13.1

Unit 30a

Nervous & Endocrine Systems

How the nervous system controls physiological processes

How the endocrine system contributes to homeostasis

13.1: The importance of the Nervous

System

Organization of the Nervous System

Divided into:

● central nervous system (CNS)

○ Brain, spine

○ Coordinating center

● peripheral nervous system (PNS)

○ Other nerves

○ Relays info between body and CNS

Organization of the Nervous System

Anatomy of a Nerve Cell

● Neurons - Transmit impulses

● Glial cells - structural and metabolic support to neurons.

● Copy and label:

Synaptic gap

Anatomy of a Nerve Cell

● Axons that send messages faster:

○ Myelinated - have nodes of ranvier, ↑ diameter

● PNS nerves have neurilemma - promote repair.

○ Formed by Schwann cells.

● CNS: no neurilema - damage often permanent

○ White matter vs Grey matter (myelinated?)

3 types of Nerve Cells

● Sensory (afferent)

○ relay info from sensory receptor

○ Groups = ganglia (sing. ganglion)

● Interneurons

○ Links neurons

● Motor (efferent)

○ relay info to effectors: muscles, glands, and organs.

Repairing Damaged Nerves

● PNS allows for slow repair

○ Neurilemma

● CNS does not

● Our research into CNS repair

includes:

○ Stem cells

○ More time is needed

The Reflex Arc

● 5 Parts:

○ Sensory receptor

○ sensory neuron

○ Interneuron

○ motor neuron

○ effector

Learning and Plasticity

● Make a brief summary