Chapter 8 Flashcards
Differentiate skeletal muscle tissue from skeletal muscles by listing the tissues present in each skeletal muscle.
Skeletal muscle tissue, connective tissue proper, smooth muscle tissue, epithelium, nervous tissue, blood.
List of various functions which skeletal muscles perform in the body.
Locomotion, posturing, respiration, Prehension, Mastication (Chewing), Delutition (Swallowing), abdominal press, vocalization, eye movement, venous return.
Define muscle Belly as it relates to skeletal muscle structure.
The contractile part of a muscle.
Tendon as it relates to skeletal muscle structure.
Fibrous connective tissue attachments
Aponeurosis as it relates to skeletal muscle structure.
just like normal muscle tendons, but broad and sheet like.
Origin as it relates to skeletal muscle structure.
attachment of a muscle belly to the more fixed part of the skeleton
Insertion as it relates to skeletal muscle structure.
attachment at the moveable end of muscle belly
Epimysium as it relates to skeletal muscle structure.
sheathes of connective tissue covering the a muscle belly.
Perimysium as it relates to skeletal muscle structure.
partitions that extend inward from the epimysium and segment the muscle cells into groups termed fascicle or fascicles
Endomysium as it relates to skeletal muscle structure.
Fibrous connective tissue septae enveloping each individual muscle cell.
Fascicle as it relates to skeletal muscle structure.
thin partitions termed perimysium extend inward from the epimysium and segmant the muscle cells into groups termed fasciculi or fascicles.
Myofiber vs. myofibril
Myofiber (muscle cells are also called myofibers (muscle fibers). Myofibrils are specialized organells containing contractile structures within the muscle cell called myofilaments.
What is a myomere?
unit of skeletal muscle from Z line to Z line.
What causes the A band?
overlap of thick and thin myofilaments.
what causes I bands in myofilaments?
I (isotropic) bands do not polarize visible light, therefore they appear lighter.
what causes H bands in myomere?
The lighter central region of each A band consists of thick filaments only, therefore being a little lighter.
What is the M line in a myomere?
The slightly lighter line in the middle of an A band.
What is a Z line in a myomere?
the center of each I band is crossed by a similar dark band called the Z line.
What ultrastructural feature gets shorter during contraction
When nervous impulses cause electrochemical change in actin an myosin which makes them electrostaticly attractive to each other and they slide together (Myofilaments: thick (myosin) thin (primarily actin.)
What is the action of a skeletal muscle?
Potential movement generated by the contraction of which that muscle “envokes”.
What are 3 things that can happen when a muscle contracts?
- no movement, 2 the movement described by it’s stated action, 3 the opposite movement from its stated action.
Define agonist
Any muscle that is contracting.
Define synergist
Muscles which have the same action.
Define antagonist
Muscles who have opposing actions
Define Fixators
Antagonistic to one or more actions of multi-actioned muscles.
Why can single actioned muscles be fixators, but can not have fixators?
It’s inherent in the definition of a fixator. In order to have fixation from another muscle, that muscle must be a multi actioned muscle.
What can cause body movement besides muscle contraction?
Gravity, elastic recoil of some body components.
Define motor unit
A single motor neuron and group of myofibers that is under controll of the nervous system.
Helpful hint.
Glean as much information as possible from the name of any skeletal muscle.
How many skeletal muscles in the body?
230
How many major groups of skeletal muscles?
7
What are the seven groups of skeletal muscles?
muscles of the head, neck, back, thorax, abdomen, superior limb, and inferior limb.
How many groupings of the muscles of the head?
6
Name the devisions of muscles in the head.
muscles of the face, eye, ear, tongue,mastication, and those of the palate and gullet.
Name the groups of muscles in the neck (6 groups)
Suboccipital, suprahyoid, infrahyoid, pharyngeal, and laryngeal muscles. Plus one un named group that includes 3 scalenus muscles, the longus capitis, and longus collie, the platysma, and the sternocleidomastoideus muscles.
What re hypaxial muscles?
Those anterior to the transverse processes of the vertebrae are called hypaxial muscles.
What are epaxial muscles?
The muscles of the posterior trunk which are positioned behind the transverse processes of the vertebrae are often termed epaxial muscles.
What are the 6 muscles groups of the superior limb?
muscles of the, (1) shoulder and scapula (2) anterior brachium; (3) posterior brachium; (4) anterior ante brachium; (5) posterior ante brachium; and (6) manus.
What is the motion of the muscles of the shoulder and scapula?
Move humerus relative to the scapula causing flexion, extension, adduction, abduction, and rotation at the shoulder joint.
Name the 9 muscle groups of the inferior limb.
- anterior muscles of the hip 2. posterior muscles of the hip; 3. medial muscles of the hip; 4. anterior muscles of the thigh; 5. medial muscles of the thigh; 6. posterior muscles of the thigh; 7. anterolateral muscles of the crus; 8. posterior muscles of the crus; and 9. intrinsic muscles of the pes
