Organization & Function of the Nervous System Flashcards
How many parts is the nervous system divide into?
Divided into central nervous system (CNS) & peripheral nervous system (PNS)
Central Nervous System (CNS) is divided into
The brain and spinal cord
Peripheral Nervous System (PNS) is divided into
Somatic Nervous System (SNS) and
Autonomic Nervous System (ANS)
Somatic Nervous System (SNS) is divided into
Cranial Nerves and Spinal Nerves
Autonomic Nervous System (ANS) is split into
Sympathetic Division (Arousal) Parasympathetic Division (Calming)
Cranial Nerves are split into
Twelve pairs of nerves that control:
- Afferent functions (sensation to eyes, ears, mouth & nose);
- Efferent functions (motor control over facial muscles, tongue & eyes)
What are the Spinal Nerves
Functionally equivalent to the cranial nerves of the head;
Control and carry information about the body, trunk & limbs.
What type of fibers does the Somatic Nervous System have
Dorsal fibers
Ventral fibers
Dorsal fibers are
Ventral fibers are
Dorsal fibers – afferent.
Ventral fibers – efferent.
Collection of fibers entering/exiting spinal- cord segment is called
a root (i.e. dorsal root, ventral root).
Law of Bell & Magendie
Dorsal spinal cord is sensory & ventral side is motor;
• Allows inferences about location of spinal- cord damage on the basis of changes in sensation or movement that a patient experiences.
Divisions of the Autonomic Nervous System (ANS):
Sympathetic Division
Parasympathetic Division
Sympathetic Division is the
Fight or Flight;
- Connected to thoracic & lumbar spinal-cord regions;
- Spinal cord connects to autonomic control center, made up of ganglia.
Parasympathetic Division is the
Rest & Digest;
- Connects through cranial nerves: 3, 7 & 10;
- Also connected to sacral region of spinal cord.
Spinal Cord is split into
Vertebrae and Dermatomes
Vertebrae is
Segments of the spinal cord;
Divided into 5 anatomical regions (from top to bottom: cranial, cervical, thoracic, lumbar, sacral)
Dermatomes is
Segments of the body;
Each dermatome contains sensory nerve& motornerves (spinal nerves).
The spinal cord Controls most body movements what are the vertebra sections?
Series of vertebrae, divided into sections:
- Cervical (C1-C8)
- Thoracic (T1-T12)
- Lumbar (L1-L5)
- Sacral (S1-S5)
The spine can act independently off the brain through
Spinal reflex and Automatic movements, hard for the brain to inhibit
What are the layers of Cerebral Security
Dura Mater (L. hard mother), Arachnoid Layer (L. spider layer), Pia Mater (L. soft mother)
Proprieties of the Dura Mater (L. hard mother)
Tough, double layered fibrous tissue;
- Encloses brain & spinal cord.
Proprieties of the Arachnoid Layer (L. spider layer)
Thin sheet of delicate connective tissue;
- Follows the brain’s contour.
Proprieties of the Pia Mater (L. soft mother)
Moderately tough membrane of connective tissue;
- Clings to brain surface.
Cerebral Security is the
Meninges
What is Meningitis
Bacterial infection of the meninges
- Particularly the pia mater and arachnoid
space;
- CSF implicated as well.
• Intra-Cranial Pressure (ICP)
- Inflammation puts pressure on the brain; - Leads to drowsiness, delirium, coma.
What is atop of the brain called?
Dorsal
What is toward midline of the brain called?
Medial
What is toward front of the brain called?
Anterior
What is behind of the brain called?
Posterior
What is away from the brain midline called?
Lateral
What is down the brain called
ventral
