REVIEW TIME! • (This includes your “What I already know” handout)
PLACE THE FLOW OF AIR IN ORDER FROM OUTSIDE BODY TO INSIDE BODY -Bronchioles -Larynx -Alveolar duct -Trachea -Nostrils -Pharynx -Bronchi -Alveoli
The Respiratory System • _________ Respiratory Tract (outside of the lungs) • Nostrils, Nasal passages, Pharynx, Larynx, Trachea • _________ Respiratory Tract (within the lungs) • Bronchi, Bronchioles, Alveolar ducts, Alveoli • Respiratory system + _____________ system = BFFs • The primaryfunction of the respiratory system is to bring ___________ into the body and to carry _________ __________ out of body. • Secondary functions: • Phonation (voice production), Regulation of body temperature, Regulation of acid-base balance, Sense of smell
Two types of Respiration • ____________ Respiration • Capillaries of pulmonary circ. • Exchange of O2 and CO2 between the air that is inhaled and the blood flowing through the pulmonary capillaries. • ____________ Respiration • Capillaries of systemic circ. • Exchange of O2 and CO2 between the blood in the systemic capillaries and all of the cells of the body.
The Nose • ____________: nostrils • ___________ ________________: between the nostrils and pharynx • Nasal __________- separates the left nasal passage from the right • Hard and Soft __________- separate the nasal passages from the mouth. • Contains _____________ (nasal conchae): thin, scroll-like bones covered with nasal epithelium • 2 sets (dorsal and ventral) that divide each nasal passage into 3 main passageways • Each passageway is called a ____________. • Ventral, middle, dorsal and common
Lining of the nasal passages • Lined with _____________ _____________ epithelium • _________ project from the cell surfaces up into a layer of mucus • Mucus is secreted by _________ cells. • Extensive complex of large blood vessels lies just beneath the nasal epithelium.
Pharynx (Throat) • Common passageway for both _____________ and _____________ systems. • Rostral end is divided into: • _______pharynx (respiratory passageway, dorsal) • _______pharynx (digestive passageway, ventral) • Divided by the soft palate • Caudal end is divided into: • ___________ (digestive passageway, dorsal) • ___________ (respiratory passageway, ventral)
Larynx • Short, irregular tube that connects the pharynx with the trachea. • Made of segments of ___________ that are connected to each other and the surrounding tissues by muscles. • Supported by the hyoid bone. • Cartilage components: *epiglottis, *arytenoid cartilages, thyroid cartilage, cricoid cartilage
Laryngeal Cartilages • Epiglottis • Single, leaf-shaped; projects forward from the ventral portion of the larynx • During swallowing, the epiglottis is pulled back to cover the opening of the larynx
Laryngeal Cartilages • Arytenoid cartilages • Paired; attachment site of the vocal cords • Muscles adjust the tension of the vocal cords by moving the cartilages. • Lessening tension of the vocal cords allows for __________ pitched sounds. • Tightening of the vocal cords allows for _________ pitched sounds. • Arytenoid cartilages and the vocal cords form the boundaries of the _________-the opening into the larynx.
Laryngeal Cartilages • Thyroid cartilages • Shaped as a V that forms and supports the ventral portion of the larynx. • Cricoid cartilage • Ring-shaped, helps form and support the caudal portion of the larynx.
Breathing and Swallowing • Larynx and pharynx work together to prevent swallowing from interfering with breathing and vice versa. • Swallowing: • Breathing stops • Opening to the larynx is covered (by epiglottis) • Moving of material to be swallowed to rear of pharynx • Esophagus opens and material moves into it • Larynx reopens when epiglottis lays down • Breathing resumes
___________ surface has a gap in the cartilage that is bridged by smooth muscle • Lined with pseudostratifiedcolumnar ciliated epithelium (same as nasal passages). • Mucous on the surface traps debris and the cilia move it up toward the larynx/pharynx to be swallowed. • If large amounts of debris are inhaled, mucous production is increased. This traps debris and irritates the tracheal lining, stimulating a cough. • Divides into the two main _________ that enter the lungs • _____________ of the trachea • Located near the base of the heart Trachea
Bronchial Tree • After the bifurcation, the airways lead to the left and right lungs and are termed Bronchi. • The diameter of the airway opening along the bronchial tree can be adjusted by smooth muscle fibers in the wall. The animal’s nervous system controls this smooth muscle.
Bronchial Tree continued • During times of intense physical activity, bronchial smooth muscle relaxes, allowing air passageways to dilate to their maximum capacity. Called Broncho__________. • During relaxed time, smooth muscle partially contracts, reducing size of air passageway. Called (partial) Broncho____________. • Bronchi -> bronchioles -> alveolar ducts -> alveoli. • Alveolar ducts end in groups of Alveoli that are arranged like bunches of grapes (alveolar _______).
Alveoli • Site of ___________ respiration • Where _________ and _________ _________are exchanged • Tiny, thin walled sacs surrounded by capillaries • Both are composed of simple squamous epithelium • allows for easy movement of oxygen and carbon dioxide • Each alveolus is lined with ______________ – a fluid that helps prevent the alveoli from collapsing as air moves in and out during breathing (reduces surface tension)
Lungs • Two lungs form a shape like a cone. • Each lung has a ______, an ______, and a _________ lateral surface • Base is in caudal part of thoracic cavity • Lies directly on cranial surface of diaphragm • Apex lies in cranial portion of thoracic cavity • Convex lateral surface lies against inner surface of the thoracic wall
Lobes of the Lungs • Lungs are divided into _______ (in most species) • Most species have lungs that are deeply fissured into lobes • L: Cranial and Caudal • R: Cranial, Middle, Caudal, Accessory • Horses → poorly defined lobes • L: Cranial and Caudal • R: Cranial, Caudal, and accessory
Lungs continued • __________- small, well-defined area on medial side of the lung • Location of air, blood, lymph, and nerves entering and leaving the lung.
Pulmonary Circulation • ______________ blood enters the lungs from ______ ventricle of heart through the Pulmonary ________. • Pulmonary trunk splits into left and right pulmonary arteries that enter the two lungs • The vessels become arterioles, capillaries, and venules. • Oxygenated blood returns to the left atrium in the Pulmonary _______.
Thoracic Cavity • Bound by __________ vertebrae dorsally, ______ & _____________ muscles laterally, the __________ ventrally, and the _____________caudally. • _______________ – area between lungs
Pleura • Serous membrane that lines thoracic cavity (___________) and covers the lungs (___________). • Space between the two pleural layers is filled with a small amount of pleural _________ to prevent friction. (same in abdomen, pericardium). • Too much fluid is called an ______________.
Diaphragm • Thin, dome-shaped sheet of skeletal muscle • Forms caudal boundary of thorax • Base of lungs lie directly on the cranial surface and the liver lies on the caudal surface • Important respiratory muscle • Dome-shaped when ___________ • Flattens when it __________ • Enlarges volume of thorax and aids inspiration