BIOSCI 107 Lecture 4: Muscle and Nerve Tissue

Muscle Tissue

Consists of elongated cells (muscle cells; or muscle fibres or myocytes) that use energy from the hydrolysis of ATP (adenosine triphosphate) to generate force. As a result of contraction, muscle tissue produces body movements, maintains posture and generates heat.

Skeletal Muscle

Skeletal muscle is multi-nucleated

Functions: Motion, Posture, Heat, Protection

Muscle Fibre Striations

The striations of skeletal muscle fibres (cells) are due to the highly organised arrangement of myofibrils within the cells

Myofibrils (2 μm diam) more or less fill the cytoplasm (sarcoplasm) of the muscle fibre and extend its entire length within the cell

Myofibrils

Connective tissue of skeletal muscle

Sarcomeres

Cardiac Muscle

“Purkinje fibres” are specialised muscle cells that conduct electrical activity around the heart. They have less myofibrils and more specialised “connexins”

(gap junctions).

Smooth Muscle

Contraction of Smooth Muscle

Nervous Tissue

Nervous tissue consists of two types of cells:

• neurons (nerve cells that can be very large)

• neuroglia (supportive cells – usually small).

Neurons are longest cells in body (up to 1m – spinal cord to

toe)

Conscious and unconscious control

Neurons

Multipolar Neurons

Bipolar Neurons

Unipolar Neuron

Anaxonic neuron

Neuroglia

Astrocytes

Oligodendrocytes and Microglia

Ependymal cells

Peripheral Nervous System Neuroglia