lecture 27 - breathing and respiratory adaptions

amphibians breathe using …

positive pressure

positive pressure

FILLS lungs

called positive because its higher than atmospheric pressure

negative pressure

PULLS air into lungs

called negative because below atmospheric pressure

frogs breathing cycle

1. floor of mouth is lowered, brings air thru nostrils

2. nostrils close, glottis opens, forces air out of lungs

3. glottis closes and mouth opens and shuts multiple times

4. lungs empty by contraction of body wall

mammals breathe with…

negative pressure

inhalation

muscles contract to expand the thoracic cavity

exhalation

muscles controlling thoracic cavity RELAX

ribs and diaphragm help with

exhalation

diaphragm

sheet of muscle that forms bottom wall of thoracic cavity

birds need lots of air during flight so they have…

air sacs

air sacs

in BIRDS

keep air in until it “expires”

ensures lungs come across air at every movement

bird respiration differs from humans by (list)

lack of diaphragm

inhale for them means air LEAVES lungs

air moves in a circular path

new air doesn’t mix with old air

medulla oblongata purpose

helps with the control of breathing (breathing is usually automatic and involuntary)

uses pH signals as an indicator of blood

increase CO2 = decrease of pH

CO2 diffuses from blood to cerebrospinal fluid & reacts with water to form carbonic ACID

acid = reduces pH

medulla says to increase breathing to bring back to normal/make it less acidic

is a negative feedback loop

medulla oblongata uses…

blood pH as a signal to indicate when to increase breathing

increase of CO2 decreases…

pH

acid…

reduces pH

medulla oblongata says…

increase breathing

hyperventilation

person breathes rapidly for extended period

impacts blood pH homeostasis by continuous raising

Dr. can treat with bicarbonate (acidic) to lower blood pH

respiratory pigments

something that transports O2

circulate with blood or hemolymph (open circulatory system)

O2 binds on

contained within special cells = red blood cells

increased capacity of O2 that can be carried

intertebrates respiratory pigments called…

hemocyanin

hemocyanin

BLUE respiratory pigments

copper based that will bind to oxygen

molluscs and arthropods

vertebrates use…

hemoglobin

hemoglobin

circulates with red blood cells (erythrocytes)

uses IRON that will bind to oxygen

oxygen binding component in each 4 sub groups

hemoglobin binds oxygen

REVERSIBLY

can pick up the OXYGEN and then release it too when needed

hemegroups

each one has an iron atom

are cooperative

cliquey - when one does one, the others will follow

one will bind to O2, the others will seek O2

when one unloads O2, others more likely to unload O2

bright red

oxygenated blood

dark red

deoxygenated blood

respiratory adaptations in marine animals

when they dive =

oxygen intake DEcreases

blood supply to muscles restricted or shut off

most blood put to spinal cord & brain / central nervous system

heart rate DEcreases