MAASTRICHT UNIVERSITY
PSY1023
Body and behaviour
Elective course/ 1st year psychology course
Year 2018-2019
Table of contents:
Problem 1 – your point of view ............................................................................................................... 2
Problem 2 – Insane in the membrain .................................................................................................... 14
Problem 3 – bungee jumping ................................................................................................................ 26
Problem 4 – OMG .................................................................................................................................. 35
For the post- discussion (course book) ............................................................................................. 44
Problem 5 – swiping, hitting, tapping................................................................................................... 45
Brain bits: Sensing and reacting (course book) ................................................................................. 59
Problem 6 – Dormio ergo sum .............................................................................................................. 60
Problem 7 – Rumbles in my tummy ...................................................................................................... 80
Problem 8 – A classic case of overdose ................................................................................................. 95
Problem 9 – brain in trouble ............................................................................................................... 115
Brain bits: test your post- discussion knowledge ............................................................................ 127
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Problem 1 – your point of view
1. Anatomy of the brain?
2. How to describe brain location?
3. How does the brain develops during life?
4. Function of brain parts?
Books: Carlson (2017) Physiology of behaviour (12th global edition); chapter 3 & Pinel (2017) Biopsychology
(10th global edition); chapter 3+ additional information from Kolb, B. & Whishaw, I.Q. (2015).
Basic features of the nervous system____________________________________________________
The nervous system consists of the central nervous system (CNS) and the peripheral nervous system
(PNS).
◼ CNS: brain and spinal cord
o The CNS is encased in bone: The
brain is covered by the skull,
and the spinal cord is contained
within the vertebral column
(located in the spine).
o The brain is the most protected
organ of the body, encased in a
tough, bony skull and floating in
a pool of cerebrospinal fluid
(CSF).
◼ PNS: cranial nerves, spinal nerves and
peripheral ganglia (outside the skull and spine). Composed of 2 divisions:
o Somatic nervous system (SNS): interact with external environment → composed of
afferent nerves that carry sensory signals to the central nervous system and efferent
nerves that carry motor signals from the central nervous system to the skeletal
muscles.
o Autonomic nervous system (ANS): regulates the body’s internal environment. It is
composed of afferent nerves that carry sensory signals from internal organs to the
CNS and efferent nerves that carry motor signals from the CNS to internal organs.
▪ The autonomic nervous system has two kinds of efferent nerves:
sympathetic (arousing) nerves and parasympathetic (calming) nerves.
Anatomical directions
When describing features of a structure as complex as the brain, we need to use terms denoting
directions. Directions in the nervous system are normally described relative to the neuraxis, an
imaginary line drawn through the length of the central nervous system, from the lower end
of the spinal cord up to the front of the brain → an easy example is a crocodile. Directions are
somewhat more complicated humans; because we
stand upright, our neuraxis bends, so the top of the
head is perpendicular to the back.
◼ The front is anterior and the tail is posterior.
◼ Rostal is toward the nose and mounth, while
caudal is toward the tail.
◼ The top of the head and the back are dorsal,
while ventral is towards the front and the
belly.
◼ Lateral is towards the sides and medial is
toward the middle.
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◼ Ipsilateral refers to structures on the same side of the body. Contralateral refers to
structures on opposite sides of the body.
We can slice the nervous system in three ways (planes):
◼ Coronal / frontal section – vertical plane, revealing
a frontal view.
o A transverse cut to the middle of the brain
would divide the brain into front and back
halves.
◼ Horizontal sections – horizontal plane, produces a
dorsal view (looking from above)
o A parallel cut to the middle of the brain
would result in cutting off the upper half of
the brain.
◼ Sagittal sections – lengthways, from front to back.
Reveals a medial view (from the side).
o The midsagittal plane divides the brain into
two symmetrical right and left halves.
Meninges
= The protective sheaths around the brain and spinal cord. The meninges consist of three layers:
◼ Dura matter – outer layer; durable, thick,
tough, and flexible but unstretchable.
◼ Arachnoid membrane- middle layer of the
meninges; soft and spongy, lies beneath the
dura mater → gets its name from the
weblike appearance.
◼ Pia matter - Closely attached to the brain and
spinal cord, and following every surface
convolution. The smaller surface blood
vessels of the brain and spinal cord are
contained within this layer.
◼ Between the pia mater and arachnoid membrane is a gap called the subarachnoid space.
This space is filled with cerebrospinal fluid (CSF).
The middle layer (arachnoid membrane), with its associated pool of CSF,
covers only the brain and
spinal cord. Outside the central nervous system, the outer and inner layers
(dura mater and pia mater) fuse and form a sheath that covers the spinal
and cranial nerves and the peripheral ganglia.
➔ So the peripheral nervous system is covered with two layers of
meninges.
The ventricle system and production of CSF Frontal view
Ventricles are hollow, interconnected chambers which are filled with CSF.
The largest chambers are the lateral ventricles, which are connected to the third ventricle. The third
ventricle is located at the midline of the brain; its walls divide the surrounding
part of the brain into symmetrical halves. A bridge of neural tissue called the
massa intermedia crosses through the middle of the third ventricle and serves
as a convenient reference point. The cerebral aqueduct, a long tube, connects
the third ventricle to the fourth ventricle. The lateral ventricles constitute the
first
3 Lateral view
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and second ventricles, but they are never referred to as such.
Ventricles produce and contain CSF → CSF is manufactured by special
tissue with an especially rich blood supply called the choroid plexus,
which protrudes into all four of the ventricles. CSF is produced
continuously; the total volume of CSF is approximately 125 ml.
◼ Cerebrospinal fluid produced by the choroid plexus of the The production, circulation, and reabsorption of
lateral ventricles flows into the third ventricle. More CSF is cerebrospinal fluid
produced in this ventricle, which then flows through the
cerebral aqueduct to the fourth ventricle, where still more CSF is produced.
◼ The CSF leaves the fourth ventricle through small openings that connect with the
subarachnoid space surrounding the brain.
◼ The CSF then flows through the subarachnoid space around the CNS, where it is reabsorbed
into the blood supply through the arachnoid granulations. These pouch-shaped structures
protrude into the superior sagittal sinus, a blood vessel that drains into the veins serving the
brain.
The human brain is well protected, it floats in a bath of CSF within the subarachnoid space. Because
the brain is completely immersed in liquid, its net weight is reduced to approximately 80 g; thus,
pressure on the base of the brain is considerably diminished. The CSF surrounding the brain and
spinal cord also reduces the shock to the CNS that would be caused by sudden head movement.
◼ Occasionally, the flow of CSF is interrupted at some point in its route of passage. Example:
o a brain tumor growing in the midbrain may push against the cerebral aqueduct,
blocking the flow of CSF, or an infant may be born with a cerebral aqueduct that is
too small to accommodate a normal flow of CSF.
o This occlusion results in greatly increased pressure within the ventricles, because the
choroid plexus continues to produce CSF. The walls of the ventricles then expand and
produce a condition known as obstructive hydrocephalus (“water-head”).
o If the obstruction remains and if nothing is done to reverse the increased
intracerebral pressure, blood vessels will be occluded, and permanent— perhaps
fatal—brain damage will occur.
Development of the nervous system___________________________________
➔ The CNS begins early in embryonic life as a hollow tube and maintains
this basic shape even after it is fully developed. During development,
parts of the tube elongate, pockets and folds form, and the tissue
around the tube thickens until the brain reaches its final form.
An overview of brain development
Development of the human nervous system begins around the eighteenth day
after conception. Part of the ectoderm (outer layer) of the back of the embryo
thickens and forms a plate. The edges of this plate form ridges that curl toward
each other along a longitudinal line, running in a rostral– caudal direction. → By
the 21st day the ridges touch and fuse together forming the neural tube, this
gives rise to the brain and spinal cord . → By the 28th day the neural tube is
closed and its rostral end has developed three interconnected chambers. These
chambers become ventricles, and the tissue that surrounds them becomes the
three major parts of the brain: the forebrain, the midbrain, and the hindbrain.
◼ The forebrain/ procencephalon divides into three separate parts, which
become the two lateral ventricles and the third ventricle. The region
around the lateral ventricles becomes the telencephalon (“end brain”),
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