Chapter 2 and 7 - Anatomy of the NS Flashcards
Neuron
The basic functional unit of the nervous system
Nerve
A bundle of axons in the peripheral nervous system
Tract
A bundle of axons in the central nervous system
Ganglion
A group of cell bodies in the peripheral nervous system
Nucleus
A group of cell bodies in the central nervous system
Neuroanatomical Directions
Brain:
Dorsal - up
Ventral - down
Anterior - front
Posterior - back
Spine:
Anterior - up
Posterior - down
Ventral - front
Dorsal - back
Others:
Medial – towards the middle
Lateral – towards the side
Proximal – close to the body
Distal – further away from body
Contralateral – opposite side
Ipsilateral – same side
Sections of the Brain
Horizontal – a slice parallel to the ground
Frontal (coronal) – slicing bread or salami
Sagittal – a midsagittal section separates the left and right halves
2 Parts of the Nervous System
Central nervous system
Peripheral nervous system
Anatomy - Central Nervous System (CNS)
Brain (in the skull)
Spinal Cord (in the spine)
Anatomy - Peripheral Nervous System (PNS)
Located outside of the skull and spine
Serves to bring information into the
CNS and carry signals out of the CNS
The CNS is covered by…
three meninges and encased in bone (skull or spinal cord)
- Dura mater - tough outer membrane
- Arachnoid membrane - weblike
- Pia mater - adheres to CNS surface
Cerebrospinal fluid (CSF)
- Fluid serves as cushion
Cerebrospinal Fluid
Acts as cushion for CNS
Found in:
1. Subarachnoid space → between arachnoid membrane and pia mater
- Ventricles → Series of hollow interconnected chambers, filled with CSF
- 4 ventricles: 2 lateral, 3rd and 4th
- Cerebral aqueduct
2 Parts of the Peripheral Nervous System
- Somatic Nervous System:
- interacts with external environment
(Afferent nerves (sensory to CNS))
(Efferent nerves (motor from CNS)) - info from sense organs to CNS
- voluntary muscles control
- Autonomic Nervous System
- regulates body’s internal environment
(Afferent nerves (sensory from internal organs to CNS))
(Efferent nerves – 2 kinds) - controls heart, intestines, etc
- involuntary muscles
Autonomic Nervous System
Sympathetic and parasympathetic nerves generally have opposite effects
Sympathetic - fight or flight
Parasympathetic - rest and relaxation
Both outputs we don’t control
Cranial Nerves
I - Olfactory nerve - olfactory
II - Optic - vision
III - Oculomotor - eye movements, control of pupil, lens and tears
IV - Trochlear - eye movements
V - Trigeminal - facial sensations, chewing
VI - Abducens - eye movements
VII - Facial - facial movements, salivary glands, taste
VIII - Vestibulo-cochlear nerve - acoustic branch, vestibular branch
IX - Glossopharyngeal - throat muscles, salivary glands, taste
X - Vagus - control and sensation of internal thoracic and abdominal viscera such as bronchioles, heart and stomach
XI - Spinal accessory - head and neck muscles
XII - Hypoglossal - tongue muscles
“on old Olympus’s towering top a Finn and German viewed some hops”
Development of the Human Brain
From the ectoderm of our embryotic cells, we develop a neural tube
The 5 Major Divisions of the Human Brain
- Telencephalon
- Diencephalon
- Mesencephalon
- Metencephalon
- Myencephalon
Major Divisions of the Brain, Continued
Forebrain - Telencephalon, Diencephalon
Midbrain - Mesencephalon
Hindbrain - Metencephalon, Myelencephalon
Hindbrain Divisions - Myelencephalon
Medulla
- life support functions
- damage
Reticular formation
- gate keeper, can admit or block sensory info
- many general anesthetics work here
- damage
Hindbrain Divisions - Metencephalon
Pons
- bridge
- ventral surface
- main connection b/w cortex and cerebellum
- role in sleep, dreaming, eye movements, vestibular sense
Cerebellum
- little brain
Midbrain Divisions - Mesencephalon
Tectum - dorsal surface
Tegmentum - ventral
Tectum
“Roof”
Superior colliculus - vision
Inferior colliculus - audition
Visual reflexes and reactions to moving stimuli
