Ch 11 & 12

  1. Special Senses are:
    • Sight (eyes)
    • Sound & equilibrium (ears)
    • Taste (tongue)
    • Smell (nose)
  2. General Senses are:
    • Cutaneous senses
    • heat/cold, pain, presssure/touch
    • Visceral senses
    • nausea, thirst, hunger
    • urination/defecation
  3. 6th Sense, Controversial
  4. External structures of the eye
    • cone shaped cavity (formed by skull)
    • houses & protects the eyeball
    • padded w/ fatty tissue
    • eyeball connected by 6 short muscles
    • covered by eyelid
    • contain sebaceous glands (secrete sebum)
  5. External structures of the eye
    protective membrane that lines the exposed surface of the eyeball and acts as a protective covering for the exposed eye surface
  6. External structures of the eye
    Lacrimal Apparatus
    produces and stores tears
  7. External structures of the eye
    lacrimal gland
    transports tears
  8. External structures of the eye
    • constant cleaning & lubrication
    • act as an antiseptic
  9. Internal structures of the eye
    Eyeball separated into 2 chambers of fluid called "humors"
    • 1. Aqueous Humor - water
    • 2. Viterous Humor - jellylike fluid
  10. Internal structures of the eye
    Aqueous Humor
    • "Watery" humor
    • bathes the iris, pupil and lens
    • fills the anterious and posterior chambers of the eye
  11. Internal structures of the eye
    Vitreous humor
    • clear, jellylike fluid
    • occupies the entire eye cavity behind the lens
  12. Eyeball has 3 layers
    • sclera
    • choroid
    • retina
  13. Sclera
    • outermost laer
    • tough, fibrous tissue
    • protective shield ("whites of the eyes")
    • contains the cornea
  14. Cornea
    • transparent to allow light rays to pass into the eye
    • curved surface allowing them to bend the incoming light rays
  15. Choroid
    • Middle layer
    • Highly vascularized (rich blood supply)
    • Pigmented region that provides nourishment to the eye
    • Contains the iris and the pupil
  16. Iris
    colored ring of tissue whose muscles contract or relax to change the size of the pupil in the center of the iris
  17. Pupil
    Round opening in the iris that allows light rays to enter the intenal eye
  18. Lens
    • Located behind pupil
    • Clear, hard disk in the internal eye. The muscles and ligaments of the ciliary body change its shape to focus light rays onthe retina
  19. Retina
    • 3rd layer of the eyeball
    • contains the nerve endings that receive and help interpret the rays of light as images
    • delicate membrane that continues posteriorly and joins the optic nerve
    • contains light sensing receptors called rods and cones
  20. Rods
    • Light sensitive cells in the retia.
    • Detect black and white and function in daytime and nighttime vision
  21. Cones
    • Light sensitive cells in the retina that detect colored light.
    • three types of cones, each of which responds to either red, green or blue light.
  22. Ciliary Muscles
    Smooth muscle that alters the lens of the eye to accommodate for near vision
  23. Photopigments
    Chemicals in the retinal cells that have light sensitivity
  24. Structure of the Ear
    • External ear
    • Middle ear or tympanic cavity
    • Inner ear
  25. External Ear
    • 1. Pinna/ Auricle leads sound waves into the auditory canal or external auditory meatus
    • 2. Contains cerumen (earwax) to lubricate and protect the ear
    • 3. At the end of the canal is the eardrum or tympanic membrane
  26. Middle Ear (Tympanic Cavity)
    • 1. Contains the 3 smallest bones in the body (ossicles)
    • 2. Ossicles amplify the sound waves
    • 4. Eustachian tubes
    • 4. Oval window begins the inner ear
  27. Ossicles
    • Hammer (malleus)
    • Anvel (incus)
    • Stirrup (stapes)
  28. Eustachian Tubes
    • Equalize the air pressure on either side of the eardrum
    • Connect the nasal cavity and pharynix to the middle ear
  29. Inner Ear
    • Oval Window
    • Bony labyrinth
  30. Bony labyrinth
    • 1. Vestibule Chamber (houses the internal ear)
    • 2. Cochlea
    • 3. Semicircular canals
  31. Cochlea
    Structure of the inner ear that is associated with the sense of hearing. It relays information to the brain via the cochlear branch of the vestibulocochlear nerve (cranial nerve VIII)
  32. Perilymph
    Pale lymph fluid found in the labyrinth of the inner ear.
  33. Endolymph
    Fluid within the labyrinth of the ear.
  34. Sensorineural conduction
    Last ossicle vibrates and cuases a gentle pumping against the oval window membrane. Cochlear fluid then vibrates small hairlike neurons. Vibration sends a nerve impulse to the temporal lobe of the brain.
  35. Bone conduction
    Middle ear amplifies the sound through ossicles
  36. Sound Conduction
    Sound waves enter the external canal and vibrate the eardrum
  37. Taste (gustatory sense)
    • Papillae contain taste receptors called taste buds. Found on tongue, lips and back of the throat.
    • Taste buds send signals to the brain thru 3 distinct cranial nerves.
    • Detect 5 tastes: sweet, sour, salty, bitter and umami (savory)
  38. Smell
    • Closely related to taste (cannot taste food well with head cold)
    • Linked to memory
  39. Touch (receptors called tactile corpuscles)
    • Located on skin, tipe of tongue and concentrated in the fingertips
    • Allows perception of pain, temperature, pressure, traction and "tickled"
  40. Semicircular canals in the ear
    responsible for equilibrium
  41. Endocine translated means
    • endo - into
    • crine - to secrete
  42. endocrine system
    a series of organs and glands in your body that secretes chemical messengers called hormones into the bloodstream
  43. glands that bridge the endocrine and nervous systems
    • hypothalamus
    • pituitary gland
    • pineal gland
  44. chemical messengers
    • neurotransmitter
    • hormones
  45. negative feedback
    the control systems work to bring the body back to homeostasis if they become seriously disrupted. ie when hot, body send blood to the surface of the skin to promote sweating, thus reducing the heat
  46. positive feedback
    increases the magnatude of a change away from the set point; vicious cycle.
  47. Homone levels can be contolled by:
    • Nervous system - neural control
    • Hormones - hormonal control
    • Body fluids (ie blood) - humoral control
  48. The Hypothalamus
    • Is a link between the nervous and endocrine systems
    • Controls much of the body's physiology, including hunger, thirst, fluid balance, body temperature
    • Controls the pituitary gland
  49. Pituitary gland
    • Often called the master gland
    • But only acts on orders from the hypothalamus
  50. Posterior Pituitary
    • An extension of the hypothalamus
    • Launches 2 hormones for the hypothalamus
    • Antidiuretic hormone (ADH) and oxytocin
  51. Anterior Pituitary
    Also controlled by the hypothalamus, but is an endocrine gland too
  52. Thyroid gland
    • Secretes thyroxine (T4) and triiodothyronine (T3) under orders from the pituitary gland ("thyroid hormones")
    • Also secretes calcitonin (decreases blood calcium by stimulating bone building cells)
  53. Thymus Gland
    • produces thymosin
    • helps with the maturation of WBC during childhood to fight infection
  54. Pineal Gland
    • produces melatonin
    • thought to regulate sleep
  55. Pancreas
    • produces insulin & glucagon
    • controls blood glucose levels
  56. Adrenal Glands
    • The Adrenal Medulla
    • The Adrenal Cortex
  57. Adrenal Medulla
    produces epinephrine (adrenalin) and norepinephrine
  58. Adrenal Cortex
    • makes dozens of steroid hormones known as adrencorticosteroids
    • releases hormones under the direction of the anterior pituitary
  59. Parathyroid glands
    produce parathyroid hormone (PTH) that regulates the level of calcium in the bloodstream
  60. Common Disorders of the Endocrine System
    • Anabolic Steroids
    • Hashimoto's disease (a form of hypothyroidism)
    • Graves' disease (hyperthyroidism)
    • Pheochromocytoma (excess epinephrine)
    • Addison's disease (insufficient cortisol production)
    • Cushing's syndrome (oversecretion of cortisol)
Card Set
Ch 11 & 12
Sights & Sounds; Endocrine System