Glial Cells, Diencephalon, brainstem Flashcards
What do glial cells do.
- Support the function of neurons
- Isolate nerve fibres from each other
- Divide throughout life unlike neurons
Describe oligodendrocytes.
Glial cells of the CNS that hold nerve fibres together and produce the fatty (phospholipid) myelin sheaths around axons.
Describe Schwann cells.
Glial cells of the PNS that surround axons and form fatty (phospholipid) myelin sheaths around axons.
Describe satellite cells.
Glial cells of the PNS. A type of Schwann cells that surround neuron cell bodies within ganglia, giving them structural support and protection
Describe astrocytes.
Glial cells of the CNS that attach to neurons and ‘feed’ them with lactic acid from glucose.
astronaut food?
Where is the Diencephalon located?
Between the cerebrum and midbrain.
What is the thalamus made of?
Grey matter
What are 3 functions of the thalamus?
- Central relay station for incoming sensory impulses before they travel to the cerebral cortex
- Regulates sleep: damage->coma
- Helps produce sensations & associations to these
What is the hypothalamus?
The survival and pleasure ‘centre’
What are 3 functions of the hypothalamus?
- Connects the nervous and endocrine systems
- Regulator and coordinator of autonomic activities (blood pressure, heart rate, digestion, respiratory rate)
- Regulates homeostasis
What happens if the hypothalamus is damaged?
Major problems with homeostatic regulation-> larger issues
What are 7 homeostatic mechanisms controlled by the hypothalamus?
- Thermoregulation
- Appetite
- CO2 levels
- Growth hormone secretion
- Waking state
- Water balance
- Thyroid activity
What/where is the epithalamus?
Small structures outside the thalamus and hypothalamus
What is an important structure of the epithalamus and what does it do?
The pineal gland, an endocrine gland which regulates the body’s biological clock and produces melatonin.
What cross over in the epithalamus?
At the optic chiasma optic nerves cross and exchange fibres before entering the brain. This allows vision from both eyes to be appreciated by the occipital cortex of the opposite side
What is formed in the epithalamus?
Cerebrospinal fluid is formed here in the choroid plexuses.
What is a sub-organ of the epithalamus and what does it control?
The pretectum, controls the pupillary light reflex (dilation)
What are the three divisions of the brainstem?
- Medulla oblongata
- Pons
- Midbrain
Describe the medulla oblongata. (3 points)
- Most vital part of the brain: injury or disease causes death
- Contains ‘vital’ centres: cardiac, vasomotor, respiratory control centres
- Contains non-essential centres: coughing, sneezing, hiccuping
Where is the medulla oblongata located?
The base of the brainstem
Where is the pons located?
Between the midbrain and the medulla oblongata.
Describe the pons (2 points)
- Contains reflex centres for cranial nerves V,VI,VII,VIII
- Origin of many nerves
Where is the midbrain located?
In the literal middle of the brain: Above the pons and below the cerebrum
Describe the midbrain (2 points)
- Contains auditory and visual centres and clusters of neurons involved in muscular control
- Contains centres for pupillary reflexes and eye movements.
What are the meninges?
The inner protective covering for the brain and spinal cord.
What are the three layers of the meninges?
- The dura mater
- The arachnoid mater
- The pia mater
Describe the dura mater.
The outer layer of the meninges and the inner periosteum of the cranial bones.
Describe the arachnoid mater.
The delicate cobweb-like middle layer of the meninges
Describe the pia mater.
The innermost transparent layer of the meninges directly covering the brain and spinal cord.
