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PART 1
BIOLOGY FORM 5
CHAPTER 3
COORDINATION & RESPONSE PART 1
3.1 Understanding
response and coordination
A student is able to:
 list the changes in external and internal environment ...
Living organisms respond to changes
in the internal and external
environment
 all organs and systems in a healthy
human body are co-ordinated
 co-ordinated means :
 they co-operate with one anothe...
The changes which cause response
in the body are called stimuli
(stimulus)
Stimuli: changes in the environment
- Internal ...
Stimuli [stimulus = singular]
Cold
Heat
Sound
Chemicals
in air
Pain
2 types of stimuli:
a) Internal stimuli
- Changes in blood pressure,
sugar level
b) External stimuli
-changes in light int...
Eg.
Cells sensitive to
the level of CO2
in the blood,
blood osmotic
pressure
Sensory receptors
Detect changes in the inter...
Sensory receptors
Detect changes in the internal environment
Eg. Pancreatic
cells detect
blood glucose
level
A stimulus is:
 a change in the environment that can be
detected by a sense organ and brings about a
response
Stimulus Receptor Effector
Response
Response – Body’s reaction to stimulus
When stimulus is detected, and eventually resul...
 Consider the tennis player about to hit
the ball:
Physical activity is one function
that requires co-ordination
1 Eyes s...
Co-ordination of body functions
involves:
BY THE
Nervous System
BY THE
Endocrine System
3.2 Analysing the role of human nervous
system
A student is able to:
 state the role of nervous system,
 draw and label ...
3.2 Analysing the role of human nervous
system
A student is able to:
 describe briefly the pathway of transmission of inf...
NERVOUS CONTROL:
THE NERVOUS SYSTEM
Question:
1. What is the main function of the nervous
system? (2)
The NS contains a network of specialised
cells called ne...
Nervous System
Sensory
Receptors
Integrating Centre Effectors
• Receptors: Sensory cells that detect stimuli
• Effectors: ...
 Nervous systems process information in
three stages
Sensor
Effector
Motor output
Integration
Sensory input
Peripheral ne...
The Nervous System receives
messages from:
Receptors in Sense
organs
CNS
Integrating centre
- Central nervous system
Brain & spinal cord
-processes information
The Nervous System sends
messages to:
 Muscles
 Glands
Effectors
CNS
Salivary
glands
Effectors
- Carry out the response to stimuli
Muscle & glands
Organization of the human nervous system
BRAIN
SPINAL
NERVES
(31 pairs)
CRANIAL
NERVES
(12 pairs)
AUTONOMIC
NERVOUS
SYSTEM...
Brain & Spinal cord:
 the main parts of the NS
 are called the CNS
How is the CNS connected to the various parts
of the body?
Basic unit of the nervous system
 Nerve cells = Neurones
Neurones
 transmit
electrical
impulses
Flow of information
What are
‘stimuli’?
Skull Plates slide at Birth
Suture
The Skull protects the Brain
Meninges surround Brain & Spinal Cord
Function of the Meninges:
1. stabilise neural tissue
2. protect from bruising agains...
Meningitis: caused by an infection of the
meninges
Bacteria
Virus
Streptococcus
meningitis infection
Cerebrospinal Fluid (CSF) fills the:
1. hollow cavities of
the brain
[ventricles]
2. spinal cord
Left lateral view
Functions of the cerebrospinal
fluid:
1. acts as a shock absorber
2. to allow oxygen and
nutrients to diffuse
through it t...
CSF must be drained all the time
CSF accumulates and exerts pressure
on the brain if not allowed to drain
Parts of the brain:
Cerebrum / cerebral hemisphere
Cerebellum
Medulla
oblongata
Pituitary
gland
Hypothalamus
What happened to the size of the cerebrum
as more complex nervous systems evolved?
The cerebrum came to make up a larger
p...
The cerebrum is highly folded
Many neurones can be
packed into a small
space.
Two Cerebral hemispheres =
cerebrum
Regions of the Brain: Cerebrum
• Layers of the cerebrum
Grey matter:
- outer layer in the
cerebral cortex
- composed mostl...
Position of Grey and White Matter
Grey
matter
Brain
Spinal Cord
White
matter
The Cerebrum is the site of:
1) consciousness, our sense of self
2) intelligence, reasoning,
personality, learning,
emotions and the ‘will’
Regions of the Cerebral Cortex
receives and
processes visual
information
concerned with
planning and
decision making
recei...
Three Kinds of Functional Areas in Cerebral Cortex:
2. Sensory areas
Receive impulses from
sensory receptors
1. Motor area...
3. Association areas
Integrate or associate sensory information
or memories
Body Map of the Cortex: cortical homunculus
Summary : The cerebrum
 controls our:
 sensations
 movements
 voluntary actions
 is responsible for:
 memory
 thoug...
The cerebrum contains
2. Sensory areas:
 for sensation
1. Motor areas:
 for movement
3. Association areas :
 for thinki...
Functions of the cerebellum:
 controls balance and
muscular co-ordination
FUNCTIONS of the Cerebellum:
it receives information from
the organs of balance in the
ears
FUNCTIONS of the Cerebellum:
is concerned with the control and precision
of all movements involving voluntary muscles
What happens to a person if the
cerebellum is damaged?
A damaged cerebellum results in jerky, poorly
coordinated movements
Functions of the medulla oblongata:
 controls involuntary & automatic processes such
as:
 the rate of breathing
 heartb...
Medulla Oblangata
 Acts as a reflex centre.
Eg. Vomiting, coughing & sneezing.
Functions of:
 releases
hormones
 homeostasis
has centres which control mood and emotions
such as aggression, rage, fear and pleasure
is the most vascular region of t...
The Hypothalamus is connected to &
controls the pituitary gland:
 Anterior pituitary produces various hormones
The Pituitary Gland
 Posterior
pituitary
stores and
releases
ADH & oxytocin
Meninges
 are layers of tissue that surround the CNS
Question:
1. List the function of each of the following
parts within the central nervous system:
i. cerebrum; (2)
ii. cere...
Question:
This question concerns the nervous system of humans.
Give the main function of the following structures within t...
IQ (Intelligence Quotient)
The Spinal Cord
The Spinal Cord is a cylinder of
nervous tissue
 runs from the base of the brain down the back
Two functions of the Spinal Cord:
1)acts as a coordinating centre for:
 reflex actions
2) provides a means of
communicati...
The Structure of the Spinal Cord & its Roots
GREY MATTER
contains
cell bodies
dendrites
synapses
WHITE MATTER
contains
mye...
Myelin = FAT = white
Grey matter
White matter
TS spinal cord
Why is the white
matter white?
 due to nerve fibres
covered ...
Grey matter
White matter
 due to nuclei present
in cell bodies TS spinal cord
Remember nuclei look
DARK.
Why is the grey
...
Vertebrae protect the spinal cord
Spinal
cord
Vertebra
Vertebral
column
Protection of the Spinal Cord by:
1. Vertebral column
2. Meninges
3. Cerebrospinal fluid
The Spinal Cord is found in the Neural Canal
Neural canal
PAIN!!!
Meninges surround Spinal Cord
Neurones and nerves
Neurone = nerve cell
Nerve = a bundle of nerve cells
neurones
Neurones can be very long
Afferent / Sensory neurones
Efferent / Motor neurones
Interneurones or
Relay neurones
Three types of Neurone
Afferent
neurone
(sensory
neurone)
Interneurone
(relay neurone)
Eferent
neurone
(motor
neurone)
Basic plan of a nervous system
receptor  afferent neurones  efferent neurones
interneurones
in
central
nervous
system
...
Each neurone possesses:
Dendrites
Dendrites
Cell body
[soma] Axon
Synaptic
terminals
The Structure And Function Of A Typical
Neurone
Dendrites
Neurilemma
• Forms the cell
membrane of a neurone
Muscle fibres
...
Structure of a afferent/sensory
neurone
Afferent /Sensory Neurone
AXON
DENDRON
Direction of impulse along a
afferent/sensory neurone
Axon carries impulse:
Away from the cell body
Efferent / Motor neurone
AXON
E
F
F
E
C
T
O
R
O
R
G
A
N
Efferent/motor neurone
[axon terminal]
Direction of
impulse
Function of the myelin sheath
Protects the nerve fibre
insulates the nerve fibre
speeds up the impulses
Myelin sheath:
...
Nodes of Ranvier: gaps along the axon
 facilitate the rapid conduction of nerve impulses
impulsesimpulses occur at inter...
Differences in structure between a:
1. Long axon
2. No receptor
3. Cell body terminal &
has dendrites
4. Many short dendro...
Differences in function between a:
receptor
Afferent neuroneEfferent neurone
C
N
S
C
N
S
Carries
impulse from
the receptor...
Interneurone
 Carries impulse from the
afferent neurone to the
efferent neurone
Connections between afferent neurone,
interneurone and efferent neurone.
 Neurones DO NOT touch each other
Afferent
neuro...
A synapse is a tiny gap between
neurones
synapse
Impulses
travel in
direction
across a
synapse
Afferent neurone
Efferent neurone
Interneurone
Effector
Receptor
Two neurones Communicate at a
Synapse
A synapse forms when:
an axon of a presynaptic cell “connects” with the
dendrites of...
How many synapses on one cell
body? 1,000 to 10,000!!
A Synapse
A synapse
What happens at a chemical synapse?
• Calcium ions cause synaptic vesicles to fuse
with the presynaptic membrane, releasin...
What happens at a chemical synapse?
• neurotransmitters diffuses across the
synaptic cleft and binds to specific
neurorece...
Neurotransmitters are
cleared from the cleft.
Why is it important to
remove them from the
synaptic cleft?
To stop their ac...
1. Diffusion
The neurotransmitter is cleared from the
synaptic cleft in three ways:
2. Reuptake by
adjacent cells
3. Enzym...
Examples of neurotransmitters
Acetylcholine
Noradrenaline (Norepinephrine)
Dopamine
 All skeletal muscle motor neurones
 Some neurones in the autonomic NS
Acetylcholine (ACh) is released by:
 Blocks ACh receptors
 Circular iris muscles do not contract
Atropine from belladonna
Explain the possible effects of the following
neurotoxins based on their mode of action:
1.nerve gases used in warfare (e....
Explain the possible effects of the following
neurotoxins based on their mode of action:
Question:
2.various toxins, such ...
Drugs and the
Synapse
Amphetamine & Nicotine are stimulants
 have an excitatory effect
 cause brain to release more
dopamine [neurotransmitter...
But when the effect wears
off person feels down
Effect of Amphetamines
Amphetamine stimulates dopamine synapses:
- by increasing
the release of
dopamine
from the
presynaptic
terminal
DAT – dopa...
Nicotine binds to the presynaptic receptors:
exciting the neurone to fire more action
potentials causing an increase in do...
Drugs and alcohol bind important receptors on neurones
Repeated binding causes the neurone to die
Types Of Coordinated Response
Two types of actions controlled by the human
nervous system
Voluntary Action
Involuntary Act...
Voluntary Action
Initiated by the motor centres of the cerebral corfex
The pathway of transmission of information in volun...
Involuntary Action
The brain is not conscious of an involuntary action.
Example of involuntary action involving skeletal m...
A Reflex Action is a
 rapid, automatic, involuntary response to a
stimulus which is not under the voluntary
control of th...
A Reflex Action
 is the simplest form of response in the nervous
system
 the same stimulus produces the same response
ev...
Examples of reflex actions:
 Sneezing
 Blinking
 Coughing
 Removing the leg
when stepping on a pin
The knee jerk is a reflex action
Examples of reflex actions:
 withdrawing your hand from a hot
object
Why are reflex actions useful to
the body?
b. List the stimulus and response for each of
the following reflex actions:
i. swallowing; (3)
Stimulus: food in mouth
Res...
Question:
A student accidentally touches a beaker of hot
water. The student pulled her hand away from
the hot water very q...
Question:
b) List TWO examples of reflex actions taking
place in newborn babies. (4)
Suckling reflex
Grip reflex
Stepping
...
Reflex Arc is the:
nervous pathway taken by nerve
impulses in the reflex action
REFLEX ARC
Stimulus Afferent
Neurone
Interneurone
Receptor Synapse
Response Efferent
Neurone
Synapse
Two Types of Reflex Action:
1.Monosynaptic 2. Polysynaptic
e.g. knee jerk reflex
Has a SINGLE synapse
between the sensory
...
Reflex Action
What’s wrong
with this
animation?
The knee jerk reflex arc
MuscleSpinal cord
Stimulus Afferent
Neurone
Receptor Synapse
Response
Efferent
Neurone
Reaction Time: 0.3 SECONDS
What type of reflex action is shown?
Monosynaptic
or
Polysynaptic
Where are the cell bodies located?
Afferent/Sensory
neurone:
dorsal root ganglion
Efferent/Motor neurone &
interneurone:
g...
Dorsal [back]
TS spinal cord
Ventral [front]
A sensory neurone always
enters via the DORSAL
ROOT
Dorsal root ganglion is a
collection of cell bodies of the
sensory neurones
A Reflex Arc
- nerve pathway in a reflex action
stimulus
receptor
afferent neurone
spinal
cord of
central
nervous
system
i...
REMEMBER: Reflex Arc
Some involve 3 neurones – afferent neurone,
interneurone & efferent neurone
Eg. withdrawal of the han...
Reflex arc
Activity: Draw
The hand withdrawal reflex arc.
Question
A transverse section through the spinal cord is
examined under the high power of the
microscope. Part of it looks...
Answer
Diagram A represents nerve fibres cut in cross-
section and therefore comes from white
matter.
Diagram B shows many...
Label the diagram. Draw arrows to
show direction of impulse
A – receptor
B – sensory neurone
C – motor neurone
D – synapse
Question:
6d) The following diagram demonstrates the rapid
and automatic removal of a finger from a
flame.
i) Complete the...
ii) Use arrows to show the pathway of the
nerve impulse along the neurones. (4)
e) Some individuals suffer from a motor neurone
disease in which the neurones gradually
degenerate. How is this likely to ...
Label the two neurones. What is the
function of each?
Question:
The diagram in the figure below shows part of
the spinal cord of a human in transverse
section
a)Identify the st...
Question:
Touching a hot surface would generally cause a
person to contract their biceps, retracting the
arm and hand away...
Question:
c) Name the three types of neurones involved in
a reflex action and indicate the approximate
position of each on...
Question:
d) State ONE function of the fluid found in
structure E. (1)
Shock absorber / provides nutrients to the
nerve ce...
SOMATIC NERVOUS SYSTEM
Organization of the human nervous system
BRAIN
SPINAL
NERVES
(31 pairs)
CRANIAL
NERVES
(12 pairs)
AUTONOMIC
NERVOUS
SYSTEM...
Peripheral Nervous System
Cranial & Spinal Nerveshe nervous system of a vertebrate
mixed nerves
What does
this mean?
31 pa...
Mixed nerves have both sensory &
motor neurones
AUTONOMIC NERVOUS SYSTEM
 The part of the nervous system responsible for control of
the bodily functions not consciously ...
Organization of the human nervous system
BRAIN
SPINAL
NERVES
(31 pairs)
CRANIAL
NERVES
(12 pairs)
AUTONOMIC
NERVOUS
SYSTEM...
Autonomic Nervous System also known as the
involuntary Nervous System
Regulates activities of:
 cardiac & smooth muscles
...
The overall control of the autonomic NS
is maintained by centres in the :
medulla
&
hypothalamus
SYMPATHETIC & PARASYMPATHETIC SYSTEM
Effect on the Heart:
Organ Sympathetic Parasympathetic
Heart Increases
amplitude and
rate of heart
beat
Decreases
amplitud...
Diseases related to
the Nervous System
Parkinson’s disease
Affects nerve cells in the brain that produce neurotransmitter
dopamine.
Symptoms : muscle rigidity, t...
See Video - dbs
THE END Part 1
Chemical weapons symbol
Nerve gases
 Nerve gases, or nerve agents
 odorless , colorless or yellow-brown liquids
 eg Sarin and VX.
 Even in sma...
Effects of sarin
 Runny nose, Watery eyes, Small, pinpoint pupils, Eye pain,
Blurred vision, Drooling and excessive sweat...
BOTOX
 Botox is a drug made from a toxin produced by the
bacterium Clostridium botulinum.
 causes a life-threatening typ...
BOTOX
Doctors use it in small doses to treat health problems, including
 Temporary smoothing of facial wrinkles and impro...
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
Coordination & Response Part 1 - The Nervous System
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Coordination & Response Part 1 - The Nervous System

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Coordination & Response Part 1 - The Nervous System

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Coordination & Response Part 1 - The Nervous System

  1. 1. PART 1 BIOLOGY FORM 5 CHAPTER 3 COORDINATION & RESPONSE PART 1
  2. 2. 3.1 Understanding response and coordination A student is able to:  list the changes in external and internal environment faced by an organism,  state why organisms have to be sensitive to changes in internal and external environment,  clarify through examples the meaning of ‘stimulus’ and ‘response’,  state the main components and pathways involved in detecting and responding to changes in external environment,  state the main components and pathways involved in detecting and regulating changes in internal environment,  clarify through examples the meaning of ‘coordination’.
  3. 3. Living organisms respond to changes in the internal and external environment
  4. 4.  all organs and systems in a healthy human body are co-ordinated  co-ordinated means :  they co-operate with one another and work together efficiently
  5. 5. The changes which cause response in the body are called stimuli (stimulus) Stimuli: changes in the environment - Internal & external environment
  6. 6. Stimuli [stimulus = singular] Cold Heat Sound Chemicals in air Pain
  7. 7. 2 types of stimuli: a) Internal stimuli - Changes in blood pressure, sugar level b) External stimuli -changes in light intensity, sound , temperature, pressure, touch
  8. 8. Eg. Cells sensitive to the level of CO2 in the blood, blood osmotic pressure Sensory receptors Detect changes in the internal environment
  9. 9. Sensory receptors Detect changes in the internal environment Eg. Pancreatic cells detect blood glucose level
  10. 10. A stimulus is:  a change in the environment that can be detected by a sense organ and brings about a response
  11. 11. Stimulus Receptor Effector Response Response – Body’s reaction to stimulus When stimulus is detected, and eventually result in response, it is called coordination
  12. 12.  Consider the tennis player about to hit the ball: Physical activity is one function that requires co-ordination 1 Eyes see ball. 2 3 Information goes to brain & is processed. Brain sends messages to muscles to hit the ball.
  13. 13. Co-ordination of body functions involves:
  14. 14. BY THE Nervous System
  15. 15. BY THE Endocrine System
  16. 16. 3.2 Analysing the role of human nervous system A student is able to:  state the role of nervous system,  draw and label a diagram to show the organisation of the nervous system,  name the main parts of the brain and state their functions,  draw and label a diagram of a cross section of the spinal cord,  state the main functions of the spinal cord,  label the structure of an efferent neurone,  identify the type of the neurone from diagrams given,  state the function of each type of neurone,  state the mode of transmission of information along the neurone,
  17. 17. 3.2 Analysing the role of human nervous system A student is able to:  describe briefly the pathway of transmission of information from receptors to effectors,  draw and label a simple diagram of a synapse,  describe the transmission of information across synapses,  state the role of the synapse in transmission,  give examples of voluntary action,  give examples of involuntary action,  outline the transmission of information in voluntary action,  outline the transmission of information in involuntary action,  draw a schematic diagram showing a reflex arc,  give examples of nervous system related diseases.
  18. 18. NERVOUS CONTROL: THE NERVOUS SYSTEM
  19. 19. Question: 1. What is the main function of the nervous system? (2) The NS contains a network of specialised cells called neurones that coordinate the actions of an animal / human and transmit signals between different parts of its body.
  20. 20. Nervous System Sensory Receptors Integrating Centre Effectors • Receptors: Sensory cells that detect stimuli • Effectors: Organs/Glands that carry out responses to stimuli
  21. 21.  Nervous systems process information in three stages Sensor Effector Motor output Integration Sensory input Peripheral nervous system (PNS) Central nervous system (CNS)
  22. 22. The Nervous System receives messages from: Receptors in Sense organs CNS
  23. 23. Integrating centre - Central nervous system Brain & spinal cord -processes information
  24. 24. The Nervous System sends messages to:  Muscles  Glands Effectors CNS Salivary glands
  25. 25. Effectors - Carry out the response to stimuli Muscle & glands
  26. 26. Organization of the human nervous system BRAIN SPINAL NERVES (31 pairs) CRANIAL NERVES (12 pairs) AUTONOMIC NERVOUS SYSTEM SPINAL CORD CENTRAL NERVOUS SYSTEM HUMAN NERVOUS SYSTEM PERIPHERAL NERVOUS SYSTEM SOMATIC NERVOUS SYSTEM SYMPATHETIC SYSTEM PARASYMPATHETIC SYSTEM
  27. 27. Brain & Spinal cord:  the main parts of the NS  are called the CNS
  28. 28. How is the CNS connected to the various parts of the body?
  29. 29. Basic unit of the nervous system  Nerve cells = Neurones Neurones  transmit electrical impulses
  30. 30. Flow of information What are ‘stimuli’?
  31. 31. Skull Plates slide at Birth Suture The Skull protects the Brain
  32. 32. Meninges surround Brain & Spinal Cord Function of the Meninges: 1. stabilise neural tissue 2. protect from bruising against bones
  33. 33. Meningitis: caused by an infection of the meninges Bacteria Virus Streptococcus meningitis infection
  34. 34. Cerebrospinal Fluid (CSF) fills the: 1. hollow cavities of the brain [ventricles] 2. spinal cord Left lateral view
  35. 35. Functions of the cerebrospinal fluid: 1. acts as a shock absorber 2. to allow oxygen and nutrients to diffuse through it to nourish neurones 3. to allow removal of wastes
  36. 36. CSF must be drained all the time CSF accumulates and exerts pressure on the brain if not allowed to drain
  37. 37. Parts of the brain: Cerebrum / cerebral hemisphere Cerebellum Medulla oblongata Pituitary gland Hypothalamus
  38. 38. What happened to the size of the cerebrum as more complex nervous systems evolved? The cerebrum came to make up a larger proportion of the brain.
  39. 39. The cerebrum is highly folded Many neurones can be packed into a small space.
  40. 40. Two Cerebral hemispheres = cerebrum
  41. 41. Regions of the Brain: Cerebrum • Layers of the cerebrum Grey matter: - outer layer in the cerebral cortex - composed mostly of neurone cell bodies White matter: - inner layer in the cerebral cortex - composed of myelinated nerve fibres
  42. 42. Position of Grey and White Matter Grey matter Brain Spinal Cord White matter
  43. 43. The Cerebrum is the site of: 1) consciousness, our sense of self
  44. 44. 2) intelligence, reasoning, personality, learning, emotions and the ‘will’
  45. 45. Regions of the Cerebral Cortex receives and processes visual information concerned with planning and decision making receives and processes auditory information deals with incoming information from the body
  46. 46. Three Kinds of Functional Areas in Cerebral Cortex: 2. Sensory areas Receive impulses from sensory receptors 1. Motor areas Send impulses to skeletal muscles
  47. 47. 3. Association areas Integrate or associate sensory information or memories
  48. 48. Body Map of the Cortex: cortical homunculus
  49. 49. Summary : The cerebrum  controls our:  sensations  movements  voluntary actions  is responsible for:  memory  thought  intelligence Cerebrum
  50. 50. The cerebrum contains 2. Sensory areas:  for sensation 1. Motor areas:  for movement 3. Association areas :  for thinking
  51. 51. Functions of the cerebellum:  controls balance and muscular co-ordination
  52. 52. FUNCTIONS of the Cerebellum: it receives information from the organs of balance in the ears
  53. 53. FUNCTIONS of the Cerebellum: is concerned with the control and precision of all movements involving voluntary muscles
  54. 54. What happens to a person if the cerebellum is damaged? A damaged cerebellum results in jerky, poorly coordinated movements
  55. 55. Functions of the medulla oblongata:  controls involuntary & automatic processes such as:  the rate of breathing  heartbeat
  56. 56. Medulla Oblangata  Acts as a reflex centre. Eg. Vomiting, coughing & sneezing.
  57. 57. Functions of:  releases hormones  homeostasis
  58. 58. has centres which control mood and emotions such as aggression, rage, fear and pleasure is the most vascular region of the brain monitors: i) metabolite and hormone levels of the blood ii) blood temperature The Hypothalamus
  59. 59. The Hypothalamus is connected to & controls the pituitary gland:
  60. 60.  Anterior pituitary produces various hormones The Pituitary Gland  Posterior pituitary stores and releases ADH & oxytocin
  61. 61. Meninges  are layers of tissue that surround the CNS
  62. 62. Question: 1. List the function of each of the following parts within the central nervous system: i. cerebrum; (2) ii. cerebellum; (2) iii. medulla oblongata. (2) 2. In humans the cerebrum is very large and highly folded. Explain why. (2)
  63. 63. Question: This question concerns the nervous system of humans. Give the main function of the following structures within the brain: (4) 1) Medulla controls heart rate, blood pressure, breathing rate 2) Cerebellum controls posture and balance, co-ordinates muscle action 3) Cerebrum responsible for voluntary action, store memory, involved in learning 4) Hypothalamus responsible for homeostasis, acts as an integration centre for the endocrine and nervous systems
  64. 64. IQ (Intelligence Quotient)
  65. 65. The Spinal Cord
  66. 66. The Spinal Cord is a cylinder of nervous tissue  runs from the base of the brain down the back
  67. 67. Two functions of the Spinal Cord: 1)acts as a coordinating centre for:  reflex actions 2) provides a means of communication between the:  spinal nerves and  the brain
  68. 68. The Structure of the Spinal Cord & its Roots GREY MATTER contains cell bodies dendrites synapses WHITE MATTER contains myelinated nerve fibres
  69. 69. Myelin = FAT = white Grey matter White matter TS spinal cord Why is the white matter white?  due to nerve fibres covered by myelin
  70. 70. Grey matter White matter  due to nuclei present in cell bodies TS spinal cord Remember nuclei look DARK. Why is the grey matter grey?
  71. 71. Vertebrae protect the spinal cord Spinal cord Vertebra Vertebral column
  72. 72. Protection of the Spinal Cord by: 1. Vertebral column 2. Meninges 3. Cerebrospinal fluid
  73. 73. The Spinal Cord is found in the Neural Canal Neural canal PAIN!!!
  74. 74. Meninges surround Spinal Cord
  75. 75. Neurones and nerves Neurone = nerve cell Nerve = a bundle of nerve cells neurones
  76. 76. Neurones can be very long
  77. 77. Afferent / Sensory neurones Efferent / Motor neurones Interneurones or Relay neurones Three types of Neurone
  78. 78. Afferent neurone (sensory neurone) Interneurone (relay neurone) Eferent neurone (motor neurone)
  79. 79. Basic plan of a nervous system receptor  afferent neurones  efferent neurones interneurones in central nervous system stimulus change in the environment of the receptor generates nerve impulses The functional unit of the nervous system is the neurone. muscle or gland response effector
  80. 80. Each neurone possesses: Dendrites Dendrites Cell body [soma] Axon Synaptic terminals
  81. 81. The Structure And Function Of A Typical Neurone Dendrites Neurilemma • Forms the cell membrane of a neurone Muscle fibres Myelin sheath • Insulates the axon and speeds up the transmission of impulses Axon (Transmits impulse away from the cell body) Dendron (Transmits impulse towards the cell body) Nucleus Cell body • Contains a nucleus, cytoplasm and other organelles Nodes of Ranvier • Where the neurilemma constricts, helps to speed up transmission of nerve impulse • Serves as a control centre
  82. 82. Structure of a afferent/sensory neurone
  83. 83. Afferent /Sensory Neurone AXON DENDRON
  84. 84. Direction of impulse along a afferent/sensory neurone Axon carries impulse: Away from the cell body
  85. 85. Efferent / Motor neurone AXON E F F E C T O R O R G A N
  86. 86. Efferent/motor neurone [axon terminal] Direction of impulse
  87. 87. Function of the myelin sheath Protects the nerve fibre insulates the nerve fibre speeds up the impulses Myelin sheath: FAT
  88. 88. Nodes of Ranvier: gaps along the axon  facilitate the rapid conduction of nerve impulses impulsesimpulses occur at intervals of 1 to 2 m
  89. 89. Differences in structure between a: 1. Long axon 2. No receptor 3. Cell body terminal & has dendrites 4. Many short dendrons 1. Short axon 2. Receptor 3. Cell body at the side; no dendrites 4. One long dendron receptor axon axon dendron Afferent neuroneEfferent neurone C N S C N S
  90. 90. Differences in function between a: receptor Afferent neuroneEfferent neurone C N S C N S Carries impulse from the receptor to the CNS Carries impulse from the CNS to the effector
  91. 91. Interneurone  Carries impulse from the afferent neurone to the efferent neurone
  92. 92. Connections between afferent neurone, interneurone and efferent neurone.  Neurones DO NOT touch each other Afferent neurone Efferent neurone Inter neurone
  93. 93. A synapse is a tiny gap between neurones synapse
  94. 94. Impulses travel in direction across a synapse Afferent neurone Efferent neurone Interneurone Effector Receptor
  95. 95. Two neurones Communicate at a Synapse A synapse forms when: an axon of a presynaptic cell “connects” with the dendrites of a postsynaptic cell
  96. 96. How many synapses on one cell body? 1,000 to 10,000!!
  97. 97. A Synapse
  98. 98. A synapse
  99. 99. What happens at a chemical synapse? • Calcium ions cause synaptic vesicles to fuse with the presynaptic membrane, releasing neurotransmitters into the synaptic cleft. 2
  100. 100. What happens at a chemical synapse? • neurotransmitters diffuses across the synaptic cleft and binds to specific neuroreceptor sites in the post synaptic membrane. 3
  101. 101. Neurotransmitters are cleared from the cleft. Why is it important to remove them from the synaptic cleft? To stop their action. What happens to the neurotransmitter after its release?
  102. 102. 1. Diffusion The neurotransmitter is cleared from the synaptic cleft in three ways: 2. Reuptake by adjacent cells 3. Enzymes present in the cleft may destroy them: e.g. acetylcholinesterase acts on acetylcholine (ACh)
  103. 103. Examples of neurotransmitters Acetylcholine Noradrenaline (Norepinephrine) Dopamine
  104. 104.  All skeletal muscle motor neurones  Some neurones in the autonomic NS Acetylcholine (ACh) is released by:
  105. 105.  Blocks ACh receptors  Circular iris muscles do not contract Atropine from belladonna
  106. 106. Explain the possible effects of the following neurotoxins based on their mode of action: 1.nerve gases used in warfare (e.g. sarin) and organophosphate insecticides (e.g. parathion) inhibit acetylcholinesterase; (1) The neurotransmitter is not destroyed by acetylcholinesterase and continues to act on the postsynaptic membrane. Thus impulses are continuously being fired. Question:
  107. 107. Explain the possible effects of the following neurotoxins based on their mode of action: Question: 2.various toxins, such as botulinum toxin, prevent the release of acetylcholine. (1) No impulse can be fired in the postsynaptic membrane and the person remains paralysed.
  108. 108. Drugs and the Synapse
  109. 109. Amphetamine & Nicotine are stimulants  have an excitatory effect  cause brain to release more dopamine [neurotransmitter]  dopamine causes neurones to fire more often than normal: = euphoric feeling
  110. 110. But when the effect wears off person feels down Effect of Amphetamines
  111. 111. Amphetamine stimulates dopamine synapses: - by increasing the release of dopamine from the presynaptic terminal DAT – dopamine transporter
  112. 112. Nicotine binds to the presynaptic receptors: exciting the neurone to fire more action potentials causing an increase in dopamine release
  113. 113. Drugs and alcohol bind important receptors on neurones
  114. 114. Repeated binding causes the neurone to die
  115. 115. Types Of Coordinated Response Two types of actions controlled by the human nervous system Voluntary Action Involuntary Action Controlled by cerebrum Controlled by medulla oblongata
  116. 116. Voluntary Action Initiated by the motor centres of the cerebral corfex The pathway of transmission of information in voluntary action Receptors Sensory areas of the cerebral cortex Motor area of the cerebral cortex Effector Afferent nerve Efferent nerve Stimulus Response
  117. 117. Involuntary Action The brain is not conscious of an involuntary action. Example of involuntary action involving skeletal muscle knee jerk reflex withdrawal of the hand from a hot object Example of involuntary action involving smooth muscle cardiac muscle or glands regulation of blood pressure rate of breathing blood glucose level
  118. 118. A Reflex Action is a  rapid, automatic, involuntary response to a stimulus which is not under the voluntary control of the brain The pupil reflex
  119. 119. A Reflex Action  is the simplest form of response in the nervous system  the same stimulus produces the same response every time Sneeze Swallow Snail retreats inside shell
  120. 120. Examples of reflex actions:  Sneezing
  121. 121.  Blinking  Coughing  Removing the leg when stepping on a pin
  122. 122. The knee jerk is a reflex action
  123. 123. Examples of reflex actions:  withdrawing your hand from a hot object
  124. 124. Why are reflex actions useful to the body?
  125. 125. b. List the stimulus and response for each of the following reflex actions: i. swallowing; (3) Stimulus: food in mouth Response: food goes down oesophagus ii. coughing. (2) Stimulus: foreign particles in trachea Response: removal of foreign object from trachea
  126. 126. Question: A student accidentally touches a beaker of hot water. The student pulled her hand away from the hot water very quickly. This is an example of a reflex action. a) Define the term reflex action. (2)
  127. 127. Question: b) List TWO examples of reflex actions taking place in newborn babies. (4) Suckling reflex Grip reflex Stepping reflex Crying reflex
  128. 128. Reflex Arc is the: nervous pathway taken by nerve impulses in the reflex action
  129. 129. REFLEX ARC Stimulus Afferent Neurone Interneurone Receptor Synapse Response Efferent Neurone Synapse
  130. 130. Two Types of Reflex Action: 1.Monosynaptic 2. Polysynaptic e.g. knee jerk reflex Has a SINGLE synapse between the sensory and motor neurones e.g. hand withdrawal reflex Has TWO or more synapses lex
  131. 131. Reflex Action What’s wrong with this animation?
  132. 132. The knee jerk reflex arc MuscleSpinal cord Stimulus Afferent Neurone Receptor Synapse Response Efferent Neurone
  133. 133. Reaction Time: 0.3 SECONDS
  134. 134. What type of reflex action is shown? Monosynaptic or Polysynaptic
  135. 135. Where are the cell bodies located? Afferent/Sensory neurone: dorsal root ganglion Efferent/Motor neurone & interneurone: grey matter of spinal cord
  136. 136. Dorsal [back] TS spinal cord Ventral [front]
  137. 137. A sensory neurone always enters via the DORSAL ROOT
  138. 138. Dorsal root ganglion is a collection of cell bodies of the sensory neurones
  139. 139. A Reflex Arc - nerve pathway in a reflex action stimulus receptor afferent neurone spinal cord of central nervous system interneurone efferent neurone effector response
  140. 140. REMEMBER: Reflex Arc Some involve 3 neurones – afferent neurone, interneurone & efferent neurone Eg. withdrawal of the hand from a hot object Some involve 2 neurones – afferent neurone & efferent neurone Eg. knee jerk
  141. 141. Reflex arc
  142. 142. Activity: Draw The hand withdrawal reflex arc.
  143. 143. Question A transverse section through the spinal cord is examined under the high power of the microscope. Part of it looks like diagram A and part looks like diagram B. Which is grey matter and which is white matter? Give reasons for your decision. A B
  144. 144. Answer Diagram A represents nerve fibres cut in cross- section and therefore comes from white matter. Diagram B shows many cell bodies which constitute much of the grey matter. A B
  145. 145. Label the diagram. Draw arrows to show direction of impulse A – receptor B – sensory neurone C – motor neurone D – synapse
  146. 146. Question: 6d) The following diagram demonstrates the rapid and automatic removal of a finger from a flame. i) Complete the diagram by drawing and naming the neurones that bring about this reflex action.
  147. 147. ii) Use arrows to show the pathway of the nerve impulse along the neurones. (4)
  148. 148. e) Some individuals suffer from a motor neurone disease in which the neurones gradually degenerate. How is this likely to interfere with the efficiency of reflex actions? (2) Reflex actions take longer to occur – they become less efficient.
  149. 149. Label the two neurones. What is the function of each?
  150. 150. Question: The diagram in the figure below shows part of the spinal cord of a human in transverse section a)Identify the structures labelled A through D. (2) A: white matter B: dorsal root ganglion C: grey matter D: ventral root E: central canal
  151. 151. Question: Touching a hot surface would generally cause a person to contract their biceps, retracting the arm and hand away from the stimulus. This reflex action involves three neurones. b) What is a reflex action? (1) A reflex action is a rapid automatic response to a stimulus. An action which is not learned.
  152. 152. Question: c) Name the three types of neurones involved in a reflex action and indicate the approximate position of each on the diagram. (3)
  153. 153. Question: d) State ONE function of the fluid found in structure E. (1) Shock absorber / provides nutrients to the nerve cells / removes wastes of nerve cells
  154. 154. SOMATIC NERVOUS SYSTEM
  155. 155. Organization of the human nervous system BRAIN SPINAL NERVES (31 pairs) CRANIAL NERVES (12 pairs) AUTONOMIC NERVOUS SYSTEM SPINAL CORD CENTRAL NERVOUS SYSTEM HUMAN NERVOUS SYSTEM PERIPHERAL NERVOUS SYSTEM SOMATIC NERVOUS SYSTEM SYMPATHETIC SYSTEM PARASYMPATHETIC SYSTEM
  156. 156. Peripheral Nervous System Cranial & Spinal Nerveshe nervous system of a vertebrate mixed nerves What does this mean? 31 pairs 12 pairs
  157. 157. Mixed nerves have both sensory & motor neurones
  158. 158. AUTONOMIC NERVOUS SYSTEM  The part of the nervous system responsible for control of the bodily functions not consciously directed, such as breathing, the heartbeat, and digestive processes.
  159. 159. Organization of the human nervous system BRAIN SPINAL NERVES (31 pairs) CRANIAL NERVES (12 pairs) AUTONOMIC NERVOUS SYSTEM SPINAL CORD CENTRAL NERVOUS SYSTEM HUMAN NERVOUS SYSTEM PERIPHERAL NERVOUS SYSTEM SOMATIC NERVOUS SYSTEM SYMPATHETIC SYSTEM PARASYMPATHETIC SYSTEM
  160. 160. Autonomic Nervous System also known as the involuntary Nervous System Regulates activities of:  cardiac & smooth muscles  glands FUNCTION:  controls involuntary functions e.g. sweating
  161. 161. The overall control of the autonomic NS is maintained by centres in the : medulla & hypothalamus
  162. 162. SYMPATHETIC & PARASYMPATHETIC SYSTEM
  163. 163. Effect on the Heart: Organ Sympathetic Parasympathetic Heart Increases amplitude and rate of heart beat Decreases amplitude and rate of heart beat
  164. 164. Diseases related to the Nervous System
  165. 165. Parkinson’s disease Affects nerve cells in the brain that produce neurotransmitter dopamine. Symptoms : muscle rigidity, tremors, and changes in speech and gait. After diagnosis, treatments can help relieve symptoms, but there is no cure.
  166. 166. See Video - dbs
  167. 167. THE END Part 1
  168. 168. Chemical weapons symbol
  169. 169. Nerve gases  Nerve gases, or nerve agents  odorless , colorless or yellow-brown liquids  eg Sarin and VX.  Even in small quantities, nerve gases inhibit the enzyme acetylcholinesterase and disrupt the transmission of nerve impulses in the body.
  170. 170. Effects of sarin  Runny nose, Watery eyes, Small, pinpoint pupils, Eye pain, Blurred vision, Drooling and excessive sweating, Cough, Chest tightness  Rapid breathing, Diarrhea, Nausea, vomiting, and/or abdominal pain, Increased urination  Confusion, Drowsiness, Weakness, Headache, Slow or fast heart rate, Low or high blood pressure  Even a small drop of sarin on the skin can cause sweating and muscle twitching where sarin touched the skin.  Exposure to large doses of sarin by any route may result in the following harmful health effects:  Loss of consciousness, Convulsions, Paralysis, Respiratory failure possibly leading to death
  171. 171. BOTOX  Botox is a drug made from a toxin produced by the bacterium Clostridium botulinum.  causes a life-threatening type of food poisoning called botulism.
  172. 172. BOTOX Doctors use it in small doses to treat health problems, including  Temporary smoothing of facial wrinkles and improving your appearance  Severe underarm sweating  Cervical dystonia - a neurological disorder that causes severe neck and shoulder muscle contractions  Blepharospasm - uncontrollable blinking  Strabismus - misaligned eyes  Chronic migraine  Overactive bladder  Botox injections work by weakening or paralyzing certain muscles or by blocking certain nerves. The effects last about three to twelve months, depending on what you are treating. The most common side effects are pain, swelling, or bruising at the injection site. You could also have flu-like symptoms,

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