Lab 6 Flashcards
what are the three germ layers?
endoderm (inner lining of GI, respiratory, pancreas, and liver
mesoderm (notochord, muscle, mesenchyme, bone & cartilage, circulatory system)
ectoderm (epidermis and associated structures, brain & nervous system)
what is histology?
study of tissues
what are epithelial tissue?
comprise dog cells that form layer over external/internal surfaces (skin, GI, respiratory, excretory, reproductive, tubular glands
what are muscle fibers made of?
contractile units called myofibrils
what is nervous tissue comprised to?
neurons (nerve cells) & glial cells (cells that provide support & nutrients)
what are neurons made of?
cell body where nucleus is; many dendrites receive signals; one axon send off signal
what are nerve impulses (action potential)
axons conduct it away from cell body while dendrites conduct nerve impulses toward cell body
what are Schwann cell?
specialized cells provide myelin sheath (protect axon); allow much faster conduction of nerve impulse along axon
what are nodes of Ranvier?
regularly spaced gaps in sheath
what are saltatory conduction?
action potential/nervous impulse jumps from node to node by this
what are the different neurons?
sensory neurons (afferent neurons) conduct signals from sense organs to CNS
motor neurons (efferent neurons) conduct signals from CNS to muscles/glands
interneurons conduct from neuron to neuron within CNS
what are functions of glial cells?
physical support for neurons, maintain extracellular fluids, function in signaling, serve as stem cells for development of new neurons, secrete growth factors, and produce cerebrospinal fluid
what is ganglion?
nerve where cell bodies of many neurons concentrated
what are somatic and autonomic nervous system?
somatic nervous system (voluntary- controls skeletal muscle)
autonomic nervous system (involuntary)
what is neural tube?
ectoderm develops into it and runs along dorsal side of developing embryo -> into brain and spinal cord -> brain into forebrain, midbrain, and hindbrain
what is hindbrain?
metencephalon (cerebellum, pons)
myelencephalon (medulla)
what is midbrain?
mesencephalon (integrates info and coordinates motor responses
- midbrain small & made of superior & inferior colliculi
what is forebrain?
telencephalon (cerebrum & olfactory bulb)
diencephalon (thalamus & hypothalamus)
what is white and gray matter?
white matter comprised of myelinated axons
gray matter comprised of nerve cell bodies and dendrites (make up cerebral cortex)
what are the wrinkles in brain called?
sulci
what is frontal lobe?
center for judgement, creativity, problem solving, and planning
what is parietal lobes?
process & integrate sensory information
what is temporal lobes?
receive & process auditory & visual information involved in recognizing, identifying, and naming objects
what is occipital lobe?
visual processing center
