Which structure is located on the sternum?

 

Digestion begins in the mouth, where the teeth break down the food and the saliva contains enzymes that start to break down carbohydrates. This process is called ingestion.

Choice A is wrong because the esophagus is a thin tube that connects the mouth to the stomach. It does not digest food, but moves it through peristalsis, which are wave-like contractions of the muscles in the gut wall.

Choice C is wrong because the stomach is a muscular bag that mixes food with acid and enzymes. It does not start digestion, but continues it, especially for proteins.

Choice D is wrong because the small intestine is where most of the digestion and absorption of nutrients takes place. It receives enzymes and bile from the pancreas and liver, which help to break down carbohydrates, proteins and lipids.

Choice A is wrong because callus formation and callus ossification occur after hematoma formation, not before.

Choice B is wrong because bone remodeling is the last stage of bone repair, not the first.

Choice C is wrong because hematoma formation is the first stage of bone repair, not the third.

Hematoma formation is when blood clots form at the site of the fracture.

Callus formation is when a soft mass of tissue forms between the broken ends of the bone.

Callus ossification is when the callus is replaced by woven bone and cartilage.

Bone remodeling is when the excess bone tissue is removed and compact bone is formed

The correct answer is choice B. Endocrine glands secrete chemicals into the blood. This is because endocrine glands are ductless glands that release their products (hormones) directly into the bloodstream, where they can reach their target cells throughout the body.

Choice A is wrong because salivary glands are exocrine glands, not endocrine glands. Exocrine glands secrete their products into ducts that lead to an internal or external surface.

Choice C is wrong because it describes exocrine glands, not endocrine glands. Exocrine glands release their secretions on an internal or external surface via ducts.

Choice D is wrong because it also describes exocrine glands, not endocrine glands. Endocrine glands do not secrete their products into ducts, but directly into the blood.

The correct answer is choice B. Ear wax.

Ceruminous glands are specialized sweat glands that are located in the external auditory canal.

They secrete a waxy substance called cerumen or ear wax by mixing their secretion with sebum and dead epidermal cells. Cerumen helps to protect the ear from physical damage and infection.

Choice A is wrong because sebum is secreted by sebaceous glands, not ceruminous glands. Sebum is an oily substance that lubricates and protects the hair and skin.

Choice C is wrong because mucus is secreted by mucous glands, not ceruminous glands. Mucus is a slippery substance that moistens and protects the inner lining of various organs.

Choice D is wrong because keratin is not a secretion, but a protein that forms the structure of hair, nails and skin.