Through the actions of pepsin and the squeezing properties of the stomach, the food bolus enters the intestines as a liquidy mixture of partially digested food particles, called chyme. When pepsinogen and hydrochloric acid exist together in the gastric juice, pepsin takes its active form. Parietal cells produce HCl by secreting hydrogen and chloride ions. Hydrochloric acid (HCl), another component of the gastric juice, plays a crucial role in creating the pH required for pepsin activity. Since chief cells release pepsin as a zymogen, activation by an acidic environment is necessary. By doing so, the stomach prevents the auto-digestion of protective proteins in the lining of the digestive tract. Specific cells within the gastric lining, known as chief cells, release pepsin in an inactive form, or zymogen form, called pepsinogen. It breaks down proteins into smaller peptides and amino acids that can be easily absorbed in the small intestine. Of these five components, pepsin is the principal enzyme involved in protein digestion. Asides from squeezing and churning the food bolus, it also secretes a mixture of compounds, collectively known as "gastric juice." Gastric juice comprises water, mucus, hydrochloric acid, pepsin, and intrinsic factor. The stomach plays a critical role in the early stages of food digestion. The food bolus then travels down the esophagus via wave-like muscular contractions, called peristalsis, before it reaches the stomach. Saliva is rich in mucus and salivary enzymes, and together, with the effects of mastication, it creates a mass called a food bolus. Once food enters the mouth, it mixes with saliva and gets chewed through the process of mastication. Chemical digestion is the enzymatic cleavage of proteins, carbohydrates, and fats into tiny amino acids, sugars, and fatty acids. Mechanical digestion is the physical degradation of large food particles into smaller pieces that digestive enzymes can access through chemical digestion. Digestion takes place in the gastrointestinal tract in two principal forms: mechanical and chemical. It begins with ingestion and ends with defecation. The antidiuretic hormone vasopressin is also secreted by the hypothalamus.Food digestion is the breakdown of large food particles into smaller absorbable nutrients needed for energy production, growth, and cellular repair. The hormone oxytocin plays an important role in uterine contractions and lactation. and inhibit the production of prolactin (by releasing dopamine), growth hormone (by releasing somatostatin), etc.
Hormones released by the hypothalamus stimulate the release of other hormones like thyrotropin, prolactin, gonadotropin, corticotropin, growth hormone, etc. It also leads to disturbances in the brain. Dysfunction of the hypothalamus results in depression or abnormal responses to stress. As we grow older, hypothalamus requires support to maintain optimum level of performance. Located near the pituitary gland at the basal part of the skull (above the brain stem), it controls pituitary secretions.Īll the automatically adjusted factors such as hunger, thirst, sleep, emotional behavior such as anger and sexual activity, body temperature, blood pressure, function of the cardiovascular system (heart rate), and abdominal visceral regulation are controlled by the hypothalamus. It plays an important role in certain metabolic processes. The autonomic nervous system is governed by the hypothalamus. Hypothalamus (part of the brain) is known as the ‘control and relay center of the endocrine system’. The hypothalamus controls pituitary secretions
0 kommentar(er)
