Vertebrates I: Fetal Pig Dissection - Pulmonary and Digestive Systems

Question 1

Animals with true backbones are grouped into what suphylum and phylum? What are the other subphylla

Answer 1

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

Question 2

What are the four common features of chordates at some stage in their development?

Answer 2

1) presence of a notochord
2) a dorsal hollow nerve chord
3) paired pharyngeal gill slits
4) postanal tail

Question 3

Difference between chordates and invertebrates with regard to their skeleton

Answer 3

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.

Question 4

What is the form of an endoskeleton? (Chordates, which do include invertebrate animals)

Answer 4

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

Question 5

In higher chordates, what replaces the notochord?

Answer 5

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.

Question 6

Components of the skeletal support system (found in higher chordates)

Answer 6

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

Question 7

Nerve chord (chordates vs invertebrates)

Answer 7

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)

Question 8

What is the pharynx? Examples of the traces of pharyngeal gill slits in chordates

Answer 8

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

Question 9

What order do pigs belong in? What about humans

Answer 9

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

Question 10

Shared characteristics of mammals (6)

Answer 10

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.

Question 11

3 major regions of a mammal’s body

Answer 11

1) head and neck
2) trunk
3) tail

Question 12

nares (what does this term mean?)

Answer 12

nostril

Question 13

snout (what does this term mean?)

Answer 13

nose

Question 14

What are papillae? What is the function of papillae?

Answer 14

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

Question 15

When do pigs start ingesting solid foods as compared to humans?

Answer 15

pigs begin soon after birth

human babies need 6 months

Question 16

eye location of vegetarian species vs eye location of carnivores

Answer 16

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

Question 17

What will you see when you pry open the eyes of the fetal pig?

Answer 17

nictitating membrane, which is a translucent covering that keeps the eyeball clean by sweeping across its surface. Also keeps eyeball moist

Question 18

What is the auricle? compare and contrast auricle movement between humans and pigs

Answer 18

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

Question 19

what are the different kinds of locomotion that mammal limbs can do

Answer 19

walking, running, climbing, flying, swimming

Question 20

How many digits do pigs have? which digits bear the most weight

Answer 20

pigs have 4

the third and fourth digits are central to the foot, are the largest, and thus bear the most weight

Question 21

ribcage (how many attached and how many are floating)

Answer 21

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

Question 22

What is the function of the umbilical cord

Answer 22

attaches developing embryo to the placenta

Question 23

how does the umbilical chord 1) circulate blood 2) remove waste

Answer 23

1) arteries and veins carry blood to and from the fetus

2) allantoic stalk removes the waste

Question 24

what are mammary papillae? How are they organized on the pig? What is their function

Answer 24

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

Question 25

gestation period of a pig? how many per litter?

Answer 25

4 montths

5 to 13 offspring per litter

Question 26

male vs female genitals

Answer 26

female - will have an opening ventral to the anus

male - no opening ventral to anus. Will have two large folds of skin, the scrotal sacs (containing the testes) and the penis that leads to the external urogenital opening (preputial orifice) found posterior to the umbilical cord

Question 27

What is the thoracic cavity lines with?

Answer 27

Lined with epithelial tissue, sheet of tightly packed cells

Question 28

What is the epithelium that lines a body cavity called?

Answer 28

parietal

Question 29

what is the epithelium that lines organs called?

Answer 29

visceral

Question 30

What is between the visceral and parietal pleura?

Answer 30

The pleural cavity, which is filled with friction reducing liquids.

This allows the membranes to slide past each other during breathing

Question 31

What is inflammation of the pleural membranes called

Answer 31

pleurisy

Question 32

what is the pericardial sac?

Answer 32

epithelium that encases the heart

Question 33

What is the structure that lies atop the anterior portion of the heart that lies outside of the pericardial sac?

Answer 33

the posterior portion of the thymus

Question 34

What is the function of the thymus?

Answer 34

it is an endocrine gland that is active in establishing the immune system in mammals

Question 35

where is the diaphragm located

Answer 35

posterior most part of the thoracic cavity

the diaphragm separates the thoracic cavity from the abdominal cavity

Question 36

pathway of air into the lungs

Answer 36

1) nares
2) nasal cavity
3) pharynx (region behind mouth)
4) epiglottis (flap that covers the opening to the larynx, called the glottis)
5)larynx
6)trachea
7) bronchi
8) bronchioles
9) alveoli

Question 37

function of the thyroid gland

Answer 37

endocrine gland

secretes iodine containing hormones that stimulate metabolism, development and maturation in vertebrates

Question 38

What is the difference between the pericardium and plurae to the visceral peritoneum

Answer 38

the pericardium and pleurae smoothly cover the heart and lungs

the visceral peritoneum folds around itself, covers the organs and holds them in place

Question 39

what is the function of the liver?

Answer 39

plays an important role in the area of carbohydrate, lipid, and protein metabolism,
2) produces bile a mixture of emulsifying agents that aid in the digestion and absorption of fat, (3) prepares nitrogenous wastes for excretion, (4) detoxifies poisonous substances found in the bloodstream (e.g, alcohol and drugs in humans), and (5) acts as the prime storage site organ for glycogen and for certain vitamins (A, B2, D, E, and K) and minerals (iron and copper).

Question 40

what is the function of the gallbladder? what does it secrete and where?

Answer 40

the gall bladder stores the bile that the liver produces and secretes it to the duodenum through a bile duct when required for digestion

Question 41

what is the function of the spleen?

Answer 41

spleen is a lymphatic organ important in the (destruction of old red the blood cells) and is involved in aspects of the immune system and lymphocyte production.

Question 42

what moves food into the stomach?

Answer 42

peristalsis (muscular contractions)

Question 43

what are the two ways that food in broken down in the stomach?

Answer 43

muscular contraction

gastric juice (hydrochloric acid and pepsin)

Question 44

why is the pH of gastric juice important (what does it do?)

Answer 44

acidity of the gastric juice (-pH 1.5-2.0) kills most organisms ingested), breaks down connective tissue in meats, denatures many proteins, and
is essential for the activation of pepsin (converting the inactive form of the enzyme, pepsinogen, to the active form, pepsin).