Interaction and Coordination (2nd ESO)

8/19/2019 Interaction and Coordination (2nd ESO)

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INTERACTIONAND

COORDINATION



1. What is interaction?

Interaction is one of the main characteristics of living things.

All living things interact with their environment; in otherwords, they receive stimuli and respond to them.



There are different elements involved in interaction:

Stimuli are internal or external changes that can be detected and provoke responses. We can distinguish two types of stimuli:

Physical : pressure, temperature, sound, light,...

Chemical : !resence or absence of chemical substances.

Receptors are structures which can receive e"ternal or internal

stimuli. In animals, the sense organs are sets of receptors.

Coordination systems: The information generated by the

receptors must be processed, in order to elaborate a response. This

is the function of the coordination systems #in animals, nervous

and endocrine systems$.Responsie or!ans #%effectors$. These structures produce

responses. In animals they are muscles and glands.



Interaction functions are much more developed in animals than in

plants, although plants, of course, show them. We are going to

study now interaction in animals, and we will consider interaction

in plants later.

Activity 1. &ive two e"amples of interaction processes in plants.



"oun! plants #endin! to$ards the li!ht Dionaea% an insectiorous plant

Interaction functions are much more developed in animals than in

plants, although plants, of course, show them. We are going to

study now interaction in animals, and we will consider interaction

in plants later.

Activity 1. &ive two e"amples of interaction processes in plants.



&. Interaction and coordination in animals

As we know, interaction function is related basically to thefollowing processes:'Stimuli reception. This process is done by receptors, which

detect internal or e"ternal changes #stimuli, stimulus in singular$.

In many cases, receptors are grouped, giving place to sensory

organs.' Information processing , carried out by the coordination systems:

nervous system and endocrine system. They can integrate

information from different sources, process it and elaborate

responses.' Response. (esponses are carried out by responsive organs, also

called effectors: muscles and glands.



1 & ' ()* + ,

) )

Activity 2. *omplete the scheme with the following names:

*oordination systems, response, neural signal, stimulus,

receptors, signal processing, effectors.



Stimulus Receptors

Coordination

systems (si!nal

processin!*

E--ectors Response

+eural

signal

+eural

signal

1 & ' ()* + ,

) )

Activity 2. *omplete the scheme with the following names:

*oordination systems, response, neural signal, stimulus,

receptors, signal processing, effectors.



Receptors

(eceptors are often grouped, forming sensory organs, responsible

for the senses: sight , smell , taste, hearing and touch.



' Eyes are the sensory organs responsible for sight . They detect

light #photoreceptors$. ight is focused on the retina, where is

captured by cells which generate neural signals.

Activity 3. Write the names of the different parts of the eye: pupil,

retina, lens, iris, cornea, con-unctiva, optic nerve.

/

0

1

2

)

3



Activity 3. Write the names of the different parts of the eye: pupil,

retina, lens, iris, cornea, con-unctiva, optic nerve.



' Eyes are the sensory organs responsible for sight . They detect

light #photoreceptors$. ight is focused on the retina, where is

captured by cells which generate neural signals.



'In vertebrates, the nose is the organ in charge of smell . 4mell

receptors inside the nose detect airborne chemicals. Arthropods

have other smell receptors in their appendages.



'aste is the sense related to the tongue, where taste receptors are

placed. These chemical receptors detect substances dissolved in

water.



' !earing is related to ears, where there are mechanical receptors

detecting sound.



'ouch receptors are located in the skin #in most animals$. They

detect pressure and contact #mechanical receptors$, pain, and

temperature changes #thermoreceptors$.

Touch receptors



Coordination systems

Animals have two coordination systems: the nervous system and the

endocrine system. They process information in order to produce

ade5uate responses, and they send orders to effectors. Then,effectors e"ecute the response.




'The nerous system is made up of neurons, cells which are

speciali6ed in transmission of impulses. +eurons are grouped and

highly connected.'The endocrine system consist of glands #endocrine glands$, which

produce hormones, chemical substances transported by the blood.



Nerous system Endocrine system

Si!nals transmitted 7lectrical signals #alonga neuron$*hemical signals#neurotransmitters, in

synapses$

*hemical signals#hormones$

Speed o- response (apid 4low

Duration o-

response

8rief ong

What type o-

-unctions does it

coordinate?

9unctions which re5uirerapid responses #fore"ample, locomotion$

9unctions with longlastingresponses #growth,development,...$

The following table compares nervous and endocrine systems:



The nervous system: neurons

"eurons are the main cells of the nervous system. They are speciali6ed

in transmission and processing of impulses #nerve signals$. Then, there

are many connection between neurons, and also between neurons andother cells #for e"ample, muscle cells$.

ere is a neuron picture:

Activity #. Write the names of the different parts of the neuron:

cell body, node of (anvier, nucleus, myelin sheath, dendrite,

a"on, 4chwanns cell, a"on terminals.

1

&

'

)

+

,

/



Neurons

Activity #. Write the names of the different parts of the neuron:

cell body, < node of (anvier, / nucleus, 3 myelin sheath, 0

dendrite, 1 a"on, ) 4chwanns cell, 2 a"on terminals.

=irection of impulse transmission



There are connections between neurons, called synapses

#synapsis, in singular$. +erve impulses can pass from one neuron

to another through synapses, by means of chemicals called

neurotransmitters.



The nervous system: organization

=ifferent types of animals can have very different nervous systems.

Jellyfish and polyps have a diffuse nervous system #nerve net $,

without high concentrations of neurons.




In other groups, such as arthropods, there are accumulations of

neurons, called ganglia, connected by nerve cord. &anglia of the

anterior part of the body are fused, making up the brain.




In 0erte#rates, the nervous system has two main parts: the central

nervous system #*+4$ and the peripheral nervous system #!+4$.

The CNS is the main control centre in the body. It consists of the

#rain and the spinal cord.




In 0erte#rates, the nervous system has two main parts: the central

nervous system #*+4$ and the peripheral nervous system #!+4$.

The !+4 is a network of nerves e"tending from the *+4

throughout the body.



The nervous system: organization. The CNS

The #rain is the main structure of the CNS. It contains a huge

accumulation of neurons very highly connected.

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0

1

2

)

Activity $. Write the names of the different parts in the figure:

cerebrum, spinal cord, meninges, skull, medulla, cerebellum.




Cerebrum, cerebellum and medulla are important parts of the %rain.

The e"ternal layer of the cerebrum, with a very folded surface #in

mammals, especially in humans$, is the cere%ral cortex. It is

involved in functions such as thought, reasoning and planning.




The cerebellum, in the back part of the brain, is involved in

control of movements. The medulla #%medulla oblongata$, in the

lowest part of the brain, is the connection between the brain and

the spinal cord.

Th i i Th NS



The nervous system: organization. The NS

The peripheral nervous system #!+4$ consists of nerves which go from

the brain or the spinal cord to to all parts of the body.

Th t i ti Th NS




We can distinguish two types of nerves: !fferent "sensory# nerves go from the receptive organs to the *+4.

They carry impulses generated by the receptors.

$fferent "motor# nerves go from the *+4 to the responsive organs#effectors$. They carry impulses generated by the *+4 to activate the

response.

h i i h S




7ach nerve contains groups of a"ons which transport impulses from the

receptors to the *+4 #sensory or afferent nerves$, or from the *+4 to

the effectors #motor or efferent nerves$.



Coordination systems: the endocrine system

The endocrine system comprises different endocrine !lands. These

glands produce and release hormones, which are transported by the

blood. 7ach hormone reaches its target cells and provokes in them aspecific effect, usually process regulation.

Activity & . >atch each number with the proper term: hormone,

bloodstream, process regulation, target cell, endocrine gland,

specific effect.

1

&

'

)+ (*

C di ti t th d i t




Activity & . >atch each number with the proper term: hormone /,

bloodstream 0, process regulation ), target cell 1, endocrine gland

, specific effect 2.

1

&

'

)+ (*

Endocrine !land

ormone

2loodstream

Tar!et cell Speci-ic e--ect

(process

re!ulation*

C di ti t th d i t




Activity ' . ook for information about another hormone and find

its function and which endocrine gland produces it.

The following table presents three e"amples of hormones.

ormoneEndocrine !land$hich produces it

3unction

%ro&th hormone !ituitary gland It promotes growth and cell division

Testosterone Testicles Testosterone regulates developmentand functioning of testicles

'nsulin !ancreas Insulin regulates glucose concentrationin blood

Th i l d l d



The responsive organs: muscles and glands

4keletal muscles are attached to the bones by tendons.

4mooth muscles can be around organs.

>uscles contract when they receive nerve impulses.

The effectors are the structures or organs wich e"ecute the response:

muscles and glands.

Then, there are two types of responses to stimuli: motor responses,due to muscles, and secretory responses, due to glands.

' Interaction and coordination in plants



'. Interaction and coordination in plants

Activity (. Au"ins are plant hormones which promote stem growth.

What is the effect in this case?

Plants receive stimuli and respond to them, although in plants

interaction and coordination are less developed than in animals.

!lants do not have a nervous system, but they produce hormones,chemical messengers which coordinate and regulate processes such

as growth, flowering, germination,@.

Stimuli and responses in plants




!lants can detect different stimuli: light, temperature changes, gravity,

touch@

In many cases, plant responses to stimuli are related to gro&th: )hena plant gro)s to)ard a stimulus* or a)ay from it* that type of

response is called tropism #positive or negative tropism respectively$.

This is an e"ample of

positive phototropism: the

plant stem grows toward

the light.





This is an e"ample of

positive geotropism: plant

roots grow toward gravity.

higmotropism is related totouch or contact. *limbing plant

show positive thigmotropism:

they grow keeping in contact

with solid surfaces.





!lants can show other responses to stimuli, different from growth.

Nastic movements are temporary plant responses to stimuli, not

related to growth. nlike tropisms, nastic movemetns are notdirectional.

This is an e"ample of nastic

movement : some carnivorous

plants close their leaves in

response to touch. They

capture insects this way.

Activity +. 4ome plants open their flowers by day and close them

by night. Is this a tropism or a nastic movement? 7"plain.

) 3inal actiities



). 3inal actiities

Activity 1,. =raw a neuron, pointing its parts and writing their names.

Activity 11. (ead each one of the following sentences, and decide if it

is true or false, -ustifying your decission:

-"erve signals are al)ays electrical.

-A hormone can affect any cell of the %ody.

-If )e use a microscope* )e can see the neuron nuclei along anerve.

-/ost plant stems sho) positive geotropism.

-In our %ody* touch is the only sense )hich contains mechanical

receptors.

Activity 12. *ompare the general organi6ation of the nervous system in

a -ellyfish, a grasshopper and a chimpan6ee.

) 3inal actiities



). 3inal actiities

Activity 13. Where are there more neuron bodies, in the cerebral corte"

or in the inner part of the cerebrum? 7"plain.

Activity 1#. Write three e"amples of chemical stimuli which can be

detected by a person, and also the responses they can provoke.

Activity 1$. There is a chemical, called abscisic acid, which promotesleaf fall. What type of substance do you think abscisic acid is?

Activity 1& . Write three e"amples of light stimuli received by different

animals, and also the responses they provoke.

Interaction and Coordination (2nd ESO)

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