Title: Anatomy / 11 Nervous system

Q: types
of nervous systems
A: Primitive vs. Differentiated: distinction by complexity.
Vegetative (Visceral/Autonomic) vs. Somatic:
- Somatic: involving joints, skin, and skeletal muscles.
- Vegetative/Autonomic: Controls involuntary functions of visceral organs, glands, smooth muscles, and the heart.
Central vs. Peripheral:
- Central Nervous System (CNS): Consists of the brain and spinal cord.
- Peripheral Nervous System (PNS): Connects the CNS to the rest of the body.

afferences
/ efferences

Q: central
nervous system: gray / white matter
A: The CNS, which includes the brain and spinal cord, is composed of 2 distinct types of tissue:
- Gray matter: Consists of nerve cells.
- White matter: Consists of nerve fibers.
In the Brain:
- Gray matter: Located on the outside (with the exception of cerebral nuclei).
- White matter: Located on the inside.
In the Spinal Cord:
- Gray matter: Located on the inside.
- White matter: Located on the outside.

Q: Brain parts
A: - Major Parts:
  - Prosencephalon: Includes the telencephalon (orange) and diencephalon (green).
  - Mesencephalon (light blue).
  - Rhombencephalon: Includes the pons (purple), cerebellum (dark blue) , and medulla oblongata (brown).
  - Brain stem: Formed by the mesencephalon, pons, and medulla  oblongata.

Q: Telencephalon
A: - Surface Features: Characterized by gyri and sulci.
- Lobes:
  1. Frontal lobe (green).
  2. Parietal lobe (blue).
  3. Temporal lobe (brown).
  4. Occipital lobe (olive.
  5. Insula (central lobe, not visible)
- Fiber Tracts:
  - Commissural fibers: Connect the two hemispheres
  - Association fibers: Connect areas within the same hemisphere.
  - Projection fibers
- Basal Ganglia: Deep nuclei including the pallidum, putamen, caudate nucleus, claustrum, and nucleus accumbens.
  - Lentiform nucleus = pallidum + putamen.
  - Striatum = caudate nucleus + putamen.
- Limbic System: Involved in emotion and memory; includes the amygdala, hippocampus, dentate gyrus, cingular gyrus, induseum griseum, fornix, and mamillary body.
- Cortex Areas:

Q: diencephalon
(parts), mesencephalon (parts), rhombencephalon (parts)
A: Diencephalon (Interbrain):
- Thalamus
- Hypothalamus
- Epithalamus
- Subthalamus
Mesencephalon (Midbrain):
- Tectum
- Tegmentum
- Crura cerebri
Rhombencephalon (Hindbrain):
- Pons
- Cerebellum
- Medulla oblongata
- Pons
- o   Cerebellum
- o   Medulla oblongat

Q: spinal
cord
A: End: At the level of the L1​ (first lumbar) vertebra.
Terminal cone: The tapered, lower end of the spinal cord.
Terminal fiber): A thin strand of connective tissue extending from the cone to the coccyx.
Intumescences: Two enlargements where nerves for the limbs originate:
- Cervical intumescence (arms).
- Lumbar intumescence (legs).
Cauda equina: A "horse-tail" bundle of spinal nerve roots descending below the end of the spinal cord.
Segments (31 total):
- 8 Cervical (C)
- 12 Thoracic (Th)
- 5 Lumbar (L)
- 5 Sacral (S)
- 1 Coccygeal
Cross-section:

Q: meninges
(= Hirnhäute)
A: Layers:
- Pachymeninx (thick layer): Consists of the dura mater encephali & the dura mater spinalis
- Leptomeninx (thin layer): Consists of
- arachnoidea mater encephali & - spinalis
- pia mater encephali & - spinalis
Spaces:
- Epidural space: Located outside the dura mater.
- Subdural space: Located between the dura mater and the arachnoid mater.
- Subarachnoidal space: Located beneath the arachnoid mater; this is the external liquor space where cerebrospinal fluid (CSF) circulates.

Q: Intracranial
blood vessels
A: Arteries: The brain's arterial supply involves the circle of Willis, which includes three cerebral and three cerebellar arteries.
Veins: Venous drainage is handled by the cerebral sinus, which is located inside the dural duplicature (the folds of the dura mater

Q: liquor
A: Task:
- Shock absorption: Provides physical protection for the brain.
- Weight reduction: Reduces the effective weight of the brain by approximately 90% through buoyancy.
Liquor Spaces:
- Internal liquor space: Consists of the ventricles and the central canal.
- External liquor space: The subarachnoidal space.
Ventricles and their Connections:
- Ist and IInd ventricles: Located in the telencephalon.
- IIIrd ventricle: Located in the diencephalon.
- IVth ventricle: Located in the rhombencephalon.
Anatomical Connections:
- Interventricular foramen: Connects the Ist/IInd ventricles to the IIIrd ventricle.
- Cerebral aqueduct: Connects the IIIrd ventricle to the IVth ventricle.
- Apertures: Connect the IVth ventricle to the external liquor space (subarachnoidal space).
Liquor Circulation
- Production: Occurs in the choroid plexus.
- Drainage: Fluid is drained through arachnoideal granulations.
- Balance: This circulation maintains the necessary intracranial pressure.

Q: Peripheral nervous system: cranial nerves
A: There are 12 pairs of cranial nerves. They are:
- I: Olfactory nerve
- II: Optic nerve
- III: Oculomotoric nerve
- IV: Trochlear nerve
- V: Trigeminal nerve
- VI: Abducens nerve
- VII: Facial nerve
- VIII: Vestibulocochlear nerve
- IX: Glossopharyngeal nerve
- X: Vagal nerve
- XI: Accessory nerve
- XII: Hypoglossal nerve

Q: Peripheral
nervous system: spinal
nerves & plexus
A: Spinal Nerves: There is one pair of spinal nerves for each segment of the spinal cord.
Plexus: These are networks formed by the spinal nerves, specifically the:
- Cervical plexus
- Brachial plexus
- Lumbal plexus
- Sacral plexus

Q: Vegetative
nervous system: parts & characteristics
A: Parts:
- Sympathetic system: Originates in the thoracic spinal cord.
- Parasympathetic system: Primarily involves the vagal nerve
- Enteric nervous system: The intrinsic nervous system of the digestive tract.
Characteristics:
- Functional Goal: Often described by the functional dichotomy of "fight or flight" (Sympathetic) versus "rest and digest" (Parasympathetic)

Q: Organs Controlled by the Vegetative Nervous System
A: - Eye
- Lacrimal and salivatory glands
- Vessels of the head
- Heart
- Lungs
- Stomach
- Liver
- Pancreas
- Kidneys
- Bowels
- Parts of colon and rectum
- Urinary bladder
- Genitals