9/29/2010 1 Zoology 100 Lab HISTOLOGY: Key facts and Images Ma. Victoria B. Pangilinan UST - College of Science Department of Biological Sciences Metazoan Histology Histology - study of tissues and its microstructure Tissues - group of cells specialized for a common function 4 kinds of tissues: 1. Epithelial 2. Connective 3. Muscular 4. Nervous Epithelial Tissues • sheet of cells that covers external surfaces of the body or lines cavities. • also forms glands of the body. • tightly packed due to junctional complexes on cell surfaces (little extracellular spaces in between). Epithelial Tissues • firmly bound to underlying connective tissue by a thin membrane called basal lamina or basement membrane. • Lacks vascular supply , but nourished by diffusion from capillary bed in underlying connective tissues
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9/29/2010
1
Zoology 100 Lab
HISTOLOGY:
Key facts and
Images
Ma. Victoria B. PangilinanUST - College of Science
Department of Biological Sciences
Metazoan HistologyHistology - study of tissues and its microstructure
Tissues - group of cells specialized for a common
function
4 kinds of tissues:
1. Epithelial
2. Connective
3. Muscular
4. Nervous
Epithelial Tissues
• sheet of cells that covers
external surfaces of the body
or lines cavities.
• also forms glands of the
body.
• tightly packed due to
junctional complexes on cell
surfaces (little extracellular
spaces in between).
Epithelial Tissues• firmly bound to underlying connective tissue by a thin membrane called basal lamina or basement membrane.
• Lacks vascular supply, but nourished by diffusion from capillary bed in underlying connective tissues
1. Lymphocytes – large nucleus indented on one side, thin cytoplasm
2. Monocytes – oval or kindney-shaped nuclei, irregular cytoplasm
Platelets – minute cytoplasmic fragments, stain blue
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Specialized Connective Tissues:
Blood
Red Blood Cells
Muscle Tissues
Skeletal Cross section
muscle bundle
Teased skeletal
muscle
• connected to the skeleton, VOLUNTARY, striated.
• concerned with body movement
• skeletal muscles are cylindrical, striated, multinucleated, the nucleus being oval
and located at the periphery of the cell.
• fasciculi – muscle bundles
• endomysium – tissue covering single fiber
perimysium – tissue covering fasciculi
epimysium – tissue covering entire muscle mass
Muscle Tissues
Smooth Muscle
• found as part of walls of viscera / visceral organs, INVOLUNTARY.
• individual muscle cell appear as spindle-shaped cells, with single
centrally located nucleus at the widest part of the cell.
• cytoplasm is fairly homogenous, unstriated.
Muscle Tissues
Cardiac Muscle
• composes the contractile wall of the heart, INVOLUNTARY.
• arranged as branching networks interspersed with capillaries.
• nucleus centrally located, one per cell, cells striated.
•With interacalated discs – boundaries between neighboring cells.
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Nervous Tissues
Nervous system is divided into:1. Central nervous system (CNS) which includes the
brain and spinal cord, and the
2. Peripheral nervous system (PNS) which includes nerves and ganglia.*Nerves consist of axons in the PNS bundled together.*Ganglia are collections of neuron cell bodies.
Nervous Tissues
Nerve cells include neurons and neuroglia(supporting cells).
Neurons (cells) are specialized to produce and conduct
electrochemical impulses.
Neuroglia=do not conduct electrical impulses but instead
support and insulate neurons and eliminate foreign materials in and around neurons.
Myelin sheath - insulating covering of neuroglia cells
wrapped around axons
Nodes of Ranvier - separate adjacent neuroglia cells