Chapter 2

Question 1

Homeostasis

Answer 1

The internal environment in which your cell lives needs to be kept constant. Temperature, pH and concentrations of ions, glucose, water and carbon dioxide need to be within a particular range. Maintenance of this constant internal environment is called homeostasis.

Question 2

Stimulus response-model

Answer 2

This is where a change occurs and this change is picked up by the receptors, after this has happened the body corrects this change and goes back to normal.

Question 3

Negative feed back

Answer 3

This is when the body does the opposite of what is happening, for eg, if a certain chemical is not present in the blood stream then the body will start producing this chemical constantly.

Question 4

Glucose

Answer 4

This is the simplest from of sugar is and is basically a from of food for the body.

Question 5

Pancreas

Answer 5

A large gland in the body which secretes enzymes and helps the body to digest carbohydrates, fats and proteins.

Question 6

Insulin

Answer 6

This is a chemical that removes glucose from the blood stream and stores it in the liver and muscles as glycogen.

Question 7

Glycogen

Answer 7

This is the converted form of glucose and this is like the stored from of it, it can stored in muscle tissue or in the liver.

Question 8

Positive feedback

Answer 8

Whereas negative feedback involves a response in an opposite direction to the stimulus, positive feedback 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. The response continues until the baby stops sucking and the stimulus is removed.

Question 9

Oxytocin

Answer 9

As the baby moves into the cervix (the area that connects the uterus to the vagina), it causes stretching of receptors that result in the release of a hormone called oxytocin

Question 10

Nervous system

Answer 10

A 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

Endocrine

Answer 11

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

Question 12

Signalling molecules

Answer 12

A chemical involved in transmitting information.

Question 13

Multicellular organisms

Answer 13

An organism that is made up of many cells, most animals and plants are multicellular.

Question 14

Central Nervous System

Answer 14

A part of the nervous system that is composed of the brain and spinal cord

Question 15

Peripheral nervous system

Answer 15

The nerves that connect the central nervous system to the rest of the body.

Question 16

Neurons

Answer 16

Nerve cell

Question 17

Nerve

Answer 17

A bundle of Neurons

Question 18

Sensory Neurons

Answer 18

Carry the impulse created by the stimulus to the central nervous system

Question 19

Motor Neurons

Answer 19

These Neurons carry impulses from the central nervous system to effectors

Question 20

Nucleus

Answer 20

An organelle of a cell, this is the control centre of a cell and also where all the DNA for other organelles are stored.

Question 21

Interneuron

Answer 21

The Neurons that connect the sensory and motor Neurons together, the interneurons never touch the sensory or the motor Neurons but there is a small gap in between them called the synapse this is where the electrical message from the sensory Neurons travel to the interneurons through neurotransmitters then to motor Neurons.

Question 22

Organelles

Answer 22

Small structures within a cell which help it survive.

Question 23

Cytosol

Answer 23

This is a fluid found inside the cell.

Question 24

Cell membrane

Answer 24

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

Question 25

Cell body

Answer 25

This contains nucleus and Neurons, also called grey matter

Question 26

Dendrites

Answer 26

Structure that relays information towards the cell body of a neuron.

Question 27

Axon

Answer 27

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

Question 28

Myelin

Answer 28

A fatty white substance that encases the axons of the Neurons in the nervous system.

Question 29

Synapse

Answer 29

The gap between the Neurons are called synapse.

Question 30

Vesicles

Answer 30

A small cavity usually filled with fluid

Question 31

Neurotransmitter

Answer 31

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