Name: exhalation and lung pressure changes
Uploaded: 2024-09-12T13:22:46.000Z
Duration: 1 min 17 s
Channel: JoVE

K12 Standards

ohios-learning-standards-and-model-curriculum

Ohio’s Learning Standards and Model Curriculum

9-12

Human Anatomy and Physiology

Absorption And Excretion

Respiratory System

Pulmonary Cycle: Exhalation

건강한 사람이 조용히 숨을 쉬는 동안 공기를 내뿜는 과정인 날숨은 근육 수축보다는 폐의 탄력성에 의존합니다.
흡입하는 동안 늘어난 탄성 섬유의 반동은 주로 폐의 반동을 유발합니다.
또한, 내장 흉막과 두정흉막 사이의 흉막내액층에 의해 생성된 표면 장력의 내부 당기는 힘은 이러한 폐 반동에 기여합니다.
흡입에 관여하는 근육이 활동을 멈추면 횡격막과 외부 늑간이 이완되어 횡격막이 올라가고 갈비뼈가 내려갑니다.
이러한 움직임은 흉강의 크기를 줄여 폐 용적을 줄입니다.
호기를 하는 동안 폐내압은 대기압보다 1mm Hg 높습니다. 그리고 폐내압이 대기압보다 높으면 가스가 폐 밖으로 흘러나옵니다.
이러한 조용한 숨을 내쉬는 것과는 대조적으로, 힘차게 내쉬는 숨은 복부 근육과 늑간 근육의 수축을 포함한다. 그것은 다이어프램을 정상 위치에서 상승시켜 힘으로 공기를 배출하도록 합니다.

폐환기: 호기

인간의 호흡 측면에서, 호기(또는 날숨)라고 알려진 공기를 내뿜는 행위는 압력 구배의 원리에 따라 작동합니다. 날숨하는 동안 폐 내부의 압력은 주변 대기의 압력을 초과합니다. 정상적인 조건에서 조용한 호흡은 수동적인 날숨을 포함하며 근육 수축이 없습니다. 이는 날숨 과정이 폐와 흉벽의 자연스러운 탄성 반동에 의해 주도되기 때문이며, 둘 다 팽창 후 원래 위치로 돌아가려는 고유한 경향이 있습니다.

흡입에 관여하는 근육이 활동을 멈추면 횡격막과 외측 늑간근이 이완됩니다. 이로 인해 횡격막이 올라가고 갈비뼈가 내려갑니다. 이러한 움직임은 흉강의 크기를 줄여 폐 용적을 줄이고 폐포 압력을 약 762mmHg까지 높입니다. 이러한 압력 차이로 인해 폐(높은 압력)에서 대기(낮은 압력)로 공기가 흐릅니다. 호기는 운동이나 관악기를 연주하는 것과 같이 신체 활동이 격화될 때만 적극적으로 노력하면 됩니다. 이러한 경우 호기에 관여하는 근육(복부 및 내측 늑간근)이 작동하여 복부와 흉부에 압력이 가해집니다. 복부 근육의 수축은 복부 장기를 압박하여 횡격막을 위로 밀어올리고 내측 늑간근은 인접한 갈비뼈 사이의 아래쪽과 뒤쪽 확장을 통해 갈비뼈를 아래로 당깁니다. 흉막 내부의 압력은 항상 폐포 내부의 압력보다 낮게 유지되지만 기침과 같이 강제로 호기할 때 일시적으로 대기압을 초과할 수 있습니다.

폐환기와 관련된 몇 가지 임상 상태

<ol>
	<li>신생아 호흡곤란증후군
	신생아 RDS 또는 유리막 질환은 주로 미숙아에게 영향을 미칩니다. 이 질환은 폐에서 표면활성제가 충분히 생성되지 않아 발생합니다. 표면활성제는 폐포를 열어두는 데 도움이 되는 물질입니다. 표면활성제가 충분하지 않으면 호기 중에 폐포가 붕괴되어 유아의 호흡이 더 어려워집니다.

	RDS의 증상에는 빠르고 얕은 호흡, 콧구멍 벌름거림, 으르렁거리는 소리, 피부에 푸른빛 색조(청색증)가 있습니다. 치료에는 종종 보충 산소를 제공하고 폐 기능을 개선하기 위해 표면활성제 대체 요법을 시행하는 것이 포함됩니다. 대부분의 영아는 적절한 의학적 개입을 통해 며칠에서 몇 주 내에 RDS에서 회복됩니다.
	</li>
	<li>무기폐
	무기폐는 폐의 일부가 부분적으로 붕괴되는 것입니다. 이 상태는 기도 막힘, 흉부에 칼에 찔리거나 총에 맞은 상처, 흉부의 수술적 절개, 또는 폐 조직이 약해진 것과 같은 다양한 이유로 발생할 수 있습니다. 일반적인 원인으로는 점액 플러그, 종양, 이물질 및 수술 후 합병증이 있습니다.

	무기폐의 증상은 폐 붕괴의 정도에 따라 달라지며 흉통, 호흡 곤란, 심박수 증가, 기침이 포함될 수 있습니다. 치료 옵션은 심호흡 운동과 기침 기술부터 심각한 경우 기관지 확장제 또는 수술까지 다양합니다.
	</li>
	<li>기관지염
	기관지염은 기관지의 염증입니다. 이 질환은 급성 또는 만성일 수 있으며, 바이러스 감염이 급성 기관지염의 가장 흔한 원인입니다. 반면 만성 기관지염은 담배 연기와 대기 오염과 같은 자극물에 장기간 노출되는 것과 관련이 있습니다.
	</li>
</ol>

기관지염 증상에는 지속적인 기침, 점액 생성, 가슴 불편함, 천명음이 포함될 수 있습니다. 치료에는 일반적으로 휴식, 수분 공급, 산소, 기관지 확장제, 근본 원인 해결이 포함됩니다. 박테리아 감염이 있는 경우 항생제를 처방할 수 있습니다.

건강한 개인의 조용한 호흡 중 공기를 배출하는 과정인 날숨은 폐의 탄력성에 의존합니다.

Education

교육

JoVE Core

Anatomy and Physiology

해부학 및 생리학

Unit 1

제1단원

The Respiratory System

호흡기계

KEY TERMS AND CONCEPTS

주요 용어 및 개념

exhalation and lung pressure changes

Exhalation is the process of expelling air from the lungs. It depends on pressure differences between the lungs and the atmosphere. During normal quiet breathing, exhalation is passive and does not require muscle contraction. The elastic recoil of the lungs and chest wall helps both structures return to their resting positions after inhalation.

When the muscles used for inhalation stop working, the diaphragm and external intercostal muscles relax. The diaphragm moves upward, and the ribs move downward. These changes make the thoracic cavity smaller and reduce lung volume. As a result, alveolar pressure rises to about 762 mm Hg, and air flows out of the lungs into the lower-pressure atmosphere.

Active exhalation happens during exercise or when playing a wind instrument. In these cases, the abdominal muscles and internal intercostals contract. Abdominal muscle contraction compresses the abdominal organs and pushes the diaphragm upward. The internal intercostals pull the ribs downward because of their inferior and posterior position between adjacent ribs.

The pressure in the pleural space remains lower than the pressure inside the alveoli, but it can briefly rise above atmospheric pressure during forceful exhalation, such as coughing. The same pressure changes that help air leave the lungs can also relate to lung problems. Neonatal respiratory distress syndrome, atelectasis, and bronchitis are all conditions connected to pulmonary ventilation.

Neonatal respiratory distress syndrome, also called hyaline membrane disease, mainly affects premature infants. It happens when the lungs do not produce enough surfactant, a substance that helps keep alveoli open. Without enough surfactant, alveoli can collapse during exhalation, which makes breathing difficult. Common signs include rapid shallow breathing, nostril flaring, grunting, and cyanosis, or a bluish skin color. Treatment often includes supplemental oxygen and surfactant replacement therapy, and many infants recover within days to weeks.

Atelectasis is a partial collapse of part of a lung. It can result from blocked airways, stab or gunshot wounds, surgical opening of the chest, or weakened lung tissue. Common causes include mucus plugs, tumors, foreign objects, and post-surgical complications. Symptoms may include chest pain, shortness of breath, a faster heart rate, and coughing. Treatment can include deep breathing exercises, coughing techniques, bronchodilators, or surgery in severe cases.

Bronchitis is inflammation of the bronchial tubes. Acute bronchitis is most often caused by viral infections. Chronic bronchitis is often linked to long-term exposure to irritants such as tobacco smoke and air pollution. Symptoms can include a persistent cough, mucus production, chest discomfort, and wheezing. Treatment usually includes rest, hydration, oxygen, bronchodilators, and care for the underlying cause. If a bacterial infection is present, antibiotics may be used.

Exhalation and Lung Pressure Changes

overview of respiratory system

How Breathing Moves Air and Gases

The respiratory system moves air in and out of the body and exchanges oxygen and carbon dioxide with the environment. This gas exchange is part of respiration, which is essential for life. The system supplies the blood with oxygen so it can carry that oxygen to the rest of the body. Breathing starts when air enters through the nose or mouth. The nose and nasal cavity form the main external opening and the first part of the airway. Air then passes through the pharynx, or throat, which is shared...

nose and nasal cavity

How the Nose Filters and Senses Air

The nose filters, warms, moistens, and senses the air that enters the body. It also helps shape speech as sound vibrations pass through its large air spaces. The nose has an external part that is visible on the face and an internal part called the nasal cavity. The external nose is built from bone and hyaline cartilage, which gives it flexibility. It is covered by skin and muscle and lined with a mucous membrane. The frontal bone, nasal bones, and maxillary bone support this structure. The...

pharynx

Pharynx Pathways for Air and Food

The pharynx is a muscular tube lined with mucous membrane that connects the nasal cavities to the throat. It is divided into three parts: the nasopharynx, oropharynx, and laryngopharynx. Each part has a different role in moving air and food through the upper throat. The nasopharynx sits behind the nasal cavity and serves only as an air passage. Its upper region contains the pharyngeal tonsils, also called adenoids. These are clusters of lymphoid reticular tissue, similar to a lymph node, and...

larynx

Voice Box Anatomy and Function

The larynx is the voice box in the neck. It carries air into the lungs and helps produce voice. Its structure is complex because it must support both breathing and sound production. The larynx contains cartilage, muscles, and the vocal cords, also called vocal folds. It includes three large unpaired cartilages: the thyroid, cricoid, and epiglottis. It also includes three paired cartilages: the arytenoids, corniculates, and cuneiforms. Ligaments and membranes hold these parts together. The...

trachea

Trachea: Layers, Rings, and Airflow

The trachea is the windpipe, and it is a key airway in the human respiratory system. It carries air between the larynx and the bronchi so oxygen can reach the lungs. About half of the trachea lies in the neck, and it sits in front of the esophagus. In an average adult, the trachea is about 10 to 12 cm long. It extends from the larynx at the level of the sixth cervical vertebra to the level of the fifth thoracic vertebra. Its wall is supported by C-shaped cartilaginous rings. The back side is...

the bronchial tree

Bronchial Branching and Airflow Control

The bronchial tree carries air from the trachea into the lungs and helps control breathing. The trachea, or windpipe, connects the larynx to the bronchi. At the carina, the trachea splits into two primary bronchi. The right primary bronchus is wider, shorter, and more vertical than the left. Because of that shape, foreign objects and infections are more likely to enter the right lung. The carina is a cartilaginous ridge at the split in the airway. It helps keep the airway open. It also has...

alveoli and alveolar ducts

How Alveoli Enable Gas Exchange

The respiratory zone of the human body is where gas exchange happens. It begins when the terminal bronchioles branch into respiratory bronchioles, the smallest bronchiole type. These then lead into alveolar ducts and finally into clusters of alveoli. Alveoli are tiny air sacs that look like bunches of grapes. They connect to alveolar ducts, and a group of alveoli forms an alveolar sac. A single alveolus is about 200 μm wide, and its elastic shape lets it expand during inhalation. Nearby...

gross anatomy of the lungs

Lung Lobes, Airways, and Blood Flow

The lungs are paired organs that connect to the trachea through the left and right bronchi. Their base rests against the diaphragm, the dome-shaped muscle below the lungs. The lungs are covered by the pleurae and sit next to the mediastinum, the central space in the chest. The right lung is shorter and wider than the left lung, and it has a larger volume. The left lung has a cardiac notch, which is an indentation for the heart. The top of each lung is the apex, and the lower part is the base.

pleura of the lungs

Pleura Layers and Lung Protection

The pleura are membranes that protect the lungs inside the chest cavity. They are a type of serous membrane and wrap around each lung. The pleura have two layers: the visceral pleura and the parietal pleura. The visceral pleura covers the surface of the lung. The parietal pleura is the outer layer. It lines the thoracic wall, the mediastinum, and the diaphragm. The hilum is the point where the visceral and parietal layers connect. The space between these layers is called the pleural cavity. <br...

pressure relationships in thoracic cavity

pressure-relationships-in-thoracic-cavity

How Pressure Drives Breathing in the Lungs

Breathing depends on pressure changes in the lungs, chest, and airways. Pulmonary ventilation is the movement of air into and out of the lungs. It is driven by atmospheric pressure, intra-alveolar pressure inside the alveoli, and intrapleural pressure in the pleural cavity. Inhalation and exhalation rely on pressure differences between the atmosphere and the lungs. Gas pressure comes from the movement of confined molecules. Boyle’s law explains that pressure and volume are inversely...

pulmonary ventilation: inhalation

Pulmonary Ventilation and Breathing Pressures

Pulmonary ventilation depends on breathing movements and the pressure changes that move air into and out of the lungs. It supports the exchange of oxygen and carbon dioxide by letting the body take in oxygen and remove waste carbon dioxide. Boyle's law is important here because changes in volume and pressure affect how air moves in the respiratory system. Several respiratory volumes help describe how much air the lungs move. Tidal volume is the air inspired or expired during normal, quiet...

pulmonary cycle: exhalation

Exhalation is the process of expelling air from the lungs. It depends on pressure differences between the lungs and the atmosphere. During normal quiet breathing, exhalation is passive and does not require muscle contraction. The elastic recoil of the lungs and chest wall helps both structures return to their resting positions after inhalation. When the muscles used for inhalation stop working, the diaphragm and external intercostal muscles relax. The diaphragm moves upward, and the ribs move...

factors affecting pulmonary ventilation

What Changes Breathing Ease in the Lungs

Breathing ease in the lungs depends on alveolar surface tension, lung compliance, and airway resistance. These factors affect how hard it is to move air during pulmonary ventilation, along with the pressure difference between the outside environment and the lungs. Alveolar surface tension comes from the fluid lining the inside of the alveoli. Water molecules in this fluid attract each other more strongly than they attract the air, so the liquid tends to pull the alveoli inward. That force must...

respiratory volumes and capacities

Lung Volume Measurements in Breathing

Lung volume measurements show how air moves in and out of the respiratory system during breathing. They help explain how the body takes in oxygen and removes carbon dioxide. Respiratory volumes and capacities also give useful information about lung function. Tidal volume is the air breathed in and out during normal, quiet breathing. Inspiratory reserve volume is the extra air that can be forcefully inhaled beyond tidal volume. Expiratory reserve volume is the extra air that can be forcefully...

physical principles governing gas exchange

physical-principles-governing-gas-exchange

Gas Laws in Lung Gas Exchange

Gas laws explain how oxygen and carbon dioxide move during respiration. External respiration is the exchange of gases in the lungs. Oxygen diffuses into the blood, and carbon dioxide diffuses out. Internal respiration happens in body tissues, where the gases move in the opposite directions. Two gas laws guide this process: Dalton's law of partial pressures and Henry's law. Dalton's law says the total pressure of a gas mixture equals the sum of the pressures of each gas acting alone. The...

external and internal respiration

Gas Exchange in Lungs and Tissues

Gas exchange in the lungs and body tissues moves oxygen into the blood and removes carbon dioxide. External respiration happens in the lungs, where inhaled oxygen enters the alveoli, the tiny air sacs that provide a large surface area for diffusion. Oxygen moves across the thin alveolar membrane into the pulmonary capillaries because its partial pressure is higher in the alveoli than in the blood. At the same time, carbon dioxide moves in the opposite direction and is later breathed out during...

oxygen transport in the blood

How Hemoglobin Loads and Releases Oxygen

Hemoglobin is the main molecule that carries oxygen in blood. It is found in red blood cells and has four polypeptide chains, each attached to an iron-containing heme group. This structure lets one hemoglobin molecule bind up to four oxygen molecules quickly and reversibly. When hemoglobin is fully loaded with oxygen, it is called oxyhemoglobin. When it has released oxygen, it is called reduced hemoglobin, or deoxyhemoglobin. As hemoglobin binds oxygen, its shape changes, which helps it pick...

carbon dioxide transport in the blood

How Blood Carries Carbon Dioxide

Carbon dioxide is carried in the blood from body tissues to the lungs. Cells make about 200 mL of CO2 each minute, and the lungs remove about the same amount. The blood moves this waste gas in three main forms. A small amount, about 7-10%, stays dissolved in the plasma. Just over 20% binds to hemoglobin and forms carbaminohemoglobin. In this case, CO2 attaches to the amino acids of globin, not to the heme part of hemoglobin. The rest, about 70%, is carried as bicarbonate ions, or HCO3-. CO2...

hypoxia

Hypoxia: Types and Carbon Monoxide Poisoning

Hypoxia is a medical condition in which body tissues do not get enough oxygen. It can cause a bluish color in the skin and mucosae, especially in fair-skinned people. This sign is often seen when hemoglobin (Hb) saturation drops below 75%. Hypoxia can happen for several different reasons. Anemic hypoxia occurs when there are too few red blood cells (RBCs) or when RBCs have abnormal or too little Hb. Ischemic hypoxia comes from poor blood circulation or blocked blood flow, so blood becomes...

neural control of respiration

Brainstem Centers That Control Breathing

Breathing is controlled by nerve centers in the brainstem. These respiratory centers send nerve signals to the muscles that move the lungs. The main centers are in the medulla oblongata and the pons.

chemical factors affecting respiration centers

chemical-factors-affecting-respiration-centers

How Blood Gases Control Breathing Rate

Blood gases and blood pH help control breathing rate and depth. Changes in carbon dioxide, oxygen, and hydrogen ion levels in arterial blood are detected by chemoreceptors, which are special sensors in the body. Central chemoreceptors are found throughout the brain stem, including the ventrolateral medulla. Peripheral chemoreceptors are located in the aortic arch and carotid arteries. Together, these sensors help the respiratory system respond to chemical changes in the blood. Carbon dioxide...

other factors affecting respiration centers

other-factors-affecting-respiration-centers

Respiratory Reflexes That Change Breathing

Breathing is controlled by the brainstem, but it can also be changed by the nervous system and by body signals. The cerebral motor cortex can override the medullary respiratory centers and send signals directly to the breathing muscles. This makes voluntary actions like holding your breath or taking deeper breaths possible. That control is limited. When carbon dioxide, or CO2, builds up in the blood to a critical level, the brainstem respiratory centers start breathing again. This is why a...

hyperpnea and hyperventilation

Breathing Changes in Exercise and Anxiety

Breathing changes in exercise and anxiety can look similar, but they do not have the same cause. Hyperventilation is a higher-than-normal rate and depth of breathing. It often happens during anxiety attacks and can push out more carbon dioxide than the body needs to remove. When too much carbon dioxide is lost, the blood develops hypocapnia, which means an unusually low level of carbon dioxide. Hypocapnia can narrow cerebral blood vessels and reduce blood flow to the brain. This may cause...

chronic obstructive pulmonary disease

COPD Signs, Causes, and Lung Damage

COPD is a lung condition that causes ongoing breathing problems. It leads to shortness of breath, cough, and sputum production because the airways become blocked and airflow is reduced. Smoking is the main risk factor for COPD, and more than 80% of patients have a history of it. People with COPD often develop worsening dyspnea, or labored breathing. They may also cough often and get repeated lung infections. Many patients with COPD can develop respiratory failure. This happens when...

other pulmonary disorders

Asthma, TB, Lung Cancer, and Sleep Apnea

Asthma, lung cancer, tuberculosis, and sleep apnea are major pulmonary disorders. They affect breathing in different ways. Some are chronic, some are infectious, and some can become life-threatening if not found and treated early. Asthma is marked by chronic airway inflammation and hypersensitivity. It can cause airway obstruction from bronchial spasms, mucosal edema, increased mucus secretion, or epithelial damage. Triggers vary and can include allergens or emotional upset. Treatment often...

key terms and concepts

Learn how exhalation works through pressure changes, when breathing becomes active, and how conditions like RDS, atelectasis, and bronchitis affect ventilation.

Exhalation and Lung Pressure Changes | JoVE K12

anatomy and physiology

JoVE Core Anatomy and Physiology showcases the anatomical and physiological details of the human body in comprehensive, clear, and engaging video animations. This collection of lessons focuses on the structures, components, functions, and requirements of the human body. It is complemented by scientist-in-action videos that demonstrate the application of this knowledge in real-world medical and research settings.

Alabama Course of Study Science

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms: Structures and Processes

9-12.HA.1.9.b

Florida Department of Education

High School

Life Science

SC.912.L.14

SC.912.L.14.44

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Saliva is composed of 97 to 99.5% water. The remaining proportion includes enzymes such as lipases and amylases, electrolytes, dissolved gasses, IgA, ...

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&#160;The gums, or gingivae, of both the mandible and maxilla hold the ...

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The crown is visible above the gingivae and is protected by enamel.
...

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It courses through the mediastinum ...

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Deglutition, or swallowing, is a mechanism that transports food from the mouth to the stomach.
This process has three stages &#8212; the buccal, ...

Gross Anatomy of the Stomach

The stomach is a J-shaped organ connecting the esophagus to the duodenal end of the small intestine in the abdominal cavity.
The size and shape of the ...

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The stomach wall consists of several layers, including the serosa, muscularis externa, submucosa, and mucosa.
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The specialized enteroendocrine cells of the gastric glands secrete most of the digestive hormones.
These cells, such as the G, D, and ...

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The cephalic phase ...

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Cirrhosis is a liver ...

Intestinal Phase of Digestion

After the gastric phase, the chyme from the stomach moves into the small intestine, gradually decreasing the stomach distention.
In contrast, the arrival ...

Pancreas

The pancreas is a pinkish-gray organ located behind the stomach. It extends from the duodenum to the spleen.
It can be divided into a broad head located ...

Mucosal Barrier of the Stomach

In the gastric glands, the parietal cells are involved in hydrochloric acid or HCl formation.
These cells first synthesize carbonic acid, which ...

Pancreatic Juice and Secretion

Pancreatic juice is a colorless liquid composed of water, salts, sodium bicarbonate, and enzymes secreted by the exocrine cells.
During digestion, chyme ...

Gastric Motility

Gastric motility is the coordinated movement of stomach muscles and secretions, which propels food and liquids through the stomach.
As the swallowed food ...

Small Intestine

The small intestine is a tubular structure extending from the pyloric sphincter of the stomach to the ileocecal valve of the large intestine.
This long, ...

Gastric Emptying

Gastric emptying is the gradual release of chyme from the stomach into the duodenum.
Stomach distention triggers the gastroenteric reflex, releasing ...

Histology of the Small Intestine

The histology of each part of the small intestine varies. The jejunum has the most prominent folds and villi, while the distal ileum has fewer folds but ...

Gross Anatomy of the Liver

The liver is the largest gland in the body, weighing approximately 1.4 kg in adults.
It is wedge-shaped and located more in the right hypochondriac and ...

mechanical-and-chemical-digestion-in-the-small-intestine

Mechanical and Chemical Digestion in the Small Intestine

The small intestine plays a crucial role in our digestive system, performing both mechanical and chemical digestion.
Mechanical digestion in the small ...

Liver Histology

The liver comprises several histological components, such as hepatocytes, bile canaliculi, and sinusoids.
Hepatocytes are specialized epithelial cells ...

Large Intestine

The large intestine is divided into three main regions: the cecum, colon, and rectum. Extending from the ileocecal valve to the anus, it frames the small ...

Bile

Bile is a yellow-green alkaline liquid secreted by the liver into the right and left hepatic ducts and then into the common hepatic duct. From here, it ...

Histology of the Large Intestine

The large intestine, a vital component of the gastrointestinal tract, is structured with four main layers: the mucosa, submucosa, muscularis, and serosa. ...

Gallbladder

The gallbladder is a muscular sac located in a shallow fossa on the inferior surface of the liver. It measures about 10 cm in length and is roughly the ...

Bacterial Flora of the Large

Intestine

The vast and varied community of bacteria colonizing the large intestine forms the gut microbiome.
Bacteria start residing in the gut at birth and ...

Liver Physiology

Liver functions primarily include bile production, metabolic regulation, and hematological functions.
During carbohydrate metabolism, the liver regulates ...

digestive-functions-of-the-large-intestine

Digestive Functions of the Large Intestine

The final stages of digestion occur in the large intestine when the cecum receives chyme, which has little nutritional value except for the indigestible ...

Absorption of Nutrients

During digestion in the small intestine, macromolecules&#8212; carbohydrates, proteins, and fats &#8212; are broken down into their simplest forms.
These ...

Feces Formation and Defecation

After spending 3 to 10 hours in the large intestine, chyme loses a lot of water and becomes feces, the final product of digestion. Feces consist of ...

Other Disorders of Digestive System

The gastrointestinal tract of the digestive system is susceptible to various disorders.
The incompetence of the lower esophageal sphincter results in the ...

Digestive System

Content elaboration: The digestive system consists of the gastrointestinal tract (alimentary canal) as well as various accessory organs including the teeth, tongue, salivary glands, liver, gallbladder and pancreas. The digestive system processes and supplies the molecules needed to sustain the living tissues within the body through the absorption of nutrients. Six major functions of the digestive system include secretion, ingestion, mechanical processing, enzymatic digestion, absorption and excretion. The lining of the digestive system protects surrounding tissues from the mechanical and enzymatic stresses of the digestive process. Processes of the digestive system include the mechanical and chemical breakdown of food into small molecules which are then absorbed by the digestive tract. Specific actions within the digestive system include mastication, peristalsis, segmentation and the release of hormones and enzymes necessary for digestion. The metabolic functions of the accessory organs play strategic roles in the breakdown of food products, the maintenance of glucose levels within the blood and the regulation of homeostasis in the body. Indigestible material is excreted as waste. Homeostatic imbalances are explored. These include, but are not limited to, conditions such as gallstones, heartburn, ulcers, dehydration, diarrhea, cirrhosis and cancers of the digestive system. Investigations are used to understand and explain the digestive system in a variety of inquiry and design scenarios that can incorporate evolutionary concepts, scientific reasoning, comparative analysis, communication skills and real-world applications.

Digestive System

Exhalation and Lung Pressure Changes

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