Coordination n Respons

7/27/2019 Coordination n Respons

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Spinal Cord

brain

Cerebellum

Cerebrum

Medulla Oblongata

Consists of: Brain and Spinal Cord



The Brain weighs 1300 - 1400 g

made up of about 100billion neurons

“the most complex livingstructure on theuniverse” Society for Neuroscience

makes us who we are



The Brain

Phineas gage

http://www.deakin.edu.au/hmnbs/psychology/gagepage/Pgdamage.php

http://www.deakin.edu.au/hmnbs/psychology/gagepage/Pgdamage.php



Brain structure

Cerebrum

cerebellumhypothalamus

Pituitary glandmedulla brain functions

http://kidshealth.org/kid/body/brain_noSW.html

http://kidshealth.org/kid/body/brain_noSW.html



Parts of the cerebrum

alcohol and the brain

http://www.at-bristol.org.uk/alcoholandyou/Effects/brain.html

http://www.at-bristol.org.uk/alcoholandyou/Effects/brain.html



Examples of responses

Voluntary actions

Eating a cake Riding a bicycle

Walking

Playing the piano Coming to school

Involuntary actions

Your heart beat Breathing

Blinking

Removing hand

from hot object Choking

Salivating



Cerebrum Voluntary or conscious activities of the

body-learning, judgment

Cerebellum Coordinates and balances the actions

of the muscles

Medulla

Oblongata

Controls involuntary actions like blood

pressure, heart rate, breathing, and

swallowing

Hypothalamus

Important in homeostatic regulation like

body temperature, blood pressure,

thirst, hunger

Control centre of endocrine system



Spinal Cord Contains within the vertebral column.

Surrounded by cerebrospinal fluid which

acts as a shock absorber and provide

the spinal cord with nutrients

Two main parts of spinal cord are

Grey matter- shape like letter H

- consists of cell bodies of neurons

White matter- surrounding the grey matter

- consists of myelin-coated axon of neurons



Dorsal root contains the axon of afferent neurons

Conduct nerve impulse from receptor

to spinal cord

Cell bodies of afferent neurons are

clustered in the dorsal root ganglion

Ventral root contains the axon of efferent neurons

Conduct nerve impulse from spinal cordto the effectors



Functions of the spinal cordare

Receive and transmit impulsesto and from the brain

Contains the neural pathway

for reflexes



Consists of: Cranial nerves

and spinal nerves

-includes all

sensory neurons,

motor neurons,

and sense organs



The Neuron

The basicfunctional unit of the nervous

system. Function: Send

impulses to andfrom the CNS and

PNS and theeffectors(muscles/glands)



Basic nerve cell structure



Dendrite Fine hair-like extensions on theend of a neuron.

Function: receive incoming stimuli.

Cell Body The control center of theneuron.

Function: Directs impulses from the

dendrites to the axon. Nucleus Control center of the cell body.

Function: Tells the cell body what to do.



Axon Pathway for the nerve impulse(electrical message) from the soma to theopposite end of the neuron.

Myelin Sheath An insulating layeraround an axon. Made up of Schwanncells.

Nodes of Ranvier Gaps between

schwann cells.

Function: Situation where speed of animpulse is greatly increased by the

message „jumping‟ the gaps in an axon.



3 main types of nerve cells

Afferent

(sensory)

neurone

Interneurons

(relay neurone)Efferent

(motor)

neurone



Types of Neurons There are 3 types of neurons.1. Afferent (Sensory) Neurons Neurons located near

receptor organs (skin, eyes, ears).

Function: receive incoming stimuli from the

environment to brain and spinal cord.2. Efferent (Motor) Neurons Neurons located near

effectors ( muscles and glands)

Function: Carry impules to effectors to initiate aresponse.

3. Interneurons Neurons that relay messages betweenother neurons such as afferent and efferent neurons.(found most often in Brain and Spinal chord).

Participate in integrative functions are interneurones andefferent neurones respond to these integrative decision.



Sensory

Neuron

carry impulses from

sense organs to

spinal cord & brain

Fun Fact:

Where can the

largest cells in the

wor ld be found?

The giraffe’s sensory and

motor neurons! Some

must bring impulses from

the bottom of their legsto their spinal cord

several meters away!!



Interneuron

-processes impulses in

brain and spinal cord- connect sensory and

motor neurons



Motor Neurons

carry impulses from the

brain & spinal cord to

muscles & glands

Axon End

Axons branching out

to muscle fibers



Stimulus

Receptor

Sensory neurone

Central

Nervous

system

Motor neurone

Effector

Response

Neural Circuit



Based on: Mader, S., Inquiry Into Life, McGraw-Hill



Transmission of signals



SynapsesWhen a nerve ending

meets up with anothernerve ending we get amicroscopic space

This space is called asynaptic cleftThe electrical

message travellingalong a nerve has tocross the synapse as a

chemical message



Synapses

Neurotransmitter being releasedinto synaptic cleft and attaching

to receptors on dendriteBased on Harvard Medical School

Family Health Guide

Synapticcleft



When impulses reach the presynapticmembrane, it triggers the synaptic vesicle torelease the neurotransmitter into the synaptic

cleft.

Neurotransmitters moves across the synapticcleft to bind at specific protein known asreceptor on the surface of postsynaptic

membrane

The binding of the neurotransmitter to the

receptors leads to generation of new impulse



Voluntary action

Eg walking and talking are underconcius control

Govern by cerebral cortex of cerebrum in our brain

ReceptorAfferent

neuronesinterneurones

Efferent

neuroneseffector



Reacting without thinking

Sometimes a stimulus requires an

immediate response.

This is called a reflex action.

It is an involuntary response and we do

it without thinking.

These automatic responses do not

have to be learned. They can be very important in

preventing injury to ourselves.



A reflex is an

involuntaryresponse that is

processed in the

spinal cord notthe brain.

Reflexes protect

the body beforethe brain knows

what is going on.

Reflex Arc



oA reflex arc

-The nerve pathway taken in a

reflex action is called a reflex arc.

-The nervous message goes tothe spinal cord, then a message

passes from the spinal cord

directly to an effector to give animmediate response.



A reflex arc



The knee jerk reflex action

Sometimes

called arelay orConnectorneurone



Another reflex action

I l i i l h



Involuntary action involves smooth

muscles, cardiac muscles or glands

Eg: heart beat rate, blood pressure,breathing rate.

Govern by autonomic nervous system

that connects the medulla oblongataand hypothalamus with internal organs

Does not involve cerebrum, thus no

perception is generated. Allow vital function to continue even

during sleeping and fainting.



Autonomic Nervous System

Sympatheticdivision

Parasympatheticdivision

Situation emergency relaxed

Heart beat,blood pressureand breathing

rate

increase decrease

Digestive system Slow down theactivities

Stimulate theactivities



Diseases

Parkinson disease Usually affects victims around 60 years old

and above

Due to lack of dopamine in the brain

Causing the trembling of arm, jaw and legs

Alzheimer disease

Affects victims around 60 years old and

above The cause is unknown but ageing and

genetic factors can lead to the disease

Causing the patient lost abality to read,

write, eat and walk



Main Function:

It releases hormones into the blood to signal

other cells to behave in certain ways. It is a

slow but widespread form of communication. Maintain homeostasis and physiological

processes such as menstrual cycle,

development of secondary sexual characteristicand growth



Endocrine glandsRelease hormones

into the bloodstream.

Hormones are

chemicals released in

one part of the body

that travel through thebloodstream and affect

the activities of cells in

other parts of the body.

Consists of:

N E d i



Nervous system Endocrine system

Control voluntary andinvoluntary action

Control involuntaryaction only

Use electrical signal(impulse)

Use chemical signal(hormones)

Signal transferred usingneurones

Signal transferred usingblood via bloodstream

Signal transferredrapidly

Signal transferredslowly

Messages carried to

specific location

Messages carried

through various locationThe effect aretemporary andreversible

The effect are long-lasting and irreversible

Pit it Gl d

http://www.gigantism.com/david-goliath.html



Pituitary Gland

Function: It secretes nine hormonesthat directly regulate many bodyfunctions and controls functions of other glands.

Disorders: To much growthhormones (GH) in early childhoodcan result in a condition calledgigantism. To little GH can resultin Pituitary Dwarfism.

RobertWadlow

http://www.gigantism.com/david-goliath.html



Thyroid Gland Function: plays a major role in

regulation the body’s metabolism. Disorders: If the Thyroid Gland

produces to much Thyroxin, it can causea condition known as Hyperthyroidism. If

to little thyroxin produces it is calledHypothyroidism.



Pancreas Function: The Insulin

and Glucagon in thePancreas help to keepthe level of glucose inthe blood stable.

Disorders: When thePancreas fails toproduce or properly useInsulin, it can cause a

condition known asDiabetes Mellitus.



Adrenal Gland

Functions:

-The adrenal glandsrelease Adrenaline in

the body that helpsprepare for and dealwith stress.

-Also regulates kidney

function.

O i



Ovaries

Functions:

Pair of reproductive organs found inwomen that produce eggs.

Also secrete estrogen and

progesterone, which control ovulationand menstruation.



Testes

Functions:

Pair of reproductive glands that

produces sperm.

Also secrete Testosterone to give

the body its masculine

characteristics.



Interaction of Glands

The hypothalamus islocated in the brainand controls therelease of hormones

from the pituitary gland. It is animportant linkbetween theendocrine andnervous systems.

http://www.biocfarm.unibo.it/aunsnc/images/3D%20Obje

cts/Hypothalamus.gif



Regulation of Hormone Secretion

1. Impulse from nervous system

1. Neurosecretory cells inhypothalamus produced theHypothalamic Releasing Hormoneand Hypothalamic InhibitingHormones which can control the

secretion of hormone in pituitarygland.



2. Other Hormones

1. Pituitary is master endocrinegland because it secreteshormone that control the otherendocrine gland.

2. E.g ACTH can stimulate adrenal

cortex to release hormones forreabsorption of mineral salt inkidney.




3. The level of specificsubstances in body

1. Pancreas can detect the levelof glucose in our blood andproduce the glucagon to

increase it or insulin to reduceit.




What is Homeostasis?

The maintenance

of a constantenvironment in

the body is calledHomeostasis



The kidney



Kidney and bladder position



Kidney transplant



Cross section



X section to nephron



nephron



filtration



Filtration diagram - bowmans



Filtration & reabsorption



2 – Controlling Water



2 – Controlling Water

Concentration

Blood

-important part of internalenvironment

-constantly changing waterconcentration

-e.g. exercising

drinking lots of water

The body uses negative feedbackcontrol to regulate water content of

the blood



How does it work?



How?

Homeostatic mechanism is carriedout through a negative feedback mechanism in the body.



Controlling Glucose levels

Your cells also need an exact levelof glucose in the blood.

Excess glucose gets turned into

glycogen in the liver This is regulated by 2 hormones

(chemicals) from the pancreas called:

Insulin

Glucagon



If there is

too muchglucose inthe blood,Insulin

convertssome of it toglycogen

Glycogen

Glucose in the

blood



If there isnot enough

glucose inthe blood,Glucagonconvertssomeglycogen intglucose.

Glycogen

Glucose in the

blood



Diabetes

Some people do not produceenough insulin.

When they eat food, the glucoselevels in their blood cannot bereduced.

This condition is known as

DIABETES. Diabetics sometimes have to inject

insulin into their blood. They haveto be careful of their diet.



Time

Glucose

Concentration

Meal eaten

Insulin is produced

and glucose levelsfall to normal

again.

Glucose levels rise

after a meal.

Normal



Time

Glucose

Concentration

Meal eaten

Insulin is not

produced soglucose levels stay

high

Glucose levels rise

after a meal.

Diabetic

Penguins huddling



Penguins huddling



Controlling body temperature

All mammals maintain a constantbody temperature.

Human beings have a bodytemperature of about 37ºC.

E.g. If your body is in a hotenvironment your body temperature is37ºC

If your body is in a cold environmentyour body temperature is still 37ºC

What mechanisms are there to




cool the body down?

1. Sweating When your body is hot, sweat

glands are stimulated to releasesweat.

The liquid sweat turns into a gas(it evaporates)

To do this, it needs heat.

It gets that heat from your skin.

As your skin loses heat, it cools

down.



Sweating

Theskin

What mechanisms are there



What mechanisms are thereto cool the body down?

2. Vasodilation Your blood carries most of the heat energy

around your body.

There are capillaries underneath your skinthat can be filled with blood if you get toohot.

This brings the blood closer to the surfaceof the skin so more heat can be lost.

This is why you look red when you are hot!

This means more heat is lost from the surface



If thetemperaturerises, theblood vessel

dilates (getsbigger).

This means more heat is lost from the surfaceof the skin





warm the body up?

2. Piloerection This is when the hairs on your skin

“stand up” . It is sometimes called “goose

bumps” or “chicken skin”!

The hairs trap a layer of air next tothe skin which is then warmed bythe body heat

The air becomes an insulating layer.



1. What is a nerve?-a nerve is a thread like structure

containing a bundle o neurone

fibers2. Define a synapse

- A narrow gap between the axon

terminal of one neurone andthe dendrite of adjacentneurone

Wh t i l t ti ?



1. What is voluntary action?

-action that is controlled by the

conscious will of a person. Itinvolves the integration andinterpretation of information in thecerebrum

2. What is an involuntary action?

- Action that occur automatically inthe body without conscious control.

- Involves receptor, medullaoblongata and effectors.



1. Define hormone- Hormone are chemical

messenger produced by

endocrine gland and secreteddirectly into the blood stream.

2. What is an endocrine system?

- Endocrine system is a systemmake up of the endocrineglands of the body.



Sensory homunculus

Motor strip andh l

Motor strip



homunculusMotor strip



The Brain

Can you

Describe the structure and function ofthe brain

State the function and location ofcerebrum, cerebellum, medulla andhypothalamus

State the location of sensory and motorstrip

Coordination n Respons

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