Download CHAPTER 33 Respiration

2015/6/4
CHAPTER 33 Respiration
33.1 WHY EXCHANGE GASES AND NEED WHAT? (p.637L)
1. Fermentation vs. respiration
2. Connection between breathing and respiration
33.1-1 Gas Exchange Supports Cellular Respiration (p.637L)
1. The process requires a steady supply of ? and generates
2. Definition of respiration?
3. The rapid beating of heart as you relax after sprint?
33.1-2 Gas Exchange Relies on Diffusion (p.637L)
1. Diffusion to acquire ? and to eliminate
2. Respiration structures diverse, all facilitate diffusion through
3 adaptations on respiratory surface:
(1) moist, even in air; (2) thin to? (3) large surface area to? 1
3. Diffusion requires concentration gradients.
4. What must past respiratory surface to maintain gradients?
5. Bulk flow: movement of molecule mass in flowing form
6. Needs of gas transfer between environment and cells?
33.2 Adaptations to Minimize Diffusion Distances? (p.638L)
1. Gas movement by diffusion requires time.
2. Diffusion to support respiration only adequate over very
short distance (< 1mm)
33.2-1 Inactive Animals May Lack Specialized Organs (p.638L)
1. Sluggish animals: ATP & oxygen needs; diffusion adequate
2
1
2015/6/4
2. Simplest animals: sponges (pores + currents) (p.638L)
(1) Create water current by?
(2) Current moving by bulk flow through ? into ? out through?
(3) The circulation aided by ocean currents: gradient &
diffusing distance
3
2. Cnidarians (p.638R)
(1) Extremely thin outer skin: short diffusion distance
(2) Seawater flow: bulk flow + gradient
(3) Additional bulk flow generated by? water into? & out of?
(4) Gastrovascular cavity for water close to the internal cells
4
2
2015/6/4
3. Flatworms (p.638R)
(1) Also poss gastrovascular cavity
(2) Extensive gas-permeable skin surface
(3) Flattened shape: all cells close to skin
(4) Bulk flow of water over the bodies
5
3. More complex animals: earthworm (p.638R)
(1) Elongated shape: large skin area for?
(2) Circulatory system: balk flow
(3) Capillary transport: maintain concentration gradient
(4) Suffocate if skin dries out
6
3
2015/6/4
33.2-2 Respiratory Systems (p.639L)
1. In large, active animals: consist of respiratory organs
2. Major organs of gas exchange: gills, …
3. Gas exchange stages:
(1)Bulk flow (by?) of air or water
past a respiratory surface
(2) Diffusion through the
respiratory surface
(3) Bulk flow (by?) of blood
transports gases between ? & ?
(4) Diffusion transfers ? out of ?
and into ?
7
33.2-3 Gills (p.639R)
1. Structures of many aquatic animals
2. The simplest type
(1) Some amphibians, nudibranch mollusks
(2) thin projections of body surface
3. General structure of gills
(1) Elaborately branched or folded: increasing surface area
(2) Dense profusion of capillaries beneath outer membranes:
blood close to surface
8
4
2015/6/4
4. Most fish types: operculum for? (p.639R)
5. Creating currents (external bulk flow) over gills by?
(1) Pumping water into ? & ejecting it out through?
(2) Swim with mouths open
6. A challenge fish face: extracting enough oxygen for active
lifestyle
(1) Much less oxygen in water than in air
(2) Water is denser (heavier) than air.
(3) Using up more energy getting oxygen from water than
breathing
(4) In response: countercurrent exchange
- Two bulk flows in opposite directions: keep gradient
- Effect: most oxygen in water diffuses into the gill
9
5
2015/6/4
33.2-4 Terrestrial Animals: Internal Structures (p.640L)
1. Why are gills useless in air (more oxygen!)?
2. Need to protect, support, and retained the moist of cell
membranes for gas exchange
33.2-4.1 Insects Respire with Tracheae (p.640L)
1. What is tracheae? What are spiracles? Where are they?
2. tracheoles: deliver air close to each body cell
3. Pumping movement of abdomens to?
4. Inefficient circulatory system! compensation?
33.2-4.2 Terrestrial Vertebrates (p.640R…)
1. Lungs: chambers containing moist surfaces
- protection within? Supported by?
2. The first vertebrate lung: freshwater fish
(1) An outpocketing of the digestive tract
(2) Survival in stagnant water!
11
6
2015/6/4
3. Amphibians
(1) Use gills during aquatic larval stage
(2) Simple, sac-like lungs as more terrestrial adults
(3) also, thin, moist skin rich in capillaries
4. Reptiles (p.642L)
(1) Water-proof skin, not serving as a respiratory organ
(2) Lungs have a far larger surface area
5. Birds: respiratory systems differ substantially (p.642L…)
(1) Exceptionally efficient gas exchange to
(2) The lungs are connected to 7-9 air sacs as air reservoirs
(3) The lungs are rigid filled with parabronchi
- Open at both ends; connected to air sacs; surrounded by
microscopic air spaces with dense capillary network
13
(5) One-way flow of fresh air through the lungs
(6) Air travel route?
(7) Air movement in the systems? Inhalation vs. exhalation
(8) Bird lungs obtain fresh air always.
14
7
2015/6/4
33.3 AIR CONDUCTION THROUGH THE SYSTEM (p.643R)
1. In mammals: 2 parts of the system
2. Conducting vs. gas-exchange portion
33.3-1 Conducting Portion (p.643R…)
1. Air passage: nose → nasal cavity vs. mouth → oral cavity
2. Pharynx (a shared chamber) → larynx
3. Location & position of epiglottis during normal breathing vs.
during swallowing
4. Epiglottis closure reflex failure if…
5. Heimlich maneuver
6. Vocal cords: muscle control → air passage → song → words
7. Trachea: flexible but reinforced
8. Branching: trachea (within the chest) → bronchi (inside the
lung) → bronchioles
9. Diameter regulation of air pipes
10. Alveoli
15
11. Air clean process: mucus, cilia, pharynx → cough or swallow
12. How does smoking interfere with the cleansing process?
16
8
2015/6/4
33.3-2 Active Inhalation & Passive Exhalation (p.644R)
1. Breathing: cause bulk flow of air into & out
2. Inhalation
(1) Chest cavity (boundary) enlarged: contraction vs. increase
- Diaphragm muscle work: position change
- Rib muscle work: position change
(2) Lungs inflate, how?
- Fluid in the space between ? and ? → air-tight seal
- Why is a chest puncture wound dangerous?
3. Exhalation
(1) Muscle action & chest movement?
(2) Forcing additional air out by?
(3) Lungs after exhalation still contain some air?
- Prevent thin alveoli from collapsing; fill the conducting space
(4) A typical breath
- Moving 500 mL air through; only ¾ reaches the alveoli
17
9
2015/6/4
33.3-3 Breathing Control (p.644R…)
1. Breath: thinking about vs. without conscious thought
2. Heart muscle vs. breathing muscles (no self -control)
3. Nervous impulses from respiratory center
4. Cyclic bursts of electrical signals → muscle contraction
5. Between bursts → muscle relax → exhalation
6. Regulation of respiratory rate
(1) CO2 receptors also in medulla
- Adjust breathing rate → keep constant, low blood CO2 →
ensure adequate O2
- Sensitivity?
(2) Receptors in aorta and carotid arteries
- Also sensitive to high blood CO2
- Also respond to low O2
19
10