Kaplan Biology: Chapter 11 Flashcards
I band contains only:
thin filaments
H band contains only:
thick filaments
A band contains:
entire thick filament, with the thin filaments overlapping.
motor neurosn release ___ into neuromuscular junction
Ach
ach binds to receptors on the sarcolemma, causing ___
depolarization
depolarization of the muscle cell membrane causes a muscle ___ ___, which spreads down the sarcolemma to the ___ ____s
causes a muscle AP, which spreads down the sarcolemma to the T TUBULES.
when the AP reaches the sarcoplasmic reticulum, Ca 2+ from voltage gated channels is released into the sarcoplasm. this Ca2+ influx causes:
CALCIUM INDUCED CALCIUM RELEAS from the SARCOPLASMIC RETICULUM for even further Ca2+ release into the sarcolemma.
Ca2+ infux from voltage gated channels and from SR results in calcium binding to ____. What happens next?
binds to troponin. Moves TROPOMYOSIN, exposing the myosin binding sites on the actin filaments.
- myosin then hydrolyzes ATP and BINDS to exposed site on actin.
- causes a powerstroke, then ADP and Pi dissociate from myosin.
- new ATP binds to myosin, causing DETACHMENT of myosin from actin.
hydrolysis of ATP to ADP causes ___ of the myosin head
recocking
when ADP is bound to myosin:
myosin head binds to actin
when ATP is bound to myosin:
myosin dissociates from actin.
what happens to myosin with no atp
without ATP, myosin stays bound to actin. results in rigormortis.
components of the axial skeleton
skull, vertebra, ribcage and hyoid bone
componens of the appendicular skeleton
limb bones, pelvis, pectoral girdle.
long bones are part of which “skeleton”? (axial or appendicular)
appendicular. includes all bones besides skull, vertebra, ribcage, pectoral girdle.
bones are made from embryonic ___
mesoderm.
long bones have a longer portion(____), with nubs on either side (____ and then terminates at ___)
long bones have a longer portion(DIAPHYSES, with nubs on either side (METAPHYSES and then terminates at EPIPHYSES)
___ and ___ are full of bone marrow
diaphyses and metaphyses
entire bones is coated in a ___ connective tissue
periosteum
functional unit of bone
osteon
and osteon is aka:
haversian systems
each osteon looks like a cross sectional tree trunk, with each circle being called
lamellae (rings)
where are osteocytes (bone cells) located?
between lamellae (rings) in each osteon (haversian system), within a LACUNAE.
lacunae (houses an osteocyte between lamellae of haversian systems) are interconnected by:
canalculi.
haversian vs volkman canals
haversian canals: channels that connect other osteons together LONGITUDINALLY
volkman canals: channels that connect other osteons together TRANSVERSELY.
how are haversian and volkman canals interconnected?
via canalculi.
role of parathyroid hormone
causes bone RESORPTION. Releases more Ca2+ into the blood.
role of vit D
promotes bone resorption.
role of calcitonin
causes bone GROWTH. released by thyroid in response to too much Ca2+ in blood.
most bones are formed via ___ ossification. What is this?
endochondral ossification: cartilage turning into bone –> occurs in the long bones.
how do skull bones form, in comparison to long bones, whcih form via endochondral ossification?
skull bones form via intramembranous ossification via embryonic tissue (mesenchyme)
a ____ capsule encloses the joint and joint cavity
SYNOVIAL CAPSULE
____ cartilage prevents two bones from rubbing against each other.
articular cartilage.
what is in between the articular cartilage pieces that “cup” each end of the bone and prevent rubbing?
synovial fluid.
____ in the synovial capsule (encloses the joint and joint cavity) secretes synovial fluid
synovium
adductor muscles moves a part of the body ____ the midline
TOWARDS the midline
abductor muscle moves a part of the body ____ from the midline
AWAY from the midline
(BADT) –> aB-Away, aD-Towards.
