ANP EXAM 3 2025-2026 Newest
Myoglobin - Answer-Red pigment; provides some oxygen needed for muscle activity;
transport oxygen
Sarcoplasmic Reticulum (SR) - Answer-- Smooth ER that forms a network around each
myofibril
- Calcium storage
Terminal cisterns - Answer-Dilated end-sacs of SR which cross the muscle fiber from one
side to the other
T tubules - Answer-Tubular infoldings of the sarcolemma which penetrate through the cell
and emerge on the other side
Triad - Answer-- A T tubule and two terminal cisterns associated with it
- Muscle contraction
- Action potential
A band - Answer-- Both actin and myosin
,I band - Answer-- Actin only
H band - Answer-- Myosin only
Skeletal muscle - Answer-- heavily striated
- voluntary
- multiple nuclei per cell
- tree bark/bacon appearance
- muscle fiber as long as 30 cm
Endomysium of skeletal muscle - Answer-- Connective tissue around the muscle cell;
inner/individual muscle cell (fiber)
- Muscle fiber
Perimysium of skeletal muscle - Answer-Connective tissue around muscle fascicle
Epimysium of skeletal muscle - Answer-Connective tissue surrounding entire muscle
Tendon - Answer-Muscle to bone
Ligament - Answer-Bone to bone
Sarcolemma - Answer-- Plasma membrane of a muscle fiber
,- phospholipid bilayer
Sarcoplasm - Answer-Cytoplasm of a muscle fiber
Myofibrils - Answer-Long protein cords occupying most of sarcoplasm
Glycogen - Answer-Carbohydrate stored to provide energy for exercise
Excitability - Answer-Responsiveness to chemical signals, stretch, and electrical changes
across the plasma membrane
Conductivity - Answer-Local electrical excitation sets off a wave of excitation that travels
along the muscle fiber
Contractility - Answer-Shortens when stimulated
Extensibility - Answer-Capable of being stretched between contractions
Elasticity - Answer-Returns to its original rest length after being stretched
Myofilaments - Answer-- Contraction
- Contractile Proteins
- Two proteins that work together to contract
, Thick Filaments - Answer-- Myosin
- Made of several hundred myosin molecules
- Shaped like golf club
- Attached to Actin on head of Myosin
- Bare zone = H band
- Left and Right = A band
Thin Filaments - Answer-- Actin
- Troponin, Active site, and G actin
- Two intertwined strands
Actions of the thin filaments - Answer-- Troponin: Calcium binds and exposes active site and
causes tropomyosin change
- Active site: covered by tropomyosin at rest, site of myosin binding
- G-actin-active site location
Sarcomere - Answer-- Muscle unit (from z-disc to z-disc) = contractile unit
- H band = myosin only
- A band = Actin and myosin
- I band = Actin only; z-disc location
Myoglobin - Answer-Red pigment; provides some oxygen needed for muscle activity;
transport oxygen
Sarcoplasmic Reticulum (SR) - Answer-- Smooth ER that forms a network around each
myofibril
- Calcium storage
Terminal cisterns - Answer-Dilated end-sacs of SR which cross the muscle fiber from one
side to the other
T tubules - Answer-Tubular infoldings of the sarcolemma which penetrate through the cell
and emerge on the other side
Triad - Answer-- A T tubule and two terminal cisterns associated with it
- Muscle contraction
- Action potential
A band - Answer-- Both actin and myosin
,I band - Answer-- Actin only
H band - Answer-- Myosin only
Skeletal muscle - Answer-- heavily striated
- voluntary
- multiple nuclei per cell
- tree bark/bacon appearance
- muscle fiber as long as 30 cm
Endomysium of skeletal muscle - Answer-- Connective tissue around the muscle cell;
inner/individual muscle cell (fiber)
- Muscle fiber
Perimysium of skeletal muscle - Answer-Connective tissue around muscle fascicle
Epimysium of skeletal muscle - Answer-Connective tissue surrounding entire muscle
Tendon - Answer-Muscle to bone
Ligament - Answer-Bone to bone
Sarcolemma - Answer-- Plasma membrane of a muscle fiber
,- phospholipid bilayer
Sarcoplasm - Answer-Cytoplasm of a muscle fiber
Myofibrils - Answer-Long protein cords occupying most of sarcoplasm
Glycogen - Answer-Carbohydrate stored to provide energy for exercise
Excitability - Answer-Responsiveness to chemical signals, stretch, and electrical changes
across the plasma membrane
Conductivity - Answer-Local electrical excitation sets off a wave of excitation that travels
along the muscle fiber
Contractility - Answer-Shortens when stimulated
Extensibility - Answer-Capable of being stretched between contractions
Elasticity - Answer-Returns to its original rest length after being stretched
Myofilaments - Answer-- Contraction
- Contractile Proteins
- Two proteins that work together to contract
, Thick Filaments - Answer-- Myosin
- Made of several hundred myosin molecules
- Shaped like golf club
- Attached to Actin on head of Myosin
- Bare zone = H band
- Left and Right = A band
Thin Filaments - Answer-- Actin
- Troponin, Active site, and G actin
- Two intertwined strands
Actions of the thin filaments - Answer-- Troponin: Calcium binds and exposes active site and
causes tropomyosin change
- Active site: covered by tropomyosin at rest, site of myosin binding
- G-actin-active site location
Sarcomere - Answer-- Muscle unit (from z-disc to z-disc) = contractile unit
- H band = myosin only
- A band = Actin and myosin
- I band = Actin only; z-disc location
