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.