NERVOUS SYSTEM OF FARM ANIMALS


the nervous system

The nervous system includes all the organs and tissues which enable animals to respond to changes in their environment. A change in the environment is called a response.
The nervous system of mammals is composed of two parts: the central nervous system and the peripheral nervous system.





Central Nervous System

This is made up of the brain and the spinal cord. Both are made up of thousands of nerve cells or neurones. The functions of the central nervous system is correlation of impulses from various sense organs and storage of impulses as information or impressions in the brain for reaction to future similar stimuli.
(a)

The Brain:

the brain is enclosed in a bony case called the cranium. It is divided into fore, mid and bind brain
The fore brain consists of olfactory lobes which receive sensory impulses for smell and the cerebrum which is the seat of consciousness, intelligence, memory and all voluntary actions. The mid brain consists mainly of optic, lobes which control sight. The hind brain consists of the cerebellum which is concerned with balance and body posture, receives impulses and coordinates action, respiration, heartbeat, digestive movements and blood supply.
(b)

The Spinal Cord:

The spinal cord stems from the medulla oblongata and runs through the neural canal of the vertebral column or backbone. It communicates between the brain and other parts of the body. It controls all the reflex (involuntary) actions of the body.

The Peripheral Nervous System:

The peripheral nervous system consists of the cranial and spinal nerves and the autonomic nervous system. The cranial and spinal nerves of the peripheral nervous system together with the central nervous system mediate relations between the animals and its external environment. On the other hand, the autonomic nervous system, consisting of the sympathetic and parasympathetic nervous systems regulates events within the animal.

A neurone (nerve cell)

is the structural and functional unit of the nervous system. It helps in receiving and relaying of transmission of impulses.

A neurone has three main parts:

The dendrite, cell body and the axon (nerve fibre or axis cylinder).
The cell body has dendrites extending from it, and a central nucleus. The axon is surrounded by myelin sheath which is interrupted at intervals, forming nodes of ranvier. The axon terminates in dendrites.




TYPES OF NEURONES

(i) Sensory or Afferent Neurone: These neurones carry impulses from receptors, such as the eyes, skin, ears, etc. to the central nervous system.
(ii) Motor or Efferent neurone: These neurons carry impulses from the central nervous system to effectors, such as muscles and glands in the body
(iii) Intermediate or Relay neurons: These neurons receive, transmit and interpret messages in the spinal cord and brain

Transmission of Nerve Impulse:

The dendrites usually receive messages and pass them to the cell body which then passes them (messages) out through the long axon to the dendrites of another nerve cell. However, there is no direct connection between the fibres of adjacent neurones. The junction between one end of a dendrite of one neurone and that of an axon of the next neurone is known as a synapse. The message passes from cell to cell across these synapses.


Reflex actions:

These are actions carried out by animals in response to certain stimuli without first thinking or planning for them. They are not under the control of the brain. They are quick, automatic responses and entirely stereotype in nature. Examples of simple reflex or involuntary actions include: (i) the blinking of the eyes (ii) the beating of the heart (iii) sneezing (iv) sudden removal of hands, legs or skin from hot object. (v) the jerking of the legs on tapping the knee cap.


Reflex Arc:

A reflex arc is the path traced out by the impulses concerned in a simple reflex action. It consists of three neuroties - an afferent, intermediate anal efferent neurones.
The message from the external stimuli is received by the sensory or receptor organs such as the skin in the case of sudden removal of leg from hot object. The stimulus is sent to the brain or spinal cord through the sensory or efferent neurone. The intermediate or relay neurone in the brain and spinal cord receives, transmits and interpretes the message. The interpreted message is then sent through the motor or efferent neurone to the organ or effector such as the muscle, which then causes the appropriate response, leading to the sudden withdrawal of the leg from the hot object.

FUNCTIONS OF THE NERVOUS SYSTEM

(i) It coordinates body functions
(ii) It is responsible for bringing about locomotion or movement
(iii) It enables the body to respond to external stimuli




HERE YOU WILL FIND EVERY AVAILABLE TOPICS ABOUT AGRICULTURAL SCIENCE AND BIOLOGY. AND THE LINKS TO THEIR VARIOUS SOURCES.


1. DEVELOPMENT OF AGRICULTURE
2. IMPORTANCE OF AGRICULTURE
3. SUBSISTENCE AGRICULTURE
4. COMMERCIAL AGRICULTURE
5. PROBLEM OF AGRICULTURAL DEVELOPMENT
6. SOLUTIONS TO POOR AGRICULTURAL DEVELOPMENT
7. AGRICULTURAL LAWS AND REFORMS
8. ROLES OF GOVERNMENT IN AGRICULTURAL DEVELOPMENT
9. AGRICULTURAL POLICIES
10. PROGRAM PLANNING IN AGRICULTURE
34.
FORESTRY
35. WILDLIFE CONSERVATION
36. FACTORS AFFECTING LAND AVAILABILITY
37. TOPOGRAPHY
38. SOIL
39. BIOLOGICAL FACTORS
40. SOCIAL-ECONOMIC FACTORS
41. ENVIRONMENTAL FACTORS AFFECTING AGRICULTURAL PRODUCTION
42. CLIMATIC FACTORS AFFECTING AGRICULTURAL PRODUCTION
43. TEMPERATURE
44. RAINFALL
45. WIND
46. SUNLIGHT
47. SOLAR RADIATION
48. BIOTIC FACTOR AND AGRICULTURAL PRODUCTION
49. PESTS
50. BIRDS
51. DISEASES
52. SOIL MICRO-ORGANISMS
53. SOIL PH
54. ROCK FORMATION
55. IGNEOUS ROCK
56. SEDIMENTARY ROCKS
57. METAMORPHIC
58. SOIL AND ITS FORMATION
59. FACTORS OF SOIL FORMATION
60. LIVING ORGANISM
61. PARENT MATERIALS
62. SOIL FORMATION TOPOGRAPHY
63. PROCESS OF SOIL FORMATION
64. WEATHERING
65. PHYSICAL WEATHERING
66. CHEMICAL WEATHERING
67. PRESSURE
68. WATER
73. BIOLOGICAL WEATHERING
74. CHEMICAL AND BIOLOGICAL COMPOSITION OF THE SOIL
75. SOIL WATER
76. MICRO AND MACRO NUTRIENTS
77. SOIL MICRO ORGANISM
78. PROPERTIES OF SOIL
79. SOIL STRUCTURE
80. SANDY SOIL
81. CLAY SOIL
82. LOAMY SOIL

83. SOIL TEXTURE
84. IDENTIFICATION OF SOIL TYPES THROUGH EXPERIMENTS
85. RETENTION OF WATER BY VARIOUS SOIL TYPES
86. DETERMINATION OF SOIL PH REACTION
87. COLORIMETRIC DETERMINATION OF SOIL PH LEVEL
88. PH SOIL TEST
89. PLANT NUTRIENTS
90.
MACRO NUTRIENTS IN GENERAL
112.
THE MAINTENANCE OF SOIL FERTILITY
113. CROP ROTATION
114. APPLICATION OF ORGANIC MANURES
115. FARM YARD MANURE
116. APPLICATION OF INORGANIC MANURE

117. LIMING
118. FARMING PRACTICES
119. BUSH BURNING
120. CLEARING

121. FERTILIZER APPLICATION
122. ORGANIC MANURING
123. FARM YARD MANURE

124. HUMUS
125. COMPOST
126. CROP ROTATION
133. FARM POWER AND MACHINERY
134. SOURCES OF FARM POWER
135. HUMAN SOURCE
149.
PLOUGHS
142.
FIELD MACHINES
157.
PLANTERS
164.
SIMPLE FARM TOOLS
165. AGRICULTURAL MECHANIZATION
166. THE CONCEPT OF MECHANIZATION


oppurtunities

ADVANTAGES AND DISADVANTAGES OF MECHANIZATION

ADVANTAGES AND DISADVANTAGES OF MECHANIZATION ADVANTAGES OF MECHANIZED AGRICULTURE Farm mechanization has the following advantages 1. TI...

popular post of all time