3. The Neuron – basic unit if the nervous system. Responsible in making body necessary responses or actions.
4. 3 major parts of neuron : 1.Dendrites – neuron fiber carrying impulse to nerve cell body from synapse.
5. 2. Cell body – the compact central portion of a neuron 3. Axon – carries the nerve impulse away from the cell body and into the end brush.
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8. 2.Efferent or Motor Neurons – these carry messages from the central nervous system to the muscles and glands. 3.Connecting or Association Neurons – these are ‘middle-men’ between neurons. They are between the sensory and motor neurons. Most of them are found within the central nervous system.
9. Glia Cell or Neuroglia – other cells in the central nervous system. It is smaller than neurons. Their function is to provide support to the neurons.
10. Synapse – the only way that a neuron can communicate with other neurons. It is a microscopic gap, about eighteen-millionths of an inch wide, between the axon of one neuron and the dendrites of another neuron.
12. Nerve Impulse – is a wave of electro-chemical disturbance propagated along a nerve fiber.
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14. A. Brain – is that portion of the nervous system that is encased in the cranial bones.
15. It composed of soft nerve tissues covered by three membranes together known as meninges.
16. Three Major Sub–Divisions of the Brain 1. Hindbrain – within the hindbrain are the medulla oblogata, cerebellum, and pons varoli.
17. Medulla oblongata – the lowest portion of the brain. It connects the spinal cord. It contains center that regulate heart beat, blood pressure, and breathing and it controls the activities of the internal organs.
18. Cerebellum – is situated at the back of and above the medulla. It controls body balance.
19. Pons Varoli – contains nerves fibers that connect both hemispheres of the cerebellum with each other as well as with nerve fibers that transmit neutral impulses upward and downward within the nervous system.
20. 2. Midbrain – contains nerve tracks that connect the cerebrum with the brain stem and the spinal cord. It also contains neurons that are important for visual and auditory functions.
21. 3. Forebrain – the highest part of the brain, is divided into three main parts: the thalamus, the limbic system, and the cerebrum.
22. Thalamus – is the brain’s major relay station connecting the lower the lower structures of the brain and the spinal cord with cerebrum. - In the thalamus lie the cell bodies of important connecting neurons for the various senses.
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24. Limbic System – includes such areas as the amygdala, the hippocampus, the septum and portions of the hypothalamus and thalamus is a complex organization of neutral structures and pathways carrying messages between the lower and higher parts of the brain. It receives sensory messages from the visceral organs and helps control activities.
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26. Amygdala – which is connected with the hippocampus seems to be the main area involved with emotions. It is fundamental for self- preservation. Hippocampus – involved with memory, especially the formation of long-term memory.
28. Cerebrum – the largest part of the brain. It is divided into two halves called the cerebral hemispheres. These hemispheres contain the center for sensory integration and for voluntary motor activities. - They also play important roles in governing memory and intelligence.
32. Afferent nerves - the nerves carrying sensory input to the central nervous system Efferent nerves – the one’s carrying motor output away from the nervous system.
33. B. Spinal Cord The spinal cord is composed mainly of nerve connections running between the brain and the various parts of the body. It is long, tapering tube which occupy the hollow interior of the vertebral column, through the opening of which the spinal nerves enter and emerge from the cord. There are 31 pairs of spinal nerves.
43. Endocrine Glands Hormones – glands which are compose of cells that specialize in secreting highly complex chemical substance. Duct glands – glands that pour out their secretion trough tubes. Ex. milk glands, salivary glands, gastric glands on the walls of the stomach and the liver.
44. The major endocrine glands: ( Male left, female right) 1 Pineal gland 2 Pituitary gland 3 Thyroid gland 4 Thymus 5 Adrenal gland 6 Pancreas 7 Ovary 8 Testes Endocrine System
45. Ductless glands - glands secrete hormones directly into bloodstream. 1. Pituitary Glands It is found below the brain stem and is only a little larger than a pea. It is sometimes called the master glands because its secretes hormones that act on particular endocrine and stimulates their growth and activity.
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47. For example, it sends hormones to the thyroid, adrenals, gonads in order to stimulates them to produce their own hormones. The pituitary gland has two lobes, an anterior lobe and a posterior lobe. The anterior lobe secretes several hormones, one of these are growth hormones which promotes and control normal increase in size of the body.
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49. 2. The Thyroid Glands It is located in the neck produce the hormone thyroxin which influences the rate of the body metabolism especially oxidative or respiratory processes in all cells of the body.
54. 3.Parathyroid Glands - The parathyroid glands are located on the thyroid. They secrete parathormone, a hormone necessary to control the balance of various minerals in the blood stream especially calcium. It is essential to the maintenance of proper level of calcium in the blood and for the control of calcium metabolism in the cells.
62. 5. The Adrenals Located on the upper end of each kidney. Each adrenal has two parts: the medulla(inner part), which secretes adrenalin also known as epinephrine and nor-adrenalin or nor-epinephrine, the cortex or outer part which considered as an amazing endocrine factory since it produces very many different hormones.
63. - This gland continues to grow in size from infancy to puberty but after puberty, it slowly shrinks and is almost none existent in all age. The thymus gland therefore inhibits sexual development during childhood, but ceases to function after. - Sometimes called gland of childhood.
64. * Adrenalin - referred to as the emergency hormone because it enables the individual to cope with emergency situations. 6. Islets of Langerhans This are a group of cells located in the pancreas. They secrete insulin which is needed in the regulation of blood sugar by the cells. Its primary function is to control the metabolism of glucose.
65. This photograph shows a mouse pancreatic islet, an often spherical group of hormone-producing cells . Insulin is labelled here in green, glucagon in red, and the nuclei in blue. Islets of Langerhans
66. 7. The Gonads This refer to the ovaries in the female and testes in the male which produce sex hormones. The ovaries produce estrogen and progesterone. The testes produce the male sex hormone testosterone. These hormones influence the appearance of the secondary sex characteristics, the maturation of the reproductive organs, and the sex drive.
72. ASSIGNMENT: IS ADRENALIN (or Adrenaline) A HORMONE OR A NEUROTRANSMITTER? (1/2 crosswise yellow sheet)
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74. Stimulus – any from of energy capable of exiting the nervous system like light waves, sound waves, and the chemical energy that causes the sensation taste and smell. Receptor – is a specialized nerve ending capable of responding to energy. Senses – mechanisms which convert stimulus energy into neutral energy.
75. *Five Human Senses* 1.VISION The organ for vision is the eye. It is stimulated by light waves that strike the retina where the photo-sensitive cells- the rod and the cones- are located. The rods and cones are the receptor for vision.
78. Choroid Coat - the middle layer, a pigmented layer. It contains some of the blood vessels that supply the eye with blood. It also absorbs imperfectly focused light rays. In the front part of the eye, it becomes modified to from the iris and the cilliary blood. Pupil – the central opening of the iris
79. Iris – a circular arrangement of muscles that contract and expand to change the size of the pupil depending upon the intensity of illumination called light or dark adaptation. The color of the eye is due to the pigment in the iris Accommodation – the process when the lens become thinner to bring faraway objects into focus and thickens to focus on nearly objects.
89. Structure of the ear. The ear is divided into three parts: The outer ear - it is the visible part of the ear, composed of the pinna, the auditory canal, and the tympanic membrane commonly called eardrum.
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91. The middle ear – an air- filled chamber that is connected to the pharynx by the eustachian tube.
92. This connection of the middle ear to the pharynx serves to equalize the pressure on the two sides of the eardrum. The middle ear structure is composed of tree small bones or ossicles: the mallleus (hammer), the incus (anvil), and the stapes (stirrup). These bones are hanging into the system of levers, so that the movement of the eardrum is transmitted to a membrane called the oval window.
93. The inner ear – can find a cochlea which is a fluid- filled bony structure shaped like a snail shell. It is the organ of hearing. There are three canals in the cochlea–the cochlear canal, the tympanic canal, and the vestibular canal.
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96. 3. SMELL - The receptors for smell are found at the olfactory epithelium located at the very top of the nasal passages. -They are sensitive only to gases and to volatile substances that have been dissolved in the air.
98. 4. TASTE Much of the sensation depends on other factors-on warmth, coldness, the mild irritation caused by certain spices, and above all, on smell. When our nostrils are stuffed because of colds. Food seems almost tasteless. The tastebuds are the receptors for taste. They respond to four qualities of taste: sweet, sour, salty, and bitter.
100. 5. THE SKIN SENSES The skin has four separate senses: pain, pressure, cold, and warmth. The receptors fro the skin senses are nerve endings which come in four general forms: free nerve endings, globular bulbs, egg- shaped corpuscles, and “baskets” surrounding root hairs.
102. KINESTHESIS This is the sense of bodily movements. Its receptors are nerve endings found in muscles, tendons, and linings of joints. EQUILIBRIUM This is also called as the Static Sense. Two kinds of receptors give information about movements of the head and permit a sense of balance of the body.
103. These are in the semicircular canals and the vestibular canal. Both are located in the inner ear next to cochlea. THE ORGANIC SENSE This give s the result of the sensitivity of the visceral and other internal organs oft he body. Among the visceral organs are the stomach, intestines, sex structure, throat, hear and lungs.
104. PERCEPTION Chaplin defines perception as the process of knowing objects and objective events by means of senses. This sensory input consists of nerve impulses. They carry a sort of raw, undigested information about the environment. The individual must convert it into a meaningful information. Perception, then, is the organization of sensory input into meaningful experiences.
105. PERCEPTUAL CONSTANCY The perception of an object and all of its properties as constant and unchanging in spite of the continuously changing sensations of these properties outline the scope of object constancies. Our perceptual organization remains relatively stable even though some aspects of the pattern within the optical array undergo great changes.
110. * The principle of proximity – there is a tendency to perceive stimuli which are near one another as belonging together.
111. *The principle of closure – when fragmentary stimuli form enough of a familiar figure, we tend to perceive the whole figure, ignoring the missing part of parts.
112. *The principles of continuity – stimuli which from a continuous pattern are perceived as a whole, the pattern they make generally appears as a figure apart from the ground.
113. ATTENTION AND PERCEPTION Perception is selective. The direction of perception toward selected objects is called attention. A number of stimulus conditions help determine the direction of attention
114. DEPTH PERCEPTION This is the ability to see three- dimensional space and accurately judge distances. A study of perception would be incomplete without considering perceiving the third dimension- distance and depth.
Secretin is a hormone that controls the secretions into the duodenum , and also separately, water homeostasis throughout the body. It is produced in the S cells of the duodenum in the crypts of Lieberkühn . [1] Its effect is to regulate the pH of the duodenal contents via the control of gastric acid secretion and buffering with bicarbonate from the centroacinar cells of the pancreas as well as intercalated ducts. It is notable for being the first hormone to be identified
