Control and Coordination

Question 1

Multicellular Organism

Answer 1

Multicellular organisms are organisms that consist of more than one cell, in contrast to unicellular organisms.

Question 2

Homeostasis

Answer 2

Maintenance of a relatively stable internal environment. Keep internal factor in the optimal range

Question 3

Stimulus-Response model

Answer 3

The stimulus-response model is a characterization of a statistical unit

Question 4

Negative Feedback

Answer 4

the diminution or counteraction of an effect by its own influence on the process giving rise to it, as when a high level of a particular hormone in the blood may inhibit further secretion of that hormone, or where the result of a certain action may inhibit further performance of that action.

Question 5

Glucose

Answer 5

a simple sugar which is an important energy source in living organisms and is a component of many carbohydrates.

Question 6

Pancreas

Answer 6

a large gland behind the stomach which secretes digestive enzymes into the duodenum. Embedded in the pancreas are the islets of Langerhans, which secrete into the blood the hormones insulin and glucagon.

Question 7

Insulin

Answer 7

a hormone produced in the pancreas by the islets of Langerhans, which regulates the amount of glucose in the blood. The lack of insulin causes a form of diabetes.

Question 8

Glycogen

Answer 8

a substance deposited in bodily tissues as a store of carbohydrates. It is a polysaccharide which forms glucose on hydrolysis.

Question 9

Positive feedback

Answer 9

In a positive feedback system, the output enhances the original stimulus.

Question 10

Oxytocin

Answer 10

a hormone released by the pituitary gland that causes increased contraction of the uterus during labour and stimulates the ejection of milk into the ducts of the breasts.

Question 11

Nervous system

Answer 11

the system of nerves and nerve centres in an animal in which messages are sent as an electrical and then a chemical impulse. It comprises the central nervous system and the peripheral nervous system.

Question 12

Endocrine system

Answer 12

the body system of glands that produce and secrete hormones into the bloodstream in order to regulate processes in various organs

Question 13

Signalling molecules

Answer 13

a chemical involved in transmitting information between cells

Question 14

Central Nervous System

Answer 14

the part of the nervous system composed of the brain and spinal cord

Question 15

Peripheral Nervous System

Answer 15

made up of sensory and motor neurons. It connects the central nervous system to the rest of the body and detects and responds to change.

Question 16

Sensory Neurons

Answer 16

a nerve cell in the sense organs. It detects change in the environment and sends a message to the central nervous system.

Question 17

Motor Neurons

Answer 17

the nerve cell that causes an organ, such as a muscle or gland, to respond to a stimulus

Question 18

Endocrine Glands

Answer 18

organs that produce hormones. Endocrine glands release their hormones into the bloodstream for transport to target organs.

Question 19

Hormones

Answer 19

chemical substances produced by glands and circulated in the blood. Hormones have specific effects in the body.

Question 20

Thermoregulation

Answer 20

the control of body temperature

Question 21

Thermostat

Answer 21

a device that establishes and maintains a desired temperature automatically

Question 22

Neurons

Answer 22

nerve cell

Question 23

Nerves

Answer 23

a bundle of neurons

Question 24

Interneurons

Answer 24

a nerve cell that carries nervous impulses through the central nervous system. They provide the link between sensory neurons and motor neurons.

Question 25

Motor Neurons

Answer 25

the nerve cell that causes an organ, such as a muscle or gland, to respond to a stimulus

Question 26

Nucleus

Answer 26

central part of an atom, made up of protons and neutrons; roundish structure inside a cell that acts as the control centre for the cell. Plural = nuclei.

Question 27

Organelles

Answer 27

small structure in a cell with a special function

Question 28

Cytosol

Answer 28

the fluid found inside cells

Question 29

Cell Membrane

Answer 29

structure that encloses the contents of a cell and allows the movement of some materials in and out

Question 30

Cell Body

Answer 30

contains the nucleus of a neuron, also called grey matter

Question 31

Dendrites

Answer 31

structure that relays information towards the cell body of a neuron

Question 32

Axon

Answer 32

an appendage of the neuron that nervous impulses travel along to the next neuron or to an effector organ (muscle or gland)

Question 33

Myelin

Answer 33

a fatty, white substance that encases the axons (connecting branches) of the neurons in the nervous system

Question 34

Synapse

Answer 34

the gap between adjoining neurons across which electrical nervous impulses are sent

Question 35

Neurotransmitters

Answer 35

chemical released from the axon terminals into the synapse between your nerve cells (neurons) during a nerve impulse

Question 36

Effector

Answer 36

an organ that responds to a stimulus

Question 37

Reflex arc

Answer 37

a nervous pathway involving a small number of neurons. A reflex occurs when nervous impulses travel from the receptor to the spinal cord and then to the effector organ.

Question 38

Thinking

Answer 38

active consideration involving the brain neurons

Question 39

Conscious Response

Answer 39

actions taken after the brain receives information from one of the sense organs

Question 40

Vesicles

Answer 40

a small cavity, usually filled with fluid

Question 41

Sense Organs

Answer 41

a specialised structure that detects stimuli (such as light, sound, touch, taste and smell) in your environment

Question 42

Stimuli

Answer 42

changes in the environment that can be detected and responded to

Question 43

Thermoreceptors

Answer 43

special cells located in your skin, part of your brain and body core that are sensitive to temperature

Question 44

Mechanoreceptors

Answer 44

special cells within the skin, inner ear and skeletal muscles that are sensitive to touch, pressure and motion, enabling you to balance, hear and sense pressure and movement

Question 45

Chemoreceptors

Answer 45

special cells within a sense organ (especially the nose and tastebuds) that are sensitive to particular chemicals, giving you the sensations of smell and taste

Question 46

Photorecptors

Answer 46

a receptor cell located in your eye that is stimulated by light, converting it to electrical energy that is sent to the brain, giving you the sensation of light

Question 47

Pain Receptors

Answer 47

special cells located throughout the body (except the brain) that send nerve signals to the brain and spinal cord in the presence of damaged or potentially damaged cells, resulting in the sensation of pain

Question 48

Hot Thermoreceptors

Answer 48

a type of receptor in your skin that can detect an increase in skin temperature above 37.5°C (normal body temperature)

Question 49

Cold Thermoreceptors

Answer 49

a type of receptor in your skin that can detect a decrease in skin temperature below 35.8 °C

Question 50

Olfactory nerve

Answer 50

nerve that sends signals to the brain from the chemoreceptors in the nose

Question 51

Pupil

Answer 51

a hole through which light enters the eye

Question 52

Iris

Answer 52

coloured part of the eye that opens and closes the pupil to control the amount of light that enters the eye

Question 53

Reflex Action

Answer 53

a quick response to a stimulus. Reflex actions do not involve thought.

Question 54

Cornea

Answer 54

the curved, clear outer covering of your eye

Question 55

Lens

Answer 55

a transparent curved object that bends light towards or away from a point called the focus. The eye has a jelly-like lens.

Question 56

Retina

Answer 56

curved surface at the back of the eye. It is lined with sight receptors.

Question 57

Short-sightedness

Answer 57

the condition of not being able to see clearly things that are far away

Question 58

Long-sightedness

Answer 58

the condition of not being able to see clearly things that are close

Question 59

Optic nerve

Answer 59

large nerve that sends signals to the brain from the sight receptors in the retina

Question 60

Rods

Answer 60

sensory receptors in the retina that respond to low levels of light and allow you to see in black and white in dim light

Question 61

Cones

Answer 61

sensory receptors in the retina that respond to red, green or blue light. Cones are mainly in the central part of the retina.

Question 62

Colour blindness

Answer 62

an inherited condition, more common in males, in which a deficiency of one or more of the different types of cones may mean that you find it difficult to see a particular colour or combinations of colours

Question 63

Ear canal

Answer 63

the tube that leads from the outside of the ear to the eardrum

Question 64

Eardrum

Answer 64

a thin piece of stretched skin inside the ear that vibrates when sound waves reach it

Question 65

Ossicles

Answer 65

a set of three tiny bones that send vibrations from the eardrum to the inner ear. They also make the vibrations larger.

Question 66

Middle Ear

Answer 66

the section of the ear between your eardrum and the inner ear, containing the ossicles

Question 67

Cochlea

Answer 67

the snail-shaped part of the inner ear. It is lined with tiny hairs that are vibrated by sound and stimulate the hearing receptors.

Question 68

Auditory nerve

Answer 68

a large nerve that sends signals to the brain from the hearing receptors in the cochlea

Question 69

Tongue

Answer 69

the sense organ responsible for taste

Question 70

Tastebuds

Answer 70

nerve endings located in your tongue that contain receptors sensitive to sweet, salty, bitter, sour and savoury chemicals, allowing you to experience taste

Question 71

Papilla

Answer 71

bumps on your tongue that are thought to contain tastebuds