Co-ordination and Control | Jamb Biology

Jamb(UTME) tutorial on nervous coordination; The sense organs

Nervous Coordination and the Central Nervous System

1. Definition of Nervous Coordination: The process by which the nervous system controls and integrates activities in the body.
2. Central Nervous System (CNS): Comprises the brain and spinal cord.
3. Function of CNS: Processes information and coordinates responses.
4. Peripheral Nervous System (PNS): Composed of nerves connecting the CNS to the rest of the body.
5. Neuron: The basic functional unit of the nervous system.
6. Sensory Neurons: Carry information from sense organs to the CNS.
7. Motor Neurons: Transmit signals from the CNS to muscles or glands.
8. Interneurons: Relay messages within the CNS.
9. Synapse: Junction between two neurons for signal transmission.
10. Reflex Arc: The neural pathway involved in a reflex action.
    
    paragraph
11. Brain Components:
    • Cerebrum: Controls voluntary actions, reasoning, and memory.
    • Cerebellum: Coordinates balance and fine motor movements.
    • Medulla Oblongata: Regulates involuntary functions like breathing and heart rate.
12. Spinal Cord: Relays information between the brain and the body, and controls reflex actions.
13. Protection: The CNS is protected by the skull, vertebral column, and cerebrospinal fluid.
14. Cranial Nerves: 12 pairs of nerves that emerge from the brain to control sensory and motor functions.
15. Spinal Nerves: 31 pairs of nerves that originate from the spinal cord.
16. Autonomic Nervous System (ANS): Controls involuntary actions.
    • Sympathetic Division: Activates "fight or flight" responses.
    • Parasympathetic Division: Promotes "rest and digest" activities.
17. Neurotransmitters: Chemical messengers (e.g., dopamine, serotonin) facilitate communication between neurons.
18. Role of CNS in Coordination: Integrates sensory input, processes information, and sends out appropriate motor responses.
19. Importance of Coordination: Ensures smooth and efficient functioning of all body systems.
20. Disorders of the CNS: Conditions like epilepsy, Parkinson’s disease, and stroke affect coordination.
    paragraph

Components of the Nervous System

21. Sensory Division: Detects external and internal stimuli.
22. Motor Division: Executes responses to stimuli.
23. Somatic Nervous System: Controls voluntary actions like walking and writing.
24. Autonomic Nervous System: Regulates involuntary functions like digestion and heartbeat.
25. Brain: The control center for all nervous activities.
26. Spinal Cord: Facilitates communication between the brain and the body.
27. Nerves: Bundles of neurons that transmit signals to and from the CNS.
28. Ganglia: Clusters of nerve cell bodies located outside the CNS.
29. Glial Cells: Support and protect neurons.
30. Cerebrospinal Fluid (CSF): Cushions and nourishes the brain and spinal cord.
    
    paragraph
31. Sensory Receptors: Specialized cells that detect stimuli such as light, sound, and touch.
32. Effector Organs: Muscles and glands that respond to nervous impulses.
33. White Matter: Contains myelinated axons for fast signal transmission.
34. Gray Matter: Contains neuron cell bodies and is involved in processing information.
35. Peripheral Nerves: Include sensory, motor, and mixed nerves.
36. Nerve Impulse: An electrical signal that travels along a neuron.
37. Saltatory Conduction: Rapid transmission of impulses along myelinated fibers.
38. Myelin Sheath: Insulates axons and increases impulse speed.
39. Nodes of Ranvier: Gaps in the myelin sheath where impulses jump, speeding transmission.
40. Reflex Action: A quick, automatic response to a stimulus.
    paragraph

Reflex and Voluntary Actions

41. Reflex Action: Involuntary and immediate response to a stimulus.
42. Example of Reflex Action: Pulling your hand away from a hot object.
43. Voluntary Action: Conscious and deliberate movement controlled by the brain.
44. Example of Voluntary Action: Picking up a pen or running.
45. Conditioned Reflex: A learned response to a stimulus.
46. Example of Conditioned Reflex: Salivating at the smell of food.
47. Riding a Bicycle: A learned action involving muscle memory and balance.
48. Swimming: Requires coordination of voluntary movements and learned reflexes.
49. Difference Between Reflex and Voluntary Actions: Reflexes are automatic, while voluntary actions require conscious effort.
50. Importance of Reflexes: Protects the body from harm and ensures survival.
    paragraph

The Sense Organs and Their Functions

51. Eyes: Detect light and enable vision.
52. Structure of the Eye:
    • Cornea: Focuses light onto the retina.
    • Lens: Adjusts focus for near and distant vision.
    • Retina: Contains photoreceptor cells (rods and cones) that detect light intensity and color.
    • Optic Nerve: Transmits visual information to the brain.
53. Ears: Detect sound and maintain balance.
54. Structure of the Ear:
    • Outer Ear: Collects sound waves.
    • Middle Ear: Amplifies sound using ossicles (malleus, incus, stapes).
    • Inner Ear: Contains the cochlea for hearing and semicircular canals for balance.
55. Nose: Detects odors using olfactory receptors.
56. Tongue: Detects taste using taste buds (sweet, sour, salty, bitter, umami).
57. Skin: Detects touch, pressure, temperature, and pain using specialized receptors.
58. Coordination of Sense Organs: Sense organs work together to provide a comprehensive perception of the environment.
59. Protection of the Eye: Eyelids, eyelashes, and tears protect against injury and infection.
60. Protection of the Ear: Earwax traps dust and prevents infections.
    paragraph

Application of Knowledge on Sense Organs

61. Detecting Defects in Eyes:
    • Myopia (Short-Sightedness): Corrected with concave lenses.
    • Hyperopia (Long-Sightedness): Corrected with convex lenses.
62. Astigmatism: Caused by an irregularly shaped cornea; corrected with cylindrical lenses.
63. Cataracts: Clouding of the lens; treated surgically.
64. Glaucoma: Increased intraocular pressure; managed with medication or surgery.
65. Detecting Ear Defects:
    • Hearing loss caused by damage to hair cells in the cochlea.
    • Use of hearing aids or cochlear implants to restore hearing.
66. Balance Disorders: Treated with vestibular rehabilitation therapy.
67. Taste Loss: Can indicate issues with the tongue or olfactory system.
68. Skin Conditions: Neuropathy or burns can reduce skin sensitivity.
69. Protecting Sense Organs: Proper hygiene and avoiding exposure to harmful environments preserve functionality.
70. Diet and Sense Organ Health: Nutrients like Vitamin A (eyes) and Omega-3 fatty acids (nervous system) maintain sensory functions.
    paragraph

Summary and Advanced Insights

91. Nervous System Complexity: Coordinates all body functions, from reflexes to voluntary movements.
92. Integration of Systems: CNS and sense organs work together for survival and interaction with the environment.
93. Speed of Reflexes: Reflex actions are faster than voluntary responses, ensuring quick reactions to danger.
94. Importance of Conditioned Reflexes: Learning new skills enhances survival and adaptability.
95. Modern Advances: Artificial sensory devices like retinal implants and cochlear implants aid sensory defects.
96. Neuroplasticity: The brain’s ability to adapt and reorganize pathways after injury.
97. Sense Organ Adaptations: Specialized structures like the lens (focus) and ossicles (amplification) enhance functionality.
98. Holistic Care: Regular check-ups, a balanced diet, and protective measures ensure the health of the nervous system and sense organs.
99. Interdependence: Sense organs and the nervous system collaborate to provide a unified perception of the environment.
100. Future Possibilities: Advances in neuroscience and technology continue to improve understanding and treatment of nervous system disorders.
     paragraph

Jamb(UTME) tutorial on hormonal control; Homeostasis

Overview of Hormonal Control

1. Definition of Hormones: Chemical messengers secreted by endocrine glands, regulating physiological activities.
2. Endocrine System: Composed of ductless glands that release hormones directly into the bloodstream.
3. Animal Hormonal System: Includes pituitary, thyroid, parathyroid, adrenal glands, pancreas, and gonads.
4. Functions of Hormones: Control growth, metabolism, reproduction, stress response, and homeostasis.
5. Homeostasis: The maintenance of a stable internal environment by regulating body functions.
6. Feedback Mechanism: Hormones operate via negative or positive feedback to maintain balance.
7. Hypothalamus: Connects the nervous and endocrine systems, controlling hormone release from the pituitary gland.
8. Target Cells: Hormones act on specific cells with appropriate receptors.
9. Speed of Action: Hormonal responses are slower but longer-lasting than nervous responses.
10. Imbalances: Overproduction or underproduction of hormones can lead to diseases (e.g., diabetes, hyperthyroidism).
    paragraph

Animal Hormonal System and Glands

Pituitary Gland

11. Location: Base of the brain, connected to the hypothalamus.
12. Hormones Produced:
    • Growth hormone (GH): Stimulates growth and cell reproduction.
    • Prolactin: Promotes milk production.
    • Thyroid-stimulating hormone (TSH): Regulates thyroid activity.
13. Functions: Controls other endocrine glands and regulates critical processes like growth and metabolism.
    
    paragraph

Thyroid Gland

14. Location: In the neck, below the larynx.
15. Hormones Produced:
    • Thyroxine (T4) and Triiodothyronine (T3): Regulate metabolism.
    • Calcitonin: Lowers blood calcium levels.
16. Functions: Controls metabolic rate, energy use, and growth.
    paragraph

Parathyroid Glands

17. Location: Embedded in the thyroid gland.
18. Hormone Produced: Parathyroid hormone (PTH) increases blood calcium levels by stimulating bone resorption and calcium absorption.
19. Functions: Maintains calcium and phosphate balance.
    
    paragraph

Adrenal Glands

20. Location: On top of each kidney.
21. Hormones Produced:
    • Adrenaline: Prepares the body for "fight or flight" responses.
    • Cortisol: Manages stress and regulates metabolism.
    • Aldosterone: Controls salt and water balance.
22. Functions: Helps the body respond to stress and maintain homeostasis.
    paragraph

Pancreas

23. Location: Behind the stomach.
24. Hormones Produced:
    • Insulin: Lowers blood glucose by promoting its uptake into cells.
    • Glucagon: Raises blood glucose by stimulating glycogen breakdown.
25. Functions: Regulates blood sugar levels and energy availability.
    paragraph

Gonads (Ovaries and Testes)

26. Location:
    • Ovaries: In the pelvic cavity of females.
    • Testes: Outside the abdominal cavity in males.
27. Hormones Produced:
    • Estrogen and Progesterone: Regulate female reproductive functions.
    • Testosterone: Controls male reproductive functions and secondary sexual characteristics.
28. Functions: Control reproduction, development of secondary sexual characteristics, and gamete production.
    paragraph

Plant Hormones (Phytohormones)

Auxins

29. Function: Promote cell elongation, root formation, and apical dominance.
30. Effects:
    • Stimulate phototropism (growth toward light).
    • Encourage geotropism (roots growing downward).
31. Applications: Used in agriculture to induce rooting in cuttings.
    paragraph

Gibberellins

32. Function: Stimulate stem elongation, seed germination, and flowering.
33. Effects:
    • Promote bolting in plants (rapid stem elongation).
    • Break seed dormancy and support germination.
34. Applications: Used to increase fruit size (e.g., in grapes).
    paragraph

Cytokinins

35. Function: Stimulate cell division and delay aging in leaves.
36. Effects:
    • Promote shoot growth and branching.
    • Delay senescence (aging) in plant parts.
37. Applications: Used in tissue culture for plant propagation.
    paragraph

Ethylene

38. Function: Promotes fruit ripening and leaf abscission.
39. Effects:
    • Stimulates flowering in some plants.
    • Speeds up ripening of climacteric fruits (e.g., bananas, tomatoes).
40. Applications: Used commercially to ripen fruits post-harvest.
    paragraph

Relating Hormones to Functions

41. Growth and Development:
    • Growth hormone in animals and gibberellins in plants regulate growth.
42. Reproduction:
    • Gonadal hormones control reproduction in animals, while auxins influence flowering in plants.
43. Stress Response:
    • Adrenaline in animals and ethylene in plants help respond to stress.
44. Metabolism:
    • Thyroid hormones regulate metabolism in animals, while cytokinins support nutrient mobilization in plants.
45. Calcium Regulation:
    • Calcitonin and PTH maintain calcium homeostasis in animals.
46. Water Balance:
    • Aldosterone in animals conserves water and salt balance.
47. Fruit Ripening:
    • Ethylene accelerates ripening, while gibberellins improve fruit quality.
48. Leaf Abscission:
    • Controlled by ethylene, ensuring resource conservation during unfavorable conditions.
49. Seed Germination:
    • Auxins and gibberellins break dormancy and support early growth.
50. Cell Division:
    • Cytokinins drive cell proliferation in plants, akin to growth hormone in animals.
      paragraph

Hormones in Homeostasis

51. Definition: Hormones regulate internal stability in response to external changes.
52. Blood Sugar Regulation:
    • Insulin lowers blood sugar.
    • Glucagon raises blood sugar.
53. Body Temperature:
    • Thyroid hormones regulate metabolic heat production.
54. Stress Adaptation:
    • Cortisol and adrenaline prepare the body for stress.
55. Water Balance:
    • Aldosterone controls sodium reabsorption in the kidneys.
56. Calcium Balance:
    • PTH raises calcium, while calcitonin lowers it.
57. Osmoregulation in Plants:
    • Abscisic acid (ABA) helps plants conserve water during drought.
58. Energy Availability:
    • Thyroid hormones ensure efficient energy utilization.
59. Circadian Rhythms:
    • Melatonin regulates sleep-wake cycles in animals.
60. Reproductive Cycles:
    • Estrogen and progesterone control menstrual cycles in females.
      paragraph

Body Temperature, Salt, and Water Regulation

61. Body Temperature Regulation:
    • Endotherms: Use metabolic heat to maintain constant body temperature (e.g., humans).
62. Role of Thyroid Hormones:
    • Increase basal metabolic rate to generate heat.
63. Sweating and Shivering:
    • Sweating cools the body, while shivering generates heat through muscle contractions.
64. Hypothalamic Control:
    • Acts as the thermostat, detecting changes in blood temperature.
65. Behavioral Responses:
    • Animals seek shade or huddle together to regulate temperature.
      
      paragraph
66. Salt and Water Regulation:
    • Aldosterone increases sodium reabsorption, conserving water.
67. Antidiuretic Hormone (ADH):
    • Promotes water reabsorption in the kidneys, reducing water loss.
68. Role of Kidneys:
    • Maintain water and electrolyte balance by filtering blood.
69. Effect of Dehydration:
    • ADH secretion increases to conserve water.
70. Overhydration:
    • ADH levels decrease, allowing excess water to be excreted.
      paragraph
71. Osmoregulation in Plants:
    • ABA promotes stomatal closure to reduce water loss.
72. Salt Regulation in Plants:
    • Salt-tolerant plants excrete excess salts through specialized glands.
73. Drought Adaptation:
    • Increased ABA levels trigger conservation mechanisms.
74. Flood Tolerance:
    • Ethylene helps plants adapt to waterlogged conditions.
      
      paragraph
75. Importance of Regulation:
    • Ensures optimal enzyme activity and physiological function.
76. Disorders:
    • Hyperthyroidism and hypothyroidism disrupt temperature regulation.
77. Plant Tropisms:
    • Hormones like auxins mediate responses to environmental stimuli (light, gravity).
78. Stress Hormones:
    • Cortisol in animals and ABA in plants mitigate stress effects.
      paragraph
79. Coordination of Systems:
    • Hormones integrate with the nervous system to maintain equilibrium.
80. Advances in Hormone Research:
    • Synthetic hormones improve crop yields and treat endocrine disorders.

I recommend you check my Post on the following: