The Microscopic Anatomy of Muscle Tissue and Nervous Tissue

Flashcards created to aid in reviewing key concepts related to muscle and nervous tissue, including their structure, function, and components.

What are the four primary tissue types in the body?

Muscle tissue, nervous tissue, connective tissue, and epithelial tissue.

What are the three types of muscle tissue?

Skeletal muscle, cardiac muscle, and smooth muscle.

What does excitability refer to in muscle tissue?

The ability of a muscle cell's plasma membrane to change its electrical state and send an action potential.

What are the characteristics common to all three types of muscle tissue?

Excitability, contractility, extensibility, and elasticity.

How do skeletal muscle fibers differ from cardiac muscle fibers?

Skeletal muscle fibers are multinucleated and striated, while cardiac muscle fibers have one to two nuclei and are connected to form a syncytium.

What is the role of calcium ions (Ca+2) in muscle contraction?

Calcium ions trigger contractions in muscle fibers.

List the types of connective tissue membranes surrounding skeletal muscle.

Epimysium, perimysium, and endomysium.

What function does the endomysium serve in a skeletal muscle?

It provides support to each muscle fiber and enables the exchange of nutrients and wastes.

What are myofibrils?

Cylinder-shaped bundles of protein that extend the entire length of muscle fibers and provide the force of contraction.

What is a sarcomere?

A contractile unit of muscle fibers composed of thick and thin filaments.

What distinguishes a chemical synapse from an electrical synapse?

A chemical synapse involves neurotransmitter release across a synaptic cleft, while an electrical synapse involves gap junctions allowing direct ion flow between cells.

What are the parts of a motor neuron?

Dendrite, axon, cell body, axon hillock, myelin sheath, nodes of Ranvier, and axon terminals.

What are the types of neuroglia and their functions?

Astrocytes (support neurons), oligodendrocytes (form myelin in CNS), microglia (immune defense), ependymal cells (produce cerebrospinal fluid), Schwann cells (form myelin in PNS), and satellite cells (support neuron cell bodies in PNS).

What does the term synaptic cleft refer to?

The small gap between the presynaptic and postsynaptic membranes in a synapse.

What indicates the presence of I-bands and A-bands in muscle striations?

I-bands are lighter and contain only thin filaments; A-bands are darker and contain thick filaments as well as overlapping thin filaments.

What is the function of myelin in the nervous system?

Myelin insulates nerve fibers, increasing the speed of electrical signal conduction.

What distinguishes multipolar neurons from bipolar and unipolar neurons?

Multipolar neurons have one axon and multiple dendrites, while bipolar neurons have one axon and one dendrite, and unipolar neurons have a single process that splits into two branches.