CH 3: The Brain, NS & Neural Communication Flashcards
List the major divisions of the nervous system (8)
- Central Nervous System
- Brain
- Spinal Cord - Peripheral Nervous System
- Somatic NS
- Autonomic NS
- -> Sympathetic NS
- -> Parasympathetic NS
Describe the CNS
- Central Nervous System
- NS in skull & spine = brain & spinal cord
Describe the PNS
- Peripheral Nervous System
- NS outside of skull & spine
- Composed of the Somatic NS & Autonomic NS
Describe the Somatic NS
- Part of the PNS that interacts w/ EXTERNAL environ
- Composed of afferent nerves & efferent nerves
Describe AFFERENT NERVES in Somatic NS
- Carries SENSORY signals from skin, skeletal muscles, joints, eyes, ears, etc. to CNS
Describe EFFERENT NERVES in Somatic NS
- Carries MOTOR signals from CNS to skeletal muscles
Describe the Autonomic NS
- Part of PNS that regulates body’s INTERNAL environ
- Composed of afferent nerves & efferent nerves
Describe AFFERENT NERVES in Autonomic NS
- Carries SENSORY signals from internal organs to CNS
Describe EFFERENT NERVES in Autonomic NS
- Carries MOTOR signals from CNS to internal organs
Name the 2 types of nerves in Autonomic NS
- Sympathetic Nerves
- Parasympathetic Nerves
Describe Sympathetic Nerves (3)
- Autonomic motor nerves that project from CNS in the lumbar (small of back)
- ***Stimulate, organize & mobilize E resources in threatening situations
- Sympathetic changes are indicative of psychological AROUSAL
Describe Parasympathetic Nerves (3)
- Autonomic motor nerves that project from brain & sarcal (lower back) regions of spinal cord
- ***Acts to conserve E
- Parasympathetic changes are indicative of psychological RELAXATION
Define MENINGES.
- 3 protective membranes that cover the brain & spinal cord
List the 3 meninges & explain their functional role.
(1) Dura Mater = tough outer meninx
(2) Arachnoid Membrane = spiderweb-like meninx located b/w dura mater & pia mater
(3) Pia Mater = delicate, innermost meninx
Describe function of CEREBROSPINAL FLUID (CSF).
- Supports/cushions the brain
Where is CSF produced?
- Produced by CHOROID PLEXUSES = networks of capillaries that protrude into ventricles from the pia matter
Where does CSF flow? (3).
(1) Subarachnoid Space = space beneath arachnoid membrane - contains many large bv’s & CSF
(2) Central Canal = small central canal that runs length of spinal cord
(3) Cerebral Ventricles = 4 large internal chambers of brain
Define BLOOD-BRAIN BARRIER & describe its function
- Mechanism that impedes the passage of toxic substances from blood into brain
- Formed due to tightly packed bv walls of brain cells
List the 4 types of GLIAL CELLS
- Oligodendrocytes
- Schwann Cells
- Microglia
- Astrocytes
Define 1. OLIGODENDROCYTES
- Glial cells that myelinated neurons of the CNS
- -> increases speed of transduction
Define 2. SCHWANN CELLS
- Glial cells that compose the myelin sheaths of PNS axons & promote the regeneration of PNS axons
Define 3. MICROGLIA
- Glial cells that respond to injury/disease engulfing cellular debris & triggering inflammatory responses
- Plays role in regulation of cell death
Define 4. Astrocytes
- Large, star-shaped glial cells that play multiple roles in the CNS
- ie) exchange chemical signals w/ neurons & other astrocytes
List 5 neuroanatomical research techniques.
- Golgi stain
- Nissl stain
- Electron microscopy
- Anterograde tracing methods
- Retrograde tracing methods
Describe 1. GOLGI STAIN
- Neural stain that completely darkens a few of the neurons in each slice of tissue
- > reveals their silhouettes
- > see individual neurons
Describe 2. NISSL STAIN
- Neural stain that has an affinity for structures in neuron cell bodies
Describe 3. ELECTRON MICROSCOPY
- Microscopy technique used to study fine details of cellular structure
Describe 4. ANTEROGRADE TRACING METHODS
- Used when want to trace paths of axons projecting AWAY from cell bodies
Describe 5. RETROGRADE TRACING METHODS
- Used when want to trace paths of axons projecting INTO a particular area
Define ANTERIOR
- Towards the nose end
Define POSTERIOR
- Towards the tail end
Define DORSAL
- Top of human head & back of human body
Define VENTRAL
- Bottom of human head & front of human body
Define MEDIAL
- Towards midline of body
Define LATERAL
- Away from midline toward body’s lateral surfaces
List the 5 major components of the spinal cord.
- Gray Matter
- White Matter
- Dorsal Horns
- Ventral Horns
- Dorsal Root Ganglia
Describe GRAY MATTER
- Composed of cell bodies & un-myelinated interneurons
Describe WHITE MATTER
- Composed of myelinated axons
Describe DORSAL HORNS
- 2 dorsal arms of the spinal grey matter
Describe VENTRAL HORNS
- 2 ventral arms of the spinal grey matter
Describe DORSAL ROOT GANGLIA
- Structures just outside the spinal cord that are composed of cell bodies of dorsal root axons
List the 5 major divisions of the brain.
FOREBRAIN:
- Telencephalon (aka cerebral hemispheres)
- Diencephalon
MIDBRAIN:
3. Mesencephalon (aka midbrain)
HINDBRAIN:
- Metencephalon
- Myelencephalon (aka medulla)
- 2-5 = brain stem = stem on which cerebral hemispheres sit
