[UNFINISHED] Lab 11 - Comparative Anatomy and Digestion of Animals

humans cranial =

superior

humans caudal =

inferior

humans posterior =

dorsal

humans anterior =

ventral

Earthworm all levels of classification

Lumbricus terrestris

Phylum Annelida

Class Clitellata

Order Haplotaxida

Family Lumbricidae

Earthworm = ecosystem engineer

can change key properties of soil in which it lives

can have cascading effects on ecosystem functioning and biodiversity

consumes soil + extracts nutrients from dead and decaying organic material

earthworm mouth is covered by

worm’s first segment (prostomium)

clitellum

near anterior end

involved in making gelatinous egg casing during reproduction

ventral surface of earthworm

lighter colored

feel slightly rough due to small, hairlike structures help worm grip soil for locomotion

dorsal surface earthworm

distinguished w dark line running along it

dorsal vessel earthworm

major blood vessel run along dorsal surface

Cuts made into earthworm

forceps lift dorsal skin 1-2cm from anus insert scissors base of forceps

cut line slight off center thru to anus

cut along dorsal surface

keep bottom edge of scissors positioned

upward

as cut, position dissection pins

45 degree angle open and display worm

pharynx

region between mouth and esophagus

earthworms have fully functional M+F sexual organs but

typically reproduce thru cross-fertilization (w another indiv, not themself)

Sperm matures in

larger seminal vesicles

sperm received in

smaller, more spherical seminal receptacles

move reproductive organs aside to view dark, ring like structures of

aortic arches - pump blood throughout body

aortic arches surround

esophagus

septa

membranous structures that separate each segment

Esophagus

tube that transports food from pharynx → crop

Crop

stores food (soil)

Gizzard

muscular, contains rocks

crop and gizzard together

help grind and mechanically digest food

intestine

site of chemical digestion and absorption of nutrients

cells secrete digestive enzymes

anus

where feces is removed

Eastern lubber grasshopper classification

Romalea guttata

Phylum Arthropoda

Class Insecta

Order Orthoptera

Family Romaleidae

type of eater grasshoppers

herbivores

antennae

sensory appendages

3 ocelli

medial to compound eyes

function as motion detectors

thorax

posterior to head

2 sets of wings

fore wings rest atop hind wings

beneath 2 sets of wings

abdomen

Spiracles

holes run along lateral surfaces of abdomen

allow air enter/exit body → can breathe, get oxygen

Each leg of a grasshopper has

femur, tibia, tarsus

Order head going caudal grasshopper

head > esophagus > crop > gizzard (proventriculus) > gastric cecae > stomach (ventriculus) > malpighian tubules > intestine > rectum

Cuts for grasshopper

place on its back

cut along lateral body wall on each side up to its head

small cut near anus to free lower portion of integument

pull large flap of integument up toward grasshopper’s head to reveal

internal anatomy - largely the digestive system

crop of grasshopper

thin-walled and stores food

gizzard of grasshopper

muscular and mechanically digests food

pairs of gastric cecae

dump digestive enzymes into stomach

stomach (ventriculus) and intestine (hind gut)

digest and absorbs food

hind gut also

reabsorbs water

houses microbes needed to digest cellulose (primary component plant cell walls)

Malpighian tubules

secrete nitrogenous waste into hind gut for excretion

good landmark for delineation between stomach and hind gut

grasshopper feces

excreted as moist pellets from rectum thru anus

Yellow Perch classification

Perca flavescens

Phylum Chordata

Class Actinopterygii

Order Perciformes

Family Percidae

perch is bony fish - superclass

Osteichthyes

perch habitat and diet

temperate freshwater ecosystems

eats range: zooplankton, fish eggs, crustaceans, other fish

orientation of perch fins ordering begins

near anterior/cranial end - first dorsal closer to head than second dorsal fin

other perch fins

1st and 2nd dorsal fins

pectoral fins

anal fin

caudal fin

pelvic fin

caudal fin function

thrust required to propel fish

remaining fins not caudal function

steer/stabilize fish

perch lateral line

enables fish detect temperature and pressure change, sense water currents

perch dissection

remove gill operculum using scissors

cut following 1-4

scalpel for incisions - score skin then cut 1cm down

peel away skin

scissors remove muscles in layers

remove ribs w forceps and scissors

perch oral cavity

mouth - where food initially captured

gill rakers

protect gill filaments

filter/capture food particles passing over gills

gill filaments

respiratory gas exchange

stomach

stores and digests food

2 parts of stomach

cardiac - closest to esophagus

pyloric - closest to intestine

pyloric cecae

finger-like projections extending between stomach and intestine

increase SA, nutrient absorption

intestine perch

absorbs nutrients from stomach to anus

slick yellow substance - fat tissue

liver perch

maybe light cream bc bleaching preservative

metabolizes fats and carbs

produces bile emulsify fat + neutralizes acidic chyme (partially digested food) in intestine

urogenital opening

posterior to anus

urine + reproductive fluid secretion