Exam 4 Flashcards
Tissue
organized mass of similar cells with a specific function
The tissue consists of:
- Vertebrates
- Cells
- Extracellular Matrix (ECM)
- Cell Junction
Vertebrates: 4 types of tissue
- Epithelium or epithelial tissue
- Connective tissue
- Nerve tissue
- Muscle tissue
Cells
Themselves (covered in their turn)
Extracellular Matrix (ECM)
All material outside of cells but materials made by cells and composed of:
- Fibers
- Ground substance
Fibers
- Collagen
- Elastic FIber
Ground Substance
liquidy -> gel -> granular
- complex macromolecules
- filling in spaces
- lubricants and cushions
- interstitial fluids: blood plasma, lymph fluid
Cell Junctions
Specialized structures that connect cells together
Tight Junctions also include occluding junctions, zonulae occludins
- Seal neighboring epithelial cells together tightly enough to prevent liquids from passing between the cells to get to the underlying tissues.
- Make the epithelial layer water tight
Anchoring Junctions
- adhering junctions: attach cells to each other
- desmosomes: attach cells to each other
- hemidesmosomes: attach cells to the underlying ECM
Tethering filaments
- adherins junction: action
- desmosomes: keratin in epithelial cells, tonofilaments in other tissues
Gap Junctions
“tunnel” shaped protein through the plasma membrane of adjacent cells that allows the passage of water, ions, and other small molecules between cells
connexon (gap junctions)
The tubular protein composed of 6 proteins each called connexin
Epithelium or epithelial tissue
Covers surfaces - forms a continuous layer that covers most body surfaces and cavities:
- classified by cell shape and layering
Simple epithelium
One cell thick
Squamous (epithelial tissue)
flat, tile like
Cuboidal (epithelial tissue)
about as tall as wide
Columnar (epithelial tissue)
taller than wide
Basal lamina (epithelial tissue)
thin sheet of extracellular proteins-lamina: adhesive fibrous protein and sticky ECM
- anchored to the underlying connective tissue
Basement membrane (basal lamina and connective tissue) (epithelial tissue)
not a “cellular” membrane
Stratified epithelium
Multiple layers
Pseudostratified
“appearance of multiple layers” but all cells anchored to basal lamina
Connective Tissue
- Connects, supports, and protects other tissues
- The bulk of connective tissue is not composed of cells, but extracellular matrix
Cells (connective tissue)
3 general unspecialized:
1. Fibroblasts
2. Adipose cells
3. Blood cells
Fibroblasts (connective tissue)
most common type of cell synthesize and maintain ECM
- Large, flat
Blood cells (connective tissue)
Leukocytes (white blood cells)
Macrophages (connective tissue)
eat invading
- organisms, functioning in the immune system
most cells (connective tissue)
“fire alarm cells”
- initiate immune response
Plasma cells (connective tissue)
- B.T cells
- produce antibodies
Extracellular Matrix (connective tissue)
fibers- collagen, elastic fibers, ground substance - “background substance” - thick, granular -> liquid, gel-like
Interstitial fluid (connective tissue)
blood plasma, lymph fluid
Collagen (connective tissue)
the most common protein in the animal kingdom 25-30% total mass of proteins in the body
- makes up most of fibers in the ECM
Collagen filament (connective tissue)
3 polypeptide chains that wind each other in super helix
- tough fiber, high tensile strength
2 broad classes of connective tissue:
- Connective tissue proper unspecialzed
- Specialized connective tissue
connective tissue proper unspecialized
- Loose connective tissue
- dense connective tissue
specialized connective tissue
- adipose tissue
- blood
- bone
- cartilage
Central Nervous System (CNS)
brain and spinal cord
Peripheral Nervous System (PNS)
- afferent nerves
- efferent nerves
Afferent nerves
sensory organs –> CNS
- optic nerve
- auditory nerve
- touch nerve
Efferent nerves
CNS –> Effector organ (response)
somatic nervous system motor nerve system
- function voluntary
- under control of brain
Autonomic nervous system
- regulates involuntary function
includes: - smooth muscle
- cardiac muscle
- glands
- most organ systems
Sympathetic nerves
increase various metabolic processes
Parasympathetic nerves
decrease various metabolic processes
Neuron
specialized to conduct nerve impulses
Dendrites
- receive sensory impulses or nerve impulses
- short, numerous highly branched
Cell body
“ground the nucleus”
- perikaryon bilk of protoplasm and cell organelles
Axon hillock
axon potential originates
Axon
transmits nerve impulses to a receiving cell
- ex. muscle neuron
astrocyte
metabolic
-life support for neurons
- maintain proper chemical balance in “glia”
- help to maintain the “blood-brain barrier”
