Human Anatomy Chap 12, 13, 14, 15, & 16

What is the difference between sensory input, integration, and motor output?

Sensory input: (Afferent) monitors environment and detects stimulus
Integration: Receives all sensory input, makes decision, creates all motor output
Motor output: (Efferent) makes muscle contract or gland secrete, targets effector

What are examples of somatic sensory?

Outer: touch, pressure, temperature, vibration, pain, proprioception

What are examples of somatic motor?

Outer: voluntary movement, skeletal muscle

What are examples of visceral sensory?

Inner: stretch, temperature, nociception (pain), hunger, or satiety (fullness)

What are examples of visceral motor?

Inner: involuntary motor system, cardiac and smooth muscle

What organs belong in the CNS?

brain and spinal cord

What organs belong in the PNS?

cranial nerves, spinal nerves, ganglia

What is the ANS?

autonomic nervous system

What are the divisions of the ANS?

parasympathetic (resting and digesting) and sympathetic (fight or flight)

What is the difference between Nuclei and ganglia?

nuclei: clusters of somas in CNS
ganglia: clusters of somas in PNS

How are nuclei and ganglia the same?

they're both clusters of somas

What is the difference between a neuron and a neuroglia?

Neuron: functional unit of nervous system
Neuroglia: supporting cells

What are the special characteristics of a neuron?

longevity, do not divide, high metabolic rate

What is a chromatophilic substance?

rough endoplasmic reticulum and ribosomes, repairs cell membranes

What is a soma?

cell body of a neuron

What are dendrites?

has receptors, sends signals toward soma

What is an axon?

creates signals and sends signals away from soma, towards synapse

What is an axon hillock?

thickest part of soma, attaches soma to axon

What is myelin sheath?

insulating layer around axon, makes signals faster.

What are nodes of Ranvier?

gaps between schwann cells (myelin cells), only in PNS

What is a synaptic knob?

distal end of an axon (stores neurotransmitters)

What is a neurotransmitter?

a chemical that travels from one neuron to another

What is a synapse?

junction between a neuron and something else (ex: another neuron, gland, muscle)

What is an axodendritic synapse?

presynaptic axon to postsynaptic dendrite (most common)

What is an axosomatic dendrite?

Presynaptic axon and postsynaptic soma

What is a synaptic cleft?

separates plasma membrane from 2 neurons

What are the 3 structural classifications of a neuron?

1. Multipolar: 1 axon, multiple dendrites (most abundant)
2. Bipolar: 1 axon, 1 dendrite
3. Unipolar: 1 process (axon and dendrite act as one)

Where is multipolar neurons found?

in CNS

Where are bipolar neurons found?

in special senses

Where are unipolar neurons found?

somatic senses

What are the 3 functional classifications of a neuron?

1. Sensory Neuron
2. Motor Neuron
3. Interneurons

What does a sensory neuron do?

Afferent input, bipolar for senses, starts in PNS & ends in CNS

What does a motor neuron do?

motor output, starts in CNS and ends in PNS, multipolar

What does an interneuron do?

connects sensory and motor neurons, only in CNS, multipolar

What is the function of Astrocytes?

form blood brain barrier, creates nourishment for neurons

What is the function of Microglia?

phagocytosis in CNS, fights pathogens

What is the function of ependymal cells?

secretes CSF

What is the function of oligodendrocytes?

creates myelin sheath in the CNS

What is the function of the Schwann cells?

creates myelin sheath in PNS

What is the function of the satellite cells?

no known function

Which neuroglia cells are located in the CNS?

Astrocytes, microglia, ependymal, oligodendrocytes

Which neuroglia cells are located in the PNS?

Schwann and Satellite cells

What makes the myelin sheath beneficial?

makes signals faster

What is the structural difference between the myelin sheath in the CNS and the PNS?

CNS: one cell is going to myelinate multiple axons
PNS: multiple cells grow one axon

How is the grey matter and white matter organized in the CNS?

grey outside and white inside

What is a nerve?

cable-like organ in PNS

What is a nerve fiber?

an axon

What is a neurofibril?

Bundles of neurofilaments. Keeps cell from being pulled apart.

What are the connective tissues of a nerve?

epineurium, perineurium, endoneurium

Where is the endoneurium located?

superficial to the myelin sheath/ surrounds each axon

Where is the perineurium?

around each fascicle (group of nerve fibers)

Where is the epineurium?

around entire nerve

What are the parts of the reflex arc?

receptor, sensory neuron, integration center, motor neuron, effector

What is the difference between the monosynaptic reflex and polysynaptic reflex?

Monosynpatic Reflex: 1 synapse, 2 neurons
Polysynaptic Reflex: 2 synapse, 3 neurons

What is an example of monosynaptic and polysynaptic reflexes?

Monosynaptic: knee jerk
Polysynapyic: withdraw limb from danger

What is divergent circuits?

from 1 neuron to multiple neuron

What is convergent circuits?

start from multiple neurons to going to 1 neuron

What is a reverberating circuit?

repeating circuit

What does the brain stem consist of?

medulla oblongata, pons, midbrain

What does the cerebellum consist of?

right and left cerebellar hemispheres

What does the diencephalon consist of?

thalamus, hypothalamus, epithalamus

What the does the cerebrum consist of?

right and left cerebral hemispheres

What are the 5 lobes of the brain?

frontal, parietal, temporal, occipital, insula

What are brain ventricles?

hallow areas inside brain

Where are the ventricles located in the brain?

each cerebral hemisphere, around thalamus, and between pons and cerebellum

How are the ventricles connected?

interventricular foramen, cerebral aqueduct, central canal

Where does csf come from?

The ependymal cells of the brain ventricles

What are the function of csf?

buoyancy, protection, chemical stability

What is the arrangement of gray and white matter of the brain?

Gray matter is outside and white matter is inside

Which structures are in the medulla?

pyramids, inferior cerebellar peduncles, olive, reticular formation, visceral motor centers

What structures are in the pons?

middle cerebellar peduncle and pontine nucleus

What are the structures of the midbrain?

tectum, tegmentum, cerebral peduncles

What information is carried by the pyramids?

tracts for motor output

What does decussation mean?

crossing over from right to left or vice versa

What information is carried by the superior peduncles?

proprioception and motor instructions

what information is carried by the middle cerebellar peduncle?

info motor instructions from the cerebrum

What information is carried by the inferior cerebellar peduncles?

tracts into cerebellum for proprioception

What are the functions of the superior colliculi of the corpora quadrigemina?

2 superior visual reflexes

What are the functions of the inferior colliculi of the copora quadrigemina?

2 auditory reflexes

What is the path of circulation of CSF through the brain?

1. CSF is produced in choroid plexsus of each ventricle
2. CSF flows through the ventricles and into subarachnoid space via median & lateral apertures
3. CSF flows through the subarachnoid space
4. CSF is absorbed into the dural venous sinus via the subarachnoid granulations

What does decussation mean for the pyramids?

muscles on the left side are controlled by right hemisphere and vice versa

What is the function of the olive?

relay nucleus (for proprioception)

What is the function of the pontine nuclei?

relay nucleus (motor instructions from the cerebrum)

What does the cardiac center in the visceral motor center do?

sets heart rate

What does the vasomotor center do?

controls blood pressure

What does the medullary respiratory center do?

regulates respiratory rate

What does the pontine respiratory center do?

depth of breathing

What is the folia?

external ridges of the cerebellum

What is the vermis?

connects the two cerebellar hemispheres

What is the arbor vitae?

white matter underneath the cerebellar cortex

What is the cerebellar cortex?

outer layer of gray matter (covers folia)

What are the steps involved when you need to make a coordinated/balanced movement?

1. proprioception travels up spinal cord, through olive, through inferior cerebellar peduncles
2. cerebrum sends motor instruction through pontine nuclei, through middle cerebellar peduncles
3. Proprioception & motor instructions are sent from cerebellum to cerebrum through superior cerebellar peduncles. Now cerebrum knows which muscles to contract/relax

What are the parts of the diencephalon?

thalamus, hypothalamus, epithalamus

What is the function of the thalamus?

mostly relay nuclei

What is the function of the hypothalamus?

controls pituitary gland, ANS, body temp, basic drives, behavior/emotion, memory, circadian rhythm (sleep/awake cycles)

What is the function of the epithalamus?

secretes melatonin

What does the longitudinal fissure do?

separates left and right hemispheres

What would you find inside the longitudinal fissure?

corpus callosum and falx cerebri (dura mater)

What does the transverse fissure do?

separates cerebrum and cerebellum

What would you find inside the transverse fissure?

the corpora quadrigemina and tentorium cerebelli (dura mater)