Chapter 9 Flashcards
What are the 3 developmental regions of the brain?
the forebrain, midbrain, and hindbrain
What does the forebrain develop into?
The forebrain will grow into the adult brain’s cerebrum and diencephalon.
What does the midbrain develop into?
The midbrain will grow into the adults brain’s midbrain.
What does the hindbrain develop into?
The hindbrain will grow into the adult brain’s cerebellum, pons, and medulla oblongata.
What is grey matter made of?
Grey matter is composed of unmyelinated neurons, dendrites, and axons.
What is white matter made of?
White matter is composed of myelinated axons with a small amount of neuron cell bodies.
What are tracts?
They are made up of white matter and carry messages between the brain and spinal cord
What is the objective of the meninges?
They help stabilize the neural tissue in the brain and protect it from bruising from bones.
What does the dura matter layer of the meninges do?
It is made of connective tissue, surrounds the brain, and forms sinuses that drains CSF into the blood.
What does the arachnoid membrane layer of the meninges do?
It is made of a collagen web and between the fibers it the subarachnoid space where CSF circulates and vilia connected to the dura matter bring it into the dura sinuses
What is the role of the pia mater?
It is the thinnest and innermost membrane to the brain and completely encloses the brain and the spinal cord
Where are the ventricles located in the brain?
They are located deep from the surface of the brain
What do the ventricles do?
They help keep the brain afloat, absorb impact from the skull, and contains CSF which helps filter out any wastes produced from the brain
What are the choroid plexuses?
The choroid plexus is a type of transporting epithelial tissue that is located on the walls of the ventricles that secretes cerebrospinal fluid.
How is the structure and location of the chorothroid plexus related to cerebrospinal fluid formation?
It’s structure is like kidney tissue since they both include capillaries and transporting epithelium. Which allows it to secret substances into the ventricles
What kind of fluid does the choroid plexuses create?
It selectively brings in sodium along with other solutes from the plasma to the ventricles which draws in water from the osmotic gradient. Creating the salty water solution of CSF
How does CSF get reabsorbed into the bloodstream?
From the villi’s that are located on the archoid membrane within the meningies
What makes up the blood brain barrier (bbb)?
The blood-brain barrier (BBB) consists of 400 miles worth of brain capillaries that form a selectively permeable layer around the brain.
What is unique about the capillaries in the bbb?
the endothelial cells (blood vessel cells) have tight junctions rather than leaky junctions. The tight junction begins with paracrine signals from nearby cells called pericytes and astrocytes meaning that the neural tissue itself creates the blood brain barrier. (in other words, the brain protects itself!) Which allows these capillaries to put more of a limit on what can pass through.
Is the bbb selectively permiable? If so, what does it allow in?
It is selectively permiable and it allows in:
- small lipids molecules to diffuse through
- some water soluable molecules through via a carrier
Where is the BBB absent from in the brain?
- Hypothalamus because it releases neurosecretory hormones that reach the anterior pituitary gland.
- The vomiting center in the medulla oblongata can monitor what is in the blood and if it senses anything that is foreign or toxic it will send out a vomiting reflex.
What are the metabolic requirements of neural tissue?
The metabolic requirements of neural tissue include oxygen and glucose. Both materials which get transported across the BBB. It is estimated that the brain uses 1/5 of O2 supply and up to 1/2 of the glucose supply
Where is the dorsal root located?
It is located on the posterior side of spinal cord and protrudes out from that point
What is the dosal root made of and what does it do?
It is a specialized part of a spinal nerve designed to carry (afferent/ senosory information)