Flashcards in five Major Divisons Of The Brain Deck (41):
What are the components of the myelencephalon? What does it do?
- medulla oblongata: controls basic functions such as heart rate, respiratory system, and sleep.
- reticular formation (long tube from the myelencephalon to the mesencephalon) it plays a role in arousal, sleep, muscle tone, and various cardiac and respiratory reflexes
What are the components of the metencephalon? What do they do?
the metencephalon is composed of:
- pons: is a relay station between the hindbrain and cerebrum as well as houses ascending and descending tracts.
- cerebellum: controls movement and adapt them to changing conditions ... Also plays role in cognition
What are the components of mesencephalon?
Mesencephalon is also known as the midbrain.
Consists of tectum and tegmentum
What is the tectum composed of and what does it do?
the tectum is composed of two bumps called colliculi
1. superior colliculi: located in the anterior end. Involved with eye movements
2. Inferior colliculi: located in the posterior end. Involved with sound localization and filtration
What is the tegmentum composed of and what does it do?
Tegmentum is ventral to the tectum (below it)
Consists of reticular formation (dorsal part of it)
- main part of it:
1. red nucleus
2. Substantia nigra
3. Periaqueductal grey
What is the red nucleus?
involved with motor coordination in tegmentum
What is the substantia nigra?
reward, addiction and movement (dopamine) in tegmentum
What is periaqueductal grey?
releases endorphins and endorphin receptors for pain killers in tegmentum
... Also sits around the cerebral aqueduct which is the duct that connects 3rd and 4th ventricles.
What is the diencephalon composed of?
2. Hypothalamus/mammilary bodies
3. Pituitary gland
4. Optic chiasm
What is the role of the thalamus? What is massa intermedia?
- 2 lobed structure that sits around the third ventricle on top of the brain stem
- massa intermedia is the white matter that keeps the two lobes of the thalamus connected
- thalamus is composed of sensory relay nuclei
What are sensory relay nuclei? What are the three known types and their functions?
- sensory relay nuclei are located in the thalamus are relay stations for sensory input (send sensory input to corresponding part of the brain)
- the three types are:
1. Lateral geniculate nuclei: relay station for visual system
2. Medial geniculate nuclei: relay station for auditory system
3. Ventral posterior nuclei: relay station for sensory motor system
What is the role of the hypothalamus and where is it located?
Hypothalamus plays a key role in regulation of motivated behaviors like eating, sleeping and sexual behavior. (Also makes hormones)
- it is located just below the thalamus (below and anterior)
What is the pituitary gland?
Pituitary gland is a the little piece dangling off the hypothalamus and it releases hormones directed by the hypothalamus. It dangles into the blood so it can detect the properties of the blood
What is the optic chiasm? And why is it x-shaped?
Sits in the inferior surface of the hpothalamus and it's the area where each optic nerve crosses over (x shaped)
- x shaped because it decussates and bc it's conlateral projecting from one side of the body to another.
What is the telencephalon composed of?
The telencephalon is composed of:
1. Cerebral cortex
2. Major fissures
3. Major gyri
4. Four lobes
5. Limbic system
6. Basal ganglia
7. Cerebral commissures
What is the cerebral cortex? What does it mean that it's convoluted?
the cerebral cortex is the tissue covering the cerebral hemispheres.
- Made up of small unmyelinated neurons
- it's convoluted because it's lumped together to create more surface area
What are Fissures/ sulci?
The large furrows in convoluted areas (the deep valleys). Smaller furrows are called sulci
What are gyri ?
Gyri are the hills/ bumps. They are the ridges between fissures
What is a cerebral commissure? What is the largest one?
Cerebral commissures are tracts that connect the left snd right hemispheres.
- the largest cerebral commissure is called the corpus callosum
What is the central fissure? What 2 lobes are separated by it?
Central fissure is located between the frontal and parietal lobe
Where is the lateral fissure? Which lobe does it isolate?
Lateral fissure is in between temporal, parietal and frontal lobes.
What is the function of the frontal lobe?
What is the function of the parietal lobe?
The post central gyrus of the parietal lobe analyzes sensations of the body and plays a role of touch..etc..
What is the function of the temporal lobe?
Involved in memory and hearing
What is the function of the Occipital lobe?
The occipital lobe functions as analysis of visual input
Where is the precentral gyrus and what does it do?
It's in the frontal lobe and it is involved with motor function
Where is the post central gyrus and what does it do?
It is in the parietal lobe and it is involved with analyzing sensations
Where is the superior temporal gyri and what does it do?
It is in the temporal lobe under the lateral fissure and it is involved with hearing and language
What is the neocortex? And where is it located
The neocortex makes up 90% of the human cortex. It consists of 6 layers
What are the three most important characteristics of neocortical anatomy?
1. It consists of two different neurons --> pyramidal cells and stellate cells
2. The six layers of neocortex differ from one another in terms of density and size of their cell bodies
3. The neocortex has a columnar organization because long dendrites and axons extend vertically (at right angles to the cortical layers) and variation of thickness of respective layers
What are pyramidal cells?
Pyramidal cells are large multipolar neurons with pyramid shaped cell bodies.
- they contain a large dendrite that extends from apex to the cortex surgace
What are stellate cells?
- small, star shapes interneurons that have none or short axons
Where is the hippocampus located and what does it do?
It is located in part of the cortex (medial edge of cerebral cortex and folds back on itself at the temporal lobe) and it is involved in memory
what are the two large subcortical groups in the telencephalon?
1. Limbic system
2. Basal ganglia motor system
What are the 6 major parts of the limbic system?
1. Amygdala --> involved in emotion/anger.
2. Hippocampus --> involved in memory
3. Cingulate cortex --> medial surface of the cerebral hemispheres
4. Fornix --> major tract of the limbic system ... Encircles the dorsal thalamus
5. Septum --> midline nucleus located at the anterior tip of cingulate cortex
6. Mammillary body
What are the 4 major parts of the basal ganglia?
2. Caudate --> tail like structure that sweeps out of amygdala and forms an almost circle around it (looks like headphones)
3. Putamen --> series of fibre bridges that is connected to the center of the caudate
4. globus pallidus --> "pale globe". Located medial to the outamen snd between the putamen and thalamus
What is the combination of caudate and putamen called? And why is it so important
- important because theres a passage way that projects to the striatum from the substanta nigra in the tegmentum that is involved with the oroduction of dopamine. Parkingsons disease is associated with the destruction of that passage over time
What is the main role of the basal ganglia system?
Performance of voluntary motor responses
What is the nucleus accumbens?
It is a little nucleus looking thing attached to the front (ventral) striatum. it is thought to play a role in rewarding effects of addictive drugs
What is the role of limbic system?
Involved in regulation of the four F's: fighting, fleeing, feeding and sexual behaviour