Bird Respiration, Circulatory System, & Metabolism

6-12

6-12

Between how many numbers of air sacs does a bird have?

9

What is the most common number of air sacs?

interclavicular

There are 2 types of all air sacs except _________.

Cervical Interclavicular Anterior thoracic Posterior thoracic Abdominal

5 locations of air sacs

long bones & skeletal

Air sacs integrate into some of the birds ____ _____ & _______ system.

pneumatic

Air sacs extend into ___________ bones.

Differential pressure

_________ _______ causes air mvt in the lungs.

Cervical air sac

Which air sac is the main airway?

Abdominal air sac

Which air sac is the final air sac?

inflate

The lung is stiff and does not ______.

bronchi

Secondary ____ branch off primary _____ and tertiary branch off of secondary _____.

gas exchange

What occurs in the bronchi?

spaces

Blood capillaries in parabronchi are interspersed with air _____.

two-breath

What kind of cycle do birds use to breathe?

No

Is there gas exchange on the first breath of the bird's two-breath cycle?

first inhalation

During which part of the two-breath cycle does air move down the trachea & mesobronchus into the posterior thoracic and abdominal air sacs?

first expiration

During which part of the two-breath cycle does air move into the dorsobronchi, ventrobronchi and parabronchi of the lungs for gas exchange?

second inhalation

During which part of the two-breath cycle does air move into the anterior air sacs (cervical, thoracic, and interclavicular)?se

second expiration

During which part of the two-breath cycle does air move from the anterior air sacs our through the trachea and nares and mouth?

thoracic cavity

During the first expiration, the bird contracts its _______ _____ which forces air from the air sacs into the lung for gas exchange.

2

Birds always have _ breaths going through their respiratory cycle at once.

sternum

Which bone raises and lowers to create a vacuum to pull air in and push air out of the bird?

furcula, contract, expand

The ______ bone also aids in respiration by causing the interclavicular air sacs to ____ on the upstroke and ______ on the downstroke.

-one way flow of oxygenated air

• higher tracheal volume

• fast ventilation rate

• cross-current gas exchange

What 4 things make birds' respiratory systems more efficient than humans?

small

The fact that birds use one way flow of oxygen and are able to replace all of their air means that their lungs can be ______.

air sacs & lungs

The tracheal volume of birds is much higher than in mammals because it is integrated into the ____ ____ & _____.

parabronchi

Cross-current gas exchange occurs in the _________.

blood

Cross current gas exchange means that air goes in the opposite direction of ______.

Blood

Cross-current exchange starts with all the oxygen in the airflow and ends with all the oxygen in the _____.

opposite

Air and blood flow in _______ directions during cross-current exchange.

regular

Mammals use _____ current exchange.

dinosaurs

Some _____ had similar respiratory systems to birds with air sacs and pneumatic bones.

4

How many chambers are there in a bird's heart?

pulmonary (lung) & systemic (body)

Birds have a 4-chambered heart to separate which two types of circulation?

larger

Birds have a larger/smaller heart than mammals.

more, slower

Every bird heart beat pumps more/less blood than mammals but beats slower/faster.

Hemoglobin

___________ in birds has ahigher affinity for O2 which means that they are effective at grabbing it and moving it through the body.

thinner, more

Bird muscle fibers are thinner/thicker and have more/less than mammals.

more

Birds have more/less mitochondria.

more

Birds have more/less RBCs per unit volume blood.

Diving birds

What type of birds have reduced oxygen flow (except to their heart and nervous system), slower heart rates, reduced oxygen consumption, and anaerobic metabolism in their muscles during a certain reflex?

higher

Birds have an average higher/lower body temperature than mammals.

protein

As body temperature increases, more _______ breaks down, and more must be replaced.

• not limited by ambient temp

• can exploit more habitats

• active when/where it's cold

3 advantages to being warm-blooded

• intrinsic

• nerve

• muscle

• diffusion

• rates

Pros of 40 C body temp

• high body temp enhances __________ reflexes

• higher speed of transmission of _____ impulses

• increased speed & endurance of _______ contraction

• increased ______ of molecules across membranes

• increased rates of ______ reactions

• expensive

• lethal overheating

Cons of 40 C body temp

• energetically _________

• risk of _____ ________b

basal metabolism

allometric relationship of metabolic rate (M) to body weight (W)

M = aW^b

basal metabolism equation

increases

On a log scale, log metabolic rate increases/decreases as log weight increases.

less

A large bird uses relatively more/less energy per unit body weight than small birds.

flight

_____ metabolism is much more expensive than daily energy expenditure.

mammals

Metabolic rate increases with weight for _____ too.

absolutely, relatively

Larger bird species require _______ more energy, but ______ less energy.

smaller

Larger birds have a smaller/larger surface area to volume ratio.

bigger

The SA/V ratio gets bigger/smaller as the bird gets smaller.

• slower

• slower

• less

• excess heat

Consequences of a low SA:V ratio in larger birds

• slower/faster metabolism

• lose heat slower/faster

• require relatively ____ energy

• difficulty getting rid of _____ ____

• higher

• faster

• more

• staying warm

Consequences of high SA:V ratios in smaller birds

• higher/lower metabolism

• lose heat slower/faster

• require relatively more/less energy

• difficulty ______ ______

seasonally

Energy expenditure varies _______.

aerobic scope

ratio of active to resting metabolism

• heat

• source

• problem

Temperature regulation

• ____ is a byproduct of metabolism

• metabolism is an important ______ of heat when ambient temperature is low

• metabolism can be a _____ when ambient temperature is high

metabolic rate

Birds must increase their _____ _____ to lose or gain heat at the upper and lower critical temperatures.

physical, physiological, behavioral

3 types of adaptations for dealing with heat loss and production

larger

Animals tend to get ______ as you go farther North because that gives relatively less SA.

Bergman's rule

rule that says animals tend to get larger as you go farther North

piloerection

behavioral adaptation for temperature regulation in which birds puff up their feathers

behaviorally, physically

Dark pigmentation can be used to regulate temperature ________ by exposing apteria to the sun and _______ with dark pigmentation of dorsal apteria.

shivering

A physiological adaptation to lower critical temperature is _______.

hypothermia

A physiological adaptation to lower the differential between inside and outside temperature is _________.

torpor

pronounced hypothermia that reduces O2 consumption by 50%

shunting, countercurrent

Heat loss in extremities is handled by _____ blood away from the feet and warming it via _________ as it goes into the body.

urohidrosis

method of evaporative cooling in which a bird excretes/pees onto their legs

panting, gular fluttering, urohidrosis

3 methods of evaporative cooling

controlled

___________ hypothermia can also be used in high temeperatures to increase body heat and reduce the differential with the outside

large

solutions for heat gain are more relevant to small/large birds

large bill

A physical adaptaion for solving heat gain is to have a _____ ____.

decreases, SA:V

The amount of water loss that a bird experiences increases/decreases with a larger body size, and has to do with the _: ratio.

metabolically, diet, drinking, water conservation

4 ways to deal with water loss

metabolic

this method of deal with water loss involves the oxidation of organic compounds to produce water

fat

Which generates the most water when oxidated: fat, carbs, or protein?

large

large/small birds produce less metabolic water, but it is almost all the water they need

small

large/small birds only compensate ~5% of water loss via metabolic water

seed-eaters

_- get the least amount of water from their diet

diet

Water needs of many species are met fully by ____ alone.

nitrogenous

Metabolic activity produces _____________ wastes.

uric acid

• semisolid

• concentrated

• bladder

the substance that birds excrete

• ________ suspension

• very _________, up to 3000x what is in the blood

• no ________

above

Bird kidneys cannot concentrate salt or electrolytes above/below

salt excreting glands

What kind of glands solve the issue that the kidneys cannot concentrate salt or electrolytes above blood level?

Concentrating nitrogenous wastes

What are avian kidneys great at?

counter-current

Salt excreting glands use what kind of system?

seabirds

Salt excreting glands are especially important in what kind of birds?

W= weight of a bird M=metabolic rate b=slope of the relationship

What do W, M, & b represent in the M=aW^b equation?

mesobronchus (primary bronchus) posterior thoracic air sacs abdominal air sacs

where air flows on the 1st inhalation (3)

parabronchi only

where air flows on the first exhalation

anterior thoracic air sacs interclavicular & cervical air sacs

where air flows on the second inhalation (3)

mesobronchus (primary bronchus)

where air flows on the second exhalation

secondary bronchi & parabronchi

where gas exchange occurs