Exam 2 Topics Flashcards
paracrine cell communication
release of paracrine factor into tissue interstitial affects target cell in close proximity
endocrine cell communication
release hormones into blood which can effects target cells in multiple organs
neuroendocrine cell communication
triggered by action potentials that cause release of hormones into blood affecting target cells in multiple organs
communication by excitable cells connected by?
gap junctions
what constitutes a target cell?
expression of a receptor that can bind to a chemical messenger
receptors that bind neurotransmitters released by neurons
ligand-gated channels and G protein coupled receptors
Ligand-gated channels
inotropic receptors
G Protein coupled receptors (GPCR)
metabotropic receptors
Types of neurons
afferent, interneurons, efferent
Afferent neurons
propagate APs to brain and or spinal cord
Orientation of afferent neurons
dendrites, hillock, cell body = outside CNS
axon terminals = inside CNS
Classification of afferent neurons
location of dendrites and by stimulus modality detected
Interneurons
propagate APs within the CNS
Orientation of interneurons
all components found in brain and/or spinal cord
Classification of interneurons
where their cell body is found
Efferent neruons
propagate APs away from the CNS
orientation of efferent neurons
dendrites, cell body, hillock = inside the CNS
axon terminals = outside CNS
Classification of efferent neurons
location of the axon terminals; somatic or autonomic
Somatic efferents
motor neurons; axon terminals found ONLY in skeletal muscle
Autonomic efferents
axon terminals in internal organs and blood vessels
Afferents transduce different stimulus modalities into…
variable magnitude receptor potentials and variable frequency APs
What is responsible for specificity of an afferent detecting only one type of stimuli?
Specific type of ion channels found within the dendrites of the afferent
interneurons function is to…
integrate information about different stimuli to coordinate activities of organs and body systems by affecting excitability of efferent neurons
Brain Organization
brainstem
cerebellum
diencephalon
cerebrum
Brainstem
midbrain
pons
medulla
Diencephalon
hypothalamus
thalamus
cerebrum
basal nuclei
cerebral cortex
Brainstem interneurons function
- coordinate activities of: Cardiovascular sys. respiratory sys., and digestive sys.
- coordinating skeletal muscle reflexes important for posture and balance
- relaying afferent information to the thalamus
cerebellar interneurons function
- coordinating skeletal muscle reflexes important for posture and balance
- involved in planning, sequencing, and execution of complex voluntary movements
Hypothalamus interneurons function
- coordinate activities of the: renal system, digestive sys., and endocrine system.
- coordinate activities of: cardiovascular sys., integumentary sys., and muscular sys.
- coordinate the thirst response by communicating with cerebral cortex
- coordinating satiety response for energy balance and nutrient level regulation
Thalamus interneurons function
- relay afferent info to cerebral cortex
- have role in eliciting emotions
Basal nuclei interneurons function
coordinating and refine posture and voluntary movement
Cerebral cortex - cortical neurons
- eliciting conscious perception of stimuli
- planning and sequencing and inhibition of voluntary movement
- more complex functions: learning and memory, cognition, decision making, and emotion
what is the sensory areas of the cortex responsible for
eliciting conscious perception of stimuli
what is the motor areas of the cortex responsible for
planning, sequencing, and inhibition of voluntary movement
voluntary control of skeletal muscle
what are the association areas of the cortex responsible for
complex functions such as:
learning and memory
cognition
decision making
emotion
what is considered evolutionary the oldest part of the brain?
brainstem
what takes up 80% mass in the brain
cerebrum
spinal cord interneurons function
- coordinate activities of: digestive sys. renal sys. and reproductive sys.
- coordinating skeletal muscle reflexes, important for posture and balance.
- coordinates skeletal muscle reflexes for protection against noxious stimuli
- relay afferent info to the brain
Areas of the spinal cord
gray matter and white matter
gray matter
area containing cell bodies of spinal cord interneurons and some efferent neurons
white matter
area containing only axons; has ascending and descending tracts
ascending tracts
axons that propagate APs UP TOWARD the brain
descending tracts
axons that propagate APs DOWN THE SPINAL CORD
what does white matter mostly consist of?
white matter
Peripheral Nervous System
any nervous tissue outside the brain and spinal cord
what constitutes the PNS?
nerves and ganglia
Classification of nerves
cranial and spinal nerves
Cranial nerves
originate from brainstem (bilateral; organized by pairs)
How many pairs are there of cranial nerves?
12 pairs
7 pairs of cranial nerves
are mixed nerves, contains both afferent and efferent axons
3 pairs of cranial nerves
are afferent axons only
2 pairs of cranial nerves
are efferent axons only
11 of the 12 cranial nerves innervate
tissues in the head and neck
Cranial nerve X
innervates many thoracic and abdominal organs
