Muscles Ch 9 Flashcards
The striated appearance of skeletal muscle fibers results from the
Sarcomere organization
The innermost layer of connective tissue and skeletal muscle is the
Endomysium
What are the three types of muscle tissue in the muscular system?
Skeletal, cardiac, smooth
What are the two types of striated muscles?
Skeletal, cardiac
What is a non-striated muscle?
Smooth
What are the connective tissues in and closely surrounding a muscle? (3)
- Epimysium
- Perimysium
- Endomysium
What ion is important for muscle contractions?
Calcium
What does the sarcoplasmic reticulum (SR) do?
Stores calcium
What is myosin?
Thick filaments in muscle fibers. Wants to act with actin to contract muscle. When not acting with actin it relaxes.
What is actin?
Thin filament surrounded by Troponin and tropomyosin
Tropomyosin holds onto what?
Troponin
Membrane bound sacs containing neurotransmitters:
Synaptic vesicles
Space between neuron and muscle fiber, across which neurotransmitter travels:
Synaptic cleft
What is a Neuro transmitter for skeletal muscle?
Acetylcholine
Enzyme for acetylcholine
Acetylcholase
Describe how a muscle contracts
A nerve impulse travels down a neuron to the synaptic cleft. Synaptic vesicles release neurotransmitters to travel through synaptic cleft to get to neural receptors in the muscle. calcium is released by SR. Calcium combines with troponins releasing it from tropomyosin so actin can connect to the myosin head, shortening the sacromeres. 
What stores extra oxygen and muscles?
Myoglobin
Inability to contract muscle
Muscle fatigue
Involuntary muscle contraction
Muscle cramp
Isometric contraction:
Equal length of muscle but change in force. (Ex: pushing a wall or holding a yoga pose)
Isotonic contraction (2)
Equal force, change in length.
1. Concentric contraction: shortening
2. Eccentric contraction: lengthening
Do smooth muscles use Troponin or calmodulin?
Calmodulin
What two neurotransmitters affect smooth muscle?
Acetylcholine and Norepinephrine
Sternocleidomastoid origin, insertion, action, nerve supply:
Origin: sternum, clavicle
Insertion: mastoid of temporal bone
Action: moves neck
Nerve: accessory, C2, C3
Serratus Anterior origin, insertion, action, nerve supply:
Origin: upper ribs
Insertion: medial scapula
Action: protracts and rotates scapula
Nerve: long thoracic nerve
Deltoid origin, insertion, action, nerve supply
Origin: acromion process, spine of scapula, clavicle
Insertion: deltoid tuberosity of humerus
Action: abducts arm, flexes shoulder, extends shoulder
Nerve: axillary nerve
Sartorius origin, insertion, action, nerve supply
Origin: iliac spine
Insertion: medial tibia
Action: flexes knee, hip. Abducts, rotates thigh laterally. Rotates leg medially
Nerve: femoral nerve
Gastrocnemius origin, insertion, action, nerve supply
Origin: lateral and medial condyles of femur
Insertion: posterior calcaneous
Action: plantar flex foot, flex knee
Nerve: tibial
Rectus femoris: origin, insertion, action, nerve supply
Origin: iliac spine, acetabulum
Insertion: patella tendon
Action: extends knee, flex hip
Nerve: femoral nerve
