Human Anatomy Lec 3 - Respiratory PDF

Human Anatomy lec 3 ‫ عبد الحسين ارزيج‬.‫د‬ ‫ مقدام محمد المياحي‬.‫د‬ RESPIRATORY SYSTEM Consists of the air passages and lungs that supply oxy...

Human Anatomy lec 3 ‫ عبد الحسين ارزيج‬.‫د‬ ‫ مقدام محمد المياحي‬.‫د‬ RESPIRATORY SYSTEM Consists of the air passages and lungs that supply oxygen to the blood for cellular respiration and eliminate carbon dioxide from it. Consists of two major parts 1.Upper respiratory tract Nose, nasal cavity, pharynx And Larynx above vocal cords. 2.Lower respiratory tract portion of larynx below the vocal cords, trachea, bronchi, and lungs. 1  The nose A special organ for smell and air intake, where air is warmed and humidified. Have two external openings called the nostrils. The dividing portion between them is the nasal septum forming the nasal cavity surrounded by paranasal sinuses. Each cavity is subdivided into three passages: superior, middle, and inferior conchae. Functions 1.Air passageway 2.Warms and moistens the air. 3.Contains smell receptors. 4.Aid phonation. 5.Filters dust, pollen, bacteria, and foreign matter. The pharynx It is a muscular and membranous tube extending downward from the base of the skull To the esophagus. The nasopharynx is behind the nose; the oropharynx is behind the mouth; the lowest portion is called the laryngopharynx is behind the larynx. The eustachian tubes from the ears opens in the pharynx. 2  Functions 1.Passageway for air and food. 2.Aids in phonation by changing its shape.. The larynx The larynx, commonly called the voice-box, is located at the upper end of the trachea below the root of the tongue and hyoid bone. It is lined with mucous membrane. The larynx contains vocal cords, which produce sound. Its wall is reinforced by cartilage that protrudes in the front of the neck and referred to as Adam's apple (thyroid , cricoid, and the inferior arytenoid cartilages). The larynx is larger in the male than in the female due to the influence of male sex hormones on its growth during puberty. The upper end of the larynx are the vocal cords, which serve in the production of speech. The space between these two vocal cords is called the glottis and the little leaf shape cartilage that cover the larynx during swallowing is called the epiglottis. 3 The Trachea Is a smooth, muscular tube conduct air between the larynx and lung, bound anteriorly by C-shaped cartilaginous rings keeps the trachea open. The trachea leads from the larynx to the main bronchi. It is lined with ciliated epithelium with goblet cell, which sweep foreign matter out of the pathway. The trachea divides into right and left bronchi, the left is smaller than the right, while the right extends downward in a more vertical direction than the left because it have to accommodate for the heart, that’s why most foreign bodies in the airways go to the right main bronchus. The main bronchi bifurcates into secondary ,tertiary bronchi, then bronchiole, alveoli. The lungs The two lungs are spongy organs located in the thoracic cavity where oxygen is taken into and carbon dioxide is expelled out, they consist of elastic tissue, filled with a network of tubes and sacs that carry air and blood vessels that carry blood, Each lung is divided into lobes, the right lung into 3 lobes and the left lung into 2 The left lung has an indentation called the cardiac depression or notch for placement of the heart. 4  Both lungs have a central recession called the hilum at the root of the lung. where the blood vessels and airways pass into the lungs. There are also bronchopulmonary lymph nodes on the hilum. Right Lung is Larger - Shorter - Broader and divided into three lobe by two fissure. Left Lung is Smaller , Longer ,Narrower and divided into two lobes by one fissure. The bronchioles within the lung ends into alveolar ducts supplying each alveoli. The alveoli is the basic component of the lung where the gas exchange occurs; oxygen and carbon dioxide exchange with the capillaries, both lungs contain about 300 million alveoli. Alveoli : Is a hollow cavity found in the lung parenchyma , and is the basic unit of respiration. Lung alveoli are the ends of the respiratory tree , which are the sites of exchange with the blood. the capillaries are surround the alveoli where carbon dioxide is released and oxygen absorbed. The diaphragm It is the principal muscle of respiration. The primary respiratory muscles: (diaphragm) , external intercostals. Normal expiration is a passive process because of elastic recoil of lungs. Accessory expiratory muscles: Any muscle attached to the upper limb and thoracic cage. ‫من هنا‬Few muscles that help in forceful expiration (internal intercostals , intercostalis intimi , sub costals, abdominal muscles). Accessory inspiratory muscles Sternomastoid , scalenus , pectoralis major and minor inferior fibers of serratus anterior , latissimus dorsi, Serratus posterior. ‫الى هنا لالطالع فقط‬ 5 The pleura A double layer serous membrane that covers the outer surface of the lungs and lines the internal surface of the thoracic cavity. The membrane attached to lung tissue is called the visceral pleura and the membrane lining the thoracic walls is the parietal pleura, between them there is very small space called the pleural cavity contains small amount of fluid called the pleural fluid. THYROID CARTILAGE Largest cartilage consist of two laminae the anterior border of which are fused with each other at an angle in the middle line of the neck and form a subcutaneous projection named as ADAM’S APPLE OR laryngeal prominence, larger in males than females. Immediately above it is the lamina are separated by a V shape notch, the superior thyroid notch. 6  CRICOID CARTILAGE A ring of hyaline cartilage known as SIGNET RING. form the inferior wall of the larynx smaller, thicker than the thyroid and forms the lower and posterior parts of the wall of the larynx. EPIGLOTTIS It is a large leaf-shaped piece of elastic cartilage that is covered with epithelium stem of the epiglottis is attached to the anterior rim of the thyroid cartilage and hyoid bone the broad superior leaf portion of epiglottis is unattached and free to move up and down like a trap door. During swallowing, it closes to prevent aspiration of food into the lungs, forcing the swallowed liquids or food to go along the oesophagus. 7