5.4 repspirtory system

Respirtory system

• cellular respiration requires oxygen to produce ATP and gives off carbone dioxids

• Animal size → complexity

• size increases=decrease surface area to volume ratio 

Three similarities

• large surface area

• contact with air or water

• moist

Direct diffusion

• no specialized structures

• cells close contact with external environment

• Cnidarians and flatworms'

• limits body size/ thickness of tissues

• requires moist membranes

Cutaneous Respiration

• skin breathing

• network of capillaries (blood vessels) under the skin

• moist environments

• annelids, amphibians, some mollusks, some fish

Tracheal Systems

• most efficient

• spiracles→ tracheae tubes → diffuses into tissues

• does not breathe through mouth, no lungs

• independent of circulatory system

• limits body size

Gills

• aquatic environments

• thin highly folded tissue that all diffusion of dissolved oxygen

• counterconcurrent exchange: blood flows against current of water

• fish amphibians, some mollusks

Lungs

• Some fish

• Terrestrial animals: lungs

• covered in mucus

• air picks up water from mucus→ humidified

• Cilia, hairs and mucus remove particulate matter

Advantages of Lungs

• internal= stays moist regardless of environment

• large surface area= more oxygen

Amphibians gas exchange

• gills: larvae

• Skin: cutaneous respiration

• Lungs: buccal pumping due to no ribs or diaphragm- pushes out stale are, intakes fresh air

Reptiles gas exchange

• lack diaphragm, but have ribs

• Snakes: right lung, underdeveloped left lung, rib muscle create negative pressure

• Turtles: ribs form shell, muscle at the back create negative pressure - cloacal respiration allows hibernation

• Crocodiles: diaphragm like muscle, alveoli with greater surface area

Carrier’s Constraint

• sideways movement when running'

• compresses one lung

• runs out of oxygen so use gular pumping or stop to breathe

Avian gas exchange

• need more oxygen due to flight

• lungs and air sacks, no diaphragm

• Trachea → posterior air sacs→ lungs→ anterior air sacs

• air sacks inflate, not the lungs

Gas exchange Avian steps

• undirectional air flow: two cycles of inhalation and exhalations

• 1. inhalation 1: air move through trachea to posterior air sacs

• 2. exhalation1: fresh air from posterior air sacs move across lungs

• 3. Inhalation2: stale air is moved into anterior air sacs

• 4. exhalation 2: stale air is expelled from body

Human Lung Structure

• nasal cavity: moistens and warms air

• Pharynx→ larynx→trachea

• lungs→bronchi→bronchioles→alveoli

Lung Function- human

lung inflation

• intercostal muscles contract→ expands rib cage→ diaphragm contracts→ increases volume of thorax and lungs→ negative pressure→ draws air into lungs

• Go back to this card to finish

Porifera circulatory system

• circulate water using  incurrent pores and one excurrent pore, lack tissue =lack system

Cniardia

finish card

Open Circulatory system

• arthropods and most mollusk

• hemolymph pumped by heart through vessels to hemocoel → bathes tissues with nutrients → diffuses back into vessels

• low pressure= low energy cost

Close circulatory system

• blood pumped by heart through body

• higher pressure= more energy

• vertebrates, annelids, cephalopods

vertebrate curculatory system- fish

• 2 chambered heart

• single circuit blood flow

• gills→body (systemic circulation, oxygenated blood)

• body→heart (deoxygenated blood)

• heart→ gills (gas exchange, gill circulation)

Vertebrate circulatory system- amphibians

• double circulation

• 3 chambered heart

• Lungs → heart (pulmonary circulation)

• heart→ body (systemic circulation)

• Left atrium: recieve o2 rich blood

• Right atrium: recieves 02 low blood

• ventricle: pumps o2 rich blood to body, o2 low to lungs

Vertebrate circulatory system- reptiles

• similar to amphibians except partial septum in ventricle

• Crocodiles: first animals with 4 chambered heart= convergent evolution

Vertebrate circulatory system: mammals and birds

• double circulation, 4 chambered heart

• O2 blood →

• finish note card