Muscular tissue Connective tissue

Muscle Tissue

• Muscle cells/fibers– Elongated – Contain many myofilaments: Actin & Myosin

• FUNCTION– Movement– Maintenance of posture– Joint Stabilization– Heat Generation

• Three types: Skeletal, Cardiac, Smooth

Skeletal Muscle Tissue(each skeletal muscle is an organ)

• Cells– Long and cylindrical, in bundles– Multinucleate– Obvious Striations

• Skeletal Muscles-Voluntary• Connective Tissue Components:

– Endomysium-surrounds fibers– Perimysium-surrounds bundles– Epimysium-surrounds the muscle

• Attached to bones, fascia, skin• Origin & Insertion

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Cardiac Muscle

• Cells– Branching, chains of cells– Single or Binucleated– Striations– Connected by Intercalated discs

• Cardiac Muscle-Involuntary• Myocardium-heart muscle

– Pumps blood through vessels

• Connective Tissue Component– Endomysium: surrounding cells www.answers.co

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Smooth Muscle Tissue

CellsSingle cells, uninucleateNo striations

Smooth Muscle-Involuntary2 layers-opposite orientation (peristalsis)

Found in hollow organs, blood vesselsConnective Tissue Component

Endomysium: surrounds cells

Nervous Tissue

• Neurons: specialized nerve cells conduct impulses– Cell body, dendrite, axon

• Characterized by:– No mitosis (cell replication)– Longevity– High metabolic rate

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Nervous Tissue: control

• Support cells (= Neuroglial): nourishment, insulation, protection– Satellite cells-surround cell bodies within ganglia– Schwann cells-surround axons (PNS)– Microglia-phagocytes– Oligodendrocytes-produce myelin sheaths around

axons– Ependymal cells-line brain/spinal cord, ciliated, help

circulate CSF

• Brain, spinal cord, nerves

Muscle Tissue

Figure 4.1

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The groups, layers of bodily musclesThe groups, layers of bodily muscles

Aponeuroses of abdominal muscles

21. External Obliques

22. Rectus Abdominus

23. Sheath of the straight muscle of the abdomen

31. Sartorius

32. Rectus Femoris

33. Pectineus

35. Adductor Longus

Psoas Major

Musculoskeletal System

• Skeleton – Muscles function by pulling against bones that rotate about joints

and transmit force through the skin to the environment.– The skeleton can be divided into the axial skeleton and the

appendicular skeleton.

• Skeletal Musculature – A system of muscles enables the skeleton to move. – Origin = proximal (toward the center of the body) attachment– Insertion = distal (away from the center of the body) attach-ment

Muscle Tissue

Muscle Tissue

• Cells are multinucleate

• Striated voluntary muscle

• Divides via satellite cells

Skeletal muscle

• Cardiocytes occur only in the heart

• Striated involuntary muscle

• Relies on pacemaker cells for regular contraction

Cardiac muscle

• Non-striated involuntary muscle

• Can divide and regenerate

Smooth muscle tissue

• Conducts electrical impulses

• Conveys information from one area to another

Neural tissue

• Neurons– Transmit information

• Neuroglia– Support neural tissue– Help supply nutrients to neurons

Neural tissue cells

Neural Tissue

• Cell body

• Dendrites

• Axon (nerve fiber)– Carries information to other neurons

Neural anatomy

The lobes of the cortex

• Parietal– Sensing

• Primary sensory cortex

Homunculus

• Injured tissues respond in coordinated fashion

• Homeostasis restored by inflammation and regeneration

Tissue Injuries and AgingInflammation and regeneration

• Isolates injured area

• Damaged cells, tissue components and dangerous microorganisms removed– Infection avoided

• Regeneration restores normal function

Tissue Injuries and AgingInflammatory response

An Introduction to Inflammation

• Change with age

• Repair and maintenance less efficient

• Structure altered

• Chemical composition altered

Aging and tissue repair

Aging and cancer incidence

• Incidence of cancer increases with age

• 70-80% of all cases due to exposure to chemicals or environmental factors

Changes in a Tissue under Stress

You should now be familiar with:• The four major tissue types and their

functions.

• The relationship between form and function for each tissue type.

• The types and functions of epithelial tissues.

• The structure and function of connective tissues.

• The structure and function of the four types of membrane.

• The three types of muscle tissue and the structural features of each.

• The basic structure and role of neural tissue.