1. Chapter 4 Anatomy of the Nervous System

2. chapter 4
Frontal lobe damage
Phineas Gage, 1848

3. chapter 4
Frontal lobe damage
Travis Bogumill, 1998
Jarod Behee, 2007

4. Wilder Penfield: Mapping the Cortex, 1947

6. Modern techniques for studying the brain
Lesion
damage to a brain area (electrical or chemical)
Ablation
removal of brain area
Stereotaxic instrument
a device that allows for precise neurosurgical procedures
Sham lesion
performing identical procedures except for damaging the brain
produced by an experimenter in a control subject

7. Modern techniques for studying the brain
Positron-emission tomography (PET Scan)
records emission of radioactivity from injected radioactive chemicals to produce a high- resolution image
shows where activity occurs in the brain

8. Modern techniques for studying the brain
Recording brain activity involves using a variety of noninvasive methods including:
Magnetic Resonance Imaging (MRI)
involves the application of a powerful magnetic field to image the brain
good for viewing soft tissue

9. Modern techniques for studying the brain
Electroencephalography (EEG)
Records electrical activity produced by cortical regions of the brain
Produces a record of brainwaves.
Widely used for sleep research

10. Structure of the Vertebrate Nervous System
Neuroanatomy is the anatomy of the nervous system.
Refers to the study of the various parts of the nervous system and their respective function(s).
The nervous system consists of many substructures, each comprised of many neurons.

12. Structure of the Vertebrate Nervous System
The Nervous System is comprised of two major subsystems:
The Central Nervous System (CNS)—brain and spinal cord
The Peripheral Nervous System (PNS)

13. Central Nervous System
Brain
Comprised of 100 billion neurons
“Command Central” of the nervous system
Spinal cord
the part of the CNS found within the spinal column
communicates with the sense organs and muscles below the level of the head
Functions according to the Bell-Magendie law

14. Central Nervous System
The Bell-Magendie law states the entering dorsal roots carry sensory information and the exiting ventral roots carry motor information.
Figure 4.3: Diagram of a cross-section through the spinal cord.
The dorsal root on each side conveys sensory information to the spinal cord; the ventral root conveys motor commands to the muscles.
Fig. 4-3, p. 84

15. Peripheral Nervous System
The Peripheral Nervous System (PNS) sends information to the CNS and is comprised of the:
Somatic Nervous System
Autonomic Nervous System

16. Peripheral Nervous System
The Somatic Nervous System consists of nerves that:
Convey sensory information to the CNS.
Transmit messages for motor movement from the CNS to the body.
Control skeletal muscles

17. Peripheral Nervous System
The autonomic nervous system regulates the automatic behaviors of the body (heart rate, blood pressure, respiration, digestion etc).
Divides into 2 subsystems:
The Sympathetic Nervous System
The Parasympathetic Nervous System

18. Peripheral Nervous System
Sympathetic nervous system: a network of nerves that prepares the organs for rigorous activity by increasing:
heart rate
blood pressure
respiration
etc.
Responsible for “fight or flight” response

19. Peripheral Nervous System
The parasympathetic nervous system facilitates vegetative, nonemergency responses by the organs.
decreases functions increased by the sympathetic nervous system.
dominant during our relaxed states.

20. Anatomical Terms: Views
Terms used to describe views when referring to the nervous system include:
Ventral: toward the stomach
Dorsal: toward the back
Ventral Dorsal

21. Anatomical Terms: Views
Terms used to describe views when referring to the nervous system include:
Anterior: toward the front end
Posterior: toward the back end
Lateral: toward the side
anterior posterior lateral

22. Anatomical Terms: Location/direction
Terms used to describe location/direction in the nervous system include:
Superior: above another part
Inferior: below another part

23. Anatomical Terms: Location/Direction
Terms used to describe location/direction in the nervous system include:
Lateral: toward the side
Medial: toward the midline

24. Anatomical Terms: Location/Direction
Terms used to describe location/direction in the nervous system include:
Ipsilateral: on same side
Contralateral: on opposite side

25. Anatomical Terms: Planes/Sections/Cuts
Terms referring to planes/sections/cuts:
Horizontal: shows brain structures as seen from the top
Sagittal: shows brain structures as seen from the side
Coronal: shows brain structures as seen from the front
Table 4-1, p. 83

26. Anatomical Terms: Specialized Parts
Terms referring to specialized parts of the nervous system:
Gray matter: cell bodies and dendrites
White matter: axons, mostly myelinated
Table 4-1, p. 83

27. Anatomical Terms: Specialized Parts
Terms referring to specialized parts of the nervous system:
Tract/projection: set of axons in the CNS
Nerve: set of axons in the PNS
Nucleus: cluster of neuron cell bodies within CNS
Ganglion: cluster of neuron cell bodies in the PNS
Table 4-1, p. 83

28. Anatomical Terms: Specialized Parts
Terms referring to specialized parts of the nervous system:
Gyrus (pl: gyri): mound on surface of brain
Sulcus (pl: sulci): fold/groove separating one gyrus from another
Fissure: long, deep sulcus
Table 4-1, p. 83

29. Neuroanatomy Handout #3: Brain Structures
The brain can be divided into three major divisions:
Hindbrain.
Midbrain.
Forebrain.

30. Neuroanatomy Handout #3: Brain Structures
The Hindbrain consists of the:
Medulla
Pons
Cerebellum
Located at the posterior portion of the brain

31. Neuroanatomy Handout #3: Brain Structures
The medulla (A):
Located just above the spinal cord
Responsible for vital reflexes such as breathing, heart rate, vomiting, salivation, coughing and sneezing.
Cranial nerves allow the medulla to control sensations from the head, muscle movements in the head, and many parasympathetic outputs to the organs.

32. Table 4-4, p. 88

33. Neuroanatomy Handout #3: Brain Structures
Pons (B)
lies on each side of the medulla (ventral and anterior).
along with the medulla, contains the reticular formation and raphe system, which work together to increase arousal and readiness of other parts of the brain

34. Neuroanatomy Handout #3: Brain Structures
Cerebellum (C):
located posterior to the brainstem with many deep folds
helps regulate motor movement, balance and coordination
also important for shifting attention between auditory and visual stimuli

35. Neuroanatomy Handout #3: Brain Structures
The midbrain (D) is comprised of the following structures:
Superior colliculus: helps process visual info
Inferior colliculus: helps process auditory information
Substantia nigra – involved in movement

36. Neuroanatomy Handout #3: Brain Structures
Brain stem consists of the:
Medulla
Pons
Midbrain
Some forebrain structures

37. Neuroanatomy Handout #3: Brain Structures
Forebrain: most prominent part of the mammalian brain, consisting of:
the outer cortex (“cerebral cortex”)
subcortical regions

38. Neuroanatomy Handout #3: Brain Structures
The limbic system is associated with motivation, emotion, drives and aggression, and includes:
Olfactory bulb
Hypothalamus
Hippocampus
Amygdala
Olfactory bulbs send info about smell to cortex

39. Neuroanatomy Handout #3: Brain Structures
Hypothalamus (F)
Conveys messages to the pituitary gland to trigger the release of hormones
Regulates autonomic nervous system
Involved in emotions and drives vital to survival:
Eating
Drinking
Sexual behavior
Fear
Feeling rewarded

40. Neuroanatomy Handout #3: Brain Structures
Pituitary gland (G)- hormone producing gland found at the base of the hypothalamus.
AKA: “Master Gland”

41. Neuroanatomy Handout #3: Brain Structures
Hippocampus is a large structure of the limbic system critical for storing certain types of memory.
H.M., 1953

42. Neuroanatomy Handout #3: Brain Structures
Amygdala: almond-shaped structure important for:
initial emotional response to stimuli
directing motivated behavior at an appropriate target

43. Neuroanatomy Handout #3: Brain Structures
Forebrain structures include:
Thalamus (E) - relay station for the sense organs and main source of input to the cortex.

44. Neuroanatomy Handout #3: Brain Structures
Basal Ganglia - comprised of the caudate nucleus, the putamen and the globus pallidus.
Associated with planning of motor movement, and aspects of memory and emotional expression .

45. Neuroanatomy Handout #3: Brain Structures
Nucleus basalis:
receives input from the hypothalamus and basal ganglia
key part of the brain’s system for arousal, wakefulness, and attention

46. Neuroanatomy Handout #3: Brain Structures
The ventricles are four fluid-filled cavities within the brain containing cerebrospinal fluid. The central canal is a fluid-filled channel in the center of the spinal cord.

47. Neuroanatomy Handout #3: Brain Structures
Cerebrospinal fluid (CSF) is a clear fluid similar to blood plasma found in the brain and spinal cord:
Provides “cushioning” for the brain
Reservoir of hormones and nutrition for the brain and spinal cord
Choroid plexus: groups of cells in the 4 ventricles that continually manufacture CSF

48. Neuroanatomy Handout #3: Brain Structures
Meninges: thin membranes surrounding brain and spinal cord

49. Neuroanatomy Handout #3: Brain Structures The Cerebral Cortex
The cerebral cortex is the most prominent part of the mammalian brain and consists of the cellular layers on the outer surface of the brain.

50. Neuroanatomy Handout #3: Brain Structures The Cerebral Cortex
The four lobes of the cerebral cortex:
Occipital lobe
Parietal lobe
Temporal lobe
Frontal lobe
2 hemispheres

51. Neuroanatomy Handout #3: Brain Structures The Cerebral Cortex
The Frontal lobe (H):
involved in attention, planning, decision-making, etc.
contains Broca’s area (principal speech area) (H1)
contains Precentral gyrus (primary motor cortex) (H2), responsible for control of fine motor movement

52. Neuroanatomy Handout #3: Brain Structures The Cerebral Cortex
Parietal lobe (I) :
involved in body sensations
contains postcentral gyrus (I1) (primary sensory area), a main target for touch sensations

53. Neuroanatomy Handout #3: Brain Structures The Cerebral Cortex
Temporal Lobe (J):
involved in hearing
also responsible for some emotional and motivational behaviors
contains primary auditory cortex (J1): Target for auditory information and essential for processing spoken language

54. Neuroanatomy Handout #3: Brain Structures The Cerebral Cortex
Occipital lobe (K):
Highly responsible for visual processing
contains striate cortex or primary visual area (K1)
damage can result in cortical blindness

55. Neuroanatomy Handout #3: Brain Structures
Central sulcus (L)
Longitudinal fissure (M)
Lateral fissure (N)

56. Neuroanatomy Handout #3: Brain Structures
Corpus callosum (O): large bundle of axons joining the 2 hemispheres
Anterior commissure (P): small bundle of axons joining the 2 hemispheres

57. The Cerebral Cortex
The binding problem refers to the question of how the visual, auditory, and other areas of the brain produce a perception of a single object.
All areas of the brain communicate with each other