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Wednesday, 1 July 2015

CONTROL & COORDINATION notes

 CONTROL & COORDINATION

KEY CONCEPTS & GIST OF THE LESSON


Coordination-The working together of various organs of the body of an organism in a proper manner to produce appropriate reaction to a stimulus is called coordination.

Stimulus- The changes in the environment to which an organism responds and reacts is called Stimulus
 Control & coordination in animals- takes place by
 (i) Nervous system & 
(ii) Endocrine system

 Nervous system
Stimulus → Receptor organ → Sensory nerve → Brain/Spinal cord

Response ← Effector organ ← Motor nerve
Endocrine system
Stimulus → Endocrine organ → Secrete hormone → Hormone in blood

Response ← Target organ

Parts of the Nervous system – 
(i) Brain 
(ii) Spinal cord 
(iii) Nerves (Neurons)


 A Neuron is the structural & functional unit of Nervous system
Parts of a neuron- 
(i) Dendrites 
(ii) Cell body 
(iii) Axon

Synapse- Space/junction between two adjacent nerves is called Synapse.

 Passing of information takes place –
(i) By Electric impulse (inside the neuron) and 
(ii) In the form of chemicals (At synapse)
 

                       Reflex action- 
Spontaneous, involuntary and automatic response to a stimulus to protect us from harmful situations. Eg. On touching a hot object unknowingly we instantly withdraw our hand.

 Reflex arc- The pathway of the reflex action is called Reflex arc.
Stimulus → Receptor organ → Sensory nerve → Spinal cord →→Effector organ→
Response


Nervous system
(1) Central Nervous system (CNS) 
(2) Peripheral Nervous system (PNS)
(i) Brain 
(i) Autonomic Nervous system
(ii) Spinal cord 
(ii) Voluntary Nervous system

Brain 
(i) Centre of coordination of all activities 
(ii) Thinking is involved 
(iii) Complex process



Parts of brain-
Fore brain                 Mid brain                                    H ind brain
(i) Cerebrum
(ii) Thalamus
(iii) Hypothallamus
----------
(i) Cerebellum
(ii) Pons
(iii) Medulla oblongata
 Fore brain
Cerebrum- (i) Main thinking and largest part of the brain.
(ii) It has 3 main areasa.
Sensory area- to receive impulses from sense organs via Receptors
b. Motor area- control voluntary movements.
c. Association areas- Reasoning, learning & intelligence.
Thalamus – It relays sensory information to the Cerebrum
Hypothallamus- It forms the link between Nervous system & Endocrine system
Mid brain- It connects Fore brain and Hind brain. Controls reflex of eyes & ears
Hind brain- Connects the Fore brain & Hind brain
Cerebellum – Controls & coordinates muscular movements, maintaining body
posture and
equilibrium.
Pons- Acts as a bridge between brain & spinal cord
Medulla oblongata- Controls involuntary actions like blood pressure, salivation, vomiting, etc.
Spinal cord- Cylindrical or tubular structure extending downwards from the Medulla oblongata.
 Protection of the brain & the spinal cord-
(i) Bony outer covering: skull for the brain & vertebral column for the spinal cord.
(ii) Cerebrospinal fluid present in between the three membranes.
 Action caused by Nervous tissue
Information → Nervous tissue → Brain Muscles → Causes action
 Path or action-
Nerve impulse → Muscle cell → Changes shape due to special proteins

Action caused ← Shorter form of muscles ← Change shape & arrangement of cell
 Chemical communication by hormones- (advantages)
(i) Electrical impulses have their limitations because they reach only those cells connected to the nervous tissue.
(ii) Also the nerve cells cannot generate & transmit impulses continuously.
(iii)Electrical communication is slower.
Hormones- (i) are chemical messengers secreted by endocrine glands
(ii) Are secreted in small amounts & may act in nearby places or distant places.
(iii) Do not take part in the reaction & are destroyed immediately.
Hormones are secreted by- Endocrine glands & Exocrine glands
S. No. Endocrine glands Exocrine glands
1. Ducts absent Ducts present
2. Secrete hormones Secrete enzymes
3. Secreted in blood Secreted in ducts of glands
4. Situated away from the site of action Situated near the site of action
 Some glands which act as both endocrine & exocrine
Gland Endocrine function Exocrine function Pancreas Produces insulin &
Glucagon hormone. Produces digestive enzyme. (pancreatic amylase)
Testes Produces hormone Testosterone Produces male gametes (reproductive cells)
Ovaries Produces hormone Oestrogen Produces female gametes (reproductive cells)
 Important Endocrine glands, the hormone they secrete & their function

Endocrine gland
Hormone Function
Pituitary gland Growth hormone Body growth, development of bones & muscles
(If excess- Gigantism)
(If less- Dwarfism)
Thyroid gland Thyroxine Regulates carbohydrate, protein & fat metabolism( If less- Goitre_
Pancreas Produces insulin & Glucagon hormone Regulates blood sugar levels (if less diabetes is caused)
Testes in males Produces hormone
Testosterone
Development of secondary male
characters like deep voice, beard, etc.
Ovaries in females
Produces hormone Oestrogen
Development of secondary female characters like mammary glands,
menstrual cycle, maintenance of pregnancy.
Coordination in plants- Only chemical coordination is present in plants.
 Tropic movements- The movements of plants in the direction of stimulus (positive) or away from it (negative) are called tropic movements. E.g. Phototropism, Geotropism. Chemotropism.

Nastic movements -The movements of plants independent of stimuli are called nastic movements. E.g.- Touch me not plant leaves close when touched.
Plant hormones (Phytohormones)
Examples- 1. Auxins- Help in growth of root & shoot tips.
2. Gibberellins- Help in vegetative growth
3. Cytokinins- Promote cell division
4. Abscissic acid - Inhibits growth & causes wilting (falling) of leaves
 Important diagrams-
1. Structure of neuron (nerve cell)
2. Reflex arc
3. Human brain
4
. Endocrine glands in human beings

Also read.
reproduction
gregor-mendel-father-of-genetics
our-environment
natural-resources-questions
reproduction-and-endocrine-system
heredity-and-evolution
the-human-eye-and-colourful-world
heredity-notes
management-of-natural-resources
control-and-co-ordination-test2
control-coordination-notes
life-process-question-part2

ONTROL & COORDINATION
KEY ideas & GIST OF THE LESSON
 Coordination-The operating along of assorted organs of the body of associate organism in an exceedinglycorrect manner to supply applicable reaction to a stimulant is named coordination.
 stimulant- The changes within the setting to that associate organism responds and reacts is named Stimulus
 management & coordination in animals- takes place by (i) systema nervosum & (ii) system
 systema nervosum
Stimulus → Receptor organ → nerve → Brain/Spinal wire

Response ← Effector organ ← nervus
 system
Stimulus → Endocrine organ → Secrete endocrine → endocrine in blood

Response ← organ
 components of the systema nervosum – (i) Brain (ii) neural structure (iii) Nerves (Neurons)
 A nerve cell is that the structural & useful unit of systema nervosum
 components of a neuron- (i) Dendrites (ii) Cell body (iii) nerve fiber
 colligation- Space/junction between 2 adjacent nerves is named Synapse.
 Passing of data takes place –(i) By electrical impulse (inside the neuron) and (ii) within the variety of chemicals (At synapse)
 Reflex action- Spontaneous, involuntary and automatic response to a stimulant to shield U.S. from harmfulthings. Eg. On touching a hot object unwittingly we have a tendency to instantly withdraw our hand.
 neural structure- The pathway of the reflex action is named Reflex arc.
Stimulus → Receptor organ → nerve → neural structure →→Effector organ→
Response

 systema nervosum- (1) Central systema nervosum (CNS) (2) Peripheral Nervous system (PNS)
(i) Brain (i) involuntary systema nervosum
(ii) neural structure (ii) Voluntary systema nervosum
 Brain (i) Centre of coordination of all activities (ii) Thinking is concerned (iii) advanced method
 components of brain-
Fore brain middle brain H ind brain
(i) neural structure
(ii) neural structure
(iii) Hypothallamus
----------
(i) neural structure
(ii) Pons
(iii) medulla
 Fore brain
Cerebrum- (i) Main thinking and largest a part of the brain.
(ii) it's three main areasa.
Sensory area- to receive impulses from sense organs via Receptors
b. Motor area- management voluntary movements.
c. Association areas- Reasoning, learning & intelligence.
Thalamus – It relays sensory info to the neural structure
Hypothallamus- It forms the link between systema nervosum & system
 middle brain- It connects Fore brain and Hind brain. Controls reflex of eyes & ears
 Hind brain- Connects the Fore brain & Hind brain
Cerebellum – Controls & coordinates muscular movements, maintaining body
posture and
equilibrium



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