✅Organisation Of The Nervous System 2 Flashcards
What are the six regions of the brain?
- Cerebrum
- Cerebellum
- Diencephalon
- Midbrain
- Pons
- Medulla oblongata
What does the cerebrum control?
• Conscious thought processes, intellectual functions
• Memory storage and processing
• Conscious and subconscious regulation
of skeletal muscle contractions
What does the cerebellum control?
• Coordinates complex somatic motor patterns
• Adjusts output of other somatic motor centers in brain and spinal cord
What is the largest part of the brain?
The cerebrum
What controls higher mental functions?
The cerebrum
What is the cerebrum divided into?
Right and left cerebral hemispheres
What is the neural Cortex?
a layer of gray matter that covers most of the cerebral surface
What does the cerebral cortex form a series of?
- Elevated ridges (gyri), that serves to increase its surface.
- The gyri are separated by shallow depressions called (sulci)
- Or by deep grooves called (fissures)
What is the second largest part of the brain?
The cerebellum
What does the cerebellum coordinate?
Coordinates repetitive body movements (by adjusting ongoing movements by comparing arriving sensations with previously experienced sensations, allowing you to perform the same movements over and over).
How many hemispheres does the cerebellum have?
2
What is the layer of grey matter that covers the cerebellum surface?
cerebellar cortex
Where is the diencephalon located?
under cerebrum and cerebellum
What does the diencephalon link?
Links cerebrum with brain stem
What are the three divisions of the diencephalon
- Left thalamus
- Right thalamus
- Hypothalamus
What do thalamus do?
Each contains relays and processing centers for sensory information
What do hypothalamus do?
contains centres involved with emotions, autonomic function, and hormone production
What is the pituitary gland
A Major endocrine gland
What is the pituitary gland connected to?
hypothalamus via infundibulum (narrow stalk)
What are the hypothalamus and the pituitary gland responsible for?
the integration of the nervous and endocrine systems.
What is the diencephalon a structural and functional link between?
the cerebral hemispheres and the components of the brain stem.
What does the brain stem do?
Processes information between spinal cord and cerebrum
or cerebellum
What does the brain stem include?
• Midbrain
• Pons
• Medulla oblongata
What does the midbrain process?
Processes sight, sound, and associated reflexes
What does the midbrain contain?
contains nuclei that process visual and auditory information and control reflexes triggered by these stimuli.
What does the midbrain maintain?
Maintains consciousness
What does the pons connects
Connects cerebellum to brain stem
What does the pons contain?
Contains nuclei involved in somatic and visceral motor control
What does the medulla oblongata connect?
Connects brain to spinal cord
What does the medulla oblongata do?
• Relays sensory information to the thalamus and to centres in other portions
of the brain stem.
• Regulates autonomic functions
• Heart rate, blood pressure, and digestion
What is the brain?
The brain is a large, delicate mass of neural tissue
What is the order for complexity in the brain?
Ascending from the medulla oblongata to the cerebrum, brain functions
become more complex and variable
Where are Conscious thought and intelligence produced?
In the neural cortex of the cerebral hemispheres
What are the physical protection for the brain
• Bones of the cranium
• Cranial meninges
• Cerebrospinal fluid
What creates biochemical isolation?
Blood-brain barrier
What are the three layers of the cranial meninges?
- Dura mater
- Arachnoid mater
- Pia mater
What are cranial meninges continuous with?
spinal meninges
What do cranial meninges protect the brain from?
cranial trauma
What does the dura mater contain?
- Inner fibrous layer (meningeal layer)
• Outer fibrous layer (periosteal layer) fused to periosteum - Venous sinuses between two layers
What does the arachnoid mater do?
Covers brain, providing a smooth surface that does not follow the brain’s
underlying folds.
• Contacts epithelial layer of dura mater
What is there a subarachnoid space between?
The arachnoid mater and the pia mater
How is the pia mater connected to the brain?
by astrocytes
What are the dural folds?
Folded inner layer of dura mater
What do the dural folds do?
• Extend into cranial cavity
• Stabilize and support brain
What do the dural folds contain?
collecting veins (dural sinuses)
What are the three largest dural folds
- Falx cerebri
- Tentorium cerebelli
- Falx cerebelli
What does Cerebrospinal Fluid (CSF) surround?
Exposed surfaces of the CNS
What are the functions of CSF?
• Cushions delicate neural structures
• Supports brain
• In essence, the brain is suspended inside the cranium and floats in the CSF.
• Transports nutrients, chemical messengers, and waste products
What effect does cerebrovascular disease have?
Disorders interfere with blood circulation to brain
When do strokes occur?
- occurs when the blood supply to a portion of the brain is shut off.
- Affected neurons begin to die in a matter of minutes
What does the BBB do?
Isolates CNS neural tissue from general circulation
How is the BBB formed?
Formed by network of tight junctions between endothelial cells of CNS capillaries
What can diffuse into interstitial fluid of brain and spinal cord?
Only lipid-soluble compounds (O2, CO2), steroids, and small alcohols
What are astrocytes?
cells that are in close contact with CNS capillaries
How do astrocytes control the BBB?
Releasing chemicals that control permeability of endothelium so these cells play a key supporting role in the blood–brain barrier
What happens if the astrocytes are damaged or stop stimulating?
the endothelial cells, the blood–brain barrier disappears.
How is the blood- CSF barrier formed?
By special ependymal cells
What does the blood-CSF barrier do?
It limits movement of compounds transferred
It allows chemical composition of blood and CSF to differ.
What do the meninges stabilise?
The position of the brain within the cranial cavity
What does cerebrospinal fluid provide?
Protection against sudden jolts and shocks
What does CSF provide?
Nutrients
What does CSF remove?
Wastes
What does the blood-brain barrier and blood- CSF barrier isolate?
The brain from chemicals in blood that might disrupt neural function
Name the six major regions of the brain.
The six major regions of the brain are cerebrum, diencephalon, midbrain, pons, medulla oblongata, and cerebellum.
What regions make up the brain stem?
The brain stem consists of the midbrain, pons, and medulla oblongata.
From superficial to deep, name the layers that make up the cranial meninges.
The layers of the cranial meninges are the outer dura mater, the middle arachnoid mater, and the inner pia mater.
Many water-soluble molecules that are abundant in the blood occur in small amounts or not at all in the extracellular fluid of the brain. Why?
Many water-soluble molecules are rare or absent in the extracellular fluid (ECF) of the brain because the blood–brain barrier regulates the movement of such molecules from the blood to the ECF of the brain.
