Chapter 2 Flashcards
Respiration
The exchange of gas
between an organism and its
environment
Inspiration
Bringing oxygen to the body’s
cells by breathing in
Expiration
Eliminating carbon dioxide
from the body’s cells by breathing out
Air Pressure
The force exerted on the
walls of a chamber by molecules of air
Boyle’s Law
As the volume of a container increases, air
pressure within the container (lungs)
decreases
As the volume of a container decreases, air
pressure within the container (lungs)
increases
Vertebral Column
- Part of the bony thorax
- Composed of 33 segments of bone
- Made of vertebra (plural, vertebrae)
-Vertebrae numbered sequentially by
section from superior to inferior
Five Divisions of the Vertebral Column
7 Cervical vertebrae 12 Thoracic vertebrae 5 Lumbar vertebrae 5 Sacral vertebrae compose sacrum 4 Fused vertebrae compose coccyx
Rib Cage
- Part of bony thorax
- Composed of twelve ribs
- 7 true ribs, 3 false ribs, 2 floating ribs
- Has a curved barrel shape
- Sternum serves as focal point
The Ribs
- Attached to the vertebral column
- Slope downward during rest
- Elevate during inspiration
Pelvic Girdle
-Part of the bony thorax
-Pelvic girdle includes the ilium, sacrum,
pubic bone, and ischium
Pectoral Girdle
-Part of the bony thorax
-Pectoral or shoulder girdle includes the
scapula and clavicle bones
- Support the upper extremities
- Attach to the sternum
Respiratory Passageway
-Part of visceral thorax
-Connects lungs with the external
environment
-Consists of these structures
Oral and nasal cavities
Larynx and trachea
Bronchial tree and tubes
-Protects lungs
Safeguards lungs against pollutants
Beating epithelia that line the passageway remove pollutants
Lymphatic system removes remaining pollutants
Coughing expels particles caught in mucus
-Warms and humidifies air as it enters lungs
Bronchial Tree
The bronchial tree is characterized by
branching of large tubes into smaller
tubes
Two main tubes go from trachea to
lungs
Bronchial tubes divide further in the
lungs
Small tubes terminate in the final
terminal respiratory bronchioles
Lungs
Located in the visceral thorax
Composed of vascular, elastic tissue
Right lung contains two lobes
Left lung contains three lobes
Composed of blood, arterial and venous
network, connective tissue, respiratory
pathway, and alveoli
Alveoli
Lungs contain over 300 million alveoli
Alveoli located at ends of bronchial tree
Each alveoli receives blood from 200,000
capillaries
Oxygen is absorbed from the capillary network
Carbon dioxide is transported out of alveoli
Primary Inspiratory Muscle
Diaphragm is the primary muscle of
inspiration
Separates the thorax from the abdomen
Central tendon is a sheet-like tendon
Fibers of diaphragm pull on central tendon
Diaphragm is pulled downward during inspiration
Lungs are expanded in the vertical dimension
Pleural Linings
Diaphragm and the lungs are covered
with pleural linings
Pleural linings are the basis for air movement
Pleura of lungs and diaphragm are in contact
Contraction of diaphragm pulls lungs down
Expands lungs and draws air into lungs
Accessory Muscles of Inspiration
Accessory muscles of thorax and neck help to promote inspiration Elevate the rib cage Expand the rib cage A person can survive on diaphragmatic support without accessory muscles
Anterior thoracic muscles of inspiration
External intercostal
Interchondral portion, internal intercostal
Accessory muscles of the neck
Important for respiration Source of stability Control neck flexion and extension Specific muscles of the neck Sternomastoid muscle Scalenes (anterior, middle, posterior) muscles
Thoracic muscles of expiration
Anterior muscles
Posterior muscles
Abdominal muscles of expiration
Anterolateral abdominal muscles
Posterior abdominal muscles
Muscles of the upper limb
Process of Forced Expiration
Contraction of the abdominal muscles
Squeezing of the abdomen
Compression of the viscera
Process of Forced Expiration
Contraction of the abdominal muscles
Squeezing of the abdomen
Compression of the viscera
Reduction of the size of the thorax
Air is pushed out of the lungs or expired
