Homeostasis and response：練習題

Which organ in the human body is responsible for monitoring and controlling blood glucose concentration?

A patient has high blood glucose levels because their body cells no longer respond to the insulin produced by their pancreas.

Identify the condition described and a common risk factor for it.

(HT only) Thyroxine levels in the human body are controlled by negative feedback. If thyroxine levels in the blood become too high, how does the endocrine system respond to restore the balance?

In the human nervous system, which of the following is the correct sequence of structures in a reflex arc?

(HT only) If blood glucose concentration falls below the normal range, the pancreas responds by releasing a specific hormone to restore the balance.

Identify this hormone and its effect on the liver.

In the human body, several organs act as coordination centres to receive and process information from receptors.

State two organs that function as coordination centres in the human automatic control systems.

When a person touches a hot object, a reflex action occurs to protect the body from harm.

Explain why these types of actions are described as automatic and why they do not involve the conscious part of the brain.

In the human endocrine system, different glands secrete hormones to regulate body functions. Identify the gland that acts as the ‘master gland’ and explain how it influences the release of hormones from other endocrine glands.

Organisms rely on homeostasis to keep their internal conditions within narrow limits for enzyme action and cell function.

(a) Define the term homeostasis. (1)
(b) State two internal conditions that are controlled by homeostasis in the human body. (2)
(c) All automatic control systems include coordination centres that receive and process information from receptors. Name one organ in the human body that acts as a coordination centre. (1)

The endocrine system uses hormones to coordinate many processes in the human body, including the menstrual cycle.

(a) Name the master gland located in the brain that releases several hormones to stimulate other glands. (1)

(b) In the menstrual cycle, different hormones interact to regulate the process. Describe the specific roles of Follicle Stimulating Hormone (FSH) and Luteinising Hormone (LH). (2)

(c) (HT only) Explain how oestrogen and progesterone interact with the pituitary gland to control the release of FSH and LH via negative feedback. (3)