Coordination

Question 1

How does nervous and hormonal communication occur?

Answer 1

Through cell signalling and cellular communication.

Question 2

What is a target cell?

Answer 2

A cell that receives and is affected by a chemical message sent from another cell.

Question 3

What are the 2 ways cells can transfer signals between each other?

Answer 3

1) Locally between neurones across synapses.

2) Across large distances using hormones.

Question 4

What are the 4 ways cell signalling occurs?

Answer 4

1) Autocrine- cell targets itself
2) Signalling across gap junctions- cell targets a cell connected by gap junctions
3) Paracrine- cell targets a nearby cell
4) Endocrine- cell targets a distant cell via the bloodstream

Question 5

The nervous system is responsible for detecting what?

Answer 5

Internal and external changes to the body

Question 6

What are stimuli?

Answer 6

Changes to the body detected by nervous system

Question 7

What pathway does an electrical impulse take?

Answer 7

Receptor, Sensory neurone, Relay neurone, Motor neurone, Effector cell

Question 8

What are the three types of neurones?

Answer 8

Sensory neurone
Relay neurone
Motor neurone

Question 9

A sensory neurone carries impulses from………to…………?

Answer 9

From receptor organs to relay/motor neurones or he brain and CNS.

Question 10

A relay neurone carries impulses from………to…………?

Answer 10

From sensory neurone to motor neurone

Question 11

A motor neurone carries impulses from………to…………?

Answer 11

From CNS to effectors

Question 12

Name one internal factor that causes a response in plants? In animals?

Answer 12

Plants- water potential

Animals- internal temperature

Question 13

Why is coordination required in multicellular organisms?

Answer 13

Few body systems work in isolation. For example,

Muscles need oxygen to contract
Oxygen is transported in RBC
RBC are made in bone marrow by stem cells

Question 14

How do cells communicate in animals, and in plants?

Answer 14

Animals- nervous system by electrical impulses

Plants- hormonal system by chemical messengers

Question 15

Name some factors in the environment that we respond to?

Answer 15

Humidity
Temperature
Light intensity
Sound
Blood glucose
Water potential
Cell pH

Question 16

What is the cell body of a neurone?

Answer 16

Contains a nucleus and is surrounded by cytoplasm. Also contains Endoplasmic Reticulum and mitochondria.

Question 17

What are the dendrons of a neurone?

Answer 17

Short extensions that come from the cell body.

Question 18

What are dendrites of a neurone?

Answer 18

Smaller branches extending off the dendrons that transmit impulses towards the cell body

Question 19

What is the axon of a neurone?

Answer 19

Singular, elongated nerve fibres that transmit impulses away from the cell body

Question 20

Name some internal environments that change.

Answer 20

Blood glucose concentration
Internal temperature
Water potential
Cell pH

Question 21

What s homeostasis?

Answer 21

The functions of organs are coordinated to maintain a relatively constant internal environment.

Question 22

What are myelinated neurones?

Answer 22

Neurones with axons covered in myelinated sheath.

Question 23

What cell causes a double bilayer of phospholipids to be laid down every time it grows around the axon?

Answer 23

Schwann cells

Question 24

How do myelinated neurones help transmit impulses faster?

Answer 24

The impulse jumps along the gaps between the schwann cells called the node of Ranvier.

Question 25

What is Multiple sclerosis?

Answer 25

An autoimmune disease involving the breakdown of myelin sheath on axons of neurones in the brain.

Question 26

What is Multiple sclerosis thought to be caused by?

Answer 26

Genetics and environmental factors like viral infection.