D2.1 - Structures of the Respiratory System (Updated 2024) PDF

D2.1 - Structures of the Respiratory System I can… Identify and discuss the purpose of principal structures of the respiratory system (nasal passages, pharynx, larynx, epiglottis, trachea, bronchi, bronchioles, alveoli, diaphragm, rib muscles, pleural membranes) The Respirato...

D2.1 - Structures of the Respiratory System I can… Identify and discuss the purpose of principal structures of the respiratory system (nasal passages, pharynx, larynx, epiglottis, trachea, bronchi, bronchioles, alveoli, diaphragm, rib muscles, pleural membranes) The Respiratory System Respiration describes all processes that supply oxygen to the cells of the body for the breakdown of glucose It also describes the process by which carbon dioxide is transported to the lungs for exhalation. Respiration: Involves the exchange of gases between an organism and the environment Cellular respiration: The process by which the cell breaks down fuel molecules, releasing CO2 and energy (requires oxygen) The Respiratory System Recall: Cells need oxygen in order to fuel the processes required for survival (O2 is required to make ATP!) A waste product of these processes is carbon dioxide; this is why we must exhale, to get rid of waste The Respiratory Tract Structures and Functions Nasal passages: Lined with ciliated cells and cells that secrete mucus, these cells filter and moisten incoming air Turbinate bones increase surface area Heat from blood vessels warms the air Structures and Functions Turbinate bones: Thin, curved, bony plates that project from the walls of the nasal cavity into the respiratory passageway Ciliated cells: Cells with tiny hairlike structures on them (cilia), found throughout the respiratory system Structures and Functions Pharynx: The passageway into the respiratory system (aka the throat) Air space at the back of the mouth and nasal cavity Also carries food/water to the digestive system Two openings branch from the pharynx: ○ Esophagus: To the stomach ○ Trachea: To lungs Structures and Functions Epiglottis: A flap of cartilage that lies behind the tongue ○ Serves to close the opening to the trachea (the glottis) when a person swallows Glottis: The opening to the trachea ○ Must be covered when swallowing in order to prevent food and drink from passing into the lungs Structures and Functions Larynx: The voice box, contains the vocal cords ○ Located at the upper end of the trachea ○ Adam’s apple (sticks out for males) is a layer of thick cartilage that protects the larynx Vocal cords: Two thin sheets of elastic ligaments that vibrate as air is forced past them Why are male Adam’s apples larger than females? Following puberty, the cartilage and larynx increase in size and thickness, more so in males than in females. In the same way a larger drum creates a lower-pitched sound, the larger voice box in males produces a deeper sound. Rapid growth of the larynx causes issues for adolescent boys as they often struggle to control the pitch of their voice. Practice Questions 1. Why is oxygen essential for survival? 2. Describe the function of cilia in the respiratory tract. Practice Questions 3. Explain how the functions of the trachea, esophagus, and epiglottis are related. 4. Differentiate between breathing and cellular respiration. The Trachea and Bronchi Structures and Functions Trachea (windpipe): Carries air to lungs ○ Covered with cilia that are coated with mucus ○ Supported with rings of cartilage that keep trachea open Bronchi: Carries air from the trachea into the left and right lung ○ Like the trachea, bronchi are supported by cartilaginous rings ○ Lined with cilia and mucus-producing cells Structures and Functions Bronchioles: Smaller airways inside each lung Less than 1 mm in diameter Made of smooth muscle walls, do not contain cartilage Lined with cilia and mucus-producing cells Structures and Functions Cilia: Tiny hair-like structures ○ Foreign particles are trapped by hairs and mucus Cilia beat upwards moving mucous, dust, and other particles back up to the pharynx where it can be coughed out Structures and Functions Alveoli: Tiny clusters of air sacs found at the end of bronchioles The site of gas exchange (carbon dioxide dissolved in the blood is exchanged for oxygen) Structures and Functions Lungs: The primary organ of the respiratory system Divided into lobes: ○ The right lung has three lobes ○ The left lung has only two in order to make room for the heart Structures and Function Pleural membrane: Thin, fluid-filled membrane surrounding the lungs Reduces friction Allows the lungs to expand and contract with the movement of the chest Structures and Functions Diaphragm: A dome shaped sheet of muscle just below the lungs that separates the lungs (thoracic cavity) from the stomach and liver (abdominal cavity) ○ Aids in breathing movements ○ Works with rib muscles to move air in and out of the lungs Structures and Functions Intercostal muscles: Muscles between ribs Allows ribs to expand and contract for breathing movements Nerve stimulus causes the muscles to contract