Unlike the rectum above it, the canal is liberally supplied by somatic sensory nerves, so that a poorly directed finger or instrument will produce pain. The rectum begins at the termination of the sigmoid colon about 12 cm from the anal verge .Two muscle bundles, known as the internal and external anal sphincters, participate in defecation. The internal anal sphincter is an enlargement of the circular smooth muscle of the colon and functions involuntarily. The external anal sphincter consists of striated muscle bands under the voluntary control of the puborectalis muscle. The rectum has the same innervation as the bladder; the hypogastric nerves innervate the internal anal sphincter, and the internal pudendal nerve (S3–S4) operates the external anal sphincter.
The cough reflex has both sensory (afferent) and motor (efferent) components. Pulmonary irritant receptors (cough receptors) in the epithelium of the respiratory tract are sensitive to both mechanical and chemical stimuli. Stimulation of the cough receptors by dust or other foreign particles produces a cough, which is necessary to remove the foreign material from the respiratory tract before it reaches the lungs. A long drawn and deep inhalation followed by a complete closure of the glottis, which results in a strong exhalation that suddenly punches the glottis open and sends a blast of air through the upper respiratory passages. C) Which structures found in the terminal bronchioles and alveoli normally would protect Cari’s lungs from infectious pathogens and particulate matter?
They come together at the glomerulus, a structure which transmits signals to the olfactory bulb (a brain structure directly above the nasal cavity and below the frontal lobe). [2] Many vertebrates, including most mammals and reptiles, have two distinct olfactory systems—the main olfactory system, and the accessory olfactory system (used mainly to detect pheromones). For air-breathing animals, the main olfactory system detects volatile chemicals, and the accessory olfactory system detects fluid-phase chemicals. [3] Olfaction, along with taste, is a form of chemoreception. The chemicals themselves that activate the olfactory system, in general at very low concentrations, are called odorants.
The head of the humerus is called the glenoid fossa and the cavity of the scapula is called the glenoid cavity, these two fit together to form the glenohumeral joint. The glenoid fossa is large when compared to the small surface area of the glenoid cavity, making the joint shallow and not supplying a snug fit. Although this allows a wide range of movement, it also makes it susceptible to injury such as dislocation. To make the joint structure more stable, it is held together by three components; ligaments,
Which substances, other than gastric acid, are secreted by the stomach? Describe their secreted and physiological roles. o Two main tubular glands are present in the stomach mucosa: • Oxyntic/gastric glands • Pyloric glands In addition, mucus-secreting cells line the entire surface of the stomach (surface mucous glands). These secrete large quantities of a very viscid mucus that coats the stomach mucosa with a gel layer of mucus, often more than 1mm thick. These glands provide a major shell of protection for the stomach wall and contribute to lubrication of food transport.
In one area of the body, it is used to line the esophagus to protect it from stomach acid. (Thompson, 2013) • Cutaneous membrane: This is the body's largest membrane the skin. It consists of a layer of epithelium resting on a layer of connective tissue. (Thompson, 2013) • Serous membrane: composed of three simple squamous epithelium resting on a thin layer of areolar connective tissue, serous membranes line some of the closed body cavities and also cover most of the organs in those cavities. (Thompson, 2013) • Connective membrane: some joints are lined by membranes made of connective tissue (Thompson, 2013) • Mucus membrane: Lines the body’s surfaces that are opened to the exterior.
Diverticulitis By Raymond Laster Ms. Cameron A digestive disease that involves the forming of pouches inside of the walls of the bowels is called Diverticulitis. Changes usually happen inside of large intestine also known as the colon and sometimes inside of the small intestine. When the mucosal and the submucosal layers of the G.I. tract bulge through the outer muscular layer, at this point the disease is called diverticulosis. When one of the diverticula become inflamed, this causes diverticulitis.
But an injury can inflame the cornea without a secondary infection occurring. Viral keratitis occurs quite commonly and the types of viruses include: Adenovirus, which is one of the causes of upper respiratory infections. Herpes simplex type 1, and Varicella zoster. Bacterial keratitis occurs less often than viral keratitis. Infectious keratitis usually begins by affecting the outer layer of the cornea, but it can go deeper into the cornea, increasing the risk of impaired vision.
The conjunctiva is exposed to bacteria and other irritants. Tears help protect the conjunctiva by washing away bacteria. Tears also contain enzymes and antibodies that kill bacteria • Allergic conjunctivitis Is typically itchy, sometimes distressingly so, and often involves some eye swelling. Chronic allergy often causes just itching or irritation. Allergic conjunctivitis shows pale watery swelling of the conjunctiva and sometimes the whole eyelid, often with a ropy, non-purulent mucoid discharge.
It also helps protect the trachea by producing a strong cough reflex if any solid objects pass the epiglottis. Lower Respiratory Tract Trachea: Also known as the windpipe this is the tube which carries air from the throat into the lungs. It ranges from 20-25mm in diameter and 10-16cm in length. The inner membrane of the trachea is covered in tiny hairs called cilia, which catch particles of dust which we can then remove through coughing. The trachea is surrounded by 15-20 C-shaped rings of cartilage at the front and side which help protect the trachea and keep it open.