Biology - Muscles and Locomotion Flashcards
how do protozoa/algae move?
beating cilia or flagella
what is the basic structure of cilia/flagella?
11 microtubules - 9 pairs in a circle with 2 in the middle
flagella achieve movement with the…
power stroke
how do amoeba move?
extending the pseudopodia
two layers of muscles in flatworms:
longitudinal and circular
contraction of circular muscles in flatworms leads to:
interstitial fluid flow longitudinally and the animal lengthens
contraction of longitudinal muscles in flatworms leads to:
the animal shortening
annelids have what that helps them move?
hydrostatic skeleton
what group of animals have exoskeletons?
arthropods
what are exoskeletons made of?
chitin that is excreted by the epidermis
two major components of the endoskeleton?
cartilage and bone
cartilage is a type of _________ tissue:
connective
two type of bone:
spongy and compact
what is compact bone?
dense and no holes
structural unit of compact bone:
osteons
which type of bone contacts marrow?
spongy
what does red bone marrow do?
blood cell formation
what does yellow bone marrow do?
inactive and infiltrated by adipose tissue
what is inside of an osteon?
Haversian canal surrounded by concentric circles of bony matrix called lamellae
what are osteoblasts?
synthesize and secrete bone matrix…they become osteocytes when they mature. (Blasts Build Bone)
what are osteoclasts?
involved in bone resorption and breakdown.
two ways that bone can form:
endochondral ossification or intramembranous ossification
how are long bones made?
endochondral ossification when cartilage is replaced by bone
what do ligaments do?
connect bones
what do tendons do?
connect skeletal muscle to bone
what is the origin and insertion?
origin: point where muscle attaches to stationary bone;
insertion: point where muscle attaches to movable bone
3 types of muscles in mammals:
skeletal, smooth and cardiac
is skeletal muscle multinucleated?
YES!
structure of skeletal muscle:
sarcolemma, sarcoplasmic reticulum, sarcomere, myofibrils
where are mitochondria in skeletal muscles?
myofibrils
what is skeletal muscle also known as?
striated muscles (from sarcomeres)
thin filaments in sarcomeres are chains of
actin molecules
thick filaments in sarcomeres are chains of
myosin molecules
what are Z lines?
boundaries of sarcomere
what are M lines?
down the middle of a sarcomere
what is the I band?
region with only thin/actin filaments
what is the H zone?
region with only thick/myosin filaments
what is the A band?
the entire length of the thick filaments and any overlapping portions
what bands/zone/lines are reduced in contraction?
the H zone and I band reduce; the A band does not.
what is released into the sarcoplasm in an action potential?
calcium ions for the T system
what does calcium bind to in muscle contraction?
tropomyosin
what happens when calcium binds to tropomyosin?
actin and myosin slide past each other and the sarcomere contracts
do muscle cells have an all-or-none response?
YES! (stimulus must meet threshold value)
how is the strength of muscle contraction increased?
by recruiting more muscle fibers
three periods of a simple twitch:
latent period, contraction period, relaxation period
what is the latent period?
between stimulation and contraction
what is the relaxation period?
absolute refractory period when the muscle cannot respond to stimulus
what is temporal summation?
when frequent stimulation cause contraction to combine and become stronger/prolonged
what is tetanus?
when the muscle cannot relax due to stimulus frequency
what is tonus?
state of partial muscle contraction
muscles are never…
completely relaxed…they are partially contracted at all times
what nervous system innervates smooth muscles?
autonomic nervous system
what are smooth muscles responsible for?
involuntary movement
how many nuclei are in smooth muscles?
1
are smooth muscles striated?
no
does cardiac muscle have striations?
yes
what nervous system controls cardiac muscle?
autonomic nervous system
how many nuclei are in cardiac muscles?
1 or 2
what is creatine phosphate?
where energy can be temporarily stored
what is myoglobin?
protein in muscle tissues
what does myoglobin do?
maintains high levels of oxygen in muscles
