Nervous System Part 2

What does the cerebrum contain?

• Right and Left hemispheres

What is the cerebrum divided by?

• Divided by; deep fissures

What divisions do they have on the surface?

1. Gyri; folds

2. Sulci; superficial cracks

Contain cerebral cortex

What are the 4 major regions of the brain?

1. Cerebrum

2. Cerebellum

3. Diencephalon

4. Brainstem

What is the cerebral cortex (aka cerebrum)?

• Superficial layer of gray matter

What are the functions of the cerebral cortex?

1. Conscious thought/control of skeletal muscles

2. Memory storage and processing

3. Sensory processing ((touch, pain, pressure, temp.)

4. Special senses

What is the diencephalon? What are its parts?

• Link between cerebral hemispheres and CNS

  1. Thalamus

  2. Hypothalamus

What is the function of the thalamus?

• Thalamus: sensory/relay processing for senses and special senses

  • “categorizing”

What is the function of the hypothalamus?

• Hypothalamus: hormone production, autonomic functions

What is located in the cerebellum? What does this mean?

• More than 50% of neurons located here; most sophisticated thinking

  • 2nd largest brain

What is the function of the cerebellum?

• Coordinates motor commands from cerebral cortex (BALANCE)

What is gray matter?

• Combination of cell bodies and nuclei

What are the 3 parts of the brain stem?

1. Midbrain

2. Pons

3. Medulla Oblongata

What does the midbrain contain?

• Contains nuclei; many cell bodies (gray matter)

What is the function of the midbrain?

• Process visual/auditory reflexes

What does the pons connect?

• Connects cerebellum to brainstem

What are tracts? What structure uses it?

• Tracts: bundles of axons

  • pons; for somatic and visceral motor control

What are the functions of the pons?

• Somatic (voluntary) and visceral motor control (digestive system)

What are the functions of the medulla oblongata? What are examples?

• Regulates autonomic function

  • breathing rate, depth

What are the lobes of the brain?

1. Frontal lobe

2. Parietal lobe

3. Occipital lobe

4. Temporal lobe

5. Insula

Does the gyri and sulci look the same in every person?

• No, unique to every person

What does the lateral sulcus separate?

• Separates frontal from temporal lobe

What does the parieto-occipital sulcus separate?

• Separates parietal lobe from occipital lobe

What does the central sulcus separate? What gyrus does it contain?

• Separates frontal from parietal lobe

  • Precentral gyrus

  • Postcentral gyrus

What does the precentral gyrus contain? What is its function?

• Contains primary motor cortex

  • Controls voluntary movement

What does the postcentral gyrus contain? What is its function?

• Contains primary somatosensory cortex

  • awareness of TOUCH, somatosensory information

Where is the motor cortex found? What does it contain?

• Frontal Lobe

  • Primary motor cortex

  • Premotor cortex

What is the function of the primary motor cortex?

• Directs voluntary movement by controlling neurons in brain stem

What is the function of the premotor cortex?

(Motor Association Area)

• Coordinates learned movements

  • Walking, writing

Where is the sensory cortex found? What does it contain?

• Parietal lobe

  • Primary somatosensory cortex

  • Somatosensory association area

What is the function of the primary somatosensory cortex?

• Ability to detect touch, pressure, pain, vibration, temperature

What is the function of the somatosensory association area?

• Monitors activity in somatosensory cortex; recognizes different sensations

Where is the gustatory cortex found? What is its function?

• Insula

• Receives information from taste receptors

Where is the olfactory cortex found? What is its function?

• Insula

• Receives sensory information from olfactory receptors

Where is the auditory cortex found? What does it contain?

• Temporal lobe (near ear)

  • Primary auditory cortex

  • Auditory association area

What is the function of the primary auditory cortex?

• Recieves auditory information, hearing

What is the function of the auditory association area?

• Recognizes different sounds

Where is the visual cortex found? What does it contain?

• Occipital lobe

  • Primary visual cortex

  • Visual association area

What is the function of the primary visual cortex?

• Receives visual information

What is the function of the visual association area?

• Interprets the information; distinguishes between colors

What is the function of the lateral ventricle?

• Stores cerebrospinal fluid

What is the function of the third ventricle?

• Stores cerebrospinal fluid

• Located in diencephalon

What is the function of the cerebral aqueduct?

• Stores cerebrospinal fluid

• Canal in midbrain

What is the fourth ventricle?

• Cerebrospinal fluid

What are integrative centers?

• Receive information multiple association areas; link uo senses

• Direct motor activities

• Perform analytical functions

What does Broca's Area combine? For what?

• Speech production:

  • Motor control of frontal lobe + auditory association area of temporal lobe

What is the function of Broca's area?

• Regulates breathing, vocal pattern for speech

  • speech production

What is the function of the prefrontal cortex?

• Intellectual functions, ability to think, learning

  • integrates from all association areas

What does the frontal eye field contain? What is its function?

• Controls learned eye movements

  • frontal (motor) + occipital

What does the wernicke's area receive information from?

• Receives information from somatosensory association areas

What is the function of wernicke's area?

• Language comprehension

• Personality; link sensory info. to memories

What is the function of the corpus callosum? How?

• Coordinate signals between cerebral hemispheres

  • axons communicating between hemispheres

What are cranial nerves?

• Nerves that exit brain (through brainstem and diencephalon)

What is the function of the olfactory nerve (I)?

• Smell

What is the function of the optic nerve (II)?

• Sight

What is the function of the oculomotor nerve (III)?

• Moves extrinsic eye muscles and size of pupil

What is the function of the trochlear nerve (IV)?

• Moves single eye muscle

What is the function of the trigeminal nerve (V)?

• Muscles of mastication and facial sensation

What is the function of the abducens nerve (VI)?

• Moves single eye muscle

What is the function of the facial nerve (VII)?

• Muscles of facial expression and glands

• Taste (anterior)

What is the function of the vestibulocochlear nerve (VIII)?

• Balance and hearing

What is the function of the glosso-pharyngeal nerve (IX)?

• Pharyngeal muscle and salivary gland

• Taste (posterior)

What is the function of the vagus nerve (X)?

• Palatal and pharyngeal muscles, visceral organs

• Sensory info. from ear, pharynx, diaphragm

What is the function of the spinal accessory nerve (XI)?

• Trapezius and sternocleidomastoid muscle

What is the function of the hypoglossal nerve (XII)?

• Tongue muscles

What are spinal cord nerves?

• Nerves that leave spinal cord

What are the spinal nerves?

1. Cervical spinal nerves

2. Thoracic spinal nerves

3. Lumbar spinal nerves

4. Sacral spinal nerves

5. Coccygeal spinal nerves

6. Filum terminate

What is the conus medullaris?

• cone shaped end, L1-L2

What is the cauda equina?

• Beginning of axons branching out, splitting up

What are the three connective tissue laters surrounding spinal nerves?

1. Epineurium

2. Perineurium

3. Endoneurium

What is the epineurium?

• Outermost layer of spinal nerve

  • collagen fibers

What is the perineurium? What does it contain?

• Middle layer; surrounds fascicles—bundles of axon

  • Provide route for blood vessels

What is the endoneurium?

• Innermost layer; surrounds individual axons

  • on top of myelin sheath

What is the meninges? What are the 3 layers?

• Meninges: membraneous layers that cover brain and spinal cord

  1. Dura mater; outer

  2. Arachnoid mater; middle

  3. Pia mater; inner

What is the dura mater? The epidural space?

• Dura mater; outermost, fibrous

  • epidural space; above dura mater and contains adipose tissue

What is the arachnoid mater? The subarachnoid space?

• Arachnoid mater; middle

  • Subarachnoid space; below arachnoid mater

What is the pia mater?

• Innermost layer

  • elastic and collagen fibers

What is the anterior root?

• Motor route; sends signals AWAY from brain, out to body

What is the posterior root? What does the posterior root ganglion contain?

• Sensory route; sends signals to brain

  • Posterior route ganglion; contains bipolar neurond

What does the subarachnoid space contain?

• Contains cerebrospinal fluid

What is the function of cerebrospinal fluid?

• Shock absorber and diffusion of gases, nutrients

What does the epidural space contain?

• Areolar and adipose tissue, blood vessels