Podcast
Questions and Answers
What is the primary role of the dura mater in cranial anatomy?
What is the primary role of the dura mater in cranial anatomy?
Which feature distinguishes the spinal dura mater from the cranial dura mater?
Which feature distinguishes the spinal dura mater from the cranial dura mater?
What is a key characteristic of the arachnoid membrane?
What is a key characteristic of the arachnoid membrane?
What is found in the subarachnoidal space?
What is found in the subarachnoidal space?
Signup and view all the answers
Which structure acts as a protective layer around the central nervous system?
Which structure acts as a protective layer around the central nervous system?
Signup and view all the answers
What type of tissue lines the external and internal surfaces of the spinal dura mater?
What type of tissue lines the external and internal surfaces of the spinal dura mater?
Signup and view all the answers
What feature distinguishes the trabeculae of the arachnoid membrane?
What feature distinguishes the trabeculae of the arachnoid membrane?
Signup and view all the answers
What type of cells are primarily located in the pia mater?
What type of cells are primarily located in the pia mater?
Signup and view all the answers
What is a characteristic of the dura mater's histological structure?
What is a characteristic of the dura mater's histological structure?
Signup and view all the answers
Which membrane is directly involved in allowing the exchange of substances between the cerebrospinal fluid and the bloodstream?
Which membrane is directly involved in allowing the exchange of substances between the cerebrospinal fluid and the bloodstream?
Signup and view all the answers
Which statement accurately describes the pia mater?
Which statement accurately describes the pia mater?
Signup and view all the answers
What is the primary role of the cerebrospinal fluid?
What is the primary role of the cerebrospinal fluid?
Signup and view all the answers
How do the meningeal layers interact with each other?
How do the meningeal layers interact with each other?
Signup and view all the answers
Which statement is true regarding the arachnoid membrane?
Which statement is true regarding the arachnoid membrane?
Signup and view all the answers
What is primarily found in the gray matter of the central nervous system?
What is primarily found in the gray matter of the central nervous system?
Signup and view all the answers
Which characteristic is associated with unmyelinated fibers found in gray matter?
Which characteristic is associated with unmyelinated fibers found in gray matter?
Signup and view all the answers
What characterizes the pia mater in terms of its structure and appearance?
What characterizes the pia mater in terms of its structure and appearance?
Signup and view all the answers
Which function is primarily associated with the ependymal cells?
Which function is primarily associated with the ependymal cells?
Signup and view all the answers
How does the blood-CSF barrier help in the regulation of substances in the cerebrospinal fluid?
How does the blood-CSF barrier help in the regulation of substances in the cerebrospinal fluid?
Signup and view all the answers
What is the primary consequence of obstruction in the circulation pathways of cerebrospinal fluid?
What is the primary consequence of obstruction in the circulation pathways of cerebrospinal fluid?
Signup and view all the answers
Which parts of the brain are involved in the circulation of cerebrospinal fluid?
Which parts of the brain are involved in the circulation of cerebrospinal fluid?
Signup and view all the answers
What is the role of cerebrospinal fluid in relation to brain weight and protection?
What is the role of cerebrospinal fluid in relation to brain weight and protection?
Signup and view all the answers
Which of the following correctly identifies a function of the arachnoid membrane?
Which of the following correctly identifies a function of the arachnoid membrane?
Signup and view all the answers
What is a possible effect of a strong blow to the brain as described in the context?
What is a possible effect of a strong blow to the brain as described in the context?
Signup and view all the answers
Study Notes
Central Nervous System Histology
- The central nervous system (CNS) includes the brain and spinal cord.
- The brain and spinal cord are composed of gray matter and white matter.
- Gray matter contains nerve cell bodies, glial cells (excluding fibrous astrocytes), and blood cells.
- White matter contains myelinated axons, glial cells (excluding protoplasmic astrocytes), and blood vessels.
- The ventricles or central canal are also part of the CNS.
Brain
- The brain surface has protrusions called gyri and indentations called sulci.
- The brain is protected by membranes called meninges.
- The meninges consist of three membranes: dura mater, arachnoid mater, and pia mater.
- The dura mater is closely attached to the skull.
- The arachnoid mater is between the dura mater and pia mater.
- The subarachnoid space is between the arachnoid mater and pia mater.
- The pia mater is the innermost layer attached to the brain.
- The dura has two layers.
- The brain has gray matter and white matter.
Spinal Cord
- The spinal cord has gray matter and white matter.
- Gray matter is centrally located and shaped like a butterfly.
- White matter surrounds the gray matter.
- The spinal cord has a central canal filled with cerebrospinal fluid.
- The central canal is lined by ependymal cells.
- It contains afferent fibres (myelinated and unmyelinated) and efferent fibres (myelinated and unmyelinated), intermediate fibres (myelinated and unmyelinated) and neuroglial cells.
- The outer white matter contains bundles of axons that carry sensory and motor information.
Cerebellum
- The cerebellum is part of the CNS.
- The cerebellum has a cortex composed of three layers, the molecular layer, the Purkinje cell layer and the granular layer.
- The cerebellum has white matter.
- Different cell types found in different layers make up the cerebellum cortex.
- The cerebellum has a white matter core containing nerve fibers.
CNS in Microscopes
- Nerve cell bodies are in the gray matter.
- Microglia are also found in the different parts of the CNS -Astrocytes, oligodendrocytes, and microglia.
Blood-CSF Barrier
- Capillary endothelium of the choroid plexus, basement membrane of capillaries, and ependymal cells make up the blood-CSF barrier.
Blood-Brain Barrier
- The blood-brain barrier is formed by the capillaries in the CNS.
- The capillaries in the CNS consist of flat endothelial cells surrounded by a basement membrane.
- The endothelium is thin, continuous, and not fenestrated.
- Tight junctions are present between the endothelial cells.
- The perivascular feet of astrocytes extend to the basement membrane.
Cerebrospinal Fluid (CSF)
- CSF is found in the subarachnoid space.
- CSF helps protect the CNS from mechanical and gravitational effects.
- CSF distributes pressure equally throughout the brain to minimize tissue damage from impact.
- CSF flows from the lateral ventricles through the interventricular foramina into the third ventricle.
- Then CSF flows down the cerebral aqueduct to the fourth ventricle.
- CSF flows out of the lateral and median apertures.
- CSF is reabsorbed into the dural venous sinuses via arachnoid villi.
Ependymal Cells
- Ependymal cells are a type of glial cell that lines the ventricles and central canal of the spinal cord.
- They have a simple cuboidal to columnar shape.
- The cytoplasm is rich in mitochondria which makes it suitable for water transport.
- They have microvilli which increases the surface area.
- CSF is secreted through these cells.
- They have basal folds.
Neuronal Cells In Cortex
- Pyramidal neurons are the most prominent neurons in the cerebral cortex.
- They have a pyramid-shaped cell body.
- Their apical dendrites extend upward and outward.
- Their axons extend deep into the white matter and also re-enter the cortex.
- They are categorized according to their diameter (small, medium, large)
- The largest are Betz cells in the inner pyramidal layer.
- Other neurons in the cortex include granular neurons, fusiform neurons, and horizontal cells.
- Granular neurons are small, star-shaped, with many synapses with other neurons.
- Fusiform neurons are modified stellate neurons.
- They are usually found in the deepest layer of the cortex.
- Horizontal cells are located superficially, lying horizontally, and are fusiform.
- Martinotti neurons are small multipolar neurons that synapse with pyramidal neurons.
Cerebral Cortex
- Divided into six layers of neurons with unique morphologies.
- Different neurons are found in different layers.
- The layers are parallel to the brain surface. - The layers have various thicknesses and cell numbers.
- Layers I - VI have unique cell and nerve fibre morphology.
- Layers 1-3 are primarily involved in receiving signals , Layers 4-6 are involved in the sending of signals.
- **
Cerebellar Cortex
- The cerebellar cortex is made up of three layers- the molecular, Purkinje, and granular layer.
- The molecular layer contains stellate cells and basket cells.
- Purkinje cells are large flask-shaped structures.
- The granular layer contains small granule cells, Golgi cells, and neuroglial cells.
White Matter of Spinal Cord
- The outer part of the spinal cord contains white matter.
- White matter consists of bundles of myelinated and unmyelinated axons.
- These axons carry specific functions like sensory and motor information.
Gray Matter of Spinal Cord
- The inner part of the spinal cord contains gray matter.
- It has a butterfly-like shape.
- The anterior horn contains multipolar neurons with large polygonal nuclei.
- Dendrites and perikarya have Nissl bodies which contains rough endoplasmic reticulum and polysomes.
Spinal Cord
- The spinal cord has a central canal which is lined with ependymal cells.
- The spinal cord has a central canal with cerebrospinal fluid .
- The spinal cord has dorsal and ventral horns.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
