lab 1: comparative anatomy - lower invertebrates

what is an invertabrate

an animal without a backbone

what is a simple digestive system

digestion and absorption occur in one cavity

what is a complex digestive system

specialized regions for digestion and absorption, combined with circulatory system

crop

store food

gizzard

muscular structure that grinds food

dentition

arrangement of teeth that aids in digestion and can be specialized

ruminants

store cud and house cellulase

respiratory system function

to intake oxygen and release carbon dioxide; temp regulation, vocalizations, and metabolic waste removal

tracheae

how insects breathe; valvular spiracular control (least efficient)

gills

how fish breathe; counter current arrangement that maximizes oxygen extraction from water (most efficient)

lungs and air sacs

how birds breathe; cross-current system (not as efficient as fish but better than tidal breathing)

circulatory system function

to carry nutrients, gasses, hormones, wastes throughout the body and to excreted

open circulatory system

the blood bathes the organs, no massive system of blood cells

closed circulatory system

closed vessels (arteries, etc.) where blood is pumped through

reproductive system function

to pass on genetic materials

external reproduction

spawning - mutual release of gametes - like fish

internal reproduction

fewer gametes produces | egg laying (oviparous), viviparous (live birth)

spermatogenesis

production of sperm

testis

inside male body or outside and produces spermatozoa (male gamete) and androgen (sex steroid hormone)

intromittent organ

male organ used to deliver sperm to females during copulation

ovaries

female organ used to produce ovas (eggs) and progestins and estrogen (sex steroid hormones)

seminal vesicle

sacs that produce seminal fluid and sperm

Typhlosole

structure that extends into the lumen of the intestine to increase surface area to absorb more nutrients