Bio 209 Ch 14

  1. Name the major parts of the brain (4) and know where each is located
    Brain Stem: continuous with spinal cord; consists of medulla oblongata, pons, midbrain

    Diencephalon: superior to brain stem; consists of hypothalamus, thalams, epithalamus

    Cerebellum: posterior to brain stem

    Cerebral Hemisphere (Cerebrum): largest part of brain; sits on diencephalon
  2. Describe the protective coverings of the brain
    Cranium: formed by cranial bones

    • Cranial Meninges: continuous with spinal meninges
    • - Dura Mater, Arachnoid Mater, Pia Mater
  3. Name the three meninges and define falx cerebri, falx cerebelli, tentorium cerebelli
    Falx Cerebri: separates the two hemispheres of the cerebrum

    Falx Cerebelli: separates the two hemispheres of the cerebellum

    Tentorium Cerebelli: separates cerebrum and cerebellum
  4. Describe the structure and function of the blood brain barrier
    • Structure:
    • - Tight Junctions: transmembrane proteins fuse together portions of adjacent epithelial cells so material cannot diffuse between cells; there are spaces between fused areas
    • - Astrocytes: processes surrounds capillaries help form BBB
    • Function:
    • - Protects brain from harmful substances and pathogens
    • - Controls entry of nonlipid soluble (hydrophilic) substances into brain from blood
    • . Glucose can cross thru by Active Transport
    • . Ions cross thru slowly
    • . Proteins and most antibiotics cannot cross thru
    • . Drugs that can be used to treat cancer and CNS diseases
    • - Cannot prevent passage of lipid soluble (hydrophobic) substances into brain. The follwing can cross easily:
    • . O, Carbon Dioxide, Alcohol, some Anesthetic Agents, lipid soluble drugs
  5. Describe the function of the CSF
    • (1) Protects brain & spinal cord
    • (2) Mechanical protection of CNS
    • (3) Transports O, Glucose, other chemicals from blood to neurons/neuroglia
    • (4) Movement of ependymal cell cilia circulates CSF thru ventricles (spaces) in brain and in the subarachnoid space of the brain and spinal cord
    • (5) Provides optimal chemical environment
    • (6) Exchanges nutrients/wastes between blood and nervous tissue
  6. Describe how CSF is formed
    - Formed in Choroid Plexuses (capillary networks in walls of ventricles)

    - Ependymal cells cover capillaries and filter fluid leaving capillaries form CSF

    - Tight junctions between ependymal cells help form the BBB
  7. Describe the circulation of CSF
    • Lateral Ventrical to Interventricular Foramen (hole in each lateral ventricle) to
    • Third Ventricle to Cerebral Aqueduct (tunnel-like space in midbrain) to
    • Fourth Ventricle to
    • Lateral & Median Apertures to
    • Subarachnoid Space & Central Canal of Spinal Cord to
    • Reabsorbed through to
    • Arachnoid Villi
  8. Name the principle structures of the brain stem
    • (1) Medulla Oblongata
    • (2) Pons
    • (3) Midbrain
  9. Describe the location of the medulla and describe the types of tracts and function of the nuclei of the medulla
    • - Located between Foramen Magnum & Pons
    • - Sensory Tracts, Motor Tracts, Nuclei (controls body functions & nuclei that are part of sensory pathways
    • - Function of Nuclei
    • 1. Controls vital body functions:
    • . Cardiovascular Center (BP, HR, contractions, BV diameter)
    • . Respiratory Center (regulates respiratory rhythm)
    • 2. Reflexes for vomiting, swallowing, sneezing, coughing, hiccups
    • 3. Somatic Sensory Pathways (touch, pressure, vibration, proprioception) and sensory pathways for taste, hearing, balance
    • 4. Adjusting muscle activity when learning new motor skills like piano, biking etc
    • 5. Associated with Cranial Nerves (VIII, IX, X, XI, XII)
  10. Describe the location of the pons
    Superior to medulla, Anterior to Cerebellum
  11. Describe the types of tracts and function of nuclei of the pons
    Sensory Tracts (ascending)

    Motor Tracts (descending) connects to Cerebellar Hemispheres

    Nuclei: helps control breathing (Pneumotaxic & Apneustic areas); Nuclei for cranial nerves (V-VIII)
  12. Describe the location of the midbrain
    Between Pons and Diencephalon
  13. Describe the types of tracts and function of the nuclei of the midbrain
    - Ascending Sensory & Descending Motor Tracts: Cerebral Penduncles contain axons that relay motor info from Cerebral Cortex to Spinal Cord, Pons, Medulla

    • - Nuclei for controlling movements of head, eyes, trunk in response to visual/auditory stimuli: (1) Superior Colliculi control movements in response
    • to visual stimuli (2) Inferior Colliculi control movements in response to auditory stimuli

    - Other nuclei that control subconscious and conscious muscle movements. Loss of neurons in one of these nuclei (substantia nigra) associated with Parkinson’s
  14. Describe the location, structure, and function of the reticular formation
    Location: extends from spinal cord to diencephalons

    Structure: netlike structure of gray and white matter

    • Function: (1) Reticular Activating System (RAS) are fibers that send sensory signals to cerebral cortex that
    • maintains consciousness and awakens us from sleep (2) Regulates muscle tone
  15. Describe the location, major anatomical structures, and function of the cerebellum
    • Location: Posterior to Medulla and Pons, Inferior to Cerebrum
    • Structures:
    • (1) Cerebellar Hemispheres
    • - 3 lobes per hemisphere
    • - Anterior/Posterior lobes control subconscious movements of skeletal muscles
    • - Flocculondular Lobe plays a role in equilibrium and balance
    • (2) Vermis located on central part of cerebellum between cerebellar hemispheres
  16. Name the principal components of the diencephalon
    Thalamus, Hypothalamus, Epithalamus
  17. Thalamus
    • - 80% of Diencephalon
    • - Functions:
    • (1) Relays most sensory info to cerebral cortex, internal capsule
    • (2) Relays motor info from cerebellum and basal nuclei to motor area of cerebral cortex (cerebral cortex is outer layer of cerebrum and is compose of gray matter)
    • (3) Plays role in maintaining consciousness
  18. Hypothalamus
    • - Located inferior to Thalamus
    • - Functions: (1) Controls ANS (2) Controls Pituitary Gland thru hormones and nerve impulses; Infundibulum connects Hypothalamus to Pituitary Gland (3) Regulates emotions/behavior patterns associated with sexual arousal (4) Regulates eating/drinking; Feeding, Satiety, Thirst Centers (5) Control body temp (6) Biological Clock; Circadian or Sleep-Wake Cycles
  19. Epithalamus
    • - Superior & Posterior to Thalamus
    • - Functions: contains (1) Pineal gland which secretes melatonin and (2) Habenular Nuclei which is involved in olfaction and emotional response to odor
  20. Describe the location and function of the circumventricular organs
    Location: walls of third/fourth ventricles

    Functions: (1) Monitor chemical changes in blood because lack of BBB (2) Participates in regulation of BP, fluid balance, hunger, thirst
  21. Describe the location of gray and white matter in the cerebrum
    Gray Matter: located outside of brain

    White Matter: located deep to cortex
  22. Describe the location, function, and major structures of the cerebral cortex
    Location: gray matter on outside of brain

    Function: (1) Sensory areas contribute to sensory perception (2) Motor areas control voluntary skeletal muscle movements (3) Associated areas involved in memory, personality traits, intelligence

    • Structures:
    • (1) Gyri are folds of the Cerebral Cortex
    • (2) Sulci are shallow groove
    • (3) Fissures are deep grooves
    • (4) Longitudinal Fissure:
    • - Separates Cerebrum into right and left Cerebral Hemispheres
    • - Falx Cerebri extends into Longitudinal Fissure
  23. Define cerebral hemispheres and describe the structures that separate the cerebral hemispheres
    Longitudinal Fissure separates Cerebrum into right and left Cerebral Hemispheres; Falx Cerebri extends into Longitudinal Fissure
  24. Name and locate the four lobes of the cerebrum. Describe the location of the central sulcus, precentral gyrus, postcentral gyrus, parieto-occipital sulcus, lateral cerebral sulcus, and insula
    Lobes: Frontal, Parietal, Occipital, Temporal

    Central Sulcus: separates Frontal and Parietal

    Precentral Gyrus: anterior to Central Sulcus

    Postcentral Gyrus: posterior to Central Sulcus

    Parieto-Occipital Sulcus: separates Parietal and Occipital

    Lateral Cerebral Sulcus: separates Frontal from Temporal

    Insula: gray matter deep to lateral Cerebral Sulcus
  25. Describe the location and function of the basal nuclei
    Location: deep within cerebral hemispheres

    Function: (1) Help control skeletal muscle movements (2) Regulate muscle tone
  26. Describe the location and function of the limbic system
    Location: ring of structures found in border between cerebrum & diencephalons

    Function: (1) Emotions (2) Memory from Hippocampus
  27. Describe the three types of functional areas of the cerebral cortex
    Sensory Areas: receive sensory info and involved in perception

    Motor Areas: initiate voluntary movement

    Association Areas: complex integrative functions such as memory, emotions, reasoning, will, judgment, personality, intelligence
  28. Describe the location and function of the following sensory areas of the cerebral cortex: primary somatosensory area, primary visual area, primary auditory area, primary gustatory area, and primary olfactory area
    • Primary Somatosensory Area
    • Location: Postcentral Gyrus of each cerebral hemisphere
    • Function: localize point(s) on body stimulated
    • Primary Visual Area
    • Location: Occipital Lobe
    • Function: receives visual info and involved in visual perception
    • Primary Auditory Area
    • Location: Temporal Lobe
    • Function: receives auditory info and involved in auditory perception
    • Primary Gustatory Area
    • Location: Parietal Lobe
    • Function: receives impulses for taste and involved in gustatory perception and taste discrimination
    • Primary Olfactory Area
    • Location: Temporal Lobe
    • Function: receives impulses for small and involved in olfactory perception
  29. Describe the correlation between sensory receptor density and size of the corresponding cerebral cortex
    The greater the density, the larger the area of the corresponding cerebral cortex
  30. Does the somatosensory cortex receive impulses from the same side (ipsilateral) or opposite side (contralateral) of the body?
  31. Describe the location and function of the following motor areas of the cerebral cortex: primary motor area and Broca’s area
    • Primary Motor
    • - Location: Precentral Gyrus in each hemisphere
    • - Function: controls voluntary contraction of skeletal muscles

    • Broca’s
    • - Location: left Frontal (for most)
    • - Function: articulation of speech
  32. Describe the correlation between motor unit size and size of the cerebral cortex
    The smaller the muscle, the smaller the motor unit
  33. Does the primary motor cortex send signals to the same side or opposite side of the body?
  34. Describe hemispheric lateralization
    (1) Left side of brain important for language and math

    (2) Right side of brain important for art, spatial discrimination, facial recognition, emotional content of language, generating mental images of sight, sound, touch, taste, smell for comparison
  35. How are brain waves produced? Define EEG. What are EEGs used for?
    • - Brain waves produced by action potentials generated by neurons
    • - EEG = Electroencephalogran is a recording of brain waves
    • - EEG used to study brain functions
  36. Name the 12 pairs of cranial nerves in order from anterior to posterior
    - Cranial Nerves I - XII

    - On Old Olympus’ Towering Top A Friendly Viking Grew Vines And Hops

    - Olfactory, Optic, Occulomotor, Trochlear, Trigeminal, Abducens, Facial, Vestibulocochlear, Glossopharyngeal, Vagus, Accesory, Hypoglossla
  37. Describe the function of each cranial nerve
    - Some Say Marry Money But My Brother Says Bad Business Marry Money

    • - Cranial Nerves I-IV
    • Olfactory (I): carries info from olfactory receptors
    • Optic (II): carries info from vision receptors
    • Occulomotor (III): movement of eyeball, pupil size, lens shape
    • Trochlear (IV): movement of eyeball
    • - Cranial Nerves V-VII
    • Trigeminal (V): somatic sensory info from head and face and motor impulses that control chewing
    • Abducens (VI): control eyeball movement
    • Facial (VII): sensory info from taste receptors, motor impulses to control salivation, tearing, contraction of facial muscles
    • - Cranial Nerves VIII-X
    • Vestibulocochlear (VIII): carries info from hearing and equilibrium receptors
    • Glossopharyngeal (IX): sensory info from taste receptors, motor info controlling salivation, muscle involved in swallowing
    • Vagus (X): sensory info from _____, motor info to viscera
    • - Cranial Nerves XI-XII
    • Accessory (XI): controls muscle involved in swallowing
    • Hypoglossal (XII): controls tongue movements during speech
Card Set
Bio 209 Ch 14
Brain & Cranial Nerves