Animal Tissue and Anatomy

The labyrinth is the complex bony structure of the inner ear that contains the cochlea and vestibular system. It's essential for hearing and balance.

The trachea, commonly called the windpipe, is the tube that connects the pharynx and larynx to the lungs, allowing air to pass through.

The skin is the largest organ in the human body. It covers the entire body surface with an area of approximately 20 square feet and weighs about 6 pounds in an average adult, making it larger than any internal organ.

Diphtheria is a bacterial infection that primarily affects the throat and respiratory tract. It causes a thick coating to develop in the throat, making breathing difficult. The other options (gums, ears, muscles) are not the primary sites of diphtheria infection.

Jaundice is a condition characterized by yellowing of skin and eyes due to elevated bilirubin levels. The liver is responsible for processing bilirubin, so liver dysfunction is the primary cause of jaundice, making option D correct.

Pyorrhoea (also called periodontal disease or periodontitis) is a gum infection that damages the soft tissue and bone supporting the teeth. It primarily affects the gums, making option C correct. Bones, abdomen, and liver are not the primary affected areas.

Typhoid fever is a bacterial infection caused by Salmonella Typhi. It primarily affects the intestines, causing intestinal inflammation and ulcers. The bacteria also spread through the bloodstream. The intestines (option B) are correct, not lungs or liver.

'Chest' is the odd one out. Nose, lip, and ear are all facial features located on the head. Chest is a torso/body region, not on the face. The other three are specific sensory or prominent features of the face, while chest refers to the front of the upper body.

Among these body parts, the chest is the only one that is not primarily a sense organ. The ear (hearing), lip (taste), and nose (smell) are all involved in sensory perception. The chest contains vital organs like the heart and lungs but is not classified as a sense organ.

The liver is the second-largest organ in the human body after skin (which is the largest overall). It is also the largest internal organ, performing vital metabolic functions. The heart, brain, and spleen are not the second-largest.

A synapse is the junction between two nerve cells (neurons) where electrical signals are converted to chemical signals via neurotransmitters. It is not related to the bile duct, blood vessels, or heart chambers.

Gangrene is the local death of body tissue (necrosis) due to loss of blood supply or bacterial infection. Leprosy (Hansen's disease) is a chronic infectious disease affecting skin and nerves. Frostbite is tissue damage from freezing. Necrophilia is a psychological condition unrelated to tissue death.

The liver is the largest internal organ by weight, averaging 1.4-1.6 kg in adults. It performs vital functions including detoxification, protein synthesis, and bile production. The skin is actually the largest organ overall by weight and surface area, but among internal organs listed, the liver dominates. The brain weighs about 1.3-1.4 kg, making it second among internal organs.

The French word 'livre' translates to 'book' in English. It's a false friend - 'liver' in English is an organ, while 'livre' is a book in French.

The orbicularis oris is the circular muscle that surrounds the mouth and is responsible for lip movements like puckering, closing, and kissing. This muscle encircles the oral opening and controls lip shape and position. The other options - infraspinatus, deltoid, and latissimus dorsi - are muscles located in the shoulder and back regions, not involved in facial expressions.