of lateral abdominal muscles
    • •Horizontal fibers
    • •Compresses abdominal contents
    • •Contributes to movements of vertebral column
  38. rectus abdominis
    • •Flexes lumbar region of vertebral column
    • •Produces forward bending at the waist
    • •Extends from sternum to pubis
    • •Rectus sheath encloses muscle
    • •Three transverse tendinousintersections divide rectus abdominisinto segments –“six pack”
  39. Perineum
    • diamond-shaped region between the thighs
    • –bordered by four bony landmarks
    • •pubic symphysis anteriorly
    • •coccyx posteriorly
    • •ischialtuberosities laterally
    • –urogenitaltriangle –anterior half of perineum
    • –anal triangle –posterior half of perineum
  40. Three layers or compartments of the perineum:
    • –superficial perinealspace –three muscles•ischiocavernosus, bulbospongiosus, superficial transverse peritoneal
    • –middle compartment -spanned by urogenitaldiaphragm•composed of a fibrous membrane and two or three muscles•deep transverse perinealmuscle, external urethral and anal sphincters•compressor urethraein females only
    • –pelvic diaphragm–deepest layer consists of two muscle pairs•levatoraniand coccygeusSuperficial
  41. Male muscles-perineum
    • •ischiocavernosus–maintains erection
    • •bulbospongiosus–aids in erection, expels remaining urine
    • •superficial transverse perineal–not always present
  42. Female muscles-perineum
    • Middle layer of pelvic floor contains urogenitaldiaphragm and external urethral and anal sphincters
    • •Deepest compartment of the perineum
    • •Pelvic diaphragm –two muscle pairs
    • –levatorani-supports viscera and defecation
    • –coccygeus-supports and elevates pelvic floor
  43. STUDY
    fascicle orientation of muscles, muscle attachments, facial muscles, muscles for chewing and swallowing, muscles acting on the head, etc
Card Set
chapter 10 muscles
chapter 10 muscles