Midterm 1-2 material
Lectures 1-10
1: Organization and function of the nervous system
The nervous system: in animals, it coordinates actions by transmitting signals to and from
different parts of its body
● It detects environmental changes
● Responds to such events
● Divided into central nervous system (CNS) and peripheral nervous system (PNS)
1. Cranial nerves
● 12 pairs of nerves that control: afferent functions (sensation to eyes, ears,
mouth and nose) as well as efferent functions (motor control over facial
muscles, tongue and eyes) or both
● Connects the brain and the internal organs, thereby influencing several
autonomic responses
2. Spinal nerves
● Functionally equivalent to the cranial nerves of the head; control and carry
information about the body, trunk and limbs
Somatic nervous system
● Spinal-nerve connection
○ Dorsal fibers: afferent
○ Ventral fibers: efferent
○ Collection of fibers entering/exiting spinal cord segment is called a root
(dorsal root, ventral root)
● Law of Bell and Magendie
○ Dorsal spinal cord is sensory and ventral side is motor
○ Allows inferences about location of spinal cord damage on the basis of
changes in sensation of movement that a patient experiences
Autonomic nervous system
1. Sympathetic division
● Fight or flight
, ● Connected to thoracic and lumbar spinal cord regions
● Spinal cord connects to autonomic control center, made up of glia
2. Parasympathetic division
● Rest and digest
● Connects through cranial nerves: 3 7 10
● Also connected to sacral region of spinal cord
CNS
● Brain
● Spinal cord
○ Vertebrae
■ Segments of the spinal cord
■ Divided into 5 anatomical regions (from top to bottom: cranial, cervical,
thoracic, lumbar, sacral)
○ Dermatomes
■ Segments of the body
■ Each dermatome contains sensory nerve and motor nerves (spinal
nerves)
The spinal cord
● Controls most body movements
● Series of vertebrae, divided into sections
-Cervical (C1 à C8)
-Thoracic (T1 à T12)
-Lumbar (L1 à L5)
-Sacral (S1 à S5)
Can act independently of the brain
● Spinal reflex
● Autonomic movements, hard for the bran to inhibit
Cerebral security: the meninges
● Dura mater (hard mother)
○ Tough, double layered fibrous tissue
○ Encloses brain and spinal cord
● Arachnoid layer (spider layer)
○ Thin sheet of delicate connective tissue
○ Follows the brains contour
● Pia mater (soft mother)
○ Moderately tough membrane of connective tissue
○ Clings to brain surface
Meningitis
● Inflammation of the meninges
● Bacterial infection of the meninges
○ Particularly the pia mater and arachnoid space: csf implicated as well
● Intracranial pressure (ICP)
Lectures 1-10
1: Organization and function of the nervous system
The nervous system: in animals, it coordinates actions by transmitting signals to and from
different parts of its body
● It detects environmental changes
● Responds to such events
● Divided into central nervous system (CNS) and peripheral nervous system (PNS)
1. Cranial nerves
● 12 pairs of nerves that control: afferent functions (sensation to eyes, ears,
mouth and nose) as well as efferent functions (motor control over facial
muscles, tongue and eyes) or both
● Connects the brain and the internal organs, thereby influencing several
autonomic responses
2. Spinal nerves
● Functionally equivalent to the cranial nerves of the head; control and carry
information about the body, trunk and limbs
Somatic nervous system
● Spinal-nerve connection
○ Dorsal fibers: afferent
○ Ventral fibers: efferent
○ Collection of fibers entering/exiting spinal cord segment is called a root
(dorsal root, ventral root)
● Law of Bell and Magendie
○ Dorsal spinal cord is sensory and ventral side is motor
○ Allows inferences about location of spinal cord damage on the basis of
changes in sensation of movement that a patient experiences
Autonomic nervous system
1. Sympathetic division
● Fight or flight
, ● Connected to thoracic and lumbar spinal cord regions
● Spinal cord connects to autonomic control center, made up of glia
2. Parasympathetic division
● Rest and digest
● Connects through cranial nerves: 3 7 10
● Also connected to sacral region of spinal cord
CNS
● Brain
● Spinal cord
○ Vertebrae
■ Segments of the spinal cord
■ Divided into 5 anatomical regions (from top to bottom: cranial, cervical,
thoracic, lumbar, sacral)
○ Dermatomes
■ Segments of the body
■ Each dermatome contains sensory nerve and motor nerves (spinal
nerves)
The spinal cord
● Controls most body movements
● Series of vertebrae, divided into sections
-Cervical (C1 à C8)
-Thoracic (T1 à T12)
-Lumbar (L1 à L5)
-Sacral (S1 à S5)
Can act independently of the brain
● Spinal reflex
● Autonomic movements, hard for the bran to inhibit
Cerebral security: the meninges
● Dura mater (hard mother)
○ Tough, double layered fibrous tissue
○ Encloses brain and spinal cord
● Arachnoid layer (spider layer)
○ Thin sheet of delicate connective tissue
○ Follows the brains contour
● Pia mater (soft mother)
○ Moderately tough membrane of connective tissue
○ Clings to brain surface
Meningitis
● Inflammation of the meninges
● Bacterial infection of the meninges
○ Particularly the pia mater and arachnoid space: csf implicated as well
● Intracranial pressure (ICP)
