Chapter 17.2- Avian Anatomy and Physiology Flashcards
one of the most obvious features of a bird that allows it to fly
a characteristic unique to birds
feathers
strong feather found on the bird’s body, wings and tail
provide for the streamlined shape by all pointing to tail
used in flight
contour feathers
special contour feathers on the wings are known as
flight feathers
soft, fluffy feathers close to the bird’s body that provide excellent insulation without adding much weight
down feathers
the breast muscles weigh as much as ______ of its bodyweight
33%
the stiff hollow quill of a feather
rachis
flat area of the feather that pushes against the air
vane
come out of the rachis
connect to form the vane
barbs
hold together the several hundred barbs in each vane
barbules
the feather’s design automatically changes its shape during flight in response to _________________ from the air
different pressures
a special aileron consisting of three feathers
on the leading edge of a bird’s wing
alula
serves as both rudder and elevator
tail
embedded in the skin near the quill of each _____________ are nerve endings which convert the feathers into sensory receptors
flight feathers
four main kinds of flight
powered flying
soaring
gliding
special flight patterns
the larger the bird the _______________ it flaps its wings
slower
kind of flight which travels the longest distance possible horizontally with the smallest possible loss of height
gliding
flying in great circles, gradually attaining great height, then diving swiftly downward to start another spiral
soaring
many avian bones are ______________ and filled with ____________
hollow
air
a retractable group of feathers on the front of the wing
alula
the most important flight muscles in a bird are the
pectoralis major (pull the wing down for the power stroke)
the wing is raised after each power stroke by the
connect the sternum to the top of each wing similar to rope and pulley
pectoralis minor
the seat of the bird’s intelligence
cerebrum
relatively thin and contains no convolutions like those of man and mammals
cerebral cortex
responsible for muscle coordination
cerebellum
birds have poor senses of ___________ and ______________, but their sense of ____________ is very good
smell;taste
hearing
the bird far surpasses the human in the ability to distinguish differences in _____________ and respond to the rapid fluctuations in _________________
intensity
pitch
birds have a third eyelid called the
transparent membrane that allows the bird to “blink” and moisten its cornea without obstructing its vision
nictitating membrane
most birds have tremendous
color vision
striking patterns on the flowers visible only in the ultraviolet part of the spectrum
nectar guides
birds must rapidly ____________ whatever they eat
digest
can digest and excrete berries in 30 min
thrush
special sac in the esophagus which serves as a storage chamber and releases food to the rest of the digestive system at the proper rate
crop
the ____________- of birds consists of two primary chambers
stomach
the second chamber of the bird’s stomach near the rear that is very muscular and is lined with horny plates that act like millstones to grind the food
serves the same purpose as molars
gizzard
crushed food from the gizzard is emptied into the ______________
where digestion continues an nutrients are absorbed
intestine
within the short intestine, digestion and absorption are completed and the remaining waste is readied for elimination in the
cloaca
a special organ in young birds which lies close to the wall of the cloaca
at this site, the lymphocytes that aid in the immune system are produced
bursa of Fabricius
birds display a unique ability to concentrate the ___________- that is collected by the kidneys
urine
marine birds have been equipped with a special excretory gland which is located above each eye
allows marine birds to obtain much needed body water by simply drinking seawater and excreting the excess salt
salt gland
the ______________________ system of birds is completely different than any other living vertebrate
respiratory
when a bird inhales, fresh air passes through the trachea into large _______________ behind the lungs
air sacs
cool the bird’s body systems during the vigorous muscular activity of flight
air sacs
a special design in birds is the voice box or
syrinx
the general pattern of __________________ in birds is not greatly different from that in mammals
circulation
the principle that we learned in mammals about the heartbeat being proportional to body size ______________ for birds
holds
bird blood looks that same as mammalian blood but contains _____________ red cells instead on __________ one
nucleated
nonnucleated
