Nervous System Brain Spinal Cord Nerves Neurons Neurons

Nervous System Brain Spinal Cord Nerves Neurons

Neurons

Parts of a Neuron • • Soma – cell body Dendrite – receive messages Axon – send messages out Myelin – help speed up messages, made up of Schwann cells

Types of Neurons • Sensory – incoming signals • Motor - movement • Interneurons – in brain and spinal cord only (processors/relay terminals)

Neural Connections • Synapse – space between axon of neuron A and dendrite of neuron B • Neurotransmitter – chemicals that diffuse across synapse to change polarity of neuron B’s dendrite membrane

Central Nervous System • Brain • Spinal Cord Control center, coordinates body functions

Peripheral Nervous System Carry messages to and from CNS Motor and sensory neurons found here. No interneurons here!

Brain Thalamus Cerebellum Brain Stem: Pons, Midbrain, Medulla Oblongata Cerebrum Corpus Callosum Hypothalamus Pituitary Gland

Autonomic Nervous System • Involuntary • Two divisions – Sympathetic – fight-or-flight responses – Parasympathetic – body at rest

Somatic Nervous System • Cranial and spinal nerves • Reflexes – automatic responses to stimuli

Senses • Chemoreceptors – chemicals • Photoreceptors – light • Mechanoreceptors – pressure, vibration

Chemoreceptors • Taste – taste buds – Sweet – Salty – Bitter – Sour • Olfaction - smell

Photoreceptors • Vision • Retina – Cones – color – Rods – black & white

Mechanoreceptors • Hearing – vibration in cochlea • Balance – semicircular canals in ears • Touch – pressure, pain, heat, cold