1. Name this muscle 2. List 3 actions of the muscle in #1 (be specific) 3. Name this muscle 4. Meg tore her semitendinosus muscle. What movement will be.

1. Name this muscle

2. List 3 actions of the muscle in #1 (be specific)

3. Name this muscle

4. Meg tore her semitendinosus muscle. What movement will be painful?

5. List one muscle that extends the knee.

Nervous tissue

• nervous system overview• NS organization • terminology• anatomy of a neuron• neuroglial cells• myelin sheath• synapse anatomy

What type of sensory information are you integrating right now (at least 3)?

An overview of the nervous system

PNS

CNS

Sensory Motor

Visceral Somatic

Sympathetic Parasympathetic

CNS = brain and SCPNS = everything else

Nervous systemdivisions

1

3

2

Peripheral NSCentral NS

Muscles

1 = sensory (afferent) neuron2 = interneuron (CNS)3 = motor (efferent) neuronSomatic Nervous System

1

3

2

Visceral Nervous System

1 = sensory neuron2 = interneuron (CNS)3 = motor neuron

Peripheral NS Central NS

Nucleus

Axons or Dendrites

Cell body

Neuroglial cells

Nervous system = neurons and glia

Typical neuron dendrites

Axon hillock

axon

Myelin sheath

TerminalArborizationswith synaptic knobs

A typical multipolar neuron

Blue = axon

Multipolar Neurons

bipolar

Unipolar or pseudounipolar

Neuroglia

• CNS– Astrocytes (green)– Microglia (purple) – Oligodendrocytes (blue)– Ependymal (pink)

• PNS– Schwann– Satellite cell

• Neuroglia can undergo mitosis (for better or worse)• gliomas (ependymoma, astrocytoma, oligodendroglioma)

Formation of the myelin sheath - PNS

Schwann cell

neurilemma

Myelinsheath

Fig. 13.7a(TE Art)

Oligodendrocyte

Nerve fiberMyelin

Myelin sheath in the CNS

CNS

PNS

oligodendrocyteSchwann cell

• Schwann cell helps damaged nerve fibers grow back to target• Oligodendrocyte does not• Nerve regeneration in PNS not CNS

axons

S

Multiple sclerosis• myelin sheath in CNS deteriorates • replaced by scar tissue• Symptoms? Signs?

Postsynaptic neuron

Synaptic vesicles

Synaptic cleft

Neurotransmitterreceptor

Presynaptic neuron

Synapses

Neurotransmitters• chemical signals• excitatory or inhibitory• drugs…