COGS 17 Handout 2 Pg. 1
Chapter 3
Label the directions in the nervous system
relative to the neuraxis (rostral/anterior, dorsal,
ventral, caudal/posterior
Define the following:
1. Ipsilateral: refers to structures on the same
side of the body
2. Contralateral: refers to structures on
opposite sides of the body
3. Lateral: toward the side
4. Medial: toward the midline
Hemispheric Specialization (in general, what are
the differences between the functions of the two
hemispheres)
a. Left: Language
b. Right: Spatial
Label the planes of section as they pertain to the
human central nervous system (horizontal,
coronal, sagittal)
Glial Cells
Astrocytes: takes away waste, feeds neuron
Micoglia: immune response
Meninges:
Label the three layers and where CSF (cerebral
spinal fluid) resides (dura, arachnoid, subarachnoid
space, pia)
__dura____ = “hard mother”
_arachnoid_ = “spider track”
___pia____ = “pious/delicate mother/saran wrap”
Directional Specialization (in general, what are the
differences between the front, mid, and back areas
of the brain)
a. Front: Motor
b. Mid: Sensory
c. Back: Visual
Ventricles:
A series of hollow, interconnected chambers that
are filled with CSF. (lateral, third, fourth, choroid
plexus creastes CSF)
Evolution
1. View 1: Quantitative difference
a. There are just more neurons in a human brain. The increase in the number of neurons is what gives us
added capabilities.
2. View 2: Qualitative difference
a. There’s something different about the human brain compared to other species. How would you get
qualitative differences from quantitative differences? Some people argue that there are emergent
properties, that the interaction of a greater number of cells creates these qualitative changes.
COGS 17 Handout 2 Pg. 2
Ontogeny: How an organism develops within a lifetime
1. Sperm + ovum
Picture
2. Blastula
3. Embryonic day 18, neural plate forms
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4. Neural groove envaginates
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5. Neural tube forms
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6. E22: Spinal cord end closes
a. If lack of folic acid, cord might not close
properly and cause spina bifida
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7. E24: Head end closes
a. If head end doesn’t close, anencephaly occurs
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8. Cells begin to multiply rapidly; thickens outside
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9. W5: forebrain, midbrain, and hindbrain form
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Forebrain divides into the telencephalon &
diencephalon
Midbrain doesn’t divide but is also known as the
mesencephalon
Hindbrain divides into the metencephalon & the
myelencephalon
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Forebrain
Telencephalon:
Diencephalon
Cerebral cortex:
Thalamus: located near the middle of the cerebral
hemispheres
- sulci (little grooves)
- gyri (bulges)
- Fissures
o Central sulcus (between S1 and M1 & frontal and
parietal lobe)
o Lateral/Sylvian fissure (between frontal and
temporal lobes)
o Calcarine fissure (medial occipital lobe)
- frontal lobe
o primary motor cortex: (located rostral to central
sulcus)
o prefrontal cortex: (formulating movement)
- parietal lobe
o primary somatosensory cortex: (located caudal to
central sulcus)
- temporal lobe
o primary auditory cortex: (located on the ventral
side of lateral fissure)
- occipital lobe
o primary visual cortex: (located around the calcarine
fissure)
- limbic cortex (located medial edge of hemispheres)
o cingulate gyrus
Limbic System:
- hippocampus (sea-horse shaped, memory)
- amygdala (almond shaped, emotion)
- fornix (connects the hippocampus with other regions of
the brain)
- mammillary bodies (contains part of the hypothalamus)
Basal Ganglia:
- caudate nucleus
- putamen
- globus pallidus
- Function:
o
Acts as gate between sensory information
and the brain
- Divisions
o lateral geniculate nucleus (receives input from the
eye, sends to the primary visual cortex)
o medial geniculate nucleus (receives input from ear,
sends to primary auditory cortex)
o ventrolateral nucleus (receives input from
cerebellum, sends to primary motor cortex)
Hypothalamus: located ventral to thalamus
- Function:
o regulates autonomic nervous system & endocrine
system (fight or flight response)
COGS 17 Handout 2 Pg. 4
Midbrain/Mesencephalon
Tectum: dorsal portion of the mesencephalon
Tegmentum: consists of the portion of the
mesencephalon beneath the tectum
Superior colliculus:
- Location:
Reticular formation:
o Ventral to the thalamus
- Function:
o Involved in visual reflexes and reactions to
moving stimuli; orienting the eyes
Inferior colliculus:
- Location:
o Inferior to the superior colliculus
- Function:
o Involved in the auditory system
For a good picture go to page 92, figure 3.21
- Location:
o Occupies the core of the brain stem from the
lower border of the medulla to the upper border
of the midbrain
- Function:
o Receives sensory information by means of
various pathways and projects axons to the
cerebral cortex, thalamus, and spinal cord; plays
role in sleep, arousal, attention, muscle tonus,
movements, and other reflexes
Periaqueductal gray matter:
- Location:
o Surrounds the cerebral aqueduct
- Function:
o Mostly cell bodies controls sequence of
movements that constitute species-typical
behaviors (fighting/mating)
Red Nucleus:
- Function:
o A bundle of axons that bring motor information
from the cortex and cerebellum to the spinal
cord
Substantia Nigra:
- Function:
o Neurons that project to parts of the basal ganglia
Metencephalon
Hindbrain
Myelencephalon
Cerebellum
- Location:
o Caudal and ventral to the cortex
- Function:
o Fine motor skills, perhaps even higher level
cognition
Pons
- Location:
o Large bulge in the brain stem between the
mesencephalon and medulla oblongata, ventral to
the cerebellum
- Function:
o Contains part of reticular formation and is
important for sleep and arousal
Medulla Oblongata
- Location:
o Most caudal part of the brain stem; its lower
border is the rostral end of the spinal cord
- Function:
o Contains part of reticular formation, controls
cardiovascular system, respiration, and skeletal
muscle tonus
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Spinal Cord
Primary functions: to distribute motor fibers to the effector organs of the body (glands and muscles) and to
collect somatosensory information to be passed on to the brain
Peripheral Nervous System
Spinal nerves: begin at the junction of dorsal and ventral roots
Afferent axons: enter the spinal cord through dorsal roots, “bear towards” the CNS, bring somatosensory
information
Efferent axons: leave the spinal cord through the ventral roots, “bear away” the CNS
Cranial Nerves
Nerves that serve sensory and motor functions of the head and neck region
Autonomic Nervous System vs. Somatic Nervous System: What’s the difference?
The somatic nervous system controls movements of the skeletal muscles whereas the autonomic nervous system
is concerned with the regulation of smooth & cardiac muscles and glands.
Autonomic Nervous System: 2 divisions
Sympathetic: involved in activities associated with
expenditure of energy from reserves that are stored in
the body
Parasympathetic: involved in activities that are
involved in increasing the body’s supply of stored
energy