1. The Brain & Learning (CH 48)-Day 6
Take notes on the following information!

2. Single-celled ancestor
All animals except sponges have a nervous system.
What distinguishes nervous systems of
different animal groups is how neurons are
organized into circuits.
Chordates
Echinoderms
Arthropods
Roundworms
Annelids
Flatworms
Mollusks
Radial Symmetry
Cnidarians
Pseudocoelom
Deuterostome Development
Radial Symmetry
Protostome Development
Coelom
Sponges
Three Germ Layers; Bilateral Symmetry
Tissues
The animal kingdom
Multicellularity
Single-celled ancestor

3. Organization of Nervous Systems
The simplest animals with nervous systems, the cnidarians, have neurons arranged in nerve nets

4. The cnidarians, have neurons arranged in nerve nets
Radial
nerve
Nerve
ring
Nerve net
Hydra (cnidarian)
Sea star (echinoderm)
Sea stars have a nerve net in each arm connected by radial nerves to a central nerve ring

5. simple cephalized animals, such as flatworms,
have a central nervous system (CNS)
Eyespot
Brain
Brain
Nerve
cord
Ventral
nerve cord
Transverse
nerve
Segmental
ganglion
Planarian (flatworm)
Leech (annelid)

6. Annelids and arthropods have segmentally arranged clusters of neurons called ganglia.
These ganglia connect to the CNS and make up a peripheral nervous system (PNS).
Ganglia
Brain
Anterior
nerve ring
Ventral
nerve cord
Longitudinal
nerve cords
Segmental
ganglia
Insect (arthropod)
Chiton (mollusc)

7. The PNS connects to the CNS.
In vertebrates, the central nervous system consists of a brain and dorsal spinal cord.
The PNS connects to the CNS.
Brain
Brain
Spinal
cord
(dorsal
nerve
cord)
Sensory
ganglion
Ganglia
Squid (mollusc)
Salamander (chordate)

8. Information Processing
Nervous systems process information in three stages: sensory input, integration, and motor output
Integration
Sensory input
Sensor
Motor output
Effector
Peripheral nervous
system (PNS)
Central nervous
system (CNS)

9. Sensory neurons transmit information from sensors that detect external stimuli and internal conditions
Sensory information is sent to the CNS, where interneurons integrate the information
Motor output leaves the CNS via motor neurons, which communicate with effector cells
The three stages of information processing are illustrated in the knee-jerk reflex

10. Gray Cell body of sensory neuron in matter dorsal root ganglion
Quadriceps
muscle
White
matter
Hamstring
muscle
Spinal cord
(cross section)
Sensory neuron
Motor neuron
Interneuron

11. Neurons have a wide variety of shapes
that reflect input and output interactions
Dendrites
Axon
Cell
body
Sensory neuron
Interneurons
Motor neuron

12. Central nervous system (CNS) Peripheral nervous system (PNS) Brain
Cranial
nerves
Spinal cord
Ganglia
outside
CNS
Spinal
nerves

13. Brain Cells are Neurons...
Dendrites
Cell body
Nucleus
Signal
direction
Synapse
Axon hillock
Axon
Presynaptic cell
Synaptic
terminals
Myelin sheath
Postsynaptic cell

14. cell body: contains nucleus & organelles
dendrites: receive incoming messages
axons: transmit messages away to other cells
myelin sheath: fatty insulation covering axon, speeds up nerve impulses
synapse: junction between 2 neurons
neurotransmitter: chemical messengers sent across synapse
Glia: cells that support neurons
Eg. Schwann cells (forms myelin sheath)

15. Supporting Cells (Glia)
Glia are essential for structural integrity of the nervous system and for functioning of neurons
Types of glia: astrocytes, radial glia, oligodendrocytes, and Schwann cells

16. In the CNS, astrocytes provide structural support for neurons and
regulate extracellular concentrations of
ions and neurotransmitters
Green cells are
the astrocytes.
Blue stains the nucleus.

17. Oligodendrocytes (in the CNS) and Schwann cells (in the PNS)
form the myelin sheaths around
axons of many vertebrate neurons.
Nodes of Ranvier
Layers of myelin
Axon
Schwann
cell
Schwann
cell
Axon
Nodes of
Ranvier
Nucleus of
Schwann cell
Myelin sheath
0.1 µm

18. Synapse….
SYNAPSE: where a nerve cell touches another nerve cell (or muscle cell, etc).
Brain uses synapse to send/receive signals

19. Central Nervous System
Brain and spinal cord
Cavities are filled with cerebrospinal fluid
cushions and supplies nutrients and white blood cells.
Meninges are layers of connective tissue surrounding the brain and spinal cord
White matter is myelinated; gray matter is not.
Evolutionarily older structures in the brain regulate essential functions.

20. Peripheral Nervous System
Cranial nerves originate in the brain and terminate mostly in organs of the head and upper body.
Spinal nerves originate in the spinal cord and extend to parts of the body below the head
The PNS has two functional components: the somatic and autonomic nervous systems

21. Peripheral Nervous System
Somatic nervous system (PNS):
Voluntary (conscious control)
Carries signals to skeletal muscles
Autonomic nervous system (PNS)
Involuntary
Smooth and cardiac muscle, GI , cardio, excretory and endocrine organs

23. regulates the internal environment in an involuntary manner
MOTOR DIVISION
Peripheral
nervous system
regulates the internal environment
in an involuntary manner
Somatic
nervous
system
Autonomic
nervous
system
carries signals to
skeletal muscles
Sympathetic
division
Parasympathetic
division
Enteric
division
Sympathetic:
speeds up
everything
but digestion
“fight or flight”
adrenaline
Parasympathetic calms
everything but digestion

24. PNS Divided into 2 Parts Sympathetic division Parasympathetic division
speeds up everything but digestion
“fight or flight”
adrenaline
Parasympathetic division
calms everything but digestion

25. Embryonic Development of the Brain Embryonic brain regions
All vertebrate brains develop from three embryonic regions:
forebrain, midbrain, and hindbrain
Embryonic brain regions
Brain structures present in adult
Cerebrum (cerebral hemispheres; includes cerebral
cortex, white matter, basal nuclei)
Telencephalon
Forebrain
Diencephalon
Diencephalon (thalamus, hypothalamus, epithalamus)
Midbrain
Mesencephalon
Midbrain (part of brainstem)
Metencephalon
Pons (part of brainstem), cerebellum
Hindbrain
Myelencephalon
Medulla oblongata (part of brainstem)
Cerebral hemisphere
Diencephalon:
Mesencephalon
Hypothalamus
Metencephalon
Midbrain
Thalamus
Myelencephalon
Pineal gland
(part of epithalamus)
Hindbrain
Diencephalon
Brainstem:
Midbrain
Pons
Spinal cord
Forebrain
Pituitary
gland
Medulla
oblongata
Telencephalon
Spinal cord
Cerebellum
Central canal
Embryo at one month
Embryo at five weeks
Adult

26. BRAIN This white matter is distinguishable from gray matter,
which consists mainly of dendrites, unmyelinated axons,
and neuron cell bodies
Gray matter
White
matter
Ventricles

27. Brainstem BRAIN in the CNS has different parts. HOMEOSTASIS……
breathing,
heart activity,
swallowing, vomiting,
digestion;
most ascending axons
cross over here
Hindbrain
Pons
Medulla oblongata

28. Cerebellum
coordination and motor learning

29. Cerebrum
Right and left hemispheres connected by corpus callosum
Cerebral cortex (gray matter) is the largest
and most complex part of the mammalian brain
Cerebrum

30. Cerebrum Frontal lobe: speech, personality, motor cortex
Parietal lobe: somatosensory cortex, speech, taste, reading
Temporal lobe: hearing, smell
Occipital lobe: vision

31. Language and Speech Brocca’s area Wernicke’s area Frontal lobe
Patients with injury can understand language but not speak
Wernicke’s area
Temporal lobe
Patients with injury can speak but not comprehend

32. Diencephalon Hypothalamus Thalamus Pituitary gland Pineal gland
Hypothalamus: homeostasis by regulating hunger, thirst, temp., circadian rhythms
Thalamus: relay center

33. Circadian Rhythms
The hypothalamus also regulates circadian rhythms such as the sleep/wake cycle
Animals usually have a biological clock, a pair of suprachiasmatic nuclei (SCN) in the hypothalamus
Biological clocks usually require external cues to remain synchronized with environmental cycles

34. PET scan

35. Magnetic resonance images (MRI)

36. The limbic system: emotions and memory including olfaction

37. Memory and Learning The frontal lobes are a site of short-term memory
They interact with the hippocampus and amygdala to consolidate long-term memory
Many sensory and motor association areas of the cerebral cortex are involved in storing and retrieving words and images

38. Learning How does an organism learn about it’s environment?
Taxis: purposeful movement
Toward stimulus = + taxis
Away from stimulus = - taxis
Kinesis: random movement
Hoping for the best

39. Cognition Cognition means to know/learn and that you are being aware.
Environment + genes
Metacognition = aware of how you learn
Learning Styles

40. Diagram of Brain
Tap into your creative side using pictures, sketches and words to form a collage in each section of the brain to represent the functions of these lobes.
Frontal lobe -- Involved with planning, interpretation, emotions, personality, deliberate movements, decision making, and turning thoughts into words.
Parietal lobe -- Perceives sensory inputs and and also associates these inputs with past memories.
Temporal lobe -- Deals with the senses of smell and sound and also is responsible for forming memories.
Occipital lobe -- Decodes images and objects that are seen in order to identify or recognize them.
Cerebellum -- Regulates movement, balance and coordination.
For example, in the frontal lobe section, drawings of people smiling, crying or communicating can be utilized.
In the parietal lobe section, images representing the five senses can be pasted.