Anatomy of the Nervous system

1
Anatomy of the Nervous system

• CNS and PNS

2
(No Transcript)
3
CNS vs PNS

• Central Nervous System
• Brain
• Spinal cord
• Peripheral Nervous system
• Everything else!
• Nerves tracts or bundles of neurons

4
Two kinds of function

• Somatic Nervous System Transmits messages
  between CNS and the sensory organs, glands, and
  muscles
• Autonomic Nervous System Controls internal
  bodily processes

5
Two parts of the Autonomic System

• Sympathetic Nervous System
• Speeds up bodily processes
• Draws energy from stored reserves
• Activation often accompanied by strong emotions
• Parasympathetic Nervous System
• Fosters bodily processes that replenish energy
  stores
• Helps conserve energy by slowing down other
  bodily processes

6
(No Transcript)
7
The CNS

• Composed of the brain and spinal cord
• Brain
• Best protected organ in body
• Hard skull
• First to get oxygen, nutrients
• Size not really THAT important
• Three layers cover the brain Meninges
• Dura (outermost)
• Arachnoid
• Pia
• Bathed in cerebral spinal fluid CNS
• Circulates through the ventricles
• Sifts wastes, protects brain from injury

8
(No Transcript)
9
Spinal Cord

• Two kinds of tissue
•   gray matter central core, mostly cell bodies
  and dendrites
•   white matter outer core mostly axons
• Spinal reflexes
• simplest CNS behavior
• action occurs within spinal cord, not have to go
  to brain
• no pain reactions here, that does have to go to
  brain
• with paralysis reflex may work but no feeling

10
Spinal Cord

• sensory AFFERENT kinesthetic fiber pathways
• motor EFFERENT
• is a reflex center
• also a large pathway to the brain

11
(No Transcript)
12
Withdrawal Reflex Spinal Reflex
13
Brain has a distinct developmental course
Ontogeny recapitulates Phylogeny!
14
Several divisions of the brain

• Hindbrain most life functions
• Midbrain transmission stations, initial
  processing, lower motor and sensory processes
• Forebrain thinking, emoting and behaving
• Two halves of the brain
•   right side controls left side of body
•   left side controls right side of body
•   thus two of each kind of structure

15
(No Transcript)
16
The Hind Brain

• Really an enlargement of spinal cord
• Controls mostly automatic life sustaining
  functions
• Medulla oblongata
• regulates HR, BP, digestion and breathing
• serious damage is fatal
• nausea center is located here Area Postrema
• Cerebellum
•   large swelling off of brain stem
•   concerned with balance, fine motor control
•   cerebral palsy often involves damage here
• Pons
• bridge or pathway
• connection between cerebellum, medulla and
  forebrain

17
(No Transcript)
18
Upper Lower and Mid Brain Areas

• Contains nerve pathways that connect the
  hindbrain with the forebrain
• Midbrain structures perform important roles
• e.g., control of automatic movements of the eye
  muscles
•   Reticular activating formation or reticular
  formation
•  controls arousal
•  attention area
•  plays key role in regulating states of
  attention, alertness, and arousal.
• what allows you to wake up at end of class

19
Forebrain

• Thalamus
• Hypothalmus
• Basal Ganglia and corpus striatum
• Limbic system
• Cerebral Cortex

20
Thalamus

• Relays sensory information to appropriate parts
  of the cerebral cortex
• Receives input from the basal ganglia
• Not process olfaction

21
(No Transcript)
22
Hypothalamus

• Regulates many vital bodily functions as well as
  emotional states, aggressive behavior, and
  response to stress
• responsible for the 4 F's
•   feeding
•   fighting
•   fleeing
•   sex
• controls actual cellular level of thirst, hunger
• Two ways can exert control
• CNS functions
• Endocrine functions Hormones

23
Endocrine System

• Another communication system in the body
• But much slower than the nervous system
• Messages conveyed through blood vessels using
  hormones
• Regulates important bodily processes
• Helps body to maintain homeostasis

24
Major Glands of the Endocrine System
25
Hormones and Behavior

• Testosterone and aggression
• Thyroid hormones and metabolism
• Excess anxiety and irritability
• Deficit sluggishness
• Premenstrual syndrome (PMS)

26
Basal Ganglia and Corpus Striatum

• Corpus Striatum Motor Habits
•    located between the cortex and the thalamus
•    composed of three very large nuclei
•   caudate nucleus
•   putamen
•   globus pallidus
•   collectively- called the striatum
• Basal Ganglia
•    diffuse system of nuclei
•    important for coordination of body movement
• Substantia Nigra
• Parkinson's disease, Huntington's chorea both
  involve damage to these area s

27
(No Transcript)
28
Limbic System

• Group of interconnected structures
• Amygdala Helps regulate states of emotional
  arousal
• Hippocampus Plays important role in the
  formation of memories
• Parts of the thalamus
• Parts of the hypothalamus
•  Frontal lobotomies

29
(No Transcript)
30
Cerebral Cortex

• 2 Hemispheres
• 4 Lobes

31
Specialized Tissue

• Thin, outer layer of the largest part of the
  forebrain which is called the cerebrum
• 2 halves of brain, so 2 of each type of lobe
•    see specialization here
• left language
• right spatial
•    highly convoluted and compacted
•   sulci valleys
•   gyri ridges
•   allows for more tissue in less space

32
(No Transcript)
33
(No Transcript)
34
(No Transcript)
35
(No Transcript)
36
Size matters somewhatby species
37
Parietal Lobe

• sensory cortex
• each part of body represented by spot on sensory
  cortex
• all sensation of touch, pressure, temperature
  controlled here
• also sensory integration
• sense of taste, smell, as well

38
Somatosensory Cortex and Motor Cortex
39
Occipital Lobe

•  Specialized area for vision
•  Certain cells within occipital lobe respond to
  unique stimuli
•  If damage cortical blindness
• eyes work, brain doesn't
• can get ambient vs focal vision blindness, too

40
Temporal Lobe

• Major hearing integration area
• Wernicke's area left hemisphere only
•   located across fissure (sulci) from Broca's
  area
•   controls understanding of speech
•   damage can talk but not understand
•    either talk nonsense
•    or not understand anything
•    or both
•    aphasia

41
Frontal Cortex

• Motor cortex
• divide from somatosensory and temporal along
  central sulcus
• controls motor movements and coordination of
  these movements
• PreFrontal Cortex
• controls ability to plan and think logically
• If damaged, lose ability to think, do, plan
•    Broca's area left hemisphere only
•   controls speech production
•   damage inability to produce speech, but can
  understand

42
Brocas and Wernickes Areas
43
Summary
44
Studying the Brain

• Imaging and Recording

45
Recording and Imaging Techniques

• Humans and Animals
• EEG (electroencephalograph)
• CT (computed tomography) scan
• PET (positron emission tomography) scan
• MRI (magnetic resonance imaging)
• fMRI (functional MRI)
• Animals
• Single Cell recording
• Fast scan cyclic voltammetry

46
Experimental Manipulations

• Lesioning
• Electrical recording
• Electrical stimulation

47
(No Transcript)
48
Hemispheric Lateralization

• Left brain or right brain?

49
What determines handedness?

• Genetics factors
• Neither parent left handed Odds are 1 in 50
• One parent left-handed Odds are 1 in 6
• Both parents left-handed Odds are 1 in 2
• Social factors
• Prenatal hormones

50
Split-Brain Research

• Severing corpus callosum as treatment for severe
  epilepsy
• Split-brain patients retain intellect and
  personality
• But differences in perception, language evident
  in special testing circumstances

51
Split-Brain Study
52
What do you see?
53
Brain Damage and Psychological Functioning

• Case of Phineas Gage Prefrontal cortex damage
• TBI Traumatic Brain injury in Iraqi War Vets
• Plasticity Ability of the brain to adapt and
  reorganize itself following trauma or surgical
  alteration