Muscle & Nervous Tissue

Chapter 5 cont….

Muscle Tissue

3 types:– Skeletal muscle tissue– Smooth muscle tissue– Cardiac muscle tissue

Skeletal Muscle Tissue• Muscles (attached to bone)• “striated voluntary” muscle

• Structure: striations, multi-nucleated, long, tread-like cells, bundles of microfilaments

Smooth Muscle Tissue• Aka: visceral muscle tissue• Lines walls of hollow internal organs

(viscera)– Stomach, intestines, blood vessels

• “non-striated involuntary” muscle

• Structure: long, narrow cells, non-striated

Smooth Muscle Tissue

Cardiac Muscle Tissue• Walls of the heart• “striated involuntary” muscle

• Structure: striations, dark band (intercalated disks (where plasma membranes meet up)

Nervous Tissue• Rapidly integrates activities of

various parts of the body• Rapid communication is made

possible b/c of the excitability & conductivity characteristics of the nervous tissue

http://www.mindcreators.com/Images/NB_Neuron.gif

Nervous System

3 Parts:• Brain• Spinal cord• Nerves

Nervous Tissue:• Common origin:

ectoderm• Two cell types:

1. Neurons (nerve cell)2. Neuroglia (supporting

cells)

Anatomy of Neurons• Cell body –

soma• Cell processes:

– Axon transmits nerve impulses away from cell body

– Dendrites carry signals towards axon

http://www.nida.nih.gov/jsp/MOD3/images/NEURON2.gif

Homework

1. Finish reading chapter 5 (pp 143-151)

2. Muscle tissue handout – Due Tuesday

Warm Up (10/5/10)Use your notes to identify the muscle

tissue below:

1.

2.

3.

Reminder

• Muscle tissue quiz on block day– Study muscle tissue notes & muscle

tissue WS

• Exam I is on Friday – will cover remainder of chapter 5

Tissue Repair

After mechanical damage or tissue injury:

• Phagocytic cells remove dead or injured cells

• Regeneration: growth of functional new tissue (via mitotic division)

Repair capacity based on tissue type

Epithelial & Connective Tissue Repair

• Greatest capacity to regenerateEpithelial Tissue:

– Cut/injury cell division tissue regeneration

Connective Tissue:– Cut/injury activation of cells that make

collagen fibers injury site filled w/ dense fibrous CT

Small injury – dense fibrous CT replaced by normal tissue

Deep/large injury – dense fibrous CT forms scar

Muscle Tissue Repair

• Limited repair capacity• Damaged muscle tissue replaced

with fibrous CT• Results in loss of some or all ability

to function normally

Nervous Tissue Repair

• Limited ability to regenerate• Some neurons outside the brain and

spinal cord can regenerate (slow process)

• Majority of the time: brain & spinal injuries always result in permanent damage

Body Membranes

• Membrane – thin, sheet-like structure• Two types:

– Epithelial membranes• Composed of epithelial tissue and

underlying connective tissue

– Connective Tissues membranes• Composed entirely of connective tissue

Epithelial Membranes1. Cutaneous membrane

– Cover body surfaces exposed to external environment (skin)

2. Serous membrane– Single membrane covering two different

surfaces• Parietal membrane – lines walls of body cavities• Visceral membrane – covers surface of organs

– Secrete thin, watery substance to prevent rubbing

3. Mucous membrane– Line body surfaces open to exterior

• Ex: respiratory, digestive, urinary & reproductive tracts

Connective Tissue Membranes

Synovial membranes• Lines spaces between bones & joints• Secrete thick, colorless, lubricating

fluid (synovial fluid)• Fluid helps reduce friction btwn bone

surfaces

Mechanisms of Disease – Tumors & Cancer

• Neoplasm – “new matter” (tumor)– Abnormal growth of cells

• Benign Tumors– Do no spread to other tissues– Slow growth– Encapsulated– Usually not lethal unless interfere w/ organs

Mechanisms of Disease – Tumors & Cancer

• Malignant tumors (cancer)– Not encapsulated– Spreads (metastasizes) – Cancer cells spread via blood or

lymphatic system– Rapid growth/spread to nearby tissue

(Known) Causes of Cancer• Genetic Factors

– Inherited cancer genes “oncogenes”– Tumor suppressor gene – fails to operate– Usually genetic predisposition coupled with cancer-

causing mechanisms• Ex: breast cancer

• Carcinogens (cancer markers)– Affect genetic activity abnormal cell reproduction– Also called mutagens– Ex: chemicals, sun, viruses

• Age– Some cancers arise based on age

• Ex: leukemia (young) & colon cancer (older adults)

Detection of Cancer• Self-examination

– Breast and testicular exams• Medical Imagining

– X-ray • Ex: mammogram – detection of breast cancer

– CT, MRI, ultrasound• Produce cross-section of body images for tumor

detection

• Blood tests– Look for tumor markers (ex: PSA)

• Biopsy– Removal of tumor tissue

Cancer Treatment Options• Stage and grade cancer

– Helps determine outcomes

• Surgical removal (if possible)– Could leave behind malignant cells

• Chemotherapy – cytotoxic (cell-killing) drugs– Destroys remaining malignant cells

• Radiation therapy– Destructive x-ray or gamma radiation destroys

cancer cells

• Immunotherapy– Boosting immune system again viruses

Anthony’s Textbook of Anatomy and Physiology 17th Edition. Thibodeau, Gary A. PhD and Patton, Kevin T. PhD. Mosby, Inc.