five Major Divisons Of The Brain Flashcards
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
- superior colliculi: located in the anterior end. Involved with eye movements
- 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?
- Thalamus
- Hypothalamus/mammilary bodies
- Pituitary gland
- 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:
- Cerebral cortex
- Major fissures
- Major gyri
- Four lobes
- Limbic system
- Basal ganglia
- 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