Neural Control and Coordination

• As you know the function of the organs system in our body must be coordinated to maintain homeostasis . Coordination is the process through which two or more organs interact and complement the function of one another . The NEURAL SYSTEM provides an organized network of point to point connection for a quick coordination

Introduction

• The neural system of all animals is composed of highly specializes cells called the NEURON which can detect, receive and transmit different kinds of stimuli.

Neural system

Human neural system

Peripheral neural system

Somatic neural system

Autonomic neural system

Central nervous neural system

• A neuron is a microscopic structure composed of three major parts namely CELL BODY (cyton), DENDTRITES AND AXON.

Neuron as Structural and Functional Unit of Neural System

A neuron is made up of two main parts;

a) Cyton

b) Axon

Cyton – also called cell body, contains a large prominent

nucleus in the center. The cell membrane is branched into

several cytoplasmic branches called dendrites which

receive impulse.

Structure of a Neuron

Axon-The long cytoplasmic projection of the neuron that extends from the cell body. An axon is covered by a myelinated sheath. Axons carry the impulse they receive from the cyton. They usually terminate into another neuron or an organ or gland or muscle.

Neuron

Generation and conduction of nerve impulse

• Neurons are excitable cells because their membranes are in a polarized state

• In resting state the axonal membrane is more permeable to potassium ions as compared to sodium ions

• Similarly the membrane is impermeable to negatively charged proteins present in the axoplasm

• The axoplasm contains high concentration of potassium ion and low concentration of sodium ions and its vice versa in the fluid outside the axon

• The gradient is maintained by the active transportation of ions by the sodium-potassium pump which transport 3 sodium ions outwards for 2 potassium ions into the cell

A nerve impulse is transmitted from one neuron to another through junction called synapses.

A synapse is formed by the membrane of a pre-synaptic neuron and a post-synaptic neuron, which may or may not be separated by a gap called synaptic cleft

Transmission of Impulse

ELECTRICAL SYNAPSES

• In this the membrane of pre and post synaptic neurons are very close to each other.

• Electric current can flow directly from one neuron to other through these synapses.

• Impulse transmission is faster

CHEMICAL SYNAPSES

• In this there is presence of synaptic cleft i.e.. The two neurons are well separated from each other.

• For the flow of current from one neuron to other, a chemical called neurotransmitter is secreted in the synaptic cleft.

• Impulse transmission is slow.

Two types of Synapses

ELECTRICAL SYNAPSES

CHEMICAL SYNAPSES

• The human brain is the central information processing organ of our body and acts as the command and control system

• it is well protected by the skull

• It is mainly divided into three parts

Forebrain

Midbrain

Hindbrain

Central Neural SystemThe Brain

• The forebrain consists of cerebrum, thalamus and hypothalamus.

• Cerebrum forms the major part of the human brain

Forebrain

• The midbrain is located between the thalamus/hypothalamus of the forebrain and pons of the hind brain

Midbrain

• The hindbrain comprises pons, cerebellum and medulla.

Hindbrain

• The process of response to a peripheral nervous stimulation, that occurs involuntarily i.e...without conscious efforts or thought and requires the involvement of a part of the central nervous system is called reflex action

Reflex Action and Reflex Arc

Now lets check how much u got it..!

3. Nervous system is made up of-______ (Understanding)

2.Which system performs the function of control and coordination in our body?

(Knowledge)

1. What is control and coordination.? (Knowledge)

4. Name the different parts of neuron. (Application)

5.What is synapse?

(Knowledge)

6.How nerve impulse is transmitted

at synapse? (Skill)

9. What happens when we touch a hot object by our hand? (Application)

8. Define reflex arc. (Understanding)

7. What is reflex action? (Knowledge)

11. Draw well-labelled diagram of neuron (Application)

12. What is hormone? (Knowledge)

10. Draw schematic outline of reflex arc (Application)

13. Which hormone maintains blood glucose level:

a) Thyroxinb) Insulin

c) Estrogend)Cytokinin

(Knowledge)

a) Synapseb) Axon

c) Dendrited) Impulse

15. Hormone secreted in human female at the

age of 10-12 yrs. is ________ (Knowledge)

16. Hormones responsible for plant growth are-_______

(Understanding)

17. Where do we find a hormone AUXIN in plants?

(Application)

18. What is the difference between movements in “ Touch-me-not” plant and our leg?

( UNDERSTANDING)

19. Match the following                  Hormones      function                 Thyroxin          caused breasts to develop in

females                 Adrenaline        causes the male to start

producing sperms                 Insulin             prepares the body for

emergency                 Estrogen         controls the metabolic rate                 Testosterone    regulates the amount of sugar

in blood

20 .Electrical impulse travels in neuron from:

       a. Dendrite→axon→axon end→cell body

       b. Cell body→Dendrite→axon→axon end

       c. Dendrite→cell body→axon→axon end

       d. Axon end→axon→cell body→Dendrite

21. What do you understand by CNS? Explain

22. Why does the food taste different when your nose is blocked?

23. Name one hormone found in male

24. Drastic changes of body features associated with puberty are mainly because of secretion of

     a) Estrogen from testes and testosterone from ovary  b) Estrogen from adrenal gland and testosterone from pituitary gland  c) Testosterone from testes and estrogen from ovary   d) Testosterone from thyroid gland and estrogen from pituitary gland

25. Learning is related to :    

a. Hypothalamus     b. Thalamus     c. Cerebrum     d. Cerebellum25.

26.Which of the following statements about transmission of nerve impulse is incorrect?    

a. Nerve impulse travels from dendritic end towards axonal end  b. At the dendritic end electrical impulses bring about the release of some chemicals which generate an electrical impulse at the axonal end of another neuron c. The chemicals released from the axonal end of one neuron cross the synapse and generate a similar electrical impulse in a dendrite of another neuron

27.The substance that triggers the fall of mature leaves and fruits from plants is due to  

  a. Auxin     b. Gibberellins     c. Abscissic acid     d. Cytokinin

28.The reflex action, the reflex arc is formed by :    

a. Muscles - receptor – brain     b. Muscles - effector – brain     c. Receptor - spinal cord – muscles     d. Spinal cord - receptor – muscles

29. Which of the following statements are true about brain?

        i. The main thinking part of brain is hind brain        ii. Centers of hearing, smell, memory, sight etc. are located in fore brain        iii. Involuntary actions like salivation, vomiting, blood pressure are controlled by the medulla in the hind brain        iv. Cerebellum does not control posture and balance of the body

1.

oestrogenprogesteroneadrenalinetestosterone

30. Male hormone is ________________.

1. vitamins2. enzymes3. proteins4. hormones

31. Auxins are _________________.

1. conditioning2. memory

3.coordination and precision

4. intelligence

32.The cerebellum is concerned with ______

1. heart rate2. blood pressure

3.amount of glucose in blood

4. all the above

33.Adrenaline increases _____________.

1. brain2. spinal cord

3.brain and spinal cord

4.brain, spinal cord and all the nerves

34.The CNS consists of _______________.

1. auxin

2.gibberellic acid

3. cytokinin4. ethylene

35.The hormone that is used to keep flowers fresh is _______.

36.The hormone that speeds up the ripening process is ______.

1. auxin2. gibberelin3. cytokinin4. ethylene

37.The hormone that causes blood sugar level to fall is _____

1. glucagon2. insulin3. somatostatin4. adrenalin3

38. Blinking of eyes is a ________________.

1. reflex action2. involuntary action3. voluntary action only4. can be a or b

39.The box enclosing the brain is called the _________

1. Forehead2. Head3. Cranium4. Vertebral column

Presented by-

1 Rakesh Kumar SarmetLecturer –in- Biology

Master Trainers Program DIET at Shamlaghat , Shimla Himachal

pradesh2-12-2013 to 6-12-2013

THANK U…