Vertebrates I: Fetal Pig Dissection - Pulmonary and Digestive Systems Flashcards
Animals with true backbones are grouped into what suphylum and phylum? What are the other subphylla
They are grouped into the subphylum Vertebrata which is part of the phylum Chordata (animals with an internal skeletal support system)
The other two divisions within the phylum consist of invertebrate animals: Urochordates and cephalochordates
What are the four common features of chordates at some stage in their development?
1) presence of a notochord
2) a dorsal hollow nerve chord
3) paired pharyngeal gill slits
4) postanal tail
Difference between chordates and invertebrates with regard to their skeleton
chordates have a living endoskeleton which grows with the animal aand therefore allows for continous growth
invertebrates must shed or molt their exoskeleton in order to increase in size.
What is the form of an endoskeleton? (Chordates, which do include invertebrate animals)
Endoskeletons take the form of a dorsally (towards the back) located flexible rod called a notochord in the invertebrate and primitive vertebrate members of the phylum chordates
In higher chordates, what replaces the notochord?
Instead of a notochord, there is a vertebral column and only remnants of the notochord persist in the adult form
For instance, the gelatinous material in the intervertebral discs in mammals is from the notochord.
Components of the skeletal support system (found in higher chordates)
consists of axial components
cranium, vertebral column, ribs and sternum, and an appendicular component composed of the pectoral and pelvic girdles and the associated skeletal components of the appendages
Nerve chord (chordates vs invertebrates)
All chordates have a dorsal hollow nerve chord. This nerve chord develops into the central nervous system consisting of brain and spinal column
invertebrates have a solid nerve chord located in the ventral portion (towards the belly)
What is the pharynx? Examples of the traces of pharyngeal gill slits in chordates
The pharynx with respect to a worm is the anterior most portion of the digestive tract. Like the very end of the digestive tract that is not the anus.
Fish - have gills that allow water to enter the mouth and exit through these same slits
Some invertebrate chordates: slits serve as filter feeding devices
Terrestrial chordates - lungs in the pharyngeal region
What order do pigs belong in? What about humans
pigs and humans are in the class of vertebrates called mammalia
pigs belong to the order artiodactyla (even-toed hoofed animals)
humans belong to the order primates
Shared characteristics of mammals (6)
1) Endo thermal regulation (ability to maintain a warm internal body temperature through heat from metabolic processes, aided by)
a) body covered with a layer of fat and hair
b) skin (integument) with sebaceous (fat- or oil-secreting) and mammary glands. Some mammals have sweat glands too, others dont.
2) movable eyelids and fleshy external ears
3) Respiratory and circulatory system with a four-chambered heart and circulating erythrocytes (red blood cells) with no nucleus
4) diaphragm (muscular partition) that separates the thoracic and abdominal cavities
5) Intrauterine embryonic development. Egg that develops in the ovaries are internally fertilized and nourished by placental membranes that they are attached to
6) nourishment of newborns with milk from mammary glands.
3 major regions of a mammal’s body
1) head and neck
2) trunk
3) tail
nares (what does this term mean?)
nostril
snout (what does this term mean?)
nose
What are papillae? What is the function of papillae?
Papillae are small bumps on the tongue’s marginal surface
Papillae are used for tasting (they contain taste buds), but also held with intaking food into the mouth
When do pigs start ingesting solid foods as compared to humans?
pigs begin soon after birth
human babies need 6 months
eye location of vegetarian species vs eye location of carnivores
vegetarian - eyes at side of head bc it allows them to spot predators better
carnivores - towards the front so that they can see prey better
What will you see when you pry open the eyes of the fetal pig?
nictitating membrane, which is a translucent covering that keeps the eyeball clean by sweeping across its surface. Also keeps eyeball moist
What is the auricle? compare and contrast auricle movement between humans and pigs
flesh covered cartilaginous structure that is the most obvious part of the ears
pigs can move their auricles towards sounds but this ability is mostly lost in humans
what are the different kinds of locomotion that mammal limbs can do
walking, running, climbing, flying, swimming
How many digits do pigs have? which digits bear the most weight
pigs have 4
the third and fourth digits are central to the foot, are the largest, and thus bear the most weight
ribcage (how many attached and how many are floating)
the first seven pairs of ribs are joined to the sternum (breastbone)
the other remaining five connect to the sternum indirectly or are not connected at all and float
What is the function of the umbilical cord
attaches developing embryo to the placenta
how does the umbilical chord 1) circulate blood 2) remove waste
1) arteries and veins carry blood to and from the fetus
2) allantoic stalk removes the waste
what are mammary papillae? How are they organized on the pig? What is their function
mammary papillae are outlets from the mammary glands that secrete milk for the young (NIPPPLES)
to each side of the umbilical chord are two rows of nipples, 5 to 7 in each
occur on both male and female pigs
