homeostasis

Question 1

What is homeostasis?

Answer 1

Regulation of internal conditions in a cell or organism to maintain a stable environment with optimal biological function.

Question 2

What is negative feedback?

Answer 2

An automatic mechanism that brings unstable levels back to normal/optimal levels.

Question 3

What do receptors do?

Answer 3

Detect a stimulus.

Question 4

What is a stimulus?

Answer 4

A physical or chemical change in the environment.

Question 5

What does an effector do?

Answer 5

Produces a response that counteracts the change.

Question 6

How is the central nervous system connected to the body?

Answer 6

By motor and sensory neurones.

Question 7

Which parts of the body are effectors?

Answer 7

Muscles and glands.

Question 8

What do sensory neurones do?

Answer 8

Carry electrical impulses from receptors to the CNS.

Question 9

What do motor neurones do?

Answer 9

Carry electrical impulses from the CNS to effectors.

Question 10

What is a synapse?

Answer 10

A connection between 2 neurones.

Question 11

What diffuses across the gap in a synapse?

Answer 11

A nerve signal that is transferred by chemicals.

Question 12

What is the reflex arc?

Answer 12

The passage of information in a reflex (receptor to effector).

Question 13

What is a reflex?

Answer 13

A rapid, automatic response to certain stimuli that doesn’t involve the conscious part of the brain.

Question 14

What is reaction time?

Answer 14

The time it takes for something to respond to stimulus.

Question 15

What factors can affect reaction time?

Answer 15

~Age
~Gender
~Drugs

Question 16

What are the control variables for the investigating reaction time practical?

Answer 16

~Use the same person catching the ruler
~Use the same hand
~Always drop from the same height

Question 17

What is the brain in charge of?

Answer 17

All complex behaviours.

Question 18

What is the brain made up of?

Answer 18

Billions of interconnected neurones.

Question 19

What is the cerebral cortex in the brain responsible for?

Answer 19

Consciousness, intelligence, memory and language.

Question 20

What is the cerebellum in the brain responsible for?

Answer 20

Muscle coordination.

Question 21

What does the medulla in the brain control?

Answer 21

Unconscious activities like breathing.

Question 22

What is the sclera in the eye?

Answer 22

A tough, supporting wall.

Question 23

What is the cornea in the eye?

Answer 23

Transparent, outer layer that refracts light.

Question 24

What does the iris in the eye contain?

Answer 24

Muscles that allow it to control pupil diameter and how much light enters the eye.

Question 25

What does the lens in the eye do?

Answer 25

Focuses the light onto the retina.

Question 26

What does the optic nerve do?

Answer 26

Carries impulses from receptors on the retina to the brain.

Question 27

What is the shape of the lens controlled by?

Answer 27

Ciliary muscles and suspensory ligaments.

Question 28

How does the eye respond to bright light?

Answer 28

Circular muscles in the iris contract and radial muscles relax which reduces the amount of light that can enter the eye.

Question 29

How does the eye respond to dim light?

Answer 29

Circular muscles relax and radial muscles contract which increases the amount of light that can enter the eye.

Question 30

What does the lens do when someone is looking at near objects?

Answer 30

Lens becomes fat which increases the amount of light refracted.

Question 31

What does the lens do when someone is looking at objects further away?

Answer 31

The lens goes thin meaning less light is refracted.

Question 32

What is the scientific name for long-sightedness?

Answer 32

Hyperopia.

Question 33

What is the scientific name for short-sightedness?

Answer 33

Myopia.

Question 34

What causes long-sightedness?

Answer 34

The lens being the wrong shape or the eye ball being too short.

Question 35

What causes short-sightedness?

Answer 35

The lens being the wrong shape or the eye ball being too long.

Question 36

What glasses lens should a person with long-sightedness use?

Answer 36

Convex lens.

Question 37

What glasses lens should a person with short-sightedness use?

Answer 37

Concave lens.

Question 38

What glasses lens should a person with short-sightedness use?

Answer 38

Concave lens.

Question 39

What are hormones?

Answer 39

Chemical molecules that are produced by endocrine glands that are carried in the blood to particular places in the body.

Question 40

What does the pituitary gland do?

Answer 40

Produces many hormones that regulate body conditions.

Question 41

What does the thyroid gland do?

Answer 41

Produces thyroxine that regulates metabolism, heart rate and temperature.

Question 42

What does the adrenal gland do?

Answer 42

Produces adrenaline that is used to prepare the body for ‘fight or flight’.

Question 43

What do the ovaries do?

Answer 43

Produce oestrogen that is involved in the menstrual cycle.

Question 44

What does the pancreas do?

Answer 44

Produces insulin to regulate blood glucose levels.

Question 45

What do the testes do?

Answer 45

Produce testosterone which controls puberty and sperm production in males.

Question 46

What does the thermoregulatory centre in the brain contain?

Answer 46

Receptors that are sensitive to blood temperature.

Question 47

What process is body temperature controlled by?

Answer 47

Negative feedback.

Question 48

What happens when sweat evaporates off the skin?

Answer 48

It transfers energy to the environment which cools you down.

Question 49

What is vasodilation?

Answer 49

When blood vessels dilate so more blood flows closer to the surface of the skin to cool you down.

Question 50

What is vasoconstriction?

Answer 50

Blood vessels supplying the skin capillaries constrict to close off the blood supply and warm you up.

Question 51

What puts glucose into the blood?

Answer 51

Eating foods containing carbohydrates.

Question 52

What removes glucose from the blood?

Answer 52

Metabolism of cells and vigorous exercise.

Question 53

Where is excess glucose stored?

Answer 53

In the liver or muscles as glycogen.

Question 54

What is the cause of type 1 diabetes?

Answer 54

When the pancreas produces little to no insulin.

Question 55

What does injecting insulin do?

Answer 55

Removed glucose from the blood quickly once food is digested.

Question 56

What causes type 2 diabetes?

Answer 56

When a person becomes resistant to their own insulin.

Question 57

What can type 2 diabetes be controlled by?

Answer 57

Exercise and a carbohydrate controlled diet.

Question 58

How do the kidneys make urine?

Answer 58

By taking waste products out of the blood (filtration).

Question 59

What is deamination?

Answer 59

When excess amino acids are converted into fats and carbohydrates in the liver.

Question 60

What is a waste product of deamination?

Answer 60

Ammonia (toxic).

Question 61

What is ammonia converted to in the liver?

Answer 61

Urea. (which is filtered out of the blood by the kidneys).

Question 62

What does having the wrong amount of water/ions result in?

Answer 62

Damaged cells.

Question 63

What is ion balance maintained by?

Answer 63

The kidneys.

Question 64

What are we ways humans can lose water?

Answer 64

Through sweating and exhaling.

Question 65

What process controls water content?

Answer 65

Negative feedback.

Question 66

Which gland releases ADH into your bloodstream?

Answer 66

Pituitary gland.

Question 67

What does ADH stand for?

Answer 67

Antidiuretic hormone.

Question 68

What does ADH cause the kidneys to do?

Answer 68

Release less water, increasing urine concentration.