What three organs Cannot pass through food?

Food is an essential part of life that provides nutrients and energy to keep our bodies functioning. After being chewed and swallowed, food passes through the digestive system, where nutrients are absorbed into the bloodstream. However, there are three major organs that food does not actually pass through during digestion.

The Digestive Process

Let’s first go over the path food takes through the digestive system:

1. Food enters the mouth where it is chewed and mixed with saliva.
2. The chewed food then travels down the esophagus to the stomach.
3. In the stomach, food is further broken down by stomach acids and churning motions.
4. The partially digested food (now called chyme) exits the stomach and enters the small intestine.
5. In the small intestine, nutrients are absorbed from the chyme into the bloodstream.
6. The leftover waste then moves into the large intestine where water is absorbed.
7. Finally, the remaining waste (feces) is stored in the rectum until it can be eliminated from the body through the anus.

Now that we’ve reviewed the basic path food takes, let’s look at the three organs that food does not actually pass through.

The Heart

The first organ that food does not pass through is the heart. The heart is a muscular organ located in the center of the chest. It pumps blood throughout the body via a vast network of blood vessels. Here are some key facts about the heart:

• The heart consists of four chambers – two upper atria and two lower ventricles.
• Heart valves prevent backflow of blood when the heart contracts.
• Coronary arteries supply the heart tissue itself with oxygenated blood.
• The pacemaker cells regulate the heartbeat and cause the heart chambers to contract in sequence.
• An average adult heart beats around 60-100 times per minute.

Now despite being centrally located in the thoracic cavity, the heart is not involved in the mechanical digestion process. Food chewed in the mouth never enters or passes through the heart on its way through the digestive tract. Instead, the heart pumps blood to absorb the nutrients from food after digestion occurs. So in summary, while the heart is critical for distributing nutrients after digestion, food does not directly pass through the heart organ itself.

Key Facts

• The heart pumps blood, it does not digest food.
• Food chewed in the mouth never enters or passes through the heart.
• The heart provides blood flow to digest food but is not part of the digestive tract.

The Liver

The second organ that food does not pass through is the liver. The liver is the largest internal organ, located in the upper right side of the abdomen behind the ribs. It performs many essential functions including:

• Bile production – bile helps digest fats and eliminate waste.
• Filtration of blood from digestive tract before circulation.
• Metabolism of nutrients absorbed after digestion.
• Storage of vitamins, minerals, and iron.
• Detoxification of drugs, alcohol, and environmental toxins.

Despite its pivotal role in digestion and metabolism, the liver does not actually come into direct contact with food. Consumed food never enters the liver tissue itself. Instead, the liver releases bile into the small intestine to chemically break down fats. It also filters nutrient-rich blood from the digestive organs after useful substances have already been extracted from food. So the liver facilitates digestion but from behind the scenes rather than being a direct part of the mechanical pathway.

Key Facts

• The liver produces bile but does not have food pass through it.
• It filters blood after nutrients have been absorbed from food.
• The liver metabolizes nutrients but is separated from the digestive tract.

The Brain

The third and final organ that food does not pass through is the brain. The brain is the command center of the nervous system, overseeing all bodily functions. Key facts about the brain include:

• Located within the skull, protected by thick bone.
• Made up of gray and white matter composed of billions of neurons.
• Divided into main regions like the cerebrum, cerebellum, and brainstem.
• Controls thoughts, memory, speech, movement, senses, and organ function.
• Requires 20% of cardiac output and oxygen despite being only 2% of body weight.

Now the brain is absolutely essential for triggering digestion by releasing hormones like ghrelin to stimulate hunger when nutrients are needed. Sensory impulses from the mouth and nose also pass through the brain when food is consumed. However, the food itself does not enter the brain or pass through any neural tissue. The blood-brain barrier selectively allows oxygen, glucose, and other beneficial molecules to enter but excludes larger foreign particles. So in summary, the brain indirectly regulates digestion through nerves and hormones but does not come into direct physical contact with food.

Key Facts

• The brain controls appetite and digestion through hormone release.
• Food does not enter or pass through the brain itself.
• The blood-brain barrier keeps neural tissue separate from food particles.

Where Does Food Actually Go?

Now that we’ve covered where food does NOT go, let’s discuss the organs and structures that food actually does pass through in the digestive tract:

Mouth

• Food enters the mouth where chewing occurs.
• Saliva moistens and lubricates food into a bolus.
• Enzymes like amylase start breaking down carbohydrates.
• The tongue helps manipulate the food for swallowing.

Esophagus

• The esophagus transports the swallowed food from mouth to stomach via peristalsis.
• Upper and lower esophageal sphincters control entry of food from mouth and into stomach.
• The inner layer of the esophagus is lined with mucus to ease passage of food.

Stomach

• The stomach stores swallowed food and mixes it with gastric juices.
• Gastric glands release hydrochloric acid and protease enzymes to digest proteins.
• Powerful churning contractions break food into chyme.
• The pyloric sphincter regulates emptying of chyme into the small intestine.

Small Intestine

• The majority of nutrient absorption occurs in the 20+ feet of small intestine.
• Villi lining the walls increase surface area for absorption into bloodstream.
• Pancreatic enzymes, liver bile, and intestinal juices all aid chemical digestion here.
• Absorbed nutrients like amino acids and simple sugars enter capillaries in the intestinal walls.

Large Intestine

• The large intestine reabsorbs about 90% of the water from undigested material.
• Microbes in the large intestine ferment fiber and produce beneficial compounds.
• Material is stored as feces before eventual elimination via the rectum.

So in summary, while the heart, liver, and brain are all vital organs for overall digestion and metabolism, they do not actually have food pass through them. Only the gastrointestinal organs like the mouth, esophagus, stomach, and intestines come into direct contact with food during the digestive process.

Digestive System Review

Let’s do a quick review of the key points:

• The digestive system allows the body to extract nutrients and energy from food.
• Food is chewed in the mouth, swallowed down the esophagus, and digested in the stomach and intestines before waste is eliminated.
• The heart, liver, and brain are critical organs but do NOT have food pass through them.
• The heart pumps nutrient-rich blood but does not contact ingested food directly.
• The liver facilitates chemical digestion but remains separated from the food pathway.
• The brain regulates appetite and digestion but is protected by the blood-brain barrier.
• Only the mouth, esophagus, stomach, and intestinal organs come into direct contact with food.

Conclusion

In summary, the three organs that do not actually have food pass through them during digestion are the heart, liver, and brain. While these organs all play supportive roles, only the gastrointestinal system comes into direct physical contact with food as it travels through the digestive tract, starting from the mouth and ending with waste excretion. The heart provides circulation, the liver facilitates chemical digestion, and the brain controls appetite – but the food itself does not pass through these three organs on its journey. I hope this overview has helped explain which organs interact with food directly and which have more indirect, behind-the-scenes functions despite their importance to the digestion process overall.