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Unit 2 - Subcortical systems, neurochemistry and brain function
Subcortical anatomy : Most of the five major subdivisions of the brain
are subcortical.
I. Telencephalon (cortical - part of forebrain)
- also contains ____________ and ______________, which are
subcortical
II. Diencephalon (_________, ____________ - part of forebrain)
III. Brainstem
- mesencephalon (_________)
- metencephalon (_____, ___________ - part of hindbrain)
- myelencephalon (________________ - part of hindbrain)
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I. Subcortical telencephalon: basal ganglia
- corpus striatum (caudate nucleus andputamen)
- globus pallidus (together with putamen - called ______________)
- nucleus accumbens (ventral part of striatum)
- Caudate nucleus
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I. Subcortical telencephalon: basal ganglia (continued)
- putamen
Corpus
callosum
Lateral
ventricle
Putamen
- Globus pallidus
Corpus
callosum
Caudate
Thalamus
Globus
pallidus
Anterior
commissure
Putamen
Basal ganglia generally involved in _________________________
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_________________.
I. Subcortical telencephalon: basal ganglia (continued)
- nucleus accumbens (ventral striatum - involved in _____________)
4. _______
__________
5. ________
__________
Thalamus
1. ________
2. _______
________
3. ________
Caudate
Putamen
Hypothalamus
Globus
pallidus
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I. Subcortical telencephalon: limbic system
- ______________
- ___________
- ______________________
- ___________________
- ___________________
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I. Subcortical telencephalon: limbic system (continued)
- hippocampus and amygdala (with fornix)
Corpus
callosum
fornix
Hippocampus
Amygdala
Anterior
commissure
- cingulate gyrus
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I. Subcortical telencephalon: limbic system (continued)
Cingulate
gyrus
fornix
caudate
cc
ic
putamen
GP
Mammillary
body
Amygdala
Hippocampus
Limbic structures generally involved in the regulation of motivated
behaviors (feeding, fleeing, fighting, sexual behaviors) and learning/
memory.
- amygdala associated with _____________________________
- hippocampus associated with ___________________.
- septal nuclei associated with __________.
- fornix connects septal nuclei and hippocampal formation
(fimbria-fornix)
- fornix also provides hippocampal output to hypothalamus
(mammillary bodies).
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II. Diencephalon composed of __________ and ______________
Thalamus : major relay station between sensory inputs to the
brain and neocortex (for most sensory systems)
- layer VI of neocortex provides significant feedback to thalamus
Massa intermedia
Cross-section through thalamus shows massa intermedia , a
major thalamic fiber decussation system across third ventricle.
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II. Diencephalon (continued)
Hypothalamus : important in
the control of ______________
_________________________
_________________________
- note the proximity of the
pituitary gland, connected to
the hypothalamus via the
_______________
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III. Brainstem:
Thalamus
Midbrain
- midbrain (mesencephalon) contains ________________________
(below and above aqueduct, respectively)
-Colliculi: ________
________________
_______
-PAG (__________)
-Reticular formation:
___________
______________
-Red nucleus: ______
_____________
____________
-Substantia nigra:
________________
________________
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III. Brainstem:
Pons and cerebellum
- pons contain nuclei for several ________________
- divided into a ventral portion (basispontis) and a dorsal
aspect (tegmentum)
- basis pontis a major relay of _________________________
- tegmentum contains reticular formation, tracts, and cranial nuclei
Tegmentum
Basis pontis
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III. Brainstem:
Medulla oblongata: contains several tracts, nuclei of reticular
formation and several cranial nerves, much like pons.
- Example: Hypoglossal nerve (XIIth cranial nerve): origin of
neurons innervating muscles of the tongue.
- Example: pyramids - begins inprecentral gyrus , enters internal
capsule to join cerebral peduncle, forms pyramids, decussates
and enters spinal cord as corticospinal tract (lateral funiculus)
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Basic chemistry and biochemistry - building blocks of biology
Remember Star Trek? We are “carbon-based” creatures, as
compared to other extraterrestrial races (if any exist)!!!
The chemical elements (periodic table) in nature combine in various
ways to form molecules (compounds).
- most common elements in biochemical compounds are:
COHN- other less common by very important ones are:
SPMost of the cellular components in our body are made of carbon
containing molecules.
Atoms: smallest particle (unit) of an element that maintains the
properties of that element.
What are atoms made of ?
Molecules are formed when 2 or more atoms combine.
Examples:
When more than one compound are mixed together, these are called
mixtures; these are most often found in nature, including our body.
Examples:
What are ions?
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Three (3) basic types of complex molecules that are important for
cellular structure and function:
lipids, proteins, and nucleic acids
Each of these complex molecules is made up of essentially a long
chain of a simpler molecule.
1. Lipids: made up of ___________________________________.
- stored in fat cells (adipose cells) which serve as _____________
_______.
- also very important in the formation of _________________.
- normally made up of a charged ________________ and the ____
______________________.
- there are 3 different types of membrane lipids:phospholipids,
glycolipids , and cholesterol.
What are phospholipids (phosphoglycerides)?
carbon chains
glycerol phosphate
Lipids can interact in different ways depending on the medium
around them:
- aqueous (polar) solvents (such as water)
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- non-aqueous (organic) solvents (such as chloroform)
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micelle
bilayer inverted micelle
In aqueous solvent
In organic solvent
Normally, phospholipids aggregate as shown in top center to form
cell membranes (_______________).
2. Proteins: made up of long chains of ___________ (called residues).
- proteins play a role in nearly every biological function known
(_________________________________________________
__________________________________________________
_______________________________________).
- 20 different amino acids serve as the building blocks of
proteins.
- each amino acid is made up of _____________, a ___________
______, and a ____________, which differentiates amino acids.
- amino acids can be combined in any order (variety of proteins).
- short chains are called: ___________________________.
- long chains are called: _________________.
amino group
carboxyl group
side chain
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Examples of different amino acids; notice the different side cha ins
Proteins are said to have structures:
- primary structure: ________________________________________
- secondary structure : ______________________________________
______________________________________________________
_____________________________________________________
- tertiary structure: ________________________________________
________________________________________________
- quaternary structure: _____________________________________
Also, proteins are said to have differentdomains (examples:
extracellular domain, intracellular domain, transmembrane domain,
binding domain).
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Examples of secondary structures based on á-helix and â-sheet
á-helix
â-sheet
Many proteins are associated with the cell membrane:
- integral proteins have peptide domains that insert ______________
_______________, once or several times.
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3. Nucleic acids (DNA, RNA): __________________________
- the “blueprint” of life.
- as with amino acids, nucleotides combine in any order.
- only four different types of nucleotides (slightly different for DNA
and RNA).
- single nucleotides made of three components:
a. __________
b. ____________________________________________
c. __________________________________________________
__________________
Base
Phosphates
Deoxyribose
The 4 bases of DNA
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Protein synthesis
Where are proteins produced in our body?
How does a cell know how to make a particular protein?
- It needs to begin with a code which tells the cell which amino acids
to string together to make a particular protein.
- That code is provided by a gene (blueprint of life).
- It is believed that the genome contains approximately 60,000
genes (Human Genome Project).
- Question: Do all cells in our body have the same genes (i.e. genetic
code)?
- Question: Are all stretches on DNA part of genes?
Major steps in protein synthesis :
DNA →
→ mRNA →
→ protein
1. ___________: make an mRNA copy of a specific gene (in nucleus )
2. mRNA transported to cytoplasm (outside of nucleus)
3. _________: use “code” from mRNA to build a protein (successive
triplets (3 nucleotides) code for one of 20 amino acids to b e linked.
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Illustrated steps of protein synthesis
Puzzle: What makes a liver cell different from a neuron?
Protein synthesis is an ongoing dynamic process.
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