1. Lecture 2 Animal Cells and Tissues
Mrs. Higgins, LVT
Locust Trace Agriscience Center
Veterinary Assistant Program

2. The Cell “Cells” construct ALL living things, both plants and animals
Ameba – single cell (simplest creature)
Capable of performing all functions commonly associated with life
Functions of the cell
Growth = increase in size
Metabolism = use of food
Response to stimuli = moving toward light
Contraction = shortening in one direction
Reproduction = development of new individuals of
the same species

3. Typical cell consists of 3 main parts Cytoplasm Nucleus Cell membrane
Figure 2.1

4. The Cell Cells – tissues – organs - systems – animal
Example: cells that specialize in holding structures together make up connective tissue.
Tissue with a common function make organs
A group of organs that share a common function make up systems
Stomach, liver, pancreas, and intestines = digestive system

5. Primary Types of Tissues
Epithelial – cover the surface of body, line body cavities, and form glands
Connective – support and bind other tissues together
Muscle – specialize in contracting
Nervous – conducts impulses from one part of the body to another

6. Epithelial Cells Classified into two groups:
Simple- made up of a single layer
Stratified- made up of many layers
Can be further broken down within each category:
Simple
Squamous (plate-like)
Cuboidal (cubic)
Columnar (cylindrical)
Pseudostratified columnar
Stratified
Squamous
Columnar
Transitional

7. Epithelial Cell
Simple (one)
Squamous
Coverings of viscera and linings of body cavities and blood vessels
Cuboidal
Found in ducts and may have glands
Columnar
Honeycomb, have cilia, cells line the trachea
Pseudostratified columnar
Found in upper respiratory tract, cells different length, but still one layer
Stratified (many)
Forms outer layer of skin
pharynx and salivary ducts
Transitional
Lining of portions of urinary system that are subjected to stretching

8. Special Glandular Epithelial Cells
Specialized for secretion or excretion
Secretion: release from the gland cell of a substance that has been synthesized by the cell that affects other cells
Excretion: expulsion of waste products from the cell
Glands are either endocrine or exocrine
Endocrine: No ducts, empty directly into blood stream (hormones)
Exocrine: empty their secretions onto epithelial surfaces, have ducts (scattered throughout body)

9. Connective Tissue Serves to connect other tissues
Give form & strength to many organs and often provide protection and leverage
Classified into the following categories:
Elastic
Collagenous (white fibrous)
Reticular (netlike)
Adipose (fat)
Cartilage
Bone

10. Connective Tissue Connective Tissues Description Elastic
Kinked fibers that regain original shape after being stretched
Collagenous
Found throughout body in various forms
Reticular
Consists of fine fibrils and cells, make up framework for endocrine and lymphatic system
Adipose
Forms when connective tissue cells (adipocytes) store fat as inclusion within the cytoplasm
Most often white or yellowish in color
Cartilage
Firm but not as hard as a bone, three types of cartilage (chondrocytes) Ex: ears and joints
Bone
Produced by bone forming cells, osteoblasts. Can form in a sponge like network to make spongy bone or in a closely packed network to form compact bone

11. Muscle Tissue 3 types of muscle tissue:
Skeletal
Smooth
Cardiac
Skeletal and cardiac consist of fibers, so they are considered striated muscle

12. Muscle Tissues Muscle Tissue Skeletal Striated
Each must have its own nerve supply, when stimulated, entire fiber contracts. (Skeletal muscle tissue and connective tissue makes up flesh of meat-producing animals)
*Voluntary*
Smooth
Line walls of the digestive tract, blood vessels, urinary organs, and reproductive organs
*Not voluntary* we can’t control these
Cardiac
Aka *Involuntary*
Not under conscious control. Have modified muscle cells called Purkinje fibers that conduct the impulses within the heart

13. Nervous Tissue Neuron- nerve cell Consist of Nerve body
Two or more nerve processes (fibers)
Axon: nerve process that conduct impulses away from the cell body
Dendrite: nerve process that conducts impulses towards the cell body
Nerves – bundles of axons in the periphery

14. Review and Pictures What are the three main parts of the cells?
______________
Epithelial cells do what? ________________________________________________________________________
Connective tissue offers __________ to other tissues.

15. Review and Pictures Muscle tissues specialize in ______________.
Function of nervous tissue ________________________________________________________________________

16. Review and Pictures
Label the pictures on the handout with the correct type of cells.