Anatomy Exam 3

• Blood-Brain Barrier (BBB)


  Protects brain from toxins, chemicals, drugs
• Capillary endothelial cells


  • Simple squamous
  • Contains tight junction
  • Basement membrane is continuous (no leaking)
  • Astrocyte feet wrapped around capillaries
• Lipid-soluble substances


  Can pass through the Blood-Brain Barrier
• Lipid-soluble substances


  • Alcohol
  • Nicotine
• Cerebrum


  • 4 lobes
  • Frontal: intellect, reasoning, creativity, social awareness
  • Parietal: general sensory functions
  • Temporal: hearing, smell
  • Occipital: vision
• White matter


  • Myelinated axons
  • Deep to grey matter
• Corpus callosum


  Band of white matter that allows communication between hemispheres (2 sides)
• Structure (review lab material)
• Gray matter


  Composed of cell bodies and dendrites
• Diencephalon


  • Superficial to white matter
  • Relay station
  • "In between" brain
  • 3 parts: Epithalamus, Thalamus, Hypothalamus
• Epithalamus


  • Superior and posterior to the thalamus
  • Pineal gland produces melatonin
• Thalamus


  Main relay station
• Hypothalamus


  Endocrine structure
• Midbrain


  • Cerebral aqueduct located there (CSF circulates)
  • Superior colliculus - visual tracking
  • Inferior colliculus - auditory tracking
• Pons


  • Relay station
  • Regulates breathing
• Medulla oblongata


  • End of brain continuous with spinal cord
  • Vital life functions located there
• Cerebellum


  • Coordinates movement
  • Cardiac centers
  • Vasomotor center - blood pressure
  • Respiratory center - breathing
• White matter


  Arbor vitae - "tree of life" of brain nuclei
• Limbic system


  Regulates emotions
• Autonomic nervous system


  • Involuntary motor response
  • Controls smooth muscle, cardiac muscle, glands
• Autonomic nervous system pathway

  1. Preganglionic neuron

  2. Ganglion

  3. Postganglionic neuron

  4. Target region
• Parasympathetic division


  Rest and digest function
• Sympathetic division


  • Fight-or-flight response
  • Prepares us for stressful situations
• Broca's area


  Coordinates muscles for speech
• Wernicke's area


  • Translates words into thought
  • Understands words but can't physically form them
• General senses are widespread and simple in structure, special senses are concentrated in the head and complex in structure
• Eye anatomy


  • Sclera
  • Cornea
  • Pupil
  • Iris
  • Ciliary body
  • Anterior chamber
  • Posterior chamber
  • Retina
  • Fovea centralis
  • Optic nerve
• Photoreceptor


  Specialized sensory neuron that responds to light
• Retina


  • Deepest layer
  • Pigmented layer contains melanin (absorbs stray light)
  • Neural layer
• Retinal layers


  • Photoreceptor cells
  • Bipolar cell layer
  • Ganglion cell layer
• Rods


  Photoreceptors for dim light/black and white vision
• Cones


  Photoreceptors for bright light/color vision
• Blind spot has no photoreceptors, located at optic disc where optic nerve leaves the eyeball
• Regions of the ear

  • External (outer) ear
  • Middle ear
  • Internal (inner) ear
• External (outer) ear


  • Auricle (pinna)
  • External auditory canal
  • Tympanic membrane (eardrum)
• Middle ear


  • Air-filled
  • Auditory ossicles (malleus, incus, stapes)
  • Muscles that protect from loud noises (tensor tympani, stapedius)
• Auditory tube (Eustachian tube)


  Connects middle ear to nasopharynx, equalizes pressure
• Internal (inner) ear


  • Cochlea
  • Vestibule
  • Semicircular canals
• Vestibule


  Contains utricle and saccule, responsible for static (linear) equilibrium
• Semicircular canals


  3 ducts in different orientations, responsible for dynamic (rotational) equilibrium