Untitled Flashcards Set

1. Functions of the Nervous System (Slide 4)

   • The nervous system is the master controlling and communication system of the body.

   • It uses electrical and chemical signals to communicate rapidly and specifically.

   • Three main functions:

     • Sensory Input – Gathers information about internal and external changes.

     • Integration – Processes and interprets sensory input.

     • Motor Output – Activates effector organs (muscles and glands) to produce a response.

2. Subdivisions of the Nervous System (Slides 6-9)

   • Central Nervous System (CNS): Brain and spinal cord; integration and control center.

   • Peripheral Nervous System (PNS): Nerves extending from the CNS.

     • Sensory (Afferent) Division: Carries sensory information to CNS.

     • Motor (Efferent) Division: Carries commands from CNS to effectors.

       • Somatic Nervous System (SNS): Voluntary control of skeletal muscles.

       • Autonomic Nervous System (ANS): Involuntary control of organs.

         • Sympathetic Division: "Fight or flight."

         • Parasympathetic Division: "Rest and digest."

3. Types of Neuroglia and Myelination (Slides 19-25)

   • CNS Neuroglia: Astrocytes, microglial cells, ependymal cells, oligodendrocytes.

   • PNS Neuroglia: Satellite cells, Schwann cells (form myelin sheaths).

   • Myelination: Schwann cells (PNS) and oligodendrocytes (CNS) wrap axons for faster impulse transmission.

4. Neuron Components and White/Gray Matter (Slides 11, 27)

   • Dendrites: Receive signals.

   • Axon: Transmits impulses.

   • Cell Body (Soma): Maintains the neuron.

   • White Matter: Myelinated axons.

   • Gray Matter: Neuron cell bodies and unmyelinated fibers.

5. Neuron Classification (Slides 13-16)

   • By Structure: Multipolar, bipolar, unipolar.

   • By Function: Sensory (afferent), motor (efferent), interneurons.

6. Neurolemma and Myelin in Regeneration (Slides 22, 25, 71)

   • Neurolemma in Schwann cells helps in PNS neuron repair.

   • Myelin insulates and speeds up conduction.

7. Resting Membrane Potential (Slides 31-39)

   • Maintained by Na+/K+ pump and selective ion permeability.

   • Ion Channels:

     • Leak channels: Always open.

     • Chemically gated: Open in response to neurotransmitters.

     • Mechanically gated: Open in response to pressure.

     • Voltage-gated: Open in response to voltage changes.

8. Nerve Impulse Transmission (Slides 44-45)

   • Step-by-step voltage and ion changes move the impulse along the axon.

9. Graded Potentials and Action Potentials (Slides 40-43, 50)

   • Graded potentials are small, localized voltage changes that can lead to an action potential.

10. Graded vs. Action Potentials (Slides 50-51)

• Graded Potentials: Local, short-distance, variable strength.

• Action Potentials: All-or-none, long-distance, constant amplitude.

11. Action Potential Development (Slides 46-49)

• Depolarization: Na+ enters the neuron.

• Repolarization: K+ exits the neuron.

• Hyperpolarization: K+ channels stay open too long.

12. Propagation and Myelination (Slides 52-54)

• Myelination increases conduction speed (saltatory conduction).

13. Refractory Periods (Slide 47)

• Absolute: No new AP possible.

• Relative: Stronger stimulus needed.

14. Synapse Components (Slides 56-57)

• Presynaptic neuron: Sends signal.

• Postsynaptic neuron: Receives signal.

• Synaptic cleft: Space between them.

15. Action Potential Across a Synapse (Slides 58-59)

• Electrical impulse → Neurotransmitter release → Postsynaptic receptor activation.

16. Neurotransmitters and EPSP/IPSP (Slides 60-63, 66)

• Excitatory (EPSP): Depolarizes neuron, increases firing chance.

• Inhibitory (IPSP): Hyperpolarizes neuron, decreases firing chance.

Chapter 12

17. Spinal Meninges and Function of the Spinal Cord

• The spinal meninges include the pia mater, arachnoid mater, and dura mater. These layers protect the spinal cord and provide structural support.

• The spinal cord functions in conducting nerve impulses and serving as a center for reflexes. It also allows for sensory and motor communication between the brain and body.

• Source: Slide 6 (Cranial Bones and Meninges), Slide 18 (Frontal Section of the Brain and Spinal Cord)

18. Flow and Location of CSF in the Spinal Cord, Composition, and Function

• CSF circulates in the subarachnoid space and within the central canal of the spinal cord. It is produced by the choroid plexuses in the ventricles.

• CSF is a clear liquid similar to blood plasma but with less protein.

• Functions: cushions the CNS, provides nutrients, removes waste, and maintains homeostasis.

• Source: Slides 13-17 (CSF and its Flow, Choroid Plexus, Ventricles)

19. Structure of the Spinal Cord, Gray and White Matter, and Their Roles

• Gray matter: Located in the center, forming an "H" shape, containing neuron cell bodies and interneurons.

• White matter: Surrounds the gray matter and contains ascending (sensory) and descending (motor) tracts for communication with the brain.

• Source: Slide 18 (Frontal Section of the Brain and Spinal Cord)

20. Location of Neurons and Their Function in the Spinal Cord

• Afferent neurons: Sensory neurons with cell bodies in dorsal root ganglia, axons enter the spinal cord via the dorsal root.

• Efferent neurons: Motor neurons with cell bodies in the ventral horn, axons exit via the ventral root.

• Interneurons: Located in gray matter, they relay signals between sensory and motor neurons.

• Source: Slide 18 (Frontal Section of the Brain and Spinal Cord)

21. Ascending and Descending Pathways, Spinal Cord Injury Effects

• Ascending tracts: Carry sensory information to the brain (e.g., spinothalamic tract for pain and temperature).

• Descending tracts: Carry motor signals from the brain (e.g., corticospinal tract for voluntary movement).

• Spinal cord injuries can result in paralysis and sensory loss, depending on the level of damage.

• Source: Slide 18 (Frontal Section of the Brain and Spinal Cord), Slide 50 (Clinical – Homeostatic Imbalance)

22. Cranial Meninges, Layers, and Subdivisions

• Dura mater (outer layer): Tough, stabilizes brain. a

• Arachnoid mater (middle layer): Contains CSF-filled subarachnoid space.

• Pia mater (inner layer): Adheres to the brain and spinal cord.

• Source: Slides 6-7 (Cranial Bones and Meninges, Dura Mater)

23. Medulla, Pons, Midbrain, Thalamus, Hypothalamus, Limbic System, and RAS

• Medulla oblongata: Controls heart rate, respiration, reflexes (Slide 22).

• Pons: Relays signals, controls breathing (Slide 24).

• Midbrain: Controls visual and auditory reflexes (Slide 25).

• Thalamus: Relay center for sensory signals (Slide 30).

• Hypothalamus: Regulates temperature, hunger, hormones, emotions (Slide 31-32).

• Limbic system: Involved in emotion and memory (Slide 52).

• RAS: Maintains consciousness and alertness (Slide 26).

24. Brain Ventricles, Choroid Plexus, CSF Flow, and Hydrocephalus

• Ventricles: Cavities containing CSF (Slide 16).

• Choroid plexus: Produces CSF (Slide 16).

• CSF Flow: Ventricles → Subarachnoid space → Arachnoid villi → Venous blood (Slide 17).

• Hydrocephalus: CSF blockage causes fluid buildup, requiring a shunt (Slide 19).

26. Basal Ganglia and Parkinson’s Disease

• Basal ganglia: Gray matter involved in voluntary movement control (Slide 41).

• Parkinson’s Disease: Dopamine deficiency in basal ganglia causes tremors and stiffness (Slide 58).

27. Cerebrum Surface, White and Gray Matter

• Gray matter: Outer cortex, processes sensory and motor functions.

• White matter: Inner tracts for communication between brain regions.

• Source: Slide 36 (The Cerebrum), Slide 39 (Cerebral Cortex), Slide 40 (Cerebral White Matter Tracts)

28. Cerebral Cortex Functions, Lobes, and Disorders

• Frontal lobe: Motor control, decision-making, speech (Broca’s area) (Slide 45).

• Parietal lobe: Somatosensory processing (Slide 46).

• Temporal lobe: Hearing, memory (Slide 49).

• Occipital lobe: Vision (Slide 49).

• Alzheimer’s: Brain cell degeneration leading to dementia (Slide 55).

• Stroke: Brain damage due to blood flow loss (Slide 50).

29. Cerebellum and Motor Control

• Functions: Coordinates movement, posture, balance.

• Injury effects: Poor coordination, tremors (Slide 27-28).

Chapter 13

30. Cranial Nerves I-XII and Functions

• Source: Slides 60-75 (Cranial Nerves, Functions, and Disorders)

31. Spinal Nerves, Plexuses, and Major Nerve Origins

• Plexuses: Networks of spinal nerves (cervical, brachial, lumbar, sacral).

• Major nerves:

  • Phrenic nerve: Diaphragm (breathing).

  • Radial & Ulnar nerves: Arm movement.

  • Sciatic nerve: Leg sensation and movement.

• Source: Not explicitly found in the slides, but part of spinal cord organization.

32. Two- and Three-Neuron Reflex Arcs

• Two-neuron reflex arc: Sensory neuron → Motor neuron (e.g., knee-jerk reflex).

• Three-neuron reflex arc: Sensory neuron → Interneuron → Motor neuron (e.g., withdrawal reflex).

• Source: Likely part of reflex discussions in spinal cord function.

33. Reflex Classification and Examples

• Monosynaptic: Direct sensory-to-motor synapse (e.g., knee-jerk).

• Polysynaptic: Involves interneurons (e.g., withdrawal reflex).

• Ipsilateral: Same-side response (e.g., stretch reflex).

• Contralateral: Opposite-side response (e.g., crossed-extensor reflex).

• Source: Reflex discussions in spinal cord function.

Chapter 14

34. Structure and Function of the Autonomic Nervous System (ANS)

• The ANS has two divisions:

  • Sympathetic (fight-or-flight): Increases alertness and metabolism.

  • Parasympathetic (rest-and-digest): Slows body functions for energy conservation.

• Preganglionic neuron cell bodies: Located in the CNS (brainstem or spinal cord).

• Postganglionic neuron cell bodies: Located in autonomic ganglia outside the CNS.

• Neurotransmitters:

  • Acetylcholine (ACh): Released by all preganglionic neurons and parasympathetic postganglionic neurons.

  • Norepinephrine (NE): Released by most sympathetic postganglionic neurons.

• Receptors:

  • Cholinergic receptors (nicotinic & muscarinic) respond to ACh.

  • Adrenergic receptors (alpha & beta) respond to NE or epinephrine.

• Effectors: Smooth muscle, cardiac muscle, and glands.

• Source: Slides 7-12 (ANS Divisions, Motor Pathways, Ganglia), Slide 14 (Neurotransmitters and Receptors)

35. Effects of Sympathetic and Parasympathetic Divisions on Effectors

• Sympathetic (Fight-or-Flight):

  • Increases heart rate, blood pressure, and airway dilation.

  • Dilates pupils, reduces digestion, stimulates adrenal glands.

• Parasympathetic (Rest-and-Digest):

  • Slows heart rate, lowers blood pressure, increases digestion.

  • Constricts pupils, promotes glandular secretions.

• Source: Slide 7 (Divisions of ANS), Slide 19 (Adrenergic Receptors – Sympathetic Effects)

36. Differences Between Motor Pathways of Somatic and Autonomic Divisions

• Somatic Nervous System:

  • Single motor neuron extends from CNS to skeletal muscle.

  • Uses ACh, always excitatory.

• Autonomic Nervous System:

  • Two-neuron chain (preganglionic and postganglionic).

  • Uses ACh (parasympathetic) or NE (sympathetic), can be excitatory or inhibitory.

• Source: Slide 3-6 (Comparison of Somatic and Autonomic Systems, Motor Pathways)

37. Differences Between Sympathetic and Parasympathetic Divisions

• Sympathetic Division (Thoracolumbar):

  • Short preganglionic axons, long postganglionic axons.

  • Ganglia close to the spinal cord.

  • Extensive divergence (widespread effects).

• Parasympathetic Division (Craniosacral):

  • Long preganglionic axons, short postganglionic axons.

  • Ganglia near or in target organs.

  • Minimal divergence (localized effects).

• Source: Slide 8-12 (Anatomy of ANS Pathways, Ganglia Locations)

38. Neurotransmitters Released in Sympathetic and Parasympathetic Divisions

• Preganglionic neurons (both divisions): Release ACh (cholinergic).

• Postganglionic neurons:

  • Sympathetic: Mostly NE (adrenergic), except sweat glands (ACh).

  • Parasympathetic: ACh (cholinergic).

• Source: Slide 16 (ANS Neurotransmitters), Slide 19 (Adrenergic Receptors)

39. Functions of Adrenergic and Cholinergic Fibers and Receptors

• Cholinergic fibers (release ACh):

  • Nicotinic receptors: Found in autonomic ganglia, always excitatory.

  • Muscarinic receptors: Found in target organs, can be excitatory or inhibitory.

• Adrenergic fibers (release NE):

  • Alpha (α) receptors: Generally excitatory (e.g., vasoconstriction).

  • Beta (β) receptors: Can be excitatory (β1 – increases heart rate) or inhibitory (β2 – bronchodilation).

• Source: Slide 17-19 (Cholinergic and Adrenergic Receptors)

Chapter 15

40. Protective structures of the eye:

• Conjunctiva: A thin, protective mucous membrane lining the eyelids and covering the sclera (Slide 7).

• Lashes: Help protect the eye from debris (Slide 4).

• Lacrimal apparatus: Produces and drains tears, consisting of lacrimal glands, ducts, puncta, canaliculi, sac, and nasolacrimal ducts (Slide 9).

41. Layers of the eyeball and their functions:

• Fibrous tunic: Outer layer, includes the cornea (refracts light) and sclera (provides shape and protection) (Slide 12).

• Vascular tunic: Middle layer, includes the choroid (supplies blood), ciliary body (controls lens shape), and iris (controls pupil size) (Slide 12).

• Retina: Inner layer, contains photoreceptors (rods and cones) for vision (Slide 16).

42. Location and functions of eye structures:

• Lens: Behind the iris; focuses light onto the retina (Slide 18).

• Ciliary body: Surrounds the lens; alters lens shape for focusing (Slide 12).

• Iris: Colored part of the eye; controls pupil size (Slide 13).

• Aqueous humor: In anterior chamber; maintains intraocular pressure and provides nutrients (Slide 19).

• Vitreous body: In posterior cavity; maintains eye shape (Slide 19).

• Fovea centralis: Center of macula lutea; highest visual acuity (Slide 15).

• Macula lutea: Central retinal area for sharp vision (Slide 15).

• Optic disc: Blind spot where the optic nerve exits (Slide 15).

• Optic nerve: Transmits visual signals to the brain (Slide 15).

43. Structure of the nervous tissue of the retina:

• Contains photoreceptors (rods/cones), bipolar cells, and ganglion cells (Slide 17).

44. Function and location of rods and cones:

• Rods: For dim light vision, located mainly in the peripheral retina (Slide 16).

• Cones: Detect color (red, green, blue), concentrated in the fovea centralis (Slide 16).

45. Image formation and refraction:

• Light passes through cornea, aqueous humor, pupil, lens, vitreous humor, and is projected onto the retina. The lens accommodates for focus (Slide 24).

• Refraction: Bending of light as it passes through substances of different densities, essential for focusing (Slide 25).

46. Refractive spaces of the eye and light path:

• Spaces: Anterior chamber (between cornea & iris, filled with aqueous humor), Posterior chamber (between iris & lens, filled with aqueous humor), Vitreous chamber (behind lens, filled with vitreous humor) (Slide 19).

• Light enters through cornea → anterior chamber → pupil → posterior chamber → lens → vitreous body → retina (Slide 24).

47. Impulse conduction from optic nerve to CNS:

• Pathway: Optic nerve → optic chiasm → optic tract → lateral geniculate nucleus (thalamus) → optic radiations → primary visual cortex in the occipital lobe (Slide 37).

48. Common eye disorders:

• Myopia (nearsightedness): Eyeball too long, image converges before the retina (Slide 29).

• Hyperopia (farsightedness): Eyeball too short, image converges behind retina (Slide 30).

• Presbyopia: Age-related loss of lens elasticity (Slide 68).

• Astigmatism: Irregular corneal/lens curvature causing distorted vision (Slide 31).

• Cataract: Clouding of the lens (Slide 32).

• Glaucoma: Increased intraocular pressure damages the optic nerve (Slide 23).

49. Anatomy and functions of the ear & auditory tube:

• Outer ear: Auricle (captures sound), external auditory canal (transmits sound), tympanic membrane (vibrates) (Slide 43).

• Middle ear: Contains ossicles (malleus, incus, stapes) which transmit vibrations to the inner ear (Slide 45).

• Inner ear: Cochlea (hearing) and semicircular canals (equilibrium) (Slide 48).

• Auditory tube: Equalizes pressure in the middle ear (Slide 46).

50. Location & function of auditory structures:

• Tympanic membrane: Separates outer/middle ear, vibrates with sound (Slide 43).

• Ossicles: Transmit sound (Slide 45).

• Oval window: Transfers vibrations to cochlea (Slide 48).

• Round window: Relieves pressure (Slide 48).

• Endolymph & perilymph: Fluids in cochlear chambers, transmit sound (Slide 50).

• Scala tympani & scala vestibuli: Chambers in cochlea (Slide 50).

• Cochlear duct: Contains organ of Corti (Slide 50).

51. Sound wave pathway & energy transformations:

• Pinna → external auditory canal → tympanic membrane → ossicles → oval window → cochlear fluid → basilar membrane → organ of Corti → cochlear nerve → brain (Slide 58).

52. Organ of Corti:

• Located in the cochlear duct, contains hair cells that convert sound into neural impulses (Slide 52).

53. Semicircular canals & vestibular apparatus:

• Semicircular canals: Detect rotational movement (Slide 63).

• Vestibular apparatus: Includes utricle & saccule, detects static equilibrium (Slide 63).

54. Static & dynamic equilibrium:

• Static equilibrium: Maintains posture (receptors in macula of utricle & saccule) (Slide 65).

• Dynamic equilibrium: Detects motion (receptors in semicircular canals) (Slide 63).

55. Neural pathways for hearing & equilibrium:

• Hearing: Cochlear nerve → cochlear nuclei (medulla) → thalamus → auditory cortex (Slide 56).

• Equilibrium: Vestibular nerve → brainstem → cerebellum for balance coordination (Slide 63).

Chapter 16

56. Functions of the Endocrine System:

• Works with the nervous system to coordinate body functions.

• Releases hormones that regulate metabolism, growth, development, reproduction, and homeostasis (Slide 4).

57. Classification of Hormones & Mechanisms of Action:

• Lipid-soluble hormones: Steroid hormones, thyroid hormones, nitric oxide (bind to intracellular receptors) (Slide 9).

• Water-soluble hormones: Amine hormones, peptide & protein hormones, eicosanoids (bind to surface receptors) (Slide 9).

• Mechanism of action: Responses vary by hormone and target cell, including altering permeability, stimulating transport, or changing metabolic rates (Slide 10).

58. Mechanism of Action of Hormones:

• Lipid-soluble hormones: Bind to intracellular receptors, activate gene transcription (Slide 11).

• Water-soluble hormones: Bind to extracellular receptors, activate second messenger pathways (Slide 12).

59. Endocrine Glands & Locations:

• Pituitary, pineal, thyroid, parathyroid, thymus, adrenal, pancreas, ovaries, and testes (Slide 7).

60. Hypothalamus & Pituitary Relationship:

• Hypothalamus controls the pituitary via the hypophyseal portal system (Slide 16).

• The anterior pituitary (adenohypophysis) produces hormones, while the posterior pituitary (neurohypophysis) stores and releases hypothalamic hormones (Slide 17).

61. Releasing & Inhibiting Hormones from the Hypothalamus:

• Hypothalamus releases hormones that stimulate or inhibit pituitary function (Slide 17).

• Examples: Thyrotropin-releasing hormone (TRH), Growth hormone-releasing hormone (GHRH), Corticotropin-releasing hormone (CRH) (Slide 21).

62. Subdivisions of the Pituitary & Hormones Released:

• Anterior pituitary: hGH, TSH, FSH, LH, PRL, ACTH, MSH (Slide 22).

• Posterior pituitary: Oxytocin & ADH (Slide 29).

• Regulates other glands via hormone secretion (Slide 22).

63. Effects of Pituitary Hormones & Pathology:

• hGH: Growth & metabolism (Slide 24).

• TSH: Stimulates thyroid (Slide 22).

• ACTH: Stimulates adrenal cortex (Slide 22).

• Pathologies: Gigantism, acromegaly (excess GH), pituitary dwarfism (GH deficiency) (Slide 25).

64. Hormone Regulation via Feedback Mechanisms:

• Negative feedback: Common mechanism (e.g., TSH regulation) (Slide 15).

• Positive feedback: Less common, used in labor contractions (Slide 15).

65. Thyroid Gland & Hormones:

• Located below the larynx, produces T3, T4 (metabolism) & calcitonin (calcium regulation) (Slide 34-35).

• Disorders: Hypothyroidism (myxedema, goiter), Hyperthyroidism (Graves’ disease) (Slides 39-40).

66. Parathyroid Gland & Hormone:

• Located on posterior thyroid; secretes parathyroid hormone (PTH) to increase blood calcium (Slide 42-43).

67. Adrenal Cortex & Hormones:

• Three zones:

  • Zona glomerulosa → Aldosterone (Na+/K+ balance) (Slide 49).

  • Zona fasciculata → Cortisol (stress response) (Slide 49).

  • Zona reticularis → Androgens (Slide 49).

• Disorders: Cushing’s syndrome (excess cortisol) (Slide 53).

68. Adrenal Medulla & Neuroendocrine Function:

• Secretes epinephrine & norepinephrine in response to stress (fight-or-flight) (Slide 55).

69. Pancreas as Endocrine & Exocrine Gland:

• Endocrine: Produces insulin & glucagon (Slide 57).

• Exocrine: Produces digestive enzymes (Slide 58).

70. Endocrine Function of the Pancreas:

• Alpha cells → Glucagon (raises blood sugar) (Slide 59).

• Beta cells → Insulin (lowers blood sugar) (Slide 59).

71. Action of Insulin & Glucagon; Diabetes Mellitus (DM):

• Insulin: Promotes glucose uptake & storage.

• Glucagon: Stimulates glycogen breakdown & glucose release.

• Diabetes:

  • Type 1 (low insulin)

  • Type 2 (insulin resistance) (Slide 61).

72. Hormones from Other Organs:

• Pineal gland → Melatonin (regulates sleep) (Slide 64).

• Thymus → Thymosin (immune system development) (Slide 64).

• Ovaries → Estrogen, progesterone (Slide 63).

• Testes → Testosterone (Slide 63).

• Adrenal Glands → Cortisol, adrenaline (stress response) (Slide 65).