Digestive and Respiratory Systems

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What is the respiratory system and what is the difference between external and internal?

The respiratory system delivers oxygen to tissues and removes waste, mostly CO2

• external: gas exchange between environment + blood

• internal: gas exchange between blood + tissue

What gases make up the atmosphere?

Nitrogen, Oxygen, CO2, water vapor

What are the disadvantages and advantages of the water environment

dis: oxygen dissolved in water is less than the oxygen concentration in the air and heat is more easily lost in water

adv: carbon dioxide dissolves more quickly

Whats with Urochordate and Cephalochordate gills

They are external and their body wall is their respiratory membrane

Whats with most water vertebrate gills

They have internal gills and they have gill lamellae attached to either a gill pouch or arch with a countercurrent blood supply

Whats with bony fish lungs

Have lungs or swim bladder

Whats with tetrapod lungs

all tetrapods have lungs

Whats with lungs

Have a large surface area and surfactant to keep respiratory passages open

inspiration vs expiration

inspiration: act of increasing cavity that holds lungs

expiration: act of elastic recoil of lung tissue

whats with bird lungs

Air sacs that extend into bones to help with flight

Whats with mammal lungs

large nasal cavity, complex larynx, enlarged “respiratory tree”

Whats with digestive system and what are those three things made of

buccal cavity: teeth, tongue, palate

pharynx

alimentary canal: esophagus, stomach, intestines

• variable accessory organs

how do Urochordates, Cephalochordates, and Ammocoete larva feed

filter feeding

How do some fishes feed

either suction feeding or ram feeding

How do most tetrapods feed

ingestion with use of muscular tongue, secrete mucus, saliva, anticoagulants, toxins

• most swallow

• some chew

How do mammalians feed

ingestion, mastication (until suitable size for swallowing, increases secretion surface area), deglutition (swallowing)

how do fishes separate tubes (pharynx)

Large chamber gill rakers prevent food from entering branchial chambers

How do tetrapods separate tubes (pharynx)

Small connection between oral cavity + esophagus, slit-like glottis prevents food from entering branchial chambers

Mucosa

inner most layer of gut tube structure with epithelium, mucus cells, blood vessels, endocrine and immune cells, and smooth muscle

Submucosa

middle layer of gut tube structure and nervous tissue

Muscularis

smooth muscle

Serosa

outer layer of gut tube structure made of strong connective tissue and more epithelium

Esophagus

connection between pharynx and stomach

function for most is food transport

• snakes: crushes eggs

• bird: crop; stores food until digested enough for momma bird to feed babies

stomach

• some primitive animals lack stomachs (Cyclostomes)

• j-shaped with Pyloric Sphincters to retain food until broken down mechanically and chemically

• secrete mucus, hydrochloric acid, pepsinogen and some hormones

what are some adaptations of the stomach

• production of chitinase or renin

• development of gizzard

• accumulation of bacteria

• Ruminants: four chambered stomach

In all but ruminants what does the intestine do

primary site for digestion and absorption

What do liver and pancreas!

liver: secretes bile, filters blood, stores nutrients

pancreas: secretes digestive enzymes, endocrine functions

secrete bile and enzymes into first part of intestines

Caeca

May develop in intestines, contains bacteria that ferments food and produces vitamins

What intestine began amphibian!

large intestine develops to reabsorb water and help with feces development

What is Coprophagy

Some animals eat their own poo