Lecture 14
Lecture 18
The Respiratory System
• Overview of the Respiratory System
o Functions:
▪ Provides ______________ and carbon dioxide exchange
▪ Serves for ______________ and other vocalizations (laughing, crying)
▪ Provides the sense of smell, which is important in social integration, food selection, and avoiding danger (such as spoiled food or a gas leak)
▪ Breathing creates blood pressure gradients between the thorax and abdomen that promote the flow of ___________ and venous blood
▪ Taking a deep breath and holding it contracts the abdominal muscles helps to expel abdominal contents during urination, defecation, and _____________________
o Divisions:
▪ Conducting division
• Passages that serve only for airflow
• Nostrils through _________________
▪ Respiratory division
• Consists of the _________________ and other distal gas-exchange regions
• The Upper Respiratory Tract
o The Nose
▪ The nose has several functions
• It warms, _______________, and humidifies the air
• It detects odors in the airstream
• It serves as a resonating chamber that amplifies the voice
▪ It extends from a pair of anterior openings called the nostrils (external nares) to a pair of posterior opening called the posterior ______________ (choanae)
▪ The nasal cavity is divided into right and left halves called nasal __________________
▪ The separation between the right and left nasal fossa is the nasal septum
▪ The facial part of the nose is shaped by ___________ and hyaline cartilage
• The superior part is shaped by the nasal bones and maxilla
• The inferior part is shaped by lateral cartilage (below the nasal bones) and alar cartilage (surrounding the nostrils)
▪ The nasal cavity begins with a chamber called the nasal ______________
• This space is lined with stratified squamous epithelium like the facial skin, and has stiff ________________ (hairs) that block insects and large airborne particles from the nose
▪ The nasal septum:
• The vomer forms the ______________ part
• The perpendicular plate of the ethmoid bone supports the superior part
▪ Much of the space inside the nasal cavity is occupied by the nasal conchae (superior, middle, and inferior)
• They project from the lateral walls towards the septum
• Beneath each of the conchae is a narrow _____________ passage
• The narrow space between the conchae forces most of the air to come in contact with the mucous membrane
o Most dust in the air sticks to the mucus
o The air picks up moisture and __________ from the mucosa
o The conchae clean, warm, and moisten the air
• The rest of the nasal cavity is covered in ciliated pseudostratified respiratory mucosa
o It consists of goblet cells that secrete mucus and ciliated cells which drive the mucus toward the posterior ________________ and into the pharynx
o Pollen, dust, and other inhaled particles stick to the ________________, and lysozyme in the mucus destroys bacteria
o The Pharynx
▪ The pharynx is a muscular funnel extending from the choanae to the larynx
▪ It has three regions
• The _____________________ lies posterior to the choanae
o It receives the auditory tubes from the middle ears
o It houses the pharyngeal tonsil
o Inhaled air turns downward ________ degrees
▪ Relatively large particles generally cannot make that turn and collide with the posterior wall, where it sticks to the mucosa near the tonsil
• The oropharynx is a space between the soft palate and the root of the _______________
o It extends inferiorly as far as the hyoid bone
o It contains the lingual and ________________ tonsils
• The laryngopharynx begins at the level of the hyoid bone
o It passes inferiorly and dorsal to the larynx and ends at the opening of the esophagus, at the level of the ___________________ cartilage of the larynx
o The Larynx
▪ The larynx is the voicebox
▪ It is a cartilaginous chamber about 4 cm long
▪ Its primary function is to keep food and drink out of the airway
▪ It also produces sounds in many animals, and ______________ in humans
▪ The glottis is the superior opening of the larynx
• The epiglottis is flap of tissue that guards the glottis
o At rest, the epiglottis stands almost ________________
o During swallowing, the extrinsic muscles of the larynx pull the larynx upward toward the ipiglottis, and the tongue pushes the epiglottis downward toward to meet it
o The epiglottis directs food and drink into the esophagus dorsal to the airway
▪ The larynx consists of nine cartilages
• The epiglottic cartilage is the most ______________ cartilage
o It’s a spoon-shaped cartilage in the tissue of the epiglottis
• The ____________________ cartilage is the largest cartilage
o It’s named for its shield-like shape
o It broadly covers the anterior and lateral aspects of the larynx
o The Adam’s apple is an anterior peak of the thyroid cartilage
▪ Testosterone stimulates the growth of the cartilage, so it is larger in ______________
• The cricoid cartilage is inferior to the thyroid cartilage
o It’s ring-like in construction and connects the larynx to the ___________________
• The arytenoid cartilages are posterior to the thyroid cartilage
• The corniculate cartilages are a pair of little horns at the upper ends of the ___________________ cartilages
• The cuneiform cartilages support soft tissues between the arytenoids and the epiglottis
▪ The interior wall of the larynx has two folds on each side that stretch from the thyroid cartilage in front to the arytenoid cartilage in the back
• The vestibular folds are the superior pair
o They close the ________________ during swallowing
• The vocal folds are the inferior pair
o They produce sound when air passes between them
o Intrinsic muscles control the vocal cords by pulling on the ____________________ and arytenoids cartilages, causing the cartilages to pivot
o When pulled taut, they produce ______________ pitch
• The Lower Respiratory Tract
o The Trachea
▪ The windpipe is a tube about 12 cm long and 2.5 cm in diameter
▪ It is supported by rings of hyaline cartilage
▪ The inner lining is pseudostratified columnar epithelium
• It’s composed of mucus-secreting _________________ cells, ciliated cells, and short basal stem cells
• The mucus traps inhaled particles, and the cilia drives the debris-laden mucus toward the pharynx where it is _________________
o The Bronchi
▪ The primary bronchi are forks branching to the right and left from the ____________________
o The Lungs
▪ Each lung is somewhat conical with a concave base resting on the diaphragm and a blunt peak called the ____________ projecting above the clavicle
▪ The costal surface is the portion pressed against the ribcage
▪ The mediastinal surface is the portion the faces medially
▪ The hilum is a slit in the __________________ surface through which the primary bronchus, blood vessels, and nerves enter the lung
▪ The right lung is shorter than the left because the liver rises higher on the right
• It has three lobes (superior, middle, and inferior)
▪ The left lung is taller but narrower
• On the medial surface, there is a cardiac impression, where the _________________ presses against it
• It has only two lobes (superior and inferior)
▪ Within each lung, there is a bronchial tree
• Branching from the trachea into the two lungs there are primary bronchi
• After entering the lung the primary bronchus branches into one __________________ bronchus for each lobe of the lung
• Each secondary bronchus divides into tertiary bronchi
▪ Bronchioles are continuations of the airway that lack supportive cartilage and are 1 mm or less in diameter
• Each bronchiole divides into terminal bronchioles, the final branches of the conducting division
• Each terminal bronchiole gives off two or more smaller _______________________ bronchioles
▪ Each respiratory bronchiole divides into thin-walled passages called alveolar ducts.
▪ The alveolar ducts end in alveolar _________ which are grapelike cluster of alveoli
• There are _______________ networks around each alveolus, for the exchange of CO2 and O2
o The Pleurae
▪ The surface of the lung is covered by a serous membrane called the visceral pleura
▪ At the hilum, the visceral pleura turns back on itself and forms the ________________ pleura
▪ The space between the parietal pleurae and visceral pleurae is called the pleural cavity
▪ The pleural cavity contains a slippery pleural ______________
▪ The pleurae and pleural fluid have 3 functions
• Reduction of friction
o The fluid acts as a __________________ that enables the lungs to expand and contract with minimal friction
• Creation of pressure gradient
o During inspiration (inhalation) the rib cage expands and draws the parietal pleura outward along with it
o The visceral pleura clings to the parietal pleura, and since the visceral pleura is the lung surface, its outward movement _________________ the lung
• Compartmentalization
o The pleurae, mediastinum, and pericardium compartmentalize the thoracic organs and prevent ____________________ of one organ from spreading easily to neighboring organs
• Neuromuscular Aspects of Respiration
o Inspiration
▪ The ___________________ does most of the work of inspiration (inhalation)
• It’s controlled by the phrenic nerves
• It drops about 1.5 cm in quiet inspiration
• It drops up to 7 cm in forced inspiration (___________ breathing)
▪ The external intercostals muscles are also important in inspiration
• They are innervated by the intercostal nerves
• The scalenes fix the first pair of ribs and the external intercostals lift the remaining ribs
o They swing up and out, ____________________ the volume of the thoracic cavity
o It creates a pressure gradient that draws air into the lungs
• Deep inspiration is further aided by the pectoralis minor, ________________________, and erector spinae muscles
o Expiration
▪ Normal expiration is achieved by the elasticity of the lungs and thoracic cage
• As structures recoil, the thoracic cage diminishes in size, the air pressure in the lungs rises above the atmospheric pressure, and the air flows _____________
• The only muscular effort involved in expiration is a braking action to keep the lungs from recoiling too _____________
▪ Forced expiration (to blow out the candles) employs internal intercostals and abdominal muscles
• The internal intercostals muscles depress the ribs
• The internal and external abdominal obliques, transverse abdominis, and rectus abdominis compress the abdominal organs, raise the intra-abdominal pressure, and push the viscera up against the __________________
o Respiration Centers of the Brainstem
▪ Rhythm of unconscious breathing is caused by nuclei in the reticular formation of the medulla oblongata and pons
▪ In the medulla, these nuclei include:
• inspiratory neurons of the inspiratory center which fire during ___________________
• expiratory neurons of the expiratory center fire during expiration
▪ The pons contains respiratory nuclei
• The lower pons has an ___________________ center whose function seems to prolong inspiration
• The upper pons has a pneumotaxic center which sends a continual stream of signals to the inspiratory center of the medulla
o It regulates the duration and _______________ of each breath
▪ Respiratory centers receive input from several sources
• Chemoreceptors respond to pH and CO2 and O2 concentrations of the blood and cerebrospinal fluid
o Peripheral chemoreceptors are found in the aortic bodies and _______________ bodies
o Central chemoreceptors are found close to the surface of the medulla oblongata
• Stretch receptors in the bronchial tree monitor inflation of the lungs
• The vagus nerves transmits singals from the respiratory __________________ when they are stimulated by irritants in the airway
• Higher brain centers allow for conscious control over breathing
................
................
In order to avoid copyright disputes, this page is only a partial summary.
To fulfill the demand for quickly locating and searching documents.
It is intelligent file search solution for home and business.
Related searches
- marketing management pdf lecture notes
- strategic management lecture notes pdf
- strategic management lecture notes
- philosophy 101 lecture notes
- philosophy lecture notes
- philosophy of education lecture notes
- financial management lecture notes
- financial management lecture notes pdf
- business management lecture notes
- introduction to philosophy lecture notes
- business management lecture notes pdf
- introduction to management lecture notes