Muscular System 1 Flashcards
Describe Skeletal Muscle:
striated/striped muscle
Skeletal Muscle Function:
“Voluntary Movement” of skeletal system, by pulling on bones
Describe Cardiac Muscle:
Specialized striated muscle ONLY in the heart walls
Cardiac Muscle Function:
“Involuntary Movement” of blood through circulatory system
Describe Smooth Muscle:
Non-striated muscle in hollow organs
stomach, arteries, glands, tissues
Smooth Muscle Function:
“Involuntary Movement” of substances in body
The Muscular System allows:
Movement Posture Stability Control of body openings Maintain body temp. Gycemic Control
How does the muscular system regulate body temperature:
Skeletal muscle can produce 85% of body heat
optimal body temp is vital for enzymes
How does the muscular system control Glycemic:
Regulation of blood glucose concentration depends on muscle’s ability to store & use glucuse
Define a Myocyte:
Muscle Fiber/skeletal muscle cell
Appearance of a Myocyte:
Long cylinder cell w/ striations
The components of a Myocyte:
Sarcolemma
Sarcoplasma
Nuclei
Define a Sarcolemma:
Plasma membrane of a myocyte
Define a Saroplasma:
Cytoplasm of a myocyte
How many Nuclei does a Myoctye have:
Multiple Nuclei per cell/myocyte due to tons of embryonic cells fusing together to form each myocyte
Define the Mitochondria:
powerhouse of the cell
converts glucose into ATP
requires oxygen
Describe the Sarcoplasmic Reticulum (SR):
Smooth endoplasmic reticulum that wraps around each myofibril
Stores & releases calcium (ca)
When the Sacroplasmic Reticulum releases Calcium what happens?
The calcium initiates muscle contraction
Describe the Transverse Tubules:
extensions of sarcolemma that run transverse to myocyte
Function of the Transverse Tubules:
Transfer electric signals from sarcolemma to the sacroplasmic reticulum
Tells the sacroplasmic ret. when to release calcium
Describe the Myofibrils:
Cylinders of contractile proteins that make up the sacroplasm
Describe Myofilaments:
Contractile proteins
thick, thin, elastic filaments
Define a Thick Filament:
Made of myosins
Define a Thin Filament:
Each one is made of 2 actins
Define an Actin:
bead-necklace structure
during muscle contraction, actin binds to myosin heads
Define Myosin:
golf-club w/ head & shaft
When a muscle isn’t contracting te binding sites are covered with?
Troponin & Tropomyosin, proteins on surfaces of ACTIN that regulate muscle contraction
When a muscle is relaxed, Tropomyosin?
Covers the binding sited on ACTIN
Blocks myosin head from inserting
When a muscle contracts Troponin?
Troponin acts as a calcium receptor
causes Tropomyosin to uncover binding sites on ACTIN
