Anatomy

  1. Nervous system vs. Endocrine system
    rapid activity (movement and thinking) vs. slow activity (growth)
  2. Nervous System
    a coordinating system of the body composed of a group of highly specialized cells for conducting nerve impulses to a center so responses can be made

    the nervous system provides a control for the rapid activities of the body
  3. Major Subdivisions of NS
    • CNS - brain and spinal cord
    • PNS
  4. Nervous Tissue functions
    • 1) to receive stimuli from the environment (receptor)
    • 2) to transform these stimuli into nerve impulses (receptor)
    • 3) to transmit these impulses to the proper nerve center of the body (neuron)
    • 4) to process the information and determine the appropriate response (brain, spinal cord)
    • 5) this response is transmitted to the effector organ (neuron)
    • 6) the effector organ carries out the response (effector)
  5. Principal cells of the NS
    neuron and neuroglia
  6. Neuron
    functional unit of the NS
  7. Dendrites
    cytoplasmis extensions that receive information and transmit it toward the cell body
  8. Cell body or soma
    contains the nucleus and controls the metabolic activity of the neuron
  9. Axon Hillock
    connects the cell body to the axon
  10. Myelin
    insulating substance which allows axons to conduct impulses faster
  11. Nodes of Ranvier
    gaps between segments of myelin
  12. Synaptic terminals
    swellings at the end of the axon, involved in neurotransmitter release
  13. Synapse
    gap between the axon terminal of one neuron and the dendrite of another
  14. Neuroglia
    supportive connective tissue that natures and protects the neurons

    Schwann, Oligodendrocytes, Microglia, Astrocytes, Ependymal Cells, Satellite Cells
  15. Schwann Cells
    neurolemmocytes

    form fatty myelin sheaths around the most axons in the PNS only; this insulatory material is not continuous along the axon but is interrupted at the nodes of Ranvier; the nerve impulses jump from node to node as they travel down the axon, a conduction called saltatory conduction
  16. Oligodendrocytes
    form similar myelin sheaths in the CNS only
  17. Microglia
    phagocytic cells that migrate throughout the CNS removing debris; may migrate to areas where nervous tissue is injured
  18. Astrocytes
    regulate the passage of molecules from blood to the brain; helps form the blood-brain barrier that regulates the passage of substances into the brain
  19. Ependymal Cells
    line the brain chambers called ventricles and help form the choroid plexus; which produces cerebrospinal fluid
  20. Satellite Cells
    support neuron cell bodies in ganglis of the PNS
  21. CNS Neuroglia
    • astrocytes
    • microglia
    • oligodendrocytes
    • ependymal cells
  22. PNS Neuroglia
    • schwann cells
    • satellite cells
  23. Classification of neurons
    multipolar: 2 or more braches of the soma

    bipolar: 2 branches of the soma

    unipolar: 1 branch of the soma

    SAME
  24. Afferent neurons
    sensory

    transmit sensory nerve impulses from receptors to the brain and spinal cord
  25. Efferent
    Motor

    convey motor nerve impulses from the brain and spinal cord to effectors (muscles and glands)
  26. Interneurons
    Internuncial neurons

    carry impulses from one neuron to another; makes up the majority of nerves in the body
  27. Action Potentials
    travel the length of the axon and invade the nerve terminal, thereby causing the release of neurotransmitter into the synapse
  28. Pituitary Gland
    hangs by a stalk from the hypothalamus of the brain

    posterior and anterior
  29. Posterior Pituitary Gland
    appears fibrous

    neurons produce ADH, and antidiuretic hormone, and oxytocin

    ADH is stored in, and released from, the post. pit. gland in response to neural stimulation from the hypothalamus via the hypothalamohypophyseal system
  30. Anterior Pituitary Gland
    appears glandular

    develps from epithelial tissue that pinches off from the roof of the embryo's mouth

    produces the hormones it secretes: growth hormone, ACTH, thyroid-stimulating hormone, luteninizing hormone, follicle-stimulating hormone, prolactin, melanocyte-stimulating hormone
  31. Thyroid Gland
    shaped like a bowtie or shield and lies just below the Adam's apple in the front of the neck

    thryoxine helps set basal metabolic rate by stimulating the rate of cell respiration

    in children, thyroid hormones also promote growth and stimulate maturation of the CNS
  32. Parathyroid Glands
    four small glands attached to the posterior surface of the thyroid gland

    produces parathyroid hormone, which is involved in calcium homeostasis
  33. Adrenal Glands
    located above each kidney

    each gland is composed of an inner portion (medulla) and an outer layer (cortex)
  34. Adrenal Cortex
    hormones from adrenal cortex are collectively referred to as corticosteroids
  35. Adrenal Medulla
    secretes epinephrine and norepinephrine in response to the ANS
  36. Pancreas
    located adjacent to the stomach and is connected to the duodenum by the pancreatic duct

    secretes insulin and a variety of digestive enxymes into small intestine
  37. Ovaries and Testes
    produce androgen

    associated with secondary sexual characteristics
  38. Pineal Gland
    secretes melatonin

    regulates biological clocks
  39. Hormone Agonist
    any chemical that can bind to receptor proteins and mimic the effects of the hormone
  40. 5 lobes of the brain
    frontal, parietal, occipital, temporal, and insula

    insula lies within the depths of the lateral sulcus
  41. Cerebrum
    largest part of the brain consisting of two hemispheres

    gyri: convolutions of the cerebrum separated by sulci

    contains various fissures and large sulci
  42. Longitudinal fissure
    separates the right and left hemispheres and is occupied by the falx cerebri
  43. Transverse fissure or sulcus
    separates the cerebrum and cerebellum and is occupied by the tentorium cerebelli
  44. Lateral sulcus or fissure
    separates the temporal lobe from the rest of the cerebrum
  45. Central sulcus
    the precentral (motor) and postcentral (sensory) gyri

    the primary motor cortex is precentral gyrus; it lies anterior to the central sulcus

    the primary sensory cortex is the postcentral gyrus; it lies posterior to the central sulcus
  46. Basal Ganglia (Nuclei)
    constitutes the central gray matter of the cerebrum

    • function in control of movement and posture
    • - diesease involve disturbances in voluntar muscular control (Parkinson's, Huntington's)
  47. Thalamus
    most important sensory relay center of the brain

    it sends incoming impulses from the receptors of the body to the cerebral cortex
  48. Hypothalamus
    • it lies between and is associated with the:
    • 1) Optic Chiasma: where optic tracts (CNII) cross
    • 2) Mammillary bodies: sensory synaptic station
    • 3) Pituitary Gland: projects inferior from it and secretes many hormones

    Functions in the regulation of visceral activity (body temperature, carb and lipid metabolism, sleep, sexual activity, and emotions)
  49. Medulla Oblongata
    part of the brain directly continuous with the spinal cord and will contain most of the ascending and descending tracts of the spinal cord

    represents an area where pyramidal tract fibers lie, called the pyramids: contain several nuclei involved in the regulation of the vital body activities: respiratory, cardiac (HR), vasomotor (BP)
  50. Pons
    acts as a bridge connecting the right and left cerebellar hemispheres

    relay impulses from the cerebral cortex to the cerebellum
  51. Cerebellum
    little brain

    connects with the midbrain, pons, and medulla oblongata; consists of two hemispheres separated by a median vermis; outer cortex contains folia separated by fissures, folia means leave; internally presents white matter branching in the form of a tree, called the arbor vitae; functions to coordinate muscular activity, regulate muscle tone, and maintain muscle equilibrium
  52. Corpora Quadrigemina
    • consists of 4 elevations
    • - superior colliculi involved in the pathway of vision
    • - inferior colliculi involved in the pathway of hearing
  53. Brainstem
    • midbrain
    • pons
    • medulla oblongata
  54. Gray Matter of the spinal cord
    area of cell bodies within the CNS
  55. White Matter of the spinal cord
    area of axons or fibers within the CNS
  56. Dorsal Root
    arises from the dorsal surface of the spinal cord; contains sensory neurons only
  57. Dorsal Root Ganglion
    enlarged part of the dorsal root

    area of cell bodies outside the CNS

    contains cell bodies of sensory neurons
  58. Ventral Root
    arises from the ventral surface of the spinal cord

    contains motor neurons only

    joins with the dorsal root to form the SPINAL NERVE
  59. Spinal Nerve
    divides into a larger ventral ramus which supplies the entire anterior trunk as well as the appendages
  60. Dorsal Ramus
    smaller

    supplies all the structure of the back
  61. Anatomy of the spinal cord
    long cyndrical mass of nervous tissue that occuplies the upper 2/3 of the vertebral canal; connected to the brain superiorly where it is continuous with the medulla oblongata and extends to the level of LV2; presents enlargements in the cervial and lumbar regions where cell bodies of the neurons for the upper and lower limb are located; lower end of the cord is termed CONUS MEDULLARIS; below LV2 is the CAUDA EQUINA which consists of the very long roots of the lower spinal nerves which descend in a bundle from the conus medullaris
  62. Meninges
    the brain and spinal cord are surrounded and protected by three layers of connective tissues, collectively termed meninges

    from external to internal, dura mater, arachnoid mater, pia mater
  63. Dura Mater
    outermost meninge composed of tough fibrous connective tissue; dura of the spinal cord extends from the foramen magnum where it is continuous with the dura mater that surrounds the brain and then courses inferiorly to the coccyx in the vertebral canal; this space external to the dura mater is the epidural space: contains adipose tissue in the form of globules of fat and veins and contains the vertebral venous plexus
  64. Arachniod Mater
    intermediate meninge

    delicate, loose, netlike membrane that extends from the foramen magnum where it is continuous with the cerebral arachnoid inferiorly through the vertebral column to coccyx; separated from the pia mater by the subarachnoid space which contains CSF
  65. Pia Mater
    innermost meninge

    very delicate connective tissue that adheres to the surface of the brain and spinal cord; extends from the foramen magnum to the coccyx
  66. PNS
    periphery means along the outside

    extends beyond the CNS, thus includes all the nervous tissue structures except the brain and spinal cord

    most not protected by bone

    composed of 12 prs of cranial nerves and 31 prs of spinal nerves
  67. Spinal nerves
    • 8 prs of cervical
    • 12 prs of thoracic
    • 5 prs of lumbar
    • 5 prs of sacral
    • 1 pr of coccygeal
  68. Chemoreceptors
    sensitive to chemical substances in the immediate area
  69. Mechanoreceptors
    stimulated by mechanical forces like pressure
  70. Proprioreceptors
    sense the degree of muscle contraction, the movement of ligaments, and the stretch of tendons
  71. Thermoreceptors
    stimulated by changes in temperature
  72. Pain receptors
    nocioceptors
  73. Photoreceptors
    detect light
  74. Somatic senses
    senses that are associated with the skin, muscles, and joints

    proprioception is a sense of knowing the position of the limbs
  75. Special senses
    sense organs for taste, smell, vision, equilibrium, and hearing
  76. Skin
    contains receptors for touch, pressure, pain, and temperature

    adaptation occurs when a receptor becomes accustomed to stimulation and stops generating impulses, even though the stimulus is still present
  77. Taste
    taste buds are groupings of cells found in the tongue epithelium and open at a taste pore; recent functional and molecular data have found that there is no tongue "map": where certain areas are responsive to the 5 basic modalities- bitter, sour, sweet, salty, and umami - all modalities are present in all areas of the tongue
  78. Olfaction
    our sense of smell is dependent on olfactory cells found in the roof of the nasal cavity
  79. Vision
    • eyeball is an elongated sphere about 2.5cm in diameter and has 3 layers:
    • -sclera: outer layed, white and fibrous except for the transparent cornea known as the window of the eye
    • - choroid: middle, dark, think brown layer; toward the front it thickens and forms the ringshaped ciliary body which contains ciliary muscle which controls the shape of the lens for near and far vision; it becomes thin, circular, muscular, pigmented diaphragm called the IRIS which regulates the size of the pupil
    • - retina: inner layer containing rods and cones, there are no cones or rods where the optic nerves passes through which is called the blind spot; vision is most acute in the fovea centralis
  80. Diseases and preventing loss of vision
    in diabetic retinopathy, capillaries to the retina burst and blood spills into the viteour humor, this blinds people between 20 and 74 yrs old

    galucoma occures when the eye drainage system fails so that fluid builds up, destroys nerve fibers that are responsible for peripheral vision

    most common cause is careless use of contacts, increases cataracts in heavy smokers, wear sunglasses that absorb UV light, glasses with large lenses offer better protection than smaller
  81. Ear functions
    hearing and equilibrium (balance)
  82. Outer ear
    pinna (external flap made of cartilage and skin) and the auditory canal
  83. Middle ear
    begins at the tympanic membrane (eardrum) and ends at a wall containing the oval window (the round window is near this area and allows fluid in the cochlea to move)

    • 3 bones are between the eardrum and oval window:
    • - malleus (or hammer): attaches to the tympanic membrane
    • - incus or anvil
    • - stapes or stirrup: contacts the oval window
  84. Inner ear
    semicircular canals and the vestibule are involved with equilibrium; cochlea is involved with hearing; cochlea appears snail-shaped and is lined with small hairs called stereocillia; the movement of these hairs transmits sensation to our brain to interpret sound; eustachian tube (auditory tube) extends from the middle ear to the nasopharynx - this permits equalization of air pressure when we swallow or yawn
  85. Preventing loss of hearing
    limiting exposure to loud noises; any noise over 80 decibels may damage hair cells of the organ of corti and cause them to disappear completely; tinnitus (ringing in ears); anticancer drugs or certain anitbiotics may increase sensitivity to loud noises
  86. Effectors of the body
    muscles: smooth, cardiac, skeletal

    glands: endocrine, exocrine
  87. ANS
    responsible for the control of smooth muscle, cardiac muscle, endocrine glands, and exocrine glands

    autonomy means self-government
Author
studyme
ID
88112
Card Set
Anatomy
Description
Unit 2
Updated