animal responses Flashcards
animals respond to changes in…
temperature
day length
food
stress
what is the function of the central nervous system
coordination centre
processes information
what are the two branches of the peripheral nervous system
motor and sensory
what is in the motor branch of the PNS. describe their roles
somatic
conscious (voluntary)
i
compare the structure of skeletal and cardiac muscle
skeletal
regular arrangement
striated
cells are multinucleated
cardiac
branched
striated
cells are mononucleated
contains intercolated discs
describe the function of a regular arrangement structure of muscle
give an example of the muscle with this arrangement
allows the muscle to pull in one direction
skeletal
describe the function of a branched structure of a muscle
give an example of a muscle with this arrangement
contracts in many directions
cardiac
describe the function of intercolated discs
what type of muscle areintercolated discs found
allows electrical impulse to be transcribed between cells
cardiac
what are the different muscles specialised for
skeletal - movement
cardiac - heart
smooth - involuntary for internal organs
how is longer cells an adaptation for muscle cells
makes muscles stronger
junction between adjacent cells act as a point of weakness
how is the electrical impulse spread throughout the sarcoplasm
parts of sarcolemma fold inwards forming T tubules
how does the sarcoplasmic reticulum adapted for muscle contraction
extends throughout the fibre
contains calcium ions required for contraction
describe a myofibril
long cylindrical organelles made of proteins and specialised for contraction
describe the arrangement of myofibrils and explain why it is adapted this way
parallel
provides maximum force when all contract
myofibrils are made up of two protein filaments
name them and describe them
actin - thin
consists of 2 strands twisted together
myosin - thick
consists of rod-shaped fibres with bulbous heads that project to one side
