Title: Nervous System: Part 2
1Nervous System Part 2
- Organization of the Nervous SystemThe Senses
2Nervous System Organization
Central Nervous System (CNS)
spinal cord
brain
Peripheral Nervous System (PNS)
Sensory nerves carry sensory information into
brain and spinal cord
Motor nerves carry motor information from CNS to
effectors
Autonomic motor nerves signals to
smooth muscle, cardiac muscle, glands, involuntary
somatic sensory nerves signals from
skin, muscles, joints, special senses
Somatic motor nerves signals to
skeletal muscles, voluntary
visceral sensory nerves signals from body organs
Sympathetic division fight or flight
Parasympathetic division rest and digest
3Parts of the Brain
Cortex thinking, learning, memory, speech
movement, senses
musclecoordination
4Spinal Cord and Reflex Arcs
pin
central canal
dorsal root ganglion
white matter
gray matter
sensory receptor (in skin)
Dorsal
dorsal horn
cell body of sensory neuron
axon of sensory neuron
cell body of interneuron
axon of motor neuron
effector (muscle)
ventral root
cell body of motor neuron
Ventral
ventral horn
5Autonomic Nervous System
6Nervous System Case Study Hemimegalenchephaly
- Dylan Catania was born with an oversized right
hemisphere in his brain that was causing constant
seizures - His only hope of survival and brain development
involved early surgery to sever the connections
between the right and left hemispheres of the
brain
7Nervous System Case Study Hemimegalenchephaly
8Nervous System Case Study Surgery for
Hemimegalenchephaly
9Nervous System Case Study Surgery for
Hemimegalenchephaly
10Nervous System Case Study Hemimegalenchephaly
11Sensation and Perception
Perception cortex interprets meaning of
sensations
Sensation impulses arrive at cerebral cortex
12Sensory Areas on Cerebral Cortex
13Sense of Vision Structure of the Eye
Photoreceptors synapse with neurons that take
signal to optic nerve
14Sense of Vision Photoreceptors
15Sense of Hearing Structure of the Ear
16Sense of Hearing Mechanoreceptors
17Sense of Taste Chemoreceptors
Signal from receptor is transmitted within the
cell
Molecules bind to receptors on microvilli of
taste cells
Taste buds occur along the walls of papillae
Nerve impulses are sent to brain
18Sense of TasteSignal Transmission for Salty and
Sour Tastes
Sodium binds and opens a channel for more sodium
to enter
Protons bind and open a channel for more protons
to enter
Release of calcium triggers neurotransmitter
release and neuron stimulation
19Sense of TasteSignal Transmission for Sweet and
Bitter Tastes
Internal communication leads to neuron stimulation