Chapter 2: Control And Coordination

Question 1

Multicellular

Answer 1

an organism that is composed of many cells. Most plants and animals are multicellular.

Question 2

Homeostasis

Answer 2

the maintenance of a relatively constant internal physiological environment of the body or part of the body (e.g. blood glucose level, pH, body temperature) in varying external conditions

Question 3

Stimulus response model

Answer 3

a system in which any changes or variations (stimuli) in the internal environment are detected (by receptors); if a response is required, this is communicated to effectors to bring about some type of change or correction so the conditions can be brought back to normal

Question 4

Negative feed back system

Answer 4

occurs when the response is in an opposite direction to the stimulus. For example, if levels of a particular chemical in the blood were too high, then the response would be to lower them. Likewise, if the levels were too low, then they would be increased.

Question 5

Glucose

Answer 5

A simple carbohydrate and the simplest form of sugar

Question 6

Pancreas

Answer 6

a large gland in the body that produces and secretes the hormone insulin and an important digestive fluid containing enzymes

Question 7

Positive feedback system

Answer 7

results in the response going in the same direction. An example of positive feedback is when a mother is breastfeeding her baby. Mechanoreceptors in her nipple detect the baby sucking. The message is transferred to her central nervous system (in this case, her spinal cord) which then sends a message to muscles lining the milk glands to respond by releasing milk

Question 8

Insulin

Answer 8

hormone that removes glucose from the blood and stores it as glycogen in the liver and muscles

Question 9

Glycogen

Answer 9

the main storage carbohydrate in animals, converted from glucose by the liver and stored in the liver and muscle tissue

Question 10

Nervous system

Answer 10

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 11

CNS (central nervous system)

Answer 11

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

Question 12

PNS (periphial Nervous system)

Answer 12

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 13

Endocrine system:

Answer 13

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

Question 14

Sensory neurons

Answer 14

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

Question 15

Motor Neurons

Answer 15

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

Question 16

Neurotransmitters

Answer 16

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

Question 17

Endocrine glands

Answer 17

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

Question 18

Hormones

Answer 18

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

Question 19

Thermoregulation

Answer 19

the control of body temperature

Question 20

Neurons

Answer 20

Nerve cell

Question 21

Interneurons

Answer 21

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

Question 22

Cell body

Answer 22

contains the nucleus of a neuron, also called grey matter

Question 23

Dendrites

Answer 23

structure that relays information towards the cell body of a neuron

Question 24

Axon

Answer 24

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

Question 25

Myelin

Answer 25

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

Question 26

Synapse

Answer 26

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

Question 27

Vesicles

Answer 27

a small cavity, usually filled with fluid

Question 28

Reflex arc

Answer 28

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 29

Sense organs

Answer 29

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

Question 30

Stimuli

Answer 30

changes in the environment that can be detected and responded to

Question 31

Thermo receptors

Answer 31

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

Question 32

Mechanoreceptors

Answer 32

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 33

Chemoreceptors

Answer 33

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 34

Photo receptor

Answer 34

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 35

Pain receptors

Answer 35

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 36

Hypothalamus

Answer 36

monitors internal systems and controls the release of hormones to maintain the normal body state (homeostasis)

Question 37

Brain Stem

Answer 37

the part of the brain connected to the spinal cord, responsible for breathing, heartbeat and digestion. Sometimes called the medulla.

Question 38

Target cells

Answer 38

cells in the body that respond to a particular hormone

Question 39

Pituitary gland

Answer 39

A pea size gland that sits at the bridge of your nose. Your thyroid gland, ovaries and testes are all controlled by hormones released by this endocrine gland. Hormones released by the pituitary gland can control water balance, growth, development and reproduction-related processes.

Question 40

Pineal Gland

Answer 40

gland that produces the hormone melatonin, which can make you feel drowsy