Overview of the anatomy of the Central Nervous System.

1. Central Nervous System

2. Organization What are the 3 general functions of the CNS and PNS? Collect information (receptors) Process and Evaluate Information Respond to information How do neurons communicate with each other? action potential propagation and neurotransmitter release

3. Sensory Division List and define the 2 subdivisions of he sensory division of the nervous system? Somatic sensory touch, pain, pressure, vibration, temperature, proprioception, and special senses Visceral sensory blood vessels and viscera-temperature and stretch Is “visceral sensory” part of autonomic system? Why or why not?

4. Motor Division List and define the 2 subdivisions of he motor division of the nervous system? Somatic motor CNS to skeletal muscles Voluntary Autonomic motor CNS to smooth muscle, cardiac muscle and glands Involuntary

5. We see the posterior root is sensory & anterior root is motor. Do they stay separate like this?

6. Nervous tissue cells of the CNS Flash cards only give us the following: Glial cells, which are supportive Neurons, which are excitable

7. Relate these structures

8. 3-week old embryo This process of forming a nervous system is called “_____” The nervous system arises from which germ layer?

9. Do you recall? In order for neurulation to occur there must already be 3 germ layers. Do you recall what the process was for making 3 germ layers? Gastrulation! It resulted in ectoderm, mesoderm, and endoderm

10. Development During the development of the nervous system, what longitudinal indentation forms from the neural plate? Neural groove During the development of the nervous system, what hollow structure is formed as the neural folds meet? Neural tube

11. Development What is the thickened portion of tissue over the notochord called? Neural plate

13. What becomes of the notochord?

14. Side note (not in flash cards) Neurons grow until they reach their target organ and form a synapse. If they don’t reach the target they die (apoptosis). Even after neuromuscular connections are made, some are eliminated until each muscle fiber is innervated by only one motor neuron. For example, 20,000 motor neurons are formed in the spinal cord of the chick but ~half die.

16. How many neurons make up the CNS? 100 billion (mostly in brain) What is the average volume of the human brain? 1200 cc Size matters not—you are ALL brilliant and possess the most complex machine in the known universe

17. Brain Tissue Organization What is the superficial sheet of gray matter covering most of the adult brain? Cortex Cerebral and Cerebellar Within the interior of the brain, what are clusters of gray matter? Cerebral nuclei

20. Discuss the dural septa

21. Name passages between ventricles How does CSF leave the brain? How is CSF drained?

23. Cerebrum What are the functions of the cerebrum? Intelligence Reasoning Sensory perception Thought Memory Judgment Voluntary motor, visual, and auditory fcns

24. Cerebral Hemispheres 3 points about the cerebral hemispheres 1) it is usually difficult to assign a precise function to a specific region 2) Usually the hemisphere receives information from and sends motor commands to the opposite side of the body 3) The hemispheres display functional differences (lateralization)

26. Lobes of the Cerebrum List the primary functions of the frontal lobe. Voluntary motor functions Concentration Verbal communication Decision making Planning Personality

27. Lobes of the Cerebrum What are the functions of the lobe of the cerebrum that forms the superoposterior part of each cerebral hemisphere (Parietal)? General sensory functions E.g. evaluating shape and texture Understanding language Shares Wernike’s with Temporal lobe

28. Lobes of the Cerebrum What are the functions of the lobe of the cerebrum that lies inferior to the lateral sulcus (Temporal)? Hearing and smell Interpretation and storage

29. Lobes of the Cerebrum What are the functions of the lobe of the cerebrum that forms the most posterior region of each cerebral hemisphere (Occipital)? Perceive visual information Store and use visual memories

30. Lobes of the Cerebrum What are the apparent functions of the small, deep lobe of each cerebral hemisphere lies deep to the lateral sulcus (Insula)? Memory Taste interpretation

31. Functional Areas of the Cerebrum The primary motor cortex is located within what structure of the brain? Precentral gyrus of the frontal lobe

33. Note motor speech area & frontal eye field in the frontal lobe

34. Functional Areas of the Cerebrum What is the function of the association areas within the cerebrum? Integrate new sensory inputs with memories

35. Note auditory association area & visual association area

36. Cerebral White Matter What are bundles of myelinated axons that lie deep to the cerebral cortex? Tracts Projection (linking cerebrum to lower brain structures) Association (linking multiple places in cerebrum, but on one side or the other) Commissural (linking similar parts on the two hemispheres)

37. Association tracts stay within a hemisphere

38. Note nuclei also

39. Diencephalon What part of the brain is composed of the epithalamus, right and left thalami, and the hypothalamus? Diencephalon

40. Diencephalon What is the function of the thalamus? Final relay for sensory information projected to the primary sensory cortex Filter sensory information Inform cerebrum where sensory information is coming from

42. Diencephalon What are the functions of the hypothalamus? Master control of ANS Master control of endocrine system Regulate temperature Control emotional behavior Control food intake Control water intake Regulate sleep/wake cycles

43. Oxytocin ADH

45. Brainstem What 3 regions form the brainstem? Midbrain Pons Medulla oblongata

48. Mesencephalon Within the midbrain what are the motor tracts located on the anterolateral surfaces? Cerebral peduncles Within the midbrain what is the “body of 4 twins”? Corpora quadrigemina

49. Mesencephalon What are the “visual reflex centers” of the midbrain? Superior colliculi What are the “auditory reflex centers” of the midbrain? Inferior colliculi

51. Cerebellum What is the function of the cerebellum? Coordinate (and fine tune) skeletal muscle movements Maintain equilibrium and posture

52. Cerebellum What thick tracts connect the cerebellum to the brainstem? Cerebellar peduncles Superior to mesencephalon Middle to pons Inferior to medulla oblongata