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CHAPTER 2
BODY COORDINATIONBODY COORDINATION
2.1 BODY COORDINATION
Definition: the adjustment of our body’s reaction towards any stimulus.
Example: reaction to temperature change
IMPORTANCE OF BODY COORDINATION
Enables all body organs to function as a unit to detect stimuli and respond towards them
Helping us to avoid injuries or dangers Enables us to adapt to the changes around us
If a certain of your nervous system does not function properly,
then you can be paralysed.
2.2 THE HUMAN NERVOUS SYSTEM
HUMAN NERVOUS SYSTEM
Brain
Spinal cord
Spinal nerve
Cranial nerve
Central nervous system
Peripheral nervous system
A) CENTRAL NERVOUS SYSTEM
It is the control centre of the body.Brain: control all activities of the bodySpinal cord: control the reflex actions
It receives impulses form the acceptor/receptor (sensory organs), interpret it and sends new impulse to the acceptor (muscle and gland).
Impulse: the electrical signals carrying messages
B) PERIPHERAL NERVOUS SYSTEM
Function: to transmit impulses from the sensory organ or receptor through the central nervous system to the muscle or the gland.
The peripheral nervous system is divided into: Somatic nervous system: control all voluntary
actionsSpinal nerve: walking, scratching, writing (limbs,
skin and abdomen)Cranial nerve: talking, smiling, seeing (head
and neck)
Autonomic nervous system: controls involuntary actions (internal organs)
THE NEURONE
A neurone is a basic unit of the nervous system. Function: to carry impulses
Cell body
dendron
dendrite
myelin sheath
Node of ranvierAxon
Nerve ending
Nucleus
cytoplasm
NEURONE PARTS AND FUNCTIONS
Neurone part Function
Cell body Control all activities of the neurone
Dendrite Receives impulses from other neurone and transmit them to cell body
Dendron Dendrite that carries impulses towards the cell body
Axon Dendrite that carries impulses out of cell body
Myelin sheath -Insulator on axon that prevents the leakage of impulses-Increases the speed of impulse transmission
Nodes of ranvier Small gaps separating myelin sheath
TYPES OF NEURONES
Neurones are divided into three types based on their functions:
COMPARISON OF THREE TYPES OF NEURONE
CHARACTERISTICS
SENSORY RELAY MOTOR
POSITION OF CELL BODY
In the middle of neurone
At the centre of neurone
At the end of neurone
LENGTH OF AXON
Short Changes Long
CHARACTERISTICS SENSORY RELAY MOTOR
MOVEMENT OF IMPULSE
Sensory organ (acceptor) central nervous system
Sensory neurone motor neurone in the central
relay neurone in the central muscle (effectors)
FUNCTION Carries impulses from sensory organ to central nervous system
Transmits impulses from sensory neurone to motor neurone
Transmits impulses from central nervous system to effector (muscles and glands)
SIMILARITIES OF THE THREE TYPES OF NEURONE
Each has a cell body containing nucleus, dendron, dendrite and axon
The main role is to receive and transmit impulses
REFLEX ACTION (INVOLUNTARY)
Definition: automatic reaction by an external stimulus without the involvement of thinking.
It takes place in the spinal cord.
The path of reflex action is called a reflex arc.
SPINAL CORD
Connect the brain with the rest of body parts.
REFLEX ARC IN THE KNEE-JERK REACTION
FLOW CHART OF A REFLEX ARC
Stimulus
Receptor
Synapses
Motor Neurone
Relay Neurone
Synapses
Effector
Automatic Response
Sensory Neurone
Synapse: a tiny space that allow impulse to travel from one neurone to another in one direction
2.4 THE ROLE OF PROPRIOCEPTORS IN MAINTAINING BALANCE AND COORDINATION
Kinaesthetic sense enable us to be aware of the movement and position of the limbs to maintain balance.
Importance: help in maintaining balance and body coordination.
Examples: Playing pianoButtoning shirt without lookingCombing hair without looking
PROPRIOCEPTORS/STRETCH RECEPTORS
Found in muscle, ligaments, tendons and joints.
Responsible for kinaesthetic senses to maintain the body balance and coordination without looking at.
Detect the movement, change of position, muscle stretching and contraction.
2.5 HUMAN BRAINCEREBRUM
-control voluntary actions: mental activity,senses and
muscle movement-Largest part
CEREBELLUM-coordinate body balance
-coordinate muscle movement
MEDULLA OBLONGATA-connected to spinal cord
-control involuntary actions
Protected by cranium.
Outer layer is grey matter consists of cell bodies.
Is highly folded to increase the surface area.
Divided into right and left cerebral hemisphere which control opposite side of the body movements.
Thinking, memory, learning
Motor centre
(movement)
Touching (sense in skin and muscle)
Smell and taste
Speech
Hearing
Vision
DIFFERENT CONTROLLING PARTS IN THE BRAIN
THE HUMAN BRAIN
Motor centre
-paralysisSmell and taste
-loss in the ability of smell and taste
Hearing region
-deafness
Sight region-blindness
EFFECTS OF INJURY TO A CERTAIN REGION OF THE BRAIN
Cerebellum-lose body
balanceMedula
oblongata-fatal injury:
death
VOLUNTARY AND INVOLUNTARY ACTIONS
DIFFERENCESVOLUNTARY INVOLUNTARY
Controlled by desire or not
Nervous system involved
Part of brain in control
Pathway of impulse
Speed of response
Yes
Somatic nervous system
Cerebrum
Impulse flows through the cerebrum
Can be slow down or fast
No
Autonomic nervous system
Medulla oblongata
Impulse flows through the medula oblongata
Very fast
2.6 HORMONAL COORDINATION
Hormones: chemical substances secreted by endocrine glands directly into the bloodstream.
Characteristics:ProteinReleased in small quantitiesSpecific to target organs Slow to respond
Endocrine glands (ductless glands): coordinate body activities in respond to stimuli by secreting hormones.
PITUITARY GLAND
-Located at the base of cerebrum
-Known as master glands, produce more hormones)
-Controls water absorptions from the kidney
-Stimulates growth
THYROID GLAND (Thyroxine, contains Iodine)
-Located in the neck region (in front of trachea)
-Controls the body’s metabolic rate
-To stimulate growth and mental development
PANCREAS
-Located above the kidney
-Controls the glucose concentration
-Insulin (decrease the glucose concentration)
-Glucagon (increase the glucose concentration)
ADRENAL GLAND (adrenaline)
-Located below the stomach
-Prepares the body to meet emergency situations
- To increase heartbeat and respiration
TESTIS (testosterone)
-Protected by scrotum
-Controls development of secondary sexual
characteristics (deepening of the voice, growth of beard)
-Controls sperms production
OVARY (oestrogen, progesterone)
-Located in the abdomen
-Controls development of secondary sexual
characteristics (development of breasts, menstrual cycle)
-Controls eggs/ovum production
THE EFFECTS OF HORMONAL IMBALANCE
HORMONESEFFECT OF
OVER SECRETION UNDER SECRETION
Growth hormone (pituitary)
Gigantism (child)
Acromegaly (adult)
Dwarfism
Thyroxine (thyroid)
Exophthalmic goitre -Stunted physical and mental (children)-Goitre-Lack of energy (adult)Protuding
eyeballs
Goitre (swelling neck)
HORMONESEFFECT OF
OVER SECRETION UNDER SECRETION
Insulin (pancreas) Low blood sugar level (hypoglecemia)- shock and coma
High blood sugar level (hyperglecemia)
High sugar level in urine (diabetes)
Oestrogen (ovary) Early puberty
Extreme feminine characteristics
Late puberty
Progesterone (ovary)
- Miscarriage
Menstrual disorder
Testosterone (testis)
Early puberty
Extreme masculine characteristics
Late puberty
Low sperm count
2.7 COORDINATION BETWEEN THE NERVOUS SYSTEM AND THE ENDOCRINE SYSTEM
SIMILARITIES
NERVOUS COORDINATION
HORMONAL COORDINATION
•Both involve the passing of information and
•To control and coordinate functions and activities of organs in the
body
COMPARISON BETWEEN NERVOUS COORDINATION AND HORMONAL
COORDINATION
DIFFERENCESNERVOUS
COORDINATIONHORMONAL
COORDINATION
Impulses are sent through
Consists of
Speed of impulses
Effect
Target area
Response
Nerve fibres
Neurones(electrical impulse)
Fast
Localised, temporary, reversible
Muscles, glands
Rapid, short-lived
Blood circulatory system
Hormone (chemical substances)
Slow
Widespread, permanent, irreversible
Target organs only
Slow, diffuse, long lasting
CONCLUSION
The Importance Of Nervous System And Hormonal System Coordination:
•To ensure body functions such as physical, chemical and physiological responses occur at their optimum level.
•It ensures that if one system is not able to respond, then the other will compensate.
2.8 EFFECTS OF DRUG ABUSE ON BODY COORDINATION AND HEALTH Drugs are externally administered chemical
substances that affect the chemical reactions within the body.
TYPES OF DRUGS
EFFECTS OF DRUG ABUSE ON BODY COORDINATION
DRUGS
Nervous system
Distortion of perception,
hallucinations, illusions
Energetic, active, erratic, and
violent behaviour
Slow reaction to stimuli, sleepy, poor muscular coordination
Heart beat, breathing rate, blood pressure(eg: stimulants)
Heart beart, breathing rate, blood pressure
(eg: depressants)
stimulatesslows down
causes
affect
2.9 EFFECTS OF EXCESSIVE CONSUMPTION OF ALCOHOL
ALCOHOLIC DRINKS
2.10 THE IMPORTANCE OF A SOUND AND A HEALTHY MIND
Definition of mind
The ability to think and reason.
a) Healthy mind
Example: short-tempered, caring, positive attitude, rational,
b) Unhealthy mind
Example: low self-esteem, hot-tempered
THE MIND
b) Internal factors
Examples:-hormonal imbalance-drug abuse-excessive consumption of alcohol-brain injury
a) External factors
Examples: -mental stress-social factor
Influenced by