Chp 11: Respiratory System

Question 0

Organs of Exchange

Answer 0

Skin
External gills
-advantage: more SA exposed
 disadvantage: more easily damaged + susceptible to bacteria 
Internal gills
-advantage: protected, uses pumping
Lungs

Question 1

Basic anatomy

Answer 1

*diffusion is key
Thin
Large SA
Moist
Exchange at surface -partial pressures
Ventilation (contains O2)
Perfusion (blood)

Question 2

Skin

Answer 2

Cutaneous respiration
Low metabolic rate; low O2 requirement
Amphibians

Question 3

External gills

Answer 3

Larval forms
Few adult salamanders
-retain juvenile structures (neoteny)

Question 4

Internal gills

Answer 4

Most common
Fish
Develop on pharyngeal bars
Unidirectional water flow (more efficient than bidirectional/tidal)

Mouth->gills->out

Question 5

Pouch gills

Answer 5

Internal & external pores

Agnatha

Question 6

Septal gills

Answer 6

Internal & external slits
Large hill chamber
Gas exchange lamella (makes SA) on septa
Sharks (Chondrichthyes)

Question 7

Opercular gills

Answer 7

Bony fish (Osteichthyes)
Gill bars
Lamellae is free-floating
Operculum = bony flap on outside
  -protects delicate gill tissue 
  -used as pump
  -used in communication (territory & mating)

Question 8

Gill structure terminology

Answer 8

Septum 
Filament
Primary lamellae
Secondary lamellae
Afferent artery -away
Efferent arteries (2)
Gill arch or bar
Hemibranch (septum w/ gill tissue on half)
Holobranch (septum covered w/ lamellae all over)

Question 9

Gill surface area

Answer 9

Tiny folding, lamellae on gill filaments
20 lamellae per mm
80-90% of O2 in water is extracted by gills
Very efficient b/c 3% dissolved O2 in water

Question 10

Blood flow in gills

Answer 10

Heart
Ventral aorta
Afferent branchial arteries (5)
Capillaries of gill filament -collector loops
Efferent branchial arteries (4) 
Dorsal aorta

Question 11

Other functions of gills

Answer 11

N excretion as ammonia
Salt & water excretion
Salt & water uptake
Heat exchange

Question 12

Lungs from gas bladders?

Answer 12

Lungs: 
Air filled *
Respiratory
Grow from digestive tract *
Ventral (projection from alimentary canal)
Paired 

Gas/Swim bladder:
Air filled*
Buoyancy 
Grow from digestive tract *
Dorsal
Single

Question 13

If Gas Bladder Ventral…

Answer 13

Expend energy to keep upright (beach ball)
Adapt -like upside down catfish
*counter-shading

Question 14

Swim Bladder mechanics

Answer 14

Reservoir for gases
Adds or releases gases for neutral buoyancy
*special case: lungfish
-seasonal ponds dry up -> switch to air-breathing gas exchange across surface

Question 15

Lungs

Answer 15

Paired
Huge SA
Joins gut tube via trachea
Only respiratory -specialized 
Blood supply from 6th aortic arch (1st up by nose -- 6th closest to heart)

Question 16

Amphibians lungs

Answer 16

1st vocal cords
Short trachea
Small, sac-like lungs, little internal partition
Positive pressure ventilation 
  -force air in & out

Question 17

Reptiles lungs

Answer 17

Lungs larger
Larger SA 
Bronchi enter further caudad
Larynx
Negative pressure ventilation 
 -ribs

Question 18

Mammals lungs

Answer 18

Lungs large
Very large SA 
Trachea, c-shaped cartilage
Negative pressure 
 -diaphragm > fully muscular

Question 19

Respiratory path

Answer 19

1. Nose
2. Nasal cavity
3. Pharynx
4. Glottis
5. Larynx
6. Trachea -bifurcates
7. Primary bronchi
8. Secondary bronchi
9. Tertiary bronchi
10. Bronchioles
11. Respiratory bronchioles
12. Alveoli (gas exchange)
    * tidal flow*

Question 20

Negative pressure ventilation

Answer 20

Diaphragm contracts, lowers, air enters *enlarge thoracic cavity
Diaphragm relaxed, raised, air pushed out
Muscle fibers radial in diaphragm
Only mammals have fully muscular diaphragm
Tidal air flow

Question 21

Diving mammals

Answer 21

Increased pressure, lots of N2 dissolves in blood
Ascend fast, dissolved gas released
Seal case study

Question 22

Birds lungs

Answer 22

Syrinx = larynx (separate or combined)
*Most efficient bc can store air
Lungs & air sacs
One way air flow
Parabronchi = alveoli (small tubes)