Chapter 2 Flashcards
Chapter 2: The Anatomy and Evolution of the Nervous System
The Meninges
3 layers in the CNS: –Dura mater •Hard mother, outermost layer –Arachnoid membrane –Pia mater •Pious mother
Ventricles
Four ventricles:
•2 lateral ventricles
•3rd ventricle
•4th ventricle
Filled with cerebral spinal fluid (CSF)
CSF moves through self-contained and separate circulation system from blood supply
Production of CSF
- Made by choroid plexus (in ventricles)
* Similar composition to clear plasma of blood
Cerebral Blood Supply
Brain ~2% of body mass but uses ~16% of blood
The 2 Divisions of the Nervous System
Central (CNS): brain and spinal cord
Peripheral (PNS): nerves connecting CNS to muscles, organs, and skin.
Efferent Nerves
(Motor) – goes out from CNS to muscles and organs
Afferent Nerves
(Sensory) – goes toward CNS from sensory receptors
Peripheral Nervous System
Somatic: –Cranial nerves and spinal nerves –Somatosensory and skeletal motor Autonomic: –Glands and organs –Sympathetic –Parasympathetic
Somatic Nervous System: Cranial Nerves
–12 pairs
–Exit/enter directly from brain
–Sensory nerves, Motor nerves, and Mixed nerves
Name the 12 Cranial Nerves
- Olfactory
- Optic
- Oculomotor
- Trochlear
- Trigeminal
- Abducens
- Facial
- Auditory
- Glossopharyngeal
- Vagus
- Spinal accessory
- Hypoglossal
Spinal nerves
–31 left/right pairs
Spinal cord has two parallel pathways
Spinal cord has 2 parallel pathways
–Sensory Nerves: Dorsal Root
–Motor Nerves: Ventral Root
Covered by only two layers of Meninges
Outside spinal cord nerves swell to form spinal ganglion
Ventral Root
Motor Nerves
Dorsal Root
Sensory Nerves
Outside the spinal cord nerves swell to form ______.
spinal ganglion
Bundle of Axons in the Central Nervous System
a Tract
Bundle of Axons in the Peripheral Nervous System
a Nerve
Group of Cell Bodies in the Central Nervous System
a Nucleus
Group of Cell Bodies in the Peripheral Nervous System
a Ganglion
Spinal cord damage
Quadriplegic: thoracic and above
Paraplegic: lumbar, sacral, coccygeal
Autonomic Nervous System
Two divisions –Sympathetic –Parasympathetic Involved in regulating four critical bodily states related to survival— i.e., the 4 Fs: –Fighting –Fleeing –Feeding –…..Reproduction
Parasympathetic Nervous System
Rest and digest •Calms body to conserve and maintain energy •Release acetylcholine •Lowers heart rate and blood pressure •Stimulates digestion
Sympathetic Nervous System
Fight or flight •Release adrenaline and norepinephrine •Raises heart rate and blood pressure •Raises blood flow to skeletal muscles •Inhibits digestion
What Develops from the Hindbrain?
- The Metencephalon: Pons and Cerebellum
* The Myencaphalon (Medulla)
What Develops from the Metencephalon?
the Pons and the Cerebellum
Medulla
–Major relay between the spinal cord and brain
–Cranial nerves
–Vital functions:
breathing, heart rate, blood pressure
Reticular Formation: Arousal
Cranial Nerve Nuclei: Various functions