Nervous System Flashcards
constitutes the CNS
brain, spinal cord
make up the peripheral NS
nerves, sensory organs
transmit and process sensory information and coordinate bodily functions
CNS, PNS
function as the control center
brain and spinal cord (CNS)
what carries incoming and outgoing signals
Nerve pathways of the PNS
receive data and feedback from the sensory organs and from nerves throughout the body, process the information, and send commands back out
CNS
receives information from the body’s environment and generates instructions, thereby controlling all the activities of the human body
CNS
conveys this two-way information flow into and out of the CNS
PNS
The central parts of the CNS are occupied by spaces called
ventricles with CSF
Where is the brain and what forms it?
Neurocranium
- cerebrum
- cerebellum
- brainstem
placed within the vertebral column
spinal cord
transmits signals to and from the brain and commands reflexes
spinal cord
elongated cylinder of neuron cell bodies, bundles of axons protected by CT
spinal cord
signals speed in and out of the spinal cord via ______ that branch out to supply the limbs, torso, and pelvis
spinal nerves
Incoming signals demanding a simple,
immediate response which spinal cord can shootout a reflex command without bothering the brain
Reflex arc
made of neuron cell bodies found in the cerebral cortex and the central portion of the spinal cord
gray matter
made of axons, which combine and build neural pathways
white matter
where the instructions generate
gray matter
the path through which the instructions travel toward the organs
white matter
conducts information from the CNS to the target tissues, and from the target tissues to the CNS
PNS
Nerves that carry information from peripheral sense organs to CNS
ascending, afferent, or sensory nerve fibers
Fibers that carry information from the CNS to the periphery (muscles and glands)
descending, efferent motor, or secretory nerve fibers
cluster of neural tissue outside of the CNS, made of neuronal cell bodies
ganglion
ganglia can be both?
sensory and autonomic
They are associated with spinal nerves and some cranial nerves. Name the nerves.
Sensory ganglia
Cranial Nerves (V, VII, IX, X)
voluntary control over our movements and responses
somatic nervous system
Major somatic peripheral nerves
- median nerve
- sciatic nerve
- femoral nerve
controls all the internal organs unconsciously, through the associated smooth muscle and glands
autonomic nervous system
producing the “flight or fight“ state as it is part of the ANS which is mostly active during stress
Sympathetic NS
Parasympathetic dominates during rest and is more active in these activities (2)
- rest and digest
- feed and breed
Spinal nerves are divided into?
8 cervical nerves
12 thoracic nerves
5 lumbar nerves
5 sacral nerves
1 coccygeal nerve
branches of one spinal nerve may join with other nerves to form meshes where information is shared
plexuses
send signals along secondary nerve branches to areas of complex function or movement
plexuses
Cervical plexuses (C1-C4) innervates? (7)
- back of the head
- pericardium
- diaphragm via great auricular
- transverse cervical nerve
- lesser occipital
- supraclavicular
- phrenic nerves
brachial plexus (C5-T1) innervates upper limb nerves such as?
- median
- ulnar radial
- musculocutaneous
- axillary nerves
lumbar plexus innervates the muscles and skin of the abdomen and pelvis, and thigh muscles via? (7)
- iliohypogastric
- ilioinguinal
- genitofemoral
- lateral femoral cutaneous
- obturator
- femoral nerves
sacral plexus innervates the muscles and skin of?
pelvis, posterior thigh, lower leg and foot
three structures of brain stem
a. the medulla oblongata
b. the pons
c. the midbrain
connects the spinal cord to the higher-thinking centers of the brain
brain stem
continuous with the spinal cord and connects to the pons above
medulla oblongata
connects the pons to the diencephalon and forebrain
midbrain or mesencephalon
pons helps control?
breathing rhythym
medulla oblongata functions (4)
- respiration
- digestion
- circulation
- reflexes (swallowing, coughing, and sneezing)
midbrain contributes to?
- motor control
- vision
- hearing
- vision and hearing-related reflexes
region of the forebrain, connected to both the midbrain and the cerebrum
diencephalon
forms most of the diencephalon
thalamus
consists of two symmetrical egg-shaped masses, with neurons that radiate out through the cerebral cortex
diencephalon
part of the brain which determines which signals require conscious awareness, and which should be available for learning and memory
thalamus
helps to process sensory impulses of smell, taste, and vision and manages emotions such as pain and pleasure, aggression and amusement
hypothalamus
the visceral control center, regulating the endocrine system and internal functions that sustain the body day to day
hypothalamus
translates nervous system signals into activating or inhibiting hormones that it sends to the pituitary gland
hypothalamus
Functions of hypothalamus
- manages the autonomic nervous system
- signals sleep cycles
- circadian rhythm
- regulates food consumption
- monitors and adjusts body chemistry and temperature
Four lobes of cerebral cortex
1) Frontal lobe
2) Temporal lobe
3) Occipital lobe
4) Parietal lobe
In a spinal cord cross-section, the axon pathways appear as “white matter”, what makes it white?
myelin sheaths
white matter forms three columns (funiculi) on each side of the spinal cord (3)
- posterior (dorsal)
- anterior (ventral)
- lateral columns
tracts which carry sensory input up to the brain
ascending
tracts that send motor commands downward to the body
descending
involve circuits of sensory nerve fibers that feed information to the spinal cord and connect directly to motor nerve fibers without the need of brain
Spinal Reflex (process: Reflex arc))
rapid, involuntary, predictable response to a stimulus
reflex
Give three examples of Reflex Arc
- coughing
- sneezing
- swallowing
area of the skin that is mainly supplied by branches of a single spinal sensory nerve root
dermatome
Give three examples of sensation in which dermatome transmit signals from to the spinal cord
- pain symptoms
- touch
- temperature
charged cells conducting electrical signals to pass information through the body
neurons
produce a fatty material called myelin which is a good insulator along the Axon of the Neuron cell
Schwann cells
a potentially disabling disease of the brain and spinal cord which immune system attack the myelin sheath
Multiple sclerosis
Name the most common neurotransmitters
- Acetylcholine
- Epinephrine
- Norepinephrine
- Serotonin
stimulate electrical signals in other neurons and encourage responses from body cells
excitatory neurotransmitters
discourage signals and cellular responses
inhibitory transmitters
produce a watery medium within the skull known as cerebrospinal fluid
ventricles (chambers)
absorbs and disperses excessive mechanical forces which might otherwise cause serious injury in the brain
CSF
protective membrane which envelops the brain
meninges
CSF is produced in clusters of thin-walled capillaries called?
Choroid plexus
contains proteins and glucose that provide energy for brain cell function as well as lymphocytes that guard against infection
cerebrospinal fluid
What part of the brain is responsible for raising particular memories when you smell certain scent?
limbic system
Limbic system both processes (2)?
- memory
- olfaction
Constitutes limbic system
- hippocampus
- amygdala
- cingulate gyrus
- dentate gyrus
specific part of the brain which gives us conscious control of our actions
cerebrum
part of the brain which mediate sensations, manages emotions, and commands whole
internal systems
diencephalon
part of the brain responsible for adjusting body movements, speech coordination, and balance
cerebellum
Which part of the brain is responsible for relaying signals from the spinal cord and directs basic internal functions and reflexes?
brainstem
What is the seat of consciousness and where does high intellectual functions occur?
Cerebrum
the largest brain structure and part of the forebrain that not only processes sensory and motor information but enables consciousness, our ability to consider ourselves, and the outside world
cerebrum
a middle region of cerebellum connecting the 2 hemispheres
vermis
Primary functions of cerebellum
maintain posture and balance
Within the cerebellum, central white stem is found that spread branches and subbranches through the hemisphere. What is it called?
Arbor vitae
Name the five sensory organs.
- hearing
- olfaction
- gustation
- tactile perception
- vision
