• “ It is the type of coordination present between the cells or different organs within the body of multicellular organisms. In this kind of coordination a group of cells releases specific chemicals, which regulates the activities of other cell of the body.”

Chemical co-ordination

In animals Nervous system & Hormonal system plays an important role in control & co-ordination.

In plants control and coordination is done by chemical substances called plant hormones or phytohormones.

• Coordination in animals :- In animals control and co ordination is done by the Nervous system and Endocrine system.

• Nervous system- The nervous system is an organ system containing a network of specialized cells called neurons.

• Types of Nervous system- • 1.Central Nervous system(CNS) – It includes – Brain &

Spinal cord. • 2.Peripheral Nervous system( PNS)- It includes a.

Somatic nervous system(SNS)- it is also known as voluntary nervous system & associated with the voluntary control of body movements via skeletal muscles.

CO-ORDINATION IN ANIMALS

Neurons

• Neurons(Nerves)- The structural & functional unit of Nervous system called as Neurons.

Structure of Neurons

• It has a cell body called cyton containing a nucleus and cytoplasm. It has several branched structures called dendrites. It has a long nerve fiber called axon which may covered by Schwann cells & a protective covering called Myelin sheath. Schwann cells separated by a gap called as Nodes of Ranvier. Neuron ends by bulb like structure at nerve ending called as Synaptic Knob.

Synapse

• Synapse-The junction between two neurons or with muscles is called synapse.

Nerve Impulse

• Nerve impulse -Messages pass through the nerve cell in the form of chemical and electrical signals called nerve impulse. The dendrites receive the information and starts a chemical reaction which produce electrical impulse which passes through the axon.

Reflex Action

• Reflex action Reflex action is a sudden, unconscious and involuntary response of the effectors to a stimulus.

• Ex :- We suddenly withdraw our hand if we suddenly touch a hot object. In this reflex action, the nerves in the skin (receptor) detects the heat and passes the message through the sensory nerves to the spinal cord. Then the information passes through the motor nerves to the muscles (effectors) of the hand and we withdraw our hand.

Reflex Arc

• REFLEX ARC- The pathway of a reflex action is called reflex arc. In a reflex arc the stimulus is received by the receptors (sense organs) and it passes through the sensory nerves to the spinal cord. From the spinal cord the information passes through the motor nerves to the effectors (muscles/glands) for the response.

Role of Brain

• The brain plays no action as the reflex action takes place at the level of spinal cord. But later brain is informed by the spinal cord and then later the thinking part of the action is done by brain. But brain is not active during A reflex action. Difference between Reflex action & walking. Reflex action 1. It is inborn, involuntary ( automatic) & require for survival & protection. Walking- 1.It is acquire by learning, under control of brain(voluntary) & for various function

Human Brain

Human Brain• The brain is the main coordinating centre in the human body. It is protected

by the cranium. It is covered by three membranes called meninges filled with a fluid called cerebrospinal fluid which protects the brain from shocks. The brain has three main parts. They are fore brain, mid brain and hind brain.

• i) Fore brain consists of the cerebrum and Thalamus. It is the thinking part of the brain and controls voluntary actions. It controls touch, smell, hearing, taste, sight, mental activities like thinking, learning, memory, emotions etc.

• ii) Mid brain controls involuntary actions and reflex movements of head, neck, eyes etc.

• iii) Hind brain consists of cerebellum, pons and medulla. Cerebellum controls body movements, balance and posture. Pons controls respiration. Medulla controls heart beat, blood pressure, swallowing, coughing, sneezing, vomitting etc.

Spinal Cord

• Spinal cord The spinal cord starts from the brain and extends through the vertebral column. It has 31 pairs of spinal nerves. It carries messages to and from the brain. It also controls reflex actions.

Muscles are 3 types • Skeletal muscles (Voluntary muscles /Striated muscles)-

attached with bones & having alternate dark and light bands.

• Smooth muscles (Involuntary muscles /Non striated muscles) present in internal body organs.

• Cardiac muscles- present in heart Nerve impulse reaches to muscle which resulted into muscular action.

ENDOCRINE GLANDS IN HUMAN BEINGS

Endocrine Glands

• Endocrine glands in human beings The endocrine glands are also known as Ductless gland. The endocrine glands produce chemical substances called as Hormones, and it directly diffuses into blood and reaches to target organ.

• The endocrine glands in our body are pineal, hypothalamus, pituitary, thyroid, parathyroid, thymus, pancreas, adrenal, testes and ovary.

Glands In our Body

• Hypothalamus gland –it forms various releasing or inhibiting hormones & regulate the Pituitory glands for further function.

• Pituitory gland- It function in response of hypothalamus & releases hormones. For ex. GH-Growth hormones – It help for body growth.

Hypothalamus, Pituitary, pineal Gland

Glands In our Body• Thyroid glands- a pair of glands present in neck region, which forms thyroxin

hormone in response of TSH of pituitory. • Thyroxin hormone - Thyroxin controls the metabolism of carbohydrates, fats

and proteins and helps in proper growth. If the diet is deficient in iodine it causes deficiency of thyroxin leads to cause the goiter in which enlargement of thyroid glands cause the swelling of neck. The goiter disease are generally found in people living in northern sub-himalayan areas where the diet are deficient of iodine. Hence one must take the iodized salt. Excess secretion of thyroxin cause exophthalmia (protrusion of eyes)

• Parathyroid glands- two pair of parathyroid glands which are close to thyroid gland. It secretes the parathormone which require to control the Calcium and phosphorous. It deficiency cause Cramps and spasms Thymus gland- It is present near the heart & secretes the hormone Thymosine. It is required for maturation of T- lymphocytes which require for immunity.

Thyroid and Parathyroid glands

Glands In our Body

• Adrenal glands –> a pair of glands present over the Kidney, Adrenal gland have two parts-

• Outer Adrenal cortex • inner medulla. • Adrenal cortex - stimulated by ACTH & forms 3 hormones namely - Gluco-

corticoids, Mineralo-corticoids, Androgens. . It requires for Glucose metabolism, mineral balance, secondary sexual characters respectively.

• Adrenal medulla- it produces two hormones – Adrenaline & Nor adrenaline hormone – It is also known as Emergency hormone or hormone of 3 F – Fight,Flight,Freight. It increase of heart beats, blood pressure, rate of breathing , causes rapid contraction of rib muscles etc to full fill the increasing demand of body. Nor adrenaline hormone- It require for normal functioning of heart beat, blood pressure, breathing rate etc.

Adrenal Glands

EFFORTS BY:JASHANPREET10TH CDAV SR. SEC. PUBLIC SCHOOL SECTOR 8 PANCHKULA