mod 11 - respiratory system

structure: upper respiratory tract

- Nares
- Nasal passages
- Pharynx
- Larynx
- Trachea
- All the air that enters the respiratory system must enter and exit the upper respiratory tract.

the nasal passages functions to:

warm air, humidify air, and filter (Cilia, mucus)

the sinuses:

they are the outpouching of the nasal passages that can be found within spaces in certain skull bones

Pharynx is also known as

throat

pharynx

common passageway for respiratory and digestive systems

larynx

- connects with the trachea
- supported by hyoid bone
- composed of cartilage segments

trachea

short, wide tube (fibrous tissue and smooth muscle held open by cartilage rings)

extends from larynx into thorax where it divides (bifurcation of the trachea)

the structure of the trachea

- C-shaped cartilage rings spaced along length of trachea prevent collapse during inhalation
- Ciliated lining
- Mucous layer

structures of the lower respiratory tract

the bronchial tree
- bronchi
- bronchioles
- alveolar ducts
- alveoli

the bronchial tree connects __________

the trachea to the lungs

autonomic nervous system: bronchial tree

controls diameter of tubes by adjusting muscle fibers in their walls
- bronchodilation
- bronchoconstriction

alveoli

tiny sacs around capillaries,

- oxygen and carbon dioxide exchange takes place in the alveoli

lungs structure

- cone-like shape
- light, spongy consistency

diaphragm

- Thin sheet of skeletal muscle
- Forms caudal boundary of thorax
- Acts as respiratory muscle
- bases of lungs lie directly on its cranial surface

function: respiratory system

respiration,
voice production,
body temperature regulation,
acid-base regulation,
sense of smell

respiration

the process of bringing oxygen to all body cells
and carrying carbon dioxide out of the body

voice production

pharynx

body temperature regulation:

- Panting can lower body temperature
- Nasal passages warms inhaled air. Thus, preventing hypothermia

acid-base regulation

by influencing the amount of CO2 in the blood

what does more CO2 run the blood mean?

acidic = pH is low

what does less CO2 run the blood mean?

basic or alkaline = pH is high

sense of smell

the nasal passage epithelial contain olfactory receptors

negative intrathoracic pressure

The pressure within the Thorax is less than the atmospheric pressure. (Negative Pressure).

if negative pressure is lost what would happen?

lungs would collapse

negative pressure pulls lungs _____

tightly against thoracic wall

where does gas exchange occur?

in the lungs (alveoli)

inhaled air:

high in oxygen and low in carbon dioxide

blood entering capillary:

low O2, high CO2

alveolar gas exchange occurs by

diffusion

explain gas exchange

- high level of O2 in air diffuses into blood where O2 level is lower

- high level of CO2 in blood diffuses into air where level is lower

exhaled air

Higher CO2, lower O2

acid-base balance

- Important homeostatic mechanism of the body

- Necessary for normal chemical reactions in cells

- respiratory system influences amount of CO2 in blood by the rate breathing

the more CO2, the lower ______

the blood pH

what is the normal pH of blood?

7.4 (range 7.35-7.45)

what are the standardized terms for describing quantity of air involved in respiration?

- tidal volume

- minute volume

- residual volume

are respiratory volumes important?

yes! very important during surgery

tidal volume

The volume of air inspired and expired during one breath.

minute volume

The volume of air inspired and expired during on minute

residual volume

The volume of air remaining in the lungs after maximum expiration