Muscular System Flashcards
Define the epimysium
A muscle that is wrapped in fibrous membrane
What are the subgroups of muscles called
Fassicles
Each fassicle consists of what
Hundreds of muscle fibers
What is a muscle fiber
An individual muscle cell (myocyte)
Each myocyte contains what
“Thread like chains” of myofibrils
What are the alternating regions of the myofibril
Sacromeres
Each sacromere contain what?
Actin and myosin protein
What does myosin do
Pulls actin ends together to create muscle contraction when ATP attaches to myosin heads
What do electrical impulses do?
Initiates muscle contraction
Define neurotransmitter’s
Cross the nerve gap & Bind to receptors on the muscle membrane
Define Acetylcholine
Causes muscle receptors to release calcium ( which triggers production of ATP)
What are the 3 sources of ATP for muscle contraction
- Creatine phosphate
- Glucose from glycogen (aerobic)
- Glucose from glycogen (anaerobic)
Define creatine phosphate
A nitrogen based molecule used to make ATP for muscle cell contraction
Define glucose from glycogen
Glycogen is a long strand of glucose molecules
Glycogen is spilt into glucose molecules
Glucose is metabolized into ATP through aerobic metabolism (presence of oxygen) or anaerobic (lactate fermentation) metabolism (no oxygen)
Define striated muscle
Muscle of skeletal system for voluntary movement
The striations are microscopic visible sacromeres
Define non striated muscle
Aka smooth, visceral
Involuntary muscles of digestive tract and blood vessels
Individual Sarcomeres run parallel to each other
Define cardiac muscle
Aka myocardial
Heart muscle that is involuntary but striated
Define the origin
The muscles proximal attachment
No movement occurs here
Define the insertion point
Muscles distal attachment
Where movement occurs
Define a tendon
Tissue that connects muscle to bone
Define a ligament
Tissue that connects bone to bone
Define the sternocleidomastoid
Located in lateral neck
Allows rotation of the head
Insertion: mastoid portion temporal bone
Origin: clavicle & sternal manubrium
Define the deltoid
Located at the top of the shoulder
Abduction of the arm
Origin: clavicle shaft acromion and acromial extremity
Insertion : proximal, lateral humerus below surgical neck
Define the rotator cuff
Group of 4 muscles surrounding the scapula
Internal and external humeral rotation
Origin: multiple places anterior and posterior scapula
Insertion: humerus greater and lesser tubercles
Define biceps brachii
Located proximal, anterior humerus
Flexion of elbow
Origin: humeral head & scapular coracoid process
Insertion: radial tuberosity and ulnar coronoid process
Define triceps brachii
Located posterior humerus
Extension at elbow
Origin: humeral neck and scapula axillary margin
Insertion: ulnar olecranon process
Define trapezius
Located on posterior surface of upper back
Rolling shoulders back
Pulling shoulders up
Origin: base of skull (EOP), cervical and thoracic spinous processes
Insertion: scapular spine
Define pectoralis major
Located anterior chest wall beneath breast tissue
Medial rotation @shoulder
Adduction/crossing the arms
Origin: sternal extremity , clavicle and sternum
Insertion: proximal, anterior humerus below surgical neck
Define intercostal muscles
Located between ribs
Inhalation during contraction of external layer
Exhalation during contraction of internal layer
Origin: shaft and costal cartilage of rib above
Insertion: shaft and costal cartilage of rib below
Define the diaphragm
Separates that from abdomen
Inhalation during contraction
Exhalation of relaxation
Origin: L1 (crus), XI & Xll
Insertion : base of lungs via central tendon
Define the rectus abdominus
Located anterior abdominal
Flexing and Turning at the waist
Origin: 5th -7th coral cartilage and xiphoid tip
Insertion : pubic bone
Define latissimus Doris
Located lower back
Adduction of arm
Medial rotation @shoulder (internal)
Arm extension
Origin: spinous process, lower thoracic and lumbar and sacral crest
Insertion: proximal, medial humerus below surgical neck
Define psoas major
Located inner abdomen and pelvis
Flexion of hip (raising knee up)
Origin: transverse processes L1-L5
Insertion: lesser trochanter femur
Define gluteus Maximus
Aka buttocks
Largest muscle in the body
Abduction and Adduction of lower thighs
Extension of hip
Lateral rotation of leg
Origin: posterior ilium and lateral sacrum
Insertion: posterior , proximal femur
Define quadriceps femoris ( rectus femoris)
Locate anterior , upper thigh
Strongest muscle in body
Extension of knee
Origin: anterior ilium (AIIS), multiple proximal femur attachments
Insertion: tibia tuberosity
Biceps femoris
1 of 3 muscles that make up the hamstring
Located posterior, medial aspect of upper thigh
Flexion at knee
Origin: ischial tuberosity
Insertion: posterior fibula head
Define gastrocnemius (calf)
Located posterior, lower leg
Plantar Flexion
Origin: posterior femoral condyles
Insertion: calcaneus tuberosity ( via Achilles tendon)
What are prime movers
Aka agonist
Muscles which initiate a movement from the anatomical position
Ex: sternocleidomastoid, biceps brachii, biceps femoris
What are antagonists
Muscles which move opposite of primes movers
Return to anatomical position
Ex : triceps brachii, quadriceps femoris
What are synergists
Muscles which act with prime movers to prevent movement of unwanted body parts
Stabilizing muscles
Staying in contracted state to maintain posture
