A & P - Unit 2 Flashcards
4 classifications of tissue in the eye
- Epithelial
- Smooth
- Connective
- Nervous
Types of epithelial based on CELL LAYERS
Simple: single layer of cells
Stratified: 2 or more layers of cells
Pseudostratified: single layer that looks like more than one
Types of epithelial based on SHAPE
Squamos: extremely thin cells like resemble the scales of fish (flat cells)
Cuboidal: cells like appear square in cross-section but are marginally longer than they are wide (cube shaped)
Columnar: elongated cells involved in absorption of materials (column shaped)
Ground Substance for cartilage, bone, and blood
Cartilage: carbohydrates and proteins
Bone: collagen and elastic fibers
Blood: plasma
Cells found in bones
Osteocytes
Red Blood Cells
Erythrocytes - carry oxygen
White Blood Cells
Leukocytes - engulf foreign substances like plaque + bacteria
Multinucleated? Single Nucleus?
Voluntary (skeletal) = multinucleated
Cardiac (heart) = single nucleus
- Striated
- Multinucleated
- The ability to increase in strength
- control of body movement
- involuntary
Voluntary (skeletal)
- Striated
- single nucleus
- branched
- only found in heart
Cardiac (heart)
- Squamous
- small, not striated
- designed for slow sustained contractions
- involuntary
- found in respiratory tract, digestive system, ciliary muscles of the eye
- respond to emotional reactions
- controls the autonomic functions
Smooth Muscle
Nervous tissue consists of?
Nerve cells and glial cells, which help transmit nerve impulses
Central Nervous System is formed by?
The spinal cord and brain
How many rods and cones are in the retina?
120 million rods and 6-7 million cones
What receives sensory input?
Dendrites
2 types of input
Excitatory - physical input to a neuron that signals it to the retina (sends message)
Inhibitory - input that makes neuron less likely to generate an action potential (does not send message)
Axon Terminal
the space between the axon and the dendrite is called the synapse or synaptic cleft
What are ligaments and tendons?
Tendons - connect muscle to bone
Ligaments - connect bone to bone
Main function of sclera
protect and/or support the eye
Types of cells found in bone and blood
bone - osteocytes
blood - red blood cells and white blood cells
Facts about Cartilage
- supports the body structures that are flexible
- ground substance of cartilage = carbohydrates and proteins
- chondrocytes are the cells in the cartilage
How much of the sclera covers the posterior globe?
5/6ths
Thickness of the sclera towards the back
thicker, 1mm
The anterior portion of the sclera is covered by?
conjunctiva
Tenon’s Capsule is also known as…
Bulbar Sheath
Tenon’s Capsule
wraps the outer surface of the eyeball from the optic nerve to the corneal limbus
Shape of the Tenon’s Capsule
like a sling
Lamina Cribrosa?
crosshatching network of collagen fibers that support the optic nerve fibers
Scleral Spur?
ridge of the sclera from which ciliary muscle fibers start
Pinguecula
small patch of yellow tissue that bulgees out of the conjunctiva
Pterygium
larger, wedge-shaped growth that can expand to the cornea and block vision
Nevus
brown spot and/or freckles on the eye
Subconjunctival hemorrhage
broken blood vessel that has leaked between the sclera and the conjunctiva just underneath the white of your eye
