Class Notes (837,446)
Canada (510,273)
BIOB34H3 (271)
Ted Petit (35)

Chapter 12.docx

3 Pages
Unlock Document

Biological Sciences
Ted Petit

Chapter 12 Nervous Tissue • Organization of the Nervous System - Central nervous system (CNS) 1. brain and spinal cord a. integrating and command center - Peripheral nervous system (PNS) 1. cranial nerves a. carry electrical signals to and from brain 2. spinal nerves a. carry electrical signals to and from the spinal cord 3. two main functional divisions a. sensory (afferent) division 1) carries signals toward CNS, from skin, muscles and joints (somatic), and from visceral organs (visceral) b. motor (efferent) division 1) carries signals away from CNS to effector organs 2) somatic division (to skeletal muscle, voluntary control) 3) autonomic division (to smooth and cardiac muscle, glands; involuntary control; further divided into sympathetic division ("fight or flight") and parasympathetic division ("resting and digesting") • Histology - Nervous tissue made up of... 1. neurons a. cells that receive and transmit electrical signals 2. neuroglia (glial cells) a. supporting cells of CNS and PNS - Neuroglia 1. in CNS a. astrocytes 1) hold neurons together 2) repair of injury and scar formation 3) induce changes in blood vessels to form the blood-brain barrier hold neurons together 4) take up and break down some neurotransmitters (chemical signal molecules) 5) maintain ion concentrations b. microglia 1) defense cells 2) ependymal cells 3) line cavities in brain and spinal cord 4) help form and circulate cerebrospinal fluid c. oligodendrocytes send out extensions that wrap neurons, forming myelin sheaths 2. in PNS a. Schwann cells make myelin sheaths b. satellite cells support clusters of neuron cell bodies (in ganglia) - Neurons (nerve cells) 1. highly specialized to conduct electrical signals 2. can vary in structure but all have some common features 3. common features a. cell body (soma) 1) nucleus and other organelles 2) well developed rough ER (Nissl bodies) 3) plasma membrane has receptors for neurotransmitters (receives chemical signals) 4) clusters in CNS called nuclei, in PNS called ganglia
More Less

Related notes for BIOB34H3

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.