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A Level Biology - Unit5 > Coordination > Flashcards

Flashcards in Coordination Deck (26):
1

How does nervous and hormonal communication occur?

Through cell signalling and cellular communication.

2

What is a target cell?

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

3

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

1) Locally between neurones across synapses.
2) Across large distances using hormones.

4

What are the 4 ways cell signalling occurs?

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

5

The nervous system is responsible for detecting what?

Internal and external changes to the body

6

What are stimuli?

Changes to the body detected by nervous system

7

What pathway does an electrical impulse take?

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

8

What are the three types of neurones?

Sensory neurone
Relay neurone
Motor neurone

9

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

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

10

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

From sensory neurone to motor neurone

11

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

From CNS to effectors

12

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

Plants- water potential
Animals- internal temperature

13

Why is coordination required in multicellular organisms?

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



14

How do cells communicate in animals, and in plants?

Animals- nervous system by electrical impulses
Plants- hormonal system by chemical messengers

15

Name some factors in the environment that we respond to?

Humidity
Temperature
Light intensity
Sound
Blood glucose
Water potential
Cell pH

16

What is the cell body of a neurone?

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

17

What are the dendrons of a neurone?

Short extensions that come from the cell body.

18

What are dendrites of a neurone?

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

19

What is the axon of a neurone?

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

20

Name some internal environments that change.

Blood glucose concentration
Internal temperature
Water potential
Cell pH

21

What s homeostasis?

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

22

What are myelinated neurones?

Neurones with axons covered in myelinated sheath.

23

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

Schwann cells

24

How do myelinated neurones help transmit impulses faster?

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

25

What is Multiple sclerosis?

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

26

What is Multiple sclerosis thought to be caused by?

Genetics and environmental factors like viral infection.