Understanding The Digestive System: Propulsion, Secretion, Mechanical And Chemical Digestion, Absorption, And Defecation

Digestive system is one of the major systems in the human and other living animals. The process of digestion is more important in case of pregnancy, because during pregnancy the uterus of the pregnant women expands and causes pressure on the wall of stomach and on pelvic veins, thus digestion issues occurs.
On the other hand, most of the pregnant women suffer from constipation. One of the main reason is the increasing progesterone that relaxes the smooth muscles including the digestive tract, thus food passes through the intestine at a slower rate.
Proper nutritional diet is important during pregnancy in order to avoid such digestion issues in an effective manner and remain healthy to give birth to a healthy child (Verghese, Futaba and Latthe 2015).
This clinical scenario is about Digestive System- in which a midwifery setting needs to design a poster to inform pregnant patients about eating, nutrition and constipation and need to explain some key knowledge required by patients such as constipation and include some nutritional recommendations to prevent constipation during pregnancy.
The assignment will also explain the normal structure and function of the digestive system, and include reference to the normal processes of eating, digestion, and excretion.
The assignment will include important information on how the digestive system and the cardiovascular system are interrelated in normal digestion.

Overview of the digestive system:

The digestive system is made of gastrointestinal tract and some accessory organs for digestion such as teeth, =tongue, salivary gland, liver, pancreas and gallbladder.
The process digestion occurs through a number of stages that starts in the mouth.
The process of digestion includes breakdown of food into smaller particles until the condition of absorption and assimilation into the body (Rizzo 2015).

The digestive tract (alimentary canal) is a continuous tube with two openings: the mouth and the anus. It includes the mouth, pharynx, esophagus, diaphragm, stomach, small intestine, and large intestine.
Food passing through the internal cavity, or lumen, of the digestive tract does not technically enter the body until it is absorbed through the walls of the digestive tract and passes into blood or lymphatic vessels.
- Mouth: It is the first part of gastrointestinal tract including salivary gland, teeth and tongue. The process of digestion starts in the mouth.
- Pharynx: It is the part of the conductive zone of respiratory system and digestive system. It is present as the part of throat behind the nasal cavity. The two lower parts of pharynx that is oropharynx and laryngopharynx are involved in the process of digestion. Laryngopharynx is connected to the esophagus and it acts as the passageway for both the food and air.
- Esophagus: It is the muscular tube through which food passes from the pharynx to stomach.
- Diaphragm: It is one of the important parts of the digestive system that separates the thoracic cavity from the abdominal cavity in which most of the major digestive organs are located. The esophagus enters the abdomen through the hole of the diaphragm.
- Stomach: It is the major part of gastrointestinal tract. The upper portion of the stomach is joined to the esophagus and the lower part is joined to duodenum. Most of the digestive enzymes are present in the stomach that helps in digestion.
- Small intestine: After one hour of ingestion food starts to arrive in the small intestine. It is made up of duodenum, jejunum and ileum. Most of the food digestion occurs in the small intestine.
- Large intestine: It is the passage for the digest food to reach colon. It is made up of rectum and anal canal (Patton 2015).
Accessory organs include the teeth and tongue, salivary glands, liver gallbladder, and pancreas (Rizzo 2015).
Function: The main functions of digestive system include ingestion, secretion, mixing, digestion, absorption and excretion (VanPutte, Regan and Russo 2013).

Ingestionis the process of eating.
Propulsionis the movement of food along the digestive tract. The major means of propulsion is peristalsis, a series of alternating contractions and relaxations of smooth muscle that lines the walls of the digestive organs and that forces food to move forward.
Secretionof digestive enzymes and other substances liquefies, adjusts the pH of, and chemically breaks down the food.
Mechanical digestionis the process of physically breaking down food into smaller pieces. This process begins with the chewing of food and continues with the muscular churning of the stomach. Additional churning occurs in the small intestine through muscular constriction of the intestinal wall. This process, called segmentation, is similar to peristalsis, except that the rhythmic timing of the muscle constrictions forces the food backward and forward rather than forward only.
Chemical digestionis the process of chemically breaking down food into simpler molecules. The process is carried out by enzymes in the stomach and small intestines.
Absorptionis the movement of molecules (by passive diffusion or active transport) from the digestive tract to adjacent blood and lymphatic vessels. Absorption is the entrance of the digested food (now called nutrients) into the body.
Defecationis the process of eliminating undigested material through the anus (Patton 2015).

Correlation of digestive system and cardiovascular system:

Digestive system provides nutrients to blood vessels, absorbs iron needed for hemoglobin synthesis, absorbs water necessary for normal plasma volume, liver secretes bilirubin resulting from hemoglobin breakdown in bile and stores iron for reuse.
Cardiovascular system transports nutrients absorbed by alimentary canal to all tissues of body, distributes hormones of the digestive tract.
It is important for the normal function of the body to supply adequate oxygen and nutrients to the body and remove CO₂and other waste materials.
The cardiovascular system ensures the transport of blood that carries oxygen and nutrients to the cells and carry CO₂and other waste materials away from the cells.
In addition the cardiovascular system carries some signals from the endocrine system in order to control the speed of digestion (Golubeva et al.2015).

Constipation in pregnancy is probably caused by rising progesterone levels that relaxes the smooth muscles including the digestive tract, thus food passes through the intestine at a slower rateLow fluid and fiber intake may also be contributing factors.
There is some evidence that pregnant women consume less fiber than is currently recommended for the non-pregnant population. Low fluid intake has been linked to constipation in pregnancy, particularly in the third trimester.
Some medications taken during pregnancy, such as iron salts and magnesium sulphate, have been also been linked to constipation. Hypothyroidism may also be a rare cause of constipation during pregnancy (Verghese, Futaba and Latthe 2015).

Nutritional requirements:

Eat a high fiber diet: Ideally, you will consume 25 to 30 grams per day of dietary fiber from fruits, vegetables, breakfast cereals, whole grain breads, prunes and bran.
Drink a lot of fluids: Drinking plenty of fluids is important, particularly when increasing fiber intake. Drink 10 to 12 cups of fluids each day. It is the combination of a high fiber diet and plenty of liquids that best help you eliminate your waste. Sweat, hot/humid climates, and exercise may increase your need for additional fluids.
Exercise routinely:If you are inactive, you have a greater chance of constipation. Walking, swimming and other moderate exercise helps the intestines work by stimulating your bowels. Schedule exercise three times a week for 20-30 minutes each.
Over-the-counter remedies: There are over-the-counter products such as Metamucil (Category B)which may help soften your bowel movements and reduce constipation. Always speak to your health care provider before using over-the-counter medications.
Reduce or eliminate iron supplements: Iron supplements may contribute to constipation. Good nutrition can often meet your iron needs during pregnancy. Taking smaller doses of iron throughout the day rather than taking it all at once can reduce constipation. Talk to your health care provider about checking your iron levels and recommendations to manage iron intake during pregnancy.
Try other prenatal vitamins: In some cases the prenatal vitamins contains large amount of irons, thus the pregnant women could ask to the health professional to switch the vitamins with some less iron containing supplement (Rungsiprakarn et al. 2015).

Motility disturbances of the gastrointestinal tract are commonduring normal and uncomplicated pregnancy.
In some cases due to constipation other severe conditions may arise for example, abdominal pain and diarrhea with mucus, puss and blood.
Thus, patients that are suffering from severe symptoms should be investigated properly and take proper recommendations from the health professionals immediately (Verghese, Futaba and Latthe 2015).