P & A - Homeostasis

During a running race, a person’s breathing rate and heart rate increase. These changes most directly help the person do which of the following?

• increase the rate of digestion

• decrease the rate of gamete production

• decrease the rate of protein synthesis in neurons

• increase the rate of cellular respiration in mitochondria

Which of the following is the best example of homeostasis?

• Heart rate increases when a person exercises.

• The chest cavity expands when the diaphragm contracts

• The biceps muscle relaxes when the triceps muscle contracts.

• Digestive enzymes are secreted when food enters the stomach.

Low blood pressure can be life-threatening. To help maintain a stable blood pressure, receptors in the heart detect changes in blood pressure. Information about blood pressure changes is then sent to the brain. If blood pressure is too low, the brain sends a message to the heart to beat faster.Based on this information, which of the following systems are directly involved in keeping blood pressure stable?

• circulatory, muscular, nervous

• circulatory, immune, skeletal

• excretory, immune, muscular

• excretory, nervous, skeletal

Which of the following is the best example of homeostasis in the human body?

• The secretions from oil glands in the skin decrease as a person ages.

• Opposite muscles are used to bend and extend a person’s arm at the elbow joint.

• The villi of the small intestine increase the absorption of nutrients from the small intestine into the blood.

• More growth hormone is released from the pituitary gland when the level of growth hormone in the blood falls too low.

Which of the following is the best example of the human body maintaining homeostasis?

• The heart beats using cardiac muscle.

• The breathing rate increases during exercise.

• The nose and ears contain cartilage for flexibility.

• The digestive system uses enzymes to break down food.

A boy jumps into a cold swimming pool and his body temperature goes down. His muscles, blood vessels, and nervous system work together to restore his body temperature. Which term best describes this process?

• homeostasis

• hypothermia

• reflex

• respiration