Homeostasis and Response Flashcards

This set of flashcards covers key concepts related to homeostasis, the nervous system, the endocrine system, human reproduction, and plant hormones.

What is homeostasis?

Regulation of internal conditions to maintain optimum conditions for function in response to internal and external changes.

What does homeostasis control in the human body?

Blood glucose concentration, body temperature, and water levels.

What are the components of all control systems?

Receptors, coordination centers, and effectors.

What makes up the central nervous system (CNS)?

Brain and spinal cord.

What are reflex actions?

Automatic and rapid responses that do not involve the conscious part of the brain.

Name three regions of the brain.

Cerebral cortex, cerebellum, and medulla.

Name the structures of the eye.

Retina, optic nerve, sclera, cornea, iris, ciliary muscles, suspensory ligaments.

What is accommodation in the context of the eye?

Changing the shape of the lens to focus on near or distant objects.

How does the body respond when body temperature is too low?

Blood vessels constrict (vasoconstriction), sweating stops, and skeletal muscles contract (shiver).

What is the endocrine system composed of?

Glands that secrete chemicals called hormones directly into the bloodstream.

How does the pancreas control blood glucose concentration when it is too high?

It produces the hormone insulin, which causes glucose to move from the blood into cells.

How can Type 1 and Type 2 diabetes be treated, and what is a risk factor for Type 2?

Type 1 is treated with insulin injections, while Type 2 is managed with diet and exercise; obesity is a risk factor for Type 2.

How is water, ions, and urea lost from the body?

Water, ions, and urea are lost in sweat via the skin, and excess water, ions, and urea are removed via the kidneys in the urine.

How do the kidneys produce urine?

Filtration of the blood and selective reabsorption of useful substances.

How does ADH control water levels in the body?

It is released by the pituitary gland when blood is too concentrated and causes more water to be reabsorbed back into the blood from the kidney tubules.

What are the main female and male reproductive hormones?

Oestrogen and testosterone.

What are the roles of FSH, LH, oestrogen, and progesterone in the menstrual cycle?

FSH causes maturation of an egg, LH stimulates the release of the egg, and oestrogen and progesterone maintain the uterus lining.

What are the hormonal and non-hormonal methods of contraception?

Oral contraceptives, injection/implant/skin patch of progesterone, barrier methods, intrauterine devices, spermicidal agents, abstaining from intercourse, and surgical methods.

How is In Vitro Fertilisation (IVF) treatment performed?

Giving FSH and LH to stimulate egg maturation, followed by fertilization in a laboratory and implantation of embryos.

What are the roles of thyroxine and adrenaline in the body?

Adrenaline produced by the adrenal glands increases heart rate and boosts oxygen and glucose delivery; thyroxine from the thyroid gland stimulates the basal metabolic rate.

Name three plant hormones.

Auxins, Gibberellins, and Ethene.

How are auxins used?

As weed killers, as rooting powders, and for promoting growth in tissue culture.

How is ethene used in the food industry?

To control ripening of fruit during storage and transport.

How can gibberellins be used?

To end seed dormancy, promote flowering, and increase fruit size.