animal structure and function 2 Flashcards
nerve cells
neurons
Name the three major types of neurons, and describe their function.
- sensory neurons - carry messages to the brain and spinal cord from nerve endings
- motor neurons - carry messages away from the brain and spinal cord to the muscles and glands
- interneurons - found in the brain and spinal cord connecting sensory and motor neurons
a change in the internal or external environment that causes a response
stimulus
a reaction to a stimulus
a response
nerve endings that detect stimuli
receptors
muscles and glands that react to motor neurons
effectors
What two systems does the body usually use to respond to stimuli?
- skeletomuscular
2. endocrine (hormones)
a nervous system that looks like a spider web with no collection of nerve cells - What kind of animals have this?
nerve net - cnidarians
a nervous system that looks like a ladder - What kind of animals have this?
nerve cord - flatworms
small clumps of nerve cells that control specific regions of the body
ganglia
ganglia in the head
cerebral ganglia
a larger collection of nerves that allows for complex behaviors including learning
brain
Name the three major parts of a chordate brain
- cerebrum
- cerebellum
- brain stem
the thinking part of the brain responsible for learning and memory
cerebrum
the balance and coordination part of the brain
cerebellum
the part of the brain the connects to the spinal cord and controls involuntary survival processes like breathing and heart rate
brain stem (medulla oblongata)
the part of the brain for vision
optic lobe
the part of the brain for smell
olfactory bulb
the nerve cord that connects the brain to the rest of the body
spinal cord
What happened to the brain through evolution from fish to amphibians to reptiles and mammals?
larger and more complex
detect light without getting an image
ocelli (eyespots)
an eye made of many lenses, good at detecting motion
compound eye
the ability of an animal to produce an image of their surroundings by sound waves bouncing back to them
echolocation
the concentration of nerves and sensory structures in the heads of organisms
cephalization
a water skeleton, fluid held in a body cavity surrounded by muscle
hydrostatic
an external skeleton
exoskeleton
an internal skeleton
endoskeleton
What is the disadvantage of an exoskeleton?
It can’t grow so it must be molted leaving the animal unprotected
What is the advantage of an endoskeleton?
It grows with the organism and doesn’t need to be molted
What is the advantage of a hydrostatic skeleton?
no structures to build - less energy
Give 2 examples of animals with hydrostatic skeletons.
worms, cnidarians
Give an example of an animal with an exoskeleton
arthropods - insects, spiders, crayfish…
Give an example of animals with an endoskeleton.
echinoderms, fish, amphibians, reptiles, birds, mammals
Of what 2 tough materials can endoskeletons be made? What is the difference in these materials?
- cartilage - flexible
2. bone - hard
Of what two materials are exoskeletons usually composed?
chitin
calcium carbonate
places where bones meet and the skeleton can bend
joints
this fiber-filled material holds bone to bone
ligament
this fiber-filled material holds muscle to bone
tendon
when muscles shorten to cause movement
contraction
Since muscles can only contract, they must exist in pairs called what?
opposable or antagonistic
Give two examples of antagonistic pairs of muscles.
- biceps and triceps
2. quadriceps and hamstrings
To bend a joint and decrease the angle between bones
flexion
the straighten a joint or increase the angle between bones
extension
What must muscles pull on in order to cause movement?
skeleton
reproduction with one parent and one set of DNA
asexual
What is the advantage of asexual reproduction?
speed of reproduction - lots of offspring
reproduction with two parents and two sets of DNA combining
sexual reproduction
What is the advantage of sexual reproduction
diversity - can survive a changing environment
What is the disadvantage of asexual reproduction
much less diversity
What is the disadvantage of sexual reproduction
takes longer and requires finding a mate - risky
when fertilization happens inside the female
internal
What is the advantage of internal fertilization
greater chance of making a baby
when fertilization happens outside the female
external
What is the disadvantage of external fertilization
less chance of making a baby
How do organisms with external fertilization compensate for the lower chance of having a baby?
release a lot more eggs
What happens to many eggs in external fertilization?
many don’t live - are eaten, freeze…
egg laying
oviparous
live birth
viviparous
have eggs that hatch inside the mother and look like live birth
ovoviviparous
a specialized organ that enables the exchange of gases, nutrients, and wastes between mother and baby during development
placenta
What connects the placenta to the baby
umbilical cord
a dramatic change in body form during development
metamorphosis
the two types of metamorphosis
complete and incomplete
the stages of incomplete metamorphosis
egg - nymph - adult
the stages of complete metamorphosis
egg - larva - pupa - adult
How are nymphs and larvae different?
larva - worm-like - goes into pupa - basically eats
nymph - looks like adult but can’t fly or reproduce
the stage at which larvae develop into adults
pupa
an egg with 4 membranes to protect the baby and keep it from drying out
amniotic egg
the sack of water in an egg where the embryo is found
amnion
the food in an amniotic egg
yolk sac
the waste sack in an amniotic egg
allantois
the membrane that surrounds the others and is for gas exchange in an amniotic egg
chorion
egg laying mammals
monotremes
pouched mammals
marsupials
mammals with an organ to nourish the baby inside the mother
placentals
the structures in mammals that produce milk
mammary glands
the three traits that identify mammals
hair, mammary glands, endothermic
the better term for cold-blooded, temperature is controlled outside the body by sitting in the sun or going into the shade
ectotherm
the better term for warm-blooded, temperature is controlled inside the body by shivering and sweating
endotherm
Why do endotherms have to eat more?
Their metabolism has to be high so they can keep themselves warm. Ectotherms use the heat from the sun to keep warm.
What animals are endothermic, and what traits about their bodies enable this?
birds and mammals - have a 4-chambered heart and efficient lungs
a group of cells that produce hormones to control the body
endocrine glands
your body’s ability to recognize its own cells vs. pathogens (germs) is accomplished by what body system?
immune system
