Central Nervous System
Consists of the brain and spinal cord
Peripheral Nervous System
All of the parts of the nervous system found outside the skull and spinal column
Brain weight?
1400 g
Uses 20% of the O2 in the body
Four Lobes
Frontal
Parietal
Temporal
Occiptal
Frontal Lobe
Higher thinking, reasoning, learning, personality, voluntary movement
Parietal Lobe
Sensory information
Temporal Lobe
Understanding of speech, hearing
Occipital Lobe
Eyesight
Cerebral Cortex
Outermost layer of the cerebral hemispheres
White Matter
Consists mostly of axons with white myelin sheaths
Gray Matter
Contains more cell bodies and dendrites, which lack myelin
Nucleus
A collection of neurons inside the CNS
Tract
A bundle of axons inside the CNS
Ganglion
A collection of neurons in the periphery
Nerve
A bundle of axons in the periphery
CNS cortex
2mm thick
Visual, auditory, somatosensory, motor
Higher cognitive function
How many layers does the cerebral cortext have?
6 layers
-type of neuron
-pattern of dendrites or axons
-pyramid shaped cell body
3 developmental subdivisions
The forebrain
The midbrain
The hindbrain
Amygdala
Emotional regulation
Hippocampus
Memory
Cingulate Gyrus
Attention
Olfactory bulb
sense of smell
Basal Ganglia
Important in motor control
Includes four nuclei
Thalamus
Cluster of nuclei that relay sensory information
Hypothalamus
Contains nuclei with many functions; also controls the pituitary
Cerebellum
Involved in motor coordination and learning
Pons
Attached to the cerebellum, contains motor and sensory nuclei and gives rise to cranial nerves
Medulla
Contains cranial nerve nuclei and marks the transition from brain to spinal cord, breathing, heart rate
Brain stem consists of
Midbrain, pons, and medulla
Meninges
Helps protect the brain
Dura matter
Arachnod mater
Pia mater
Cerebral Ventricles and CSF
Helps protect the brain, shock absorber, exchnge medium between blood and brain
Cranial nerve
Connected to the brain
Spinal nerves
Connected to the spinal cord
Autonomic nervous system
Controls internal organs
Dorsal root
Sensory
Ventral front belly root
Motor
How many pairs of spinal nerves?
31 pairs
Cervical nerves (spinal)
8
Thoracic (trunk)
12
Lumbar (lower back)
5
Sacral (pelvic)
5
Coccygeal (bottom)
1
ANS
Spans the central and peripheral nervous systems, are not subject to conscious "voluntary" control
Sympathetic Nervous System
Fight or flight response
Parasympathetic Nervous System
Prepares the body for rest
Enteric Nervous System
Controls fluid and nutrients, innervated by both sympathetic and parasympathetic nerves
Autonomic ganglia
Located outside of the CNS
Preganglionic neurons
run from the CNS to the augonomic ganglia
Postganglionic neurons
run from the autonomic ganglia to targets int he body
Neurons
Are the most important part of the nervous system
100 billion in the human brain
Glial cells
provide support for neurons. Comparabe number as neurons
Neuron Doctrine
Neuron is the fundamental structure and unit of the brain
Information is transmitted from cell to cell across tiny gaps
Connection specificity
Dynamic polarization
Mitochondria
Produce energy
Cell nucleus
Contains genetic information
Ribosomes
Translate genetic instructions into proteins
Input zone
Receives information from other cells through dendrites
Integration zone
Axon hillock
Conduction zone
Output information, electrical impulses
Output zone
Axon terminals at the end of the axon communicate activity to other cells
3 kinds of neurons
Multipolar
Bipolar
Monopolar
Motoneurons
Innvervate muscles or glands
Sensory neurons
respond to environmental stimuli like light or touch
Interneurons
receive input from and send input to other neurons
Synapse 3 components
Presynaptic membrane
Postsynaptic membrane
Synaptic cleft
Astrocyte
Gloal cell: star shaped and regulate blood flow
Microglia
Glial: small, continuously extend, cleaning crew
Oligodendrocytes
Form myelin
In the CNS small with few extensions
Schwann cells
Form myelin
Outside of the CNS