4. the Primary Bronchi, One Bronchus to the Right, One Bronchus to the Left

Unit L – Review #1 KEY

1. Epiglottis

2. Larynx

3. These C-shaped rings of cartilage support the trachea and help prevent it from collapsing under pressure changes.

4. The Primary Bronchi, one bronchus to the right, one bronchus to the left.

5. Bronchi tubes continue to branch and give rise to numerous smaller Bronchiole tubes (Bronchioli).

6. Alveoli

7. Diaphragm

8. The Pleural Membranes encase the lungs and seal the thoracic cavity, they also secrete serous fluid to lubricate the tissues to prevent inflammation. Visceral Pleural membrane wraps up the lung and the Parietal Pleural membrane lines the thoracic cavity.

LO – L-2

1. Air is cleaned, moistened and warmed.

2. Cilia act to move mucous up and out of the respiratory tract. They also play a limited role in acting as a filter.

3. The air is carrying about 99.5% of the amount of H2O that air can possibly carry. This helps keep the respiratory tissues moist, which is necessary to better facilitate gas diffusion.

4. This dirty mucous is swept up through the bronchioles and bronchi and trachea up to the the pharynx (throat) so it can be spit out or swallowed.

5. Nose hairs line the nostrils to filter out the larger particles of dust and debris.

LO – L-3

1. An alveolus is a microscopic air sac, its spherical in shape and its wall is only one-cell thick. The wall is made out of a of simple (single layer) squamous (flat) epithelial cells. The inside of the alveolus is lined with a film of lipoproteins to give it some structure so that it is less likely to collapse. These alveoli also house stretch receptors.

2. The pulmonary capillaries that surround the alveoli are for gas exchange between the alveoli and the blood. External Respiration.

3. It is estimated that there are about 300 million alveoli in the lungs. Tremendous surface area in a small volume.

4. A surfactant film of lipoproteins. (Premature baby).

5. The macrophages, that patrol the alveoli, perform phagocytosis on foreign invaders.

LO – L-4

1. Respiration is defined as "Gas Exchange"

2. Both CO2 and H2O are removed during expiration/exhalation.

3. Oxygen must be supplied to maintain the demands of cellular respiration to make ATP.

4. Four key levels of Respiration include:

- A) Breathing – Ventilation (Inspiration & Expiration)

- B) External Respiration (Gas exchange between alveoli and pulm. caps)

- C) Internal Respiration (Gas exchange between blood and tissue fluid)

- D) Cellular Respiration (Gas exchange of O2 and CO2 in the cells at mitochondria)

5. INHALATION = INSPIRATION

6. EXHALATION = EXPIRATION

7. Internal Resp = Gas exchange between systemic capillaries and bodily tissues.

8. External Resp = Gas exchange between alveoli and pulmonary capillaries.

9. See below in the part labeled Cellular Respiration. Note that it is the opposite of Photosynthesis.

10. The energy released is used to run the ATP cycle to build ATP.

11. The Medulla Oblongata is the respiratory control center. It monitors blood to pace your breathing rate.

12. When levels of CO2 in the form of (HCO3-bicarbonate ions) and H+ ions are getting high, the breathing center is stimulated to speed up the pace of breathing. Oxygen levels are also monitored in the aortic and carotid bodies of those arteries.

13. Nerve impulses go down the Intercostal nerve (à to the intercostals muscles) and the Phrenic nerve (à to the diaphragm).

14. When diaphragm pulls down and the rib cage swings up and out, the thoracic cavity expands.

15. Stretch receptors in the alveoli fire an impulse up the Vagus Nerve to the medulla oblongata signalling it to stop firing the diaphragm and intercostals.

16. VAGUS NERVE

17. When the nervous stimulation of the intercostals and the diaphragm stop, the diaphragm relaxes and comes up and the rib cage recoils to swing in and down. This reduces the volume of the thoracic cavity, and results in putting pressure on the lungs.

PRACTICE QUIZ KEY:

1. D – To decrease the thoracic pressure on the lungs we need rib cage to move out and diaphragm to move down.

2. B

3. C – Very vascular to perform external resp. They do NOT have cilia.

4. A

5. C

6. D

7. B – Trachea