1. The Brain Part 2

2. *Anterior Association Area (Prefrontal Cortex)
Most complicated cortical region
Involved with intellect, cognition, recall, and personality
Contains working memory needed for judgment, reasoning, persistence, and conscience
Development depends on feedback from social environment

3. *Hypothalamic Function
Autonomic control center for many visceral functions (e.g., blood pressure, rate and force of heartbeat, digestive tract motility)
Center for emotional response: Involved in perception of pleasure, fear, and rage and in biological rhythms and drives

4. *Hypothalamic Function
Regulates body temperature, food intake, water balance, and thirst
Regulates sleep and the sleep cycle
Controls release of hormones by the anterior pituitary
Produces posterior pituitary hormones

5. *Brain Stem
Three regions
Midbrain
Pons
Medulla oblongata

6. *Medulla Oblongata Autonomic reflex centers Cardiovascular center
Cardiac center adjusts force and rate of heart contraction
Vasomotor center adjusts blood vessel diameter for blood pressure regulation

7. *Medulla Oblongata Respiratory centers Generate respiratory rhythm
Control rate and depth of breathing, with pontine centers

8. *Medulla Oblongata Additional centers regulate Vomiting Hiccuping
Swallowing
Coughing
Sneezing

9. *Insula In each hemisphere of the mammalian brain
portion of the cerebral cortex folded deep within the lateral sulcus (the fissure separating the temporal lobe from the parietal and frontal lobes).
The insulae are believed to be involved in consciousness and play a role in diverse functions usually linked to emotion or the regulation of the body's homeostasis. These function include perception, motor control, self-awareness, cognitive functioning, and interpersonal experience. In relation to these, it is involved in psychopathology.
Functions in audio-vision integration tasks

10. *The Cerebellum 11% of brain mass Dorsal to the pons and medulla
Subconsciously provides precise timing and appropriate patterns of skeletal muscle contraction

11. Anterior lobe Cerebellar cortex Arbor vitae Cerebellar peduncles
Posterior
lobe
• Superior
• Middle
Choroid
plexus of
fourth
ventricle
• Inferior
Medulla
oblongata
Flocculonodular
lobe
(b)
Figure 12.17b

12. *Memory Storage and retrieval of information Two stages of storage
Short-term memory (STM, or working memory)—temporary holding of information; limited to seven or eight pieces of information
Long-term memory (LTM) has limitless capacity

13. Outside stimuli
General and special sensory receptors
Afferent inputs
Temporary storage
(buffer) in
cerebral cortex
Data permanently
lost
Data selected
for transfer
Automatic
memory
Forget
Short-term
memory (STM)
Forget
Data transfer
influenced by:
Retrieval
Excitement
Rehearsal
Association of
old and new data
Long-term
memory
(LTM)
Data unretrievable
Figure 12.22

14. *Transfer from STM to LTM
Factors that affect transfer from STM to LTM
Emotional state—best if alert, motivated, surprised, and aroused
Rehearsal—repetition and practice
Association—tying new information with old memories
Automatic memory—subconscious information stored in LTM

15. *Categories of Memory Declarative memory (factual knowledge)
Explicit information
Related to our conscious thoughts and our language ability
Stored in LTM with context in which it was learned

16. *Categories of Memory Nondeclarative memory
Less conscious or unconscious
Acquired through experience and repetition
Best remembered by doing; hard to unlearn
Includes procedural (skills) memory, motor memory, and emotional memory

17. (a) Declarative memory circuits
Thalamus
Basal forebrain
Touch
Prefrontal cortex
Hearing
Smell
Vision
Taste
Hippocampus
Sensory
input
Thalamus
(a) Declarative memory circuits
Association
cortex
Medial temporal lobe
(hippocampus, etc.)
Prefrontal
cortex
ACh
ACh
Basal
forebrain
Figure 12.23a

18. *Brain Structures Involved in Nondeclarative Memory
Procedural memory
Basal nuclei relay sensory and motor inputs to the thalamus and premotor cortex
Dopamine from substantia nigra is necessary
Motor memory—cerebellum
Emotional memory—amygdala

19. (b) Procedural (skills) memory circuits
Sensory and
motor inputs
Association
cortex
Basal
nuclei
Premotor
cortex
Thalamus
Dopamine
Premotor
cortex
Substantia
nigra
Basal nuclei
Thalamus
Substantia nigra
(b) Procedural (skills) memory circuits
Figure 12.23b

20. Molecular Basis of Memory
During learning:
Altered mRNA is synthesized and moved to axons and dendrites
Extracellular proteins are deposited at synapses involved in LTM
More neurotransmitter is released by presynaptic neurons

21. *Protection of the Brain
Bone (skull)
Membranes (meninges)
Watery cushion (cerebrospinal fluid)
Blood-brain barrier

22. *Meninges
Three layers
Dura mater
Arachnoid mater
Pia mater

23. Skin of scalp Periosteum Bone of skull Dura Periosteal mater Meningeal
Superior
sagittal sinus
Arachnoid mater
Pia mater
Subdural
space
Arachnoid villus
Blood vessel
Subarachnoid
space
Falx cerebri
(in longitudinal
fissure only)
Figure 12.24

24. *Cerebrospinal Fluid (CSF)
Composition
Watery solution
Less protein and different ion concentrations than plasma
Constant volume

25. *Cerebrospinal Fluid (CSF)
Functions
Gives buoyancy to the CNS organs
Protects the CNS from blows and other trauma
Nourishes the brain and carries chemical signals

26. Right lateral ventricle (deep to cut)
Superior
sagittal sinus 4
Choroid
plexus
Arachnoid villus
Interventricular
foramen
Subarachnoid space
Arachnoid mater
Meningeal dura mater
Periosteal dura mater 1
Right lateral ventricle
(deep to cut)
Choroid plexus
of fourth ventricle 3
Third ventricle
CSF is produced by the
choroid plexus of each
ventricle. 1
Cerebral aqueduct
Lateral aperture
Fourth ventricle
CSF flows through the
ventricles and into the
subarachnoid space via the
median and lateral apertures.
Some CSF flows through the
central canal of the spinal cord. 2
Median aperture 2
Central canal
of spinal cord
CSF flows through the
subarachnoid space. 3
(a) CSF circulation
CSF is absorbed into the dural venous
sinuses via the arachnoid villi. 4
Figure 12.26a

27. *Blood-Brain Barrier Helps maintain a stable environment for the brain
Separates neurons from some bloodborne substances
Antibodies are too large to cross the blood–brain barrier, and only certain antibiotics are able to pass
Exceptions are the bacteria that causes Lyme’s disease and syphilis

28. *Blood-Brain Barrier
There are also some biochemical poisons that are made up of large molecules that are too big to pass through the blood–brain barrier.
Composition
Continuous endothelium of capillary walls
Basal lamina
formation of tight junctions

29. (a) Astrocytes are the most abundant CNS neuroglia.
Capillary
Neuron
Astrocyte
(a) Astrocytes are the most abundant CNS neuroglia.
Figure 11.3a

30. *Blood-Brain Barrier: Functions
Selective barrier
Allows nutrients to move by facilitated diffusion
Allows any fat-soluble substances to pass, including alcohol, nicotine, and anesthetics
Absent in some areas, e.g., vomiting center and the hypothalamus, where it is necessary to monitor the chemical composition of the blood

31. *Homeostatic Imbalances of the Brain
Traumatic brain injuries
Concussion—temporary alteration in function
Contusion—permanent damage
Subdural or subarachnoid hemorrhage—may force brain stem through the foramen magnum, resulting in death
Cerebral edema—swelling of the brain associated with traumatic head injury

32. *Homeostatic Imbalances of the Brain
Cerebrovascular accidents (CVAs)(strokes)
Blood circulation is blocked and brain tissue dies, e.g., blockage of a cerebral artery by a blood clot
Typically leads to hemiplegia, or sensory and speed deficits
Transient ischemic attacks (TIAs)—temporary episodes of reversible cerebral ischemia
Tissue plasminogen activator (TPA) is the only approved treatment for stroke

33. *Homeostatic Imbalances of the Brain
Degenerative brain disorders
Alzheimer’s disease (AD): a progressive degenerative disease of the brain that results in dementia
Parkinson’s disease: degeneration of the dopamine-releasing neurons of the substantia nigra
Huntington’s disease: a fatal hereditary disorder caused by accumulation of the protein huntingtin that leads to degeneration of the basal nuclei and cerebral cortex

34. The cranial nerves are:
I - Olfactory nerve
II - Optic nerve
III - Oculomotor nerve
IV - Trochlear nerve
V - Trigeminal nerve/dentist nerve
VI - Abducens nerve
VII - Facial nerve
VIII - Vestibulocochlear nerve/Auditory nerve
IX - Glossopharyngeal nerve
X - Vagus nerve
XI - Accessory nerve/Spinal accessory nerve
XII - Hypoglossal nerve

35. Odor Of Orangutan Terrified Tarzan After Forty Voracious Gorillas Viciously Attacked Him
Old Opie Occasionally Tries Trigonometry And Feels Very Gloomy, Vague And Hypoactive

36. I - Olfactory nerve OLD
II - Optic nerve OPIE
III - Oculomotor nerve OCCASIONALLY
IV - Trochlear nerve TRIES
V - Trigeminal nerve/dentist nerve TRIGONOMETRY
VI - Abducens nerve AND
VII - Facial nerve FEELS
VIII - Vestibulocochlear nerve/Auditory nerve VERY
IX - Glossopharyngeal nerve GLOOMY
X - Vagus nerve VAGUE
XI - Accessory nerve/Spinal accessory nerve AND
XII - Hypoglossal nerve HYOPOACTIVE

37. *Sleep
State of partial unconsciousness from which a person can be aroused by stimulation
Two major types of sleep (defined by EEG patterns)
Nonrapid eye movement (NREM)
Rapid eye movement (REM)

38. The Need for Sleep

39. *Sleep The first stage of sleep is a quick REM stage.
First two stages of NREM occur during the first 30–45 minutes of sleep
Fourth stage is achieved in about 90 minutes, and then REM sleep begins abruptly

40. Awake
REM: Skeletal
muscles (except
ocular muscles
and diaphragm)
are actively
inhibited; most
dreaming occurs.
NREM stage 1:
Relaxation begins;
EEG shows alpha
waves, arousal is easy.
NREM stage 2: Irregular
EEG with sleep spindles
(short high- amplitude
bursts); arousal is more
difficult.
NREM stage 3: Sleep
deepens; theta and
delta waves appear;
vital signs decline.
NREM stage 4: EEG is
dominated by delta
waves; arousal is difficult;
bed-wetting, night terrors,
and sleepwalking may
occur.
(a) Typical EEG patterns
Figure 12.21a

41. *Sleep Patterns
Alternating cycles of sleep and wakefulness reflect a natural circadian (24-hour) rhythm
A typical sleep pattern alternates between REM and NREM sleep

42. (b) Typical progression of an adult through one night’s sleep stages
Awake
REM
Stage 1
Stage 2
Non
REM
Stage 3
Stage 4
Time (hrs)
(b) Typical progression of an adult through one night’s sleep stages
Figure 12.21b

44. *Importance of Sleep
Slow-wave sleep (NREM stages 3 and 4) is presumed to be the restorative stage
People deprived of REM sleep become moody and depressed
REM sleep may be a reverse learning process where superfluous information is purged from the brain
Daily sleep requirements decline with age
Stage 4 sleep declines steadily and may disappear after age 60

45. *Sleep Disorders Narcolepsy Insomnia Sleep apnea
Lapsing abruptly into sleep from the awake state
Insomnia
Chronic inability to obtain the amount or quality of sleep needed
Sleep apnea
Temporary cessation of breathing during sleep