glia Flashcards
what is sensory input
sensory receptor gathering information mointoring changes inside and outside the body
what is integration
processing information from sensory output and deciding what to do at each moment
motor output
nervous system activates effector organs (muscles and glands) to cause a response
what is the central nervous system
brain and spinal cord; integrating system interpreting sensory input and dictating motor output based on reflexs, past experiences, and current conditions
what is the peripheral nervous system
consists mainly of nerve extended from CNS to carry impulses to spinal cord
sensory. Afferent division (toward)
consist of axons that convey impulses to CNS from sensory recptors
-somatic sensory fibres: impulses from skin,skeleton muscles,joints
visceral: organs
motor, efferent divisions (away)
PNS transmits impulses from CNS to effector organs
-somatic: cns to skeletal (voluntary)
-autonomic: visceral motor nerve fibers (involunatry) heart beating, movement of food in digestive tract
what are nueroglia or glial cells
small cells that surround and wrap around the more delicate neurons
what are neurons
nerve cell that are excitable (respond to stimuli by changing membrane potential and transmit electrical signals
what are the four types of nueroglia in the CNS
astrocytes, ,microglial,ependymal,oligodenocydrates
what are astrocytes
-star shaped, most abundant and versatile
- support and anchor neurons to nutrient supply (capillaries)
-mop up leaked potassium and recycle released neurotransmitter
connected by gap junction
what are microglial?
small monitor health and sense when neurons are injured and migrate towards them
-kills invading cell (phagocytosis)
what are ependymal cells?
circulate cerebrospinal fluid that cushions brain and spinal cord
what are oligodendrocytes?
wraps around fibers producing insulating coverings called myelin sheath
what are the two types of glial cells in PNS?
satellitel cells and schwann cells
what do satellite cells do?
same function of astrocytes (hold them together for nutrients)
what are schwann cells?
form myelin sheaths
why do neurons have extreme longevity
because they are amitotic
do neurons have a high metabolic rate
yes
what is the neuron body called?
soma
what do neuron bodys contain?
mitochondria, protein, RER, ribosomes, Golgi, neurofibrils, pigment
what are cluster of cells at CNS location called? PNS?
nuclei, ganglia
what are dendrites?
twiglike, main receptive or input region, provide large SA for recieving signals from other neurons
-convey incoming messages towards cell body
-not action potential; its graded potential
how many axons can a nueron have
1
