Human Physiology: Circulatory, Respiratory and Digestive Systems

The splenic artery branches off from the aorta and the celiac trunk to deliver oxygenated blood to the spleen, while the splenic vein carries deoxygenated blood away from the spleen to the hepatic portal vein. 

Hyperbilirubinemia is excessive bilirubin in blood. It is also called jaundice. It leads to deposition of bilirubin in mucous membrane, sclera and skin so that the patient looks yellow or icterus. Urine is yellow. It is caused by obstruction in bile duct, excessive hemolysis, or viral infection.

Stomach - Foveolar cells are mucus-producing cells, which cover the inside of the stomach, protecting it from the corrosive nature of gastric acid. The mucus produced by these cells is extremely important, as it prevents the stomach from digesting itself.
Duodenum - Brunner's glands (or duodenal glands) are compound tubular submucosal glands present in the duodenum. The main function of these glands is to produce a mucus-rich alkaline secretion (containing bicarbonate) in order to: protect the duodenum from the acidic content of chyme (which is introduced into the duodenum from the stomach); provide an alkaline condition for the intestinal enzymes to be active, thus enabling absorption to take place and lubricate the intestinal walls.
Large intestine - Goblet cells reside throughout the length of the small and large intestine and are responsible for the production and maintenance of the protective mucus blanket by synthesizing and secreting high-molecular-weight glycoproteins, known as mucins. 

Human blood is slightly basic, with a normal pH range typically between 7.35 and 7.45. Option C (7.5-8.0) is the closest range provided.

Lymph does not transport oxygen (that is the role of blood/hemoglobin). Lymph returns interstitial fluid to the blood and is similar to blood plasma but lacks RBCs and certain large proteins.

All four statements are correct: CO2 is transported as bicarbonate, O2 is carried by hemoglobin, carbon monoxide binds to hemoglobin (forming carboxyhemoglobin), and pneumoconiosis is a lung disease caused by inhaling dust like coal dust.

The average resting heart rate for a healthy adult is typically between 60 and 100 beats per minute, with 72 beats per minute being the commonly cited average.

The left ventricle is the thick-walled chamber responsible for pumping oxygenated blood into the aorta, which then distributes it throughout the systemic circulation. The right side of the heart handles deoxygenated blood.

According to the principles of fluid dynamics, as the radius of a blood vessel decreases (vasoconstriction), the resistance to blood flow increases. To maintain flow, the blood pressure must increase.

Individuals with blood group AB possess both A and B antigens on their red blood cells and lack anti-A and anti-B antibodies in their plasma, making them universal recipients.

The hepatic portal vein is a unique vessel that carries nutrient-rich, deoxygenated blood from the gastrointestinal tract and spleen directly to the liver for processing before it enters the systemic circulation.

Blood transfusion is possible when the donor's antigens do not react with the recipient's antibodies. Type A blood can be donated to an AB recipient because AB lacks anti-A antibodies.

A person with blood group B has B antigens and anti-A antibodies. They can donate to those who do not have anti-B antibodies, which includes individuals with blood group B or AB.

Oxygen transport involves the lungs (uptake), blood (transport via hemoglobin), and tissues (delivery). The logical sequence of the process is lungs to blood to tissues.

Platelets are significantly more numerous in human blood than white blood cells. WBC counts are typically in the thousands per microliter, while platelet counts are in the hundreds of thousands.

If the father is blood group A (genotype AA or AO) and the mother is O (genotype OO), the possible offspring genotypes are AO or OO, resulting in blood group A or O.

All statements are correct. Arteries generally carry oxygenated blood away from the heart, except for the pulmonary artery. Veins generally carry deoxygenated blood toward the heart, except for the pulmonary vein.

Lymphocytes are a type of white blood cell produced in the primary lymphoid organs, specifically the bone marrow, where they originate from hematopoietic stem cells.

An ECG records the electrical activity of the heart over time, which allows clinicians to assess the heart rate and the regularity of the cardiac rhythm.

Coronary arteries supply the heart muscle. Pulmonary veins carry oxygenated blood from the lungs to the heart. Hepatic arteries supply the liver, not the kidneys (renal arteries do that). Renal veins drain the kidneys.

Heparin is produced by the liver and mast cells. The SA node is the natural pacemaker. Leukopenia is defined as a decrease in the number of white blood cells.

All statements are accurate. Blood pressure is the force against vessel walls; systolic/diastolic pressures correspond to heart contraction/relaxation; and the sphygmomanometer is the standard clinical tool for measurement.

Thrombin is a serine protease that plays a central role in the blood coagulation cascade by converting soluble fibrinogen into insoluble fibrin strands.

The aorta is the main systemic artery that receives blood from the left ventricle and is the largest artery in the human body.

Coronary artery disease develops when the major blood vessels that supply our heart with blood, oxygen, and nutrients become damaged or diseased. The disease is caused when plaque blocks the arteries which supply blood to the heart.

Hemoglobin is a protein present in the red blood cells. The hemoglobin carries oxygen in the blood and transfers it in our body, it is the element that gives red color to our blood. Iron works as a booster towards hemoglobin production in the blood.

The oesophagus leads into the stomach. The stomach is a muscular sac. The stomach is the most important site of protein digestion. Stomach wall has peptic cells, chief cells secrete pepsinogen and oxyntic and parietal cells secrete hydrochloric acid. The pepsinogen is activated to pepsin on exposure to hydrochloric acid. The pepsin is a chief proteolytic enzyme of the alimentary canal. Another important enzyme of the stomach is lysozyme which is antibacterial. Thus, the correct answer is option C.

The pylorus is a narrow cone shaped constriction present at the end of the stomach and the beginning of the small intestine. It contains two region antrum which connects the parts of the stomach and pyloric canal which connects the stomach and small intestine.  Thus, the correct answer is option B.

The gastric mucosa is present is in the inner wall of the stomach which secretes 1.2 to 1.5 litres of gastric juice per day. Gastric juice is a mixture of HCl, mucous and digestive enzymes which makes food particles soluble, initiates protein digestion and converts the gastric contents to a semiliquid mass called chyme, thus preparing it for further digestion in the small intestine. This juice is highly acidic because of its hydrochloric acid content, and it is rich in enzymes. 

Indigestion is inability to properly digest food resulting in abdominal distension due to gas or flatus. It is caused by overeating, spicy food, anxiety and disturbed secretions of digestive tract.

Anatomical dead space refers to the volume of the respiratory tract where gas exchange does not occur, such as the trachea and bronchi.

Gas exchange in the alveoli occurs via simple diffusion, where gases move from an area of higher partial pressure to an area of lower partial pressure across the respiratory membrane.

• The lowest part of pharynx is the laryngopharynx. It has two apertures, the anterior slit is 'glottis', through which it opens into the larynx and the posterior slit is 'gullet', which leads to the oesophagus.
• Thus, larynx opens into the pharynx by glottis. The glottis bear a leaf-like a cartilaginous flap, called the 'epiglottis'. Epiglottis cover the glottis during swallowing, to prevent the entry of food into it.
  Hence, the correct answer is B.

The palate is the roof the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior bony hard palate, and the posterior fleshy soft palate (or velum). The diaphragm, located below the lungs, is the major muscle of respiration. It is a large, dome-shaped muscle that contracts rhythmically and continuously, and most of the time, involuntarily. The trachea, colloquially called windpipe, is a tube that connects the pharynx and larynx to the lungs, allowing the passage of air. Thus, option B is correct.

Respiratory membrane must be semi- permeable in nature to allow the passage of small molecules and ions. It should also support the process of diffusion. Only large molecules are transported using channels or porins. In root, the ascent of sap takes place through simple diffusion. If cell membrane was not semi permeable then it could have never happen. If it was permeable or impermeable then it is difficult for cell to survive. Thus, option C is correct.

Air enters the body through the nose and mouth. After the nose and mouth air goes through the pharynx or throat. After the pharynx, air goes into the larynx or voice box. 

Respiratory membrane must be semi- permeable in nature to allow the passage of small molecules and ions. It should also support the process of diffusion. only large molecules are transported using channels or porins. In root, the ascent of sap takes place through simple diffusion. If cell membrane was not semi permeable then it could have never happen. If, it was permeable or impermeable then it is difficult for cell to survive. 

Smoking is a practice in which a substance is burned and the smoke is breathed in and absorbed into the bloodstream. Most commonly used substance is the dried leaves of the tobacco plant. Smoking is primarily practised for recreational drug use.
 The combustion of the dried plant leaves vaporizes and delivers active substances into the lungs where they are rapidly absorbed into the bloodstream and reach bodily tissue. 
Smoking generally has negative health effects, because smoke inhalation may cause effects on physiologic processes such as respiration.
Hence, the smoke inhaled by the respiratory system.
So, the correct option is ' the respiratory system'.

Puncturing the thoracic wall (pneumothorax) disrupts the negative intrapleural pressure required to keep the lungs inflated against their natural elastic recoil, leading to lung collapse and respiratory failure.

Actually, only about 350 mL of air (out of total 500 mL tidal volume) enters the lung alveoli for the exchange of gases. The remaining 150 mL fills the respiratory passage and is termed as dead air space because no exchange of gases takes place here.

Liver is the largest organ in the body. It helps in digestion and removes waste products and worn-out cells from the blood. Liver performs many functions, like it forms and secretes bile that contains bile acids to aid in the intestinal absorption of fats and the fat-soluble vitamins as A, D, E, K and $B _{12}$. Hence, it stores vitamins as A, D, E, K and $B _{12}$.

• The oral and nasal cavities lie near the body midline, inferior and medial to the orbital cavities, anterior to the pharynx and medial to the infratemporal fossa.
• They are separated from one another by the palate. 
• Each cavity has an entrance and an exit. Hence, Nasal chambers and buccal cavity are separated by the palate.

Pharynx  connects the nasal cavity and mouth to the larynx and esophagus. It is the common pathway for food and air. There are three regions nasopharynx, oropharynx, and laryngopharynx. Nasopharynx  an air passage; uvula prevents food from entering it during swallowing. Oropharynx posterior to the mouth, passageway for food and air. Laryngopharynx passageway for food and air. Directly posterior to the epiglottis and extends to the larynx, then becomes continuous with esophagus. 

Small intestine is made up of three parts- duodenum, jejunum and ileum. The intestinal wall bears microscopic finger like projections called villi. The Mucosa layer forms crypts in between the bases of villi in the intestine (crypts of Lieberkuhn). The crypts produce digestive juice.

Various smooth muscle sphincters regulate the flow of bile and pancreatic juice through the ampulla: the sphincter of the pancreatic duct, the sphincter of the bile duct, and the hepatopancreatic sphincter (Sphincter of Oddi).The sphincter of Oddi controls the introduction of bile and pancreatic secretions into the duodenum, as well as preventing the entry of duodenal contents into the ampulla.

Folds of small intestine are conical shaped villi.  Small slit like space is found at the base of villi. These spaces are called crypts of Lieberkuhn. The crypts of Leiberkuhn secrete succus entericus or intestinal juice. The succus entericus mainly contains water (99%) and various digestive enzymes (1%). 

Gastric pits are depressions in the stomach lining. Scientific literature estimates the density of these pits to be approximately 300 per square millimeter.

• The liver breaks down and filters out harmful substances in the body. It also converts vitamins, nutrients and medicines into substances that our bodies can use.
•  A central role in the toxicity of alcohol may be played by acetaldehyde itself. Although the liver converts acetaldehyde into acetic acid, it reaches a saturation point where some of it escapes into the blood stream.
•  The accumulated acetaldehyde exerts its toxic effects by inhibiting the mitochondria reactions and functions. Hence, The reason why the liver of alcohol addicts gets damaged is that it Accumulate excess of fats.

Liver along with muscles stores excess glucose as glycogen, which can be used in times of starvation to maintain blood glucose levels. Excess carbohydrates are also stored as fat in adipose tissue around visceral organs and underneath the skin. During starvation the fat in the adipose tissue can be metabolised to derive energy.