Exam 2 Flashcards
What are some functions of the nervous system?
Communication and control of all body activities
Monitor of internal and external environment
What are the 3 componenets of the nervous system?
Brain
Spinal cord
Nerves
What are the 2 main divisions of the nervous system? What is a minor third section?
Central nervous system (CNS)
Peripheral nervous system (PNS)
Enteric nervous system (ENS)
What composes the CNS?
Brain and spinal cord
What composes the PNS? What is it’s function?
All nerves of the body
Carries information between CNS and other parts of the body
What is the ENS in charge of? What is the ENS controlled by?
Digestive activities
Controlled by autonomic nervous system
What are the two divisions of the PNS? What direction does the nervous signal go for each?
Afferent - sensors to CNS
Efferent - CNS to effector organs (muscles, glands, other organs)
What are the 3 nervous systems that fall under the efferent classification? What environments do they interact with?
Somatic - outside world
Autonomic - internal
Includes enteric - digestive
What do the somatic nervous system signal to?
Fibers of motor neurons that supply skeletal muscles
Voluntary organs
What do the autonomic nervous system signal to?
Smooth muscle, cardiac muscle, glands, other motor organs
Involuntary organs
What are the 2 divisions of the autonomic nervous system? What “catch phrase” summarizes their function?
Sympathetic - fight or flight (stimulation)
Parasympathetic - feed and breed (relaxation)
What are the primary cells that encompass nervous tissue?
Neurons - make up brain, spinal cord, and nerves
What are some characteristics of neurons?
High maintenance:
High requirement for O2
Cannot reproduce
Need support cells called glial cells
What are the 3 structures in a neuron?
Central cell body
Dendrites
Axon
Describe the central cell body of a neuron -
resembles the typical cell
Describe dendrites in a neuron -
process and increase surface area
Describe the axon in a neuron -
outgoing information
<1 micrometer to >1 meter in length
What are the neuron cell types in the CNS called? Where are they found?
Interneurons
In the CNS between afferent and efferent neurons
What are some things interneurons are responsible for?
planning, memory, creativity, intellect, motivation, and other complex actions
more interneurons = more complex action
What are the neuron cell types in the PS called? Where are they found?
Afferent neuron - cell body in PNS and axon terminals in CNS
Efferent neuron - cell body in CNS with axon terminals in PNS
What are the support cells for neurons called? How many per neuron?
glial cells
10 glial cells per 1 neuron
connective tissue of the CNS
What are the 6 types of glial cells in the CNS?
astrocytes
oligodendrocytes
ependymal
microglia
schwan cells
satellite cells
Describe astrocytes
glial cell
star shaped
most abundant
“glue” of the CNS - BBB, brain injury repair, nutrient transport from blood to neurons
Describe oligodendrocytes
glial cell
insulator
form myelin sheath
multilayered
white
phospholipid
segmented covering
Describe ependymal cells
glial cells
neural stem cells
line ventricles of brain and help form/move cerebrospinal fluid
Describe microglia
glial cell
immune cell derived from type of white blood cell
stationary until infection/injury
Describe schwan cells
glial cell
form myelin sheath
multilayered
white
phospholipid
segmented
Nodes of Ranvier
Describe stellite cells
glial cell
“glue” of the CNS - BBB, brain injury repair, nutrient transport from blood to neurons
What are nerves?
bundles of peripheral neuronal axons
afferent and efferent neurons encased in connective tissue
How do afferent nerves work?
incoming signals –> enter through dorsal root of nerve
sensory nerves
How do efferent nerves work?
outgoing signals –> leave through the ventral root
motor nerves
What are the 3 parts of the vertebrate brain? What are the other terminology for each term and parts of them?
hindbrain - brainstem
medulla, pons, midbrain
midbrain - cerebellum
forebrain
hypothalamus, thalamus, basal nuclei, cerebral cortex
Describe the brainstem
the smallest region of the CNS
continuous to the spinal cord
midbrain, pond, and medulla
What are the functions of the brainstem?
sensation inputs and motor outputs via 12 pairs of cranial nerves
reflex control of the heart, blood vessels, respiration, and digestion via the pons and medulla
modulating sense of pain
regulation of muscle reflexes related to the equilibrium and posture
reticular activating system
controls the degree of cortical alertness
some sleep function
Describe the cerebellum
Rear portion of the brain
more individual neurons than rest of brain
made of 3 distinct parts
vestibulocerebellum
cerebrocerebellum
spinocerebellum
very convulated (wrinkly) - more neurons
What are the three parts of the cerebellum?
vestibulocerebellum
cerebrocerebellum
spinocerebellum
What is the function of the vestibulocerebellum?
balance and eye movement
What is the function of the cerebrocerebellum?
planning nonreflex muscle activity
What is the function of the spinocerebellum?
enhances muscle tone and coordinates skilled, nonreflex movements
What are the two major subdivisions of the forebrain?
diencephalon (inner)
cerebrum (outer)
What are the two sections of the diencephalon?
hypothalamus
thalamus
Describe the thalamus
relay station for preliminary processing of sensory input
direct attention to stimuli of interest
Describe the hypothalamus
homeostatic and endocrine functions
What are the two sections of the cerebrum?
basal nuclei (inner layer)
cerebral cortex (outer layer)
Describe the cerebrum
largest part of brain
more convoluted (grooves)
left and right side connected by corpus callosum
What is the corpus callosum
connective tissue between the left and right sides of the cerebrum
Describe the basal nuclei/ganglia
inhibition of muscle tone
coordination of slow, sustained movement
suppression of useless patterns of movement
Describe the cerebral cortex
has left and right half seperated by corpus callosum
contains white and gray matter
4 pairs of functional lobes
Describe grey matter of the cerebral cortex
neural cell bosies, dendrites, and glial cells
computer of the brain
Describe white matter of the cerebral cortex
bundles/tracts of myelinated axons
contains myelin (white due to lipids)
wires of the brain
What are the lobes of the cerebral cortex?
Occipital
Temporal
Paritel
Frontal
What does the occipital lobe do? Where is it located?
initial perception and visual input
back of head
What does the temporal lobe do? Where is it located?
auditory sensation
sides of the head
What does the parietal lobe do? WHere is it located?
receiving and processing body sensory input
behind the central sulcus
top of head
What does the frontal lobe do? Where is it located?
nonreflex motor activity, vocal ability, long-term memory, higher mental functions
in front of central sulcus
front of head
What nervous system does the spinal cord belong to?
CNS
What is the vertebrate spinal cord?
long, slender cylinder of nerve tissue
18 inches long, thumb wide
How far does the vertebrate spinal cord extend?
to the 1st or 2nd lumbar vertebrate
ascends and descends signals
How do you identify spinal nerves?
number determined by species and length of body
named by region of vertebral column
How many cervical spinal nerve pairs? Thoracic? Lumbar? Sacral? Coccygeal?
8
12
5
5
1
spinal cord ends at beginning of lumbar with sacral and coccygeal being extension of nerves
What are the 4 major features for protection of the CNS?
skull
meninges
cerebrospinal fluid
blood-brain barrier
What encompasses the meninges?
dura mater (outer)
arachnoid mater (middle)
pia mater (inner)
What encompasses cerebrospinal fluid?
clear fluid
shock absorber
carries nutrients
removes waste
What encompasses the blood-brain barrier?
capillary bed
transporeters
What are the layers of protection of the CNS starting from outermost to innermost?
skin
aponeurosis
periosteum
bone
dura mater
arachnoid mater
Nerve impulses help maintain what?
homeostasis
What is the number of the resting membrane potential for nerves? What ions are used and what is their concentration?
-70 mV
K+ high intracellular
Na+ higher extracellular
What is active transport?
Na+ per 2 K+
Na+ is actively transported outside the cell
K+ is actively transported into the neuron
What is action potential?
sequence of rapidly occurring events that depolarize the membrane potential, then repolarize back to resting membrane potential
What are the two components of action potential?
excitability - ability of nerve impulses to respond to stimuli and convert it to nerve impulses
stimulus - change in environment initiates an impulse. examples are electrical, physical, chemical, mechanical, and temperature
What does the phrase All or None apply to?
action potential
Describe depolarization of the membrane of a neuron
stimuli opens Na+ channels, Na+ enters the cell
inside of cell becomes positively charged
membrane p[potential becomes +30mV
Describe repolarization of the membrane of a neuron
inflow of Na+ slows, causing Na+ channels to close and K+ channels to open
K+ leaves cell and establishes the resting membrane potential of -70 mV
What is hyperpolarization?
membrane potential becomes lower than -70mV after repolarization
What are the two types of action potential conduction?
continous
saltatory
What is continuous conduction of action potential?
step-by-step depolarization
unmyelinated fibers
continous transmission of nerve impulse
What is saltatory conduction of action potentials?
conduction pulse jumps between Nodes of Ranvier
myelinated fibers
requires less energy –> less membrane depolariazation
Define electrical synapse/gap junction. Where does it occur? What are some advantages?
ion current directly from one cell to another
visceral smooth muscle
cardiac muscle
developing embryos
faster than chemical synapse
synchronized nerve/muscle activity
Define chemical synapse. What are some characteristics?
extracellular fluid is in synaptic cleft, preventing pulses from continuously transmitting
neurotransmitters help transport nerve pulses
Ca2+
lower than electrical synoapses
susceptible to lack of oxygen (fatigue)
drugs can inhibit impulse
What type of cellular component are axons missing?
rough endoplasmic reticulum
Describe axonal transport
slow axonal transport
-cytoplasmic flow
fast axonal transport
-motor proteins cause movement
What is the neurotransmitter involved in the PNS? Is it excitatory or inhibitory?
acetylcholine
excitatory or inhibitory
What are the neurotransmitters involved in the CNS? Are they excitatory or inhibitory?
acetylcholine - excitatory or inhibitory
glutamate/asparate - excitatory
GABA/glycine - inhibitory
norepinephrine/epinephrine/dopamine - excitatory or inhibitory
nitric oxide/carbon monoxide - not indicated
What are the neuropeptides in the CNS and PNS? Are they excitatory or inhibitory?
hormone - oxytocin, melatonin, etc
excitatory or inhibitory
What are the different types of muscle tissue?
skeletal
cardiac
smooth
What muscle types are striated? Unstriated?
skeletal and cardiac
smooth
What muscle tissues are voluntary? Involuntary?
skeletal
cardiac + smooth
What are the characteristics of skeletal muscle?
causes movement of the skeleton
voluntary striated muscle
multinucleated
How much of total body weight is skeletal muscle?
40%
What are the muscle terminology for muscle cell? Cell membrane? Cytoplasm? Modified endoplasmic reticulum?
muscle fiber
sarcolemma
sarcoplasm
sarcoplasmic reticulum
What is the purpose of connective tissue in muscles?
houses the group of muscle fibers into muscle fasicles
What are muscle fascicles?
groups of adjacent muscle fibers bundled together
What are the 4 main components of the skeletal muscle?
connective tissue
muscle fasicles
blood vessels
nerves
What are muscle fibers?
large, elongated, cylindrical cells that run parallel and the entire length of the muscle
What are the sarcolemma/t-tubules?
continuation of muscle fiber membrane
Muscle fibers contain what?
sarcolemma
sarcoplasm
-MYOFIBRILS
multiple nuclei
What is the sarcoplasmic reticulum?
modified ER with longitudinal tubules
What are myofibrils?
specialized contractile units
What encompasses the sarcoplasm of the muscles?
sarcoplasmic reticulum
myofribrils
mitochondria
glycogen granules
What are myofribrils composed of?
troponin
actin
tropomyosin
myosin
titin
nebulin
What are the layers of muscle connective tissue? What do they surround?
epimysium - muscle
perimysium - muscle bundle
endomysium - muscle fibers
What is myosin?
thick filament
protein chains that intertwine with tadpole heads
-stiff tail and hinge region
creates movement
head is actin binding site
myosin ATPase binding site
What is the myosin ATPase binding site?
motor domain
binds ATP
considered an enzyme
Describe actin
thin filament
-g actin (globular)
-f actin (filament)
f actin is made of a chain of g actin
Define tropomyosin
thin filament
protein that lie on the edge of the actin spiral
blocks actin-binding site to block muscle contraction
Describe troponin
thin filament
3 binding units
-tropomyosin binding TnT
-actin bindingTnI
-calcium bindingTnC
Describe titin
huge elastic molecule
stabilizes position of contractile filaments
elasticity returns stretched muscle to resting length
Describe nebulin
huge inelastic molecule
aligns actin filamnent
attaches to Z disk
Define sarcomere
contractile unit of myofibril
What are the 5 elements of the sarcomere?
z line
I band
A band
H zone
M line
Describe Z line of sarcomere
zigzag proteins structure
attachment site for THIN filaments
2 per sarcomere (one on each end)
Describe I band of the sarcomere
lightest colored band
only thin filament space
Z line runs between I bands
Describe A band of the sarcomere
darkest colored band
entire length of thick filament
overlaps with thin filament at edges
Describe H zone of the sarcomere
central region of A band
thick filament only
Describe M line of the sarcomere
protein structure that is attachment site for THICK filaments
divides A band in half
Define contraction
creation of force to move or resist a load
active process requiring ATP
escribe the sliding filament theory of contraction
thin filament move inward
z lines move closer together
sarcomere shortens
Define neuromuscular junction
chemical synapse formed by a motor neuron terminal and a muscle fiber
release ACh to stimulate contraction
release AChE to stop contraction
What is the path from interpreting pain to stopping pain (feel heat and pul away from heat) inmuscular contration?
Sensation of environment
actional potential created in afferent neuron
depolarization of afferent neuron
hyperpolarization of afferent
repolarization of afferent neuron
action potential to neuron
action potential to efferent neuron
depolarization of efferent neuron
hyperpolarization of efferent neuron
repolarization of efferent neuron
action potential causes Ca2+ channels to open
exocytosis of ACh via chemical synapse
action potential to muscle cell
impulse through sarcolemma/t-tubules
terminal cisternaw release Ca2+
Ca2+ binds to troponin
troponin binds to tropomyosin and moves
ATP binds myosin
myosin binds actin and forms crossbridge
power stroke pushes actin towards sarcomere
movement of skeletal muscle
Describe power stroke
in presence of Ca2+-troponin binding, myosin cross bridge swivels and pushes actin filaments towards center of sarcomere
Describe smooth muscle. What are some characteristics?
encloses and controls movement of contents via hollow tubes
spindle shaped
no striations
single nucleus
smooth involuntary
What filaments are in smooth muscle?
myosin and actin
Describe the cardiac muscle. What are some characteristics?
responsible for pumping blood out of heart
found only in the heart
shape-branching network of cells
striated
single nuclei
involuntary
What are the necessary functions of cells to be able to regulate body functions?
grow
reproduce
metabolize nutrients
process information
What are other components besides cells that can help regulate the body?
biochemical reactions caused by nervous/endocrine systems
-chemical messengers
Describe hormones
chemical messenger produced by a specific gland
secreted into the blood or other fluid spaces
acts on distant tissues or cells
What do hormone receptors allow?
tissue specificity
Where are hormone receptors located?
cell membrane
-protein hormones
nuclear
-steroid and thyroid hormones
cyctolic
-possible steroid and protein
What are some characteristics of hormones?
modify an exisiting process
act as a stimulus
not be secreted at a constant rate
secreted independently
be present in very small amounts
What are the 3 types of hormones? How are they categorized?
peptide
amine
steroid
biochemical structure
Define peptide hormones
specific amino acid chains
short chain - peptide
long chain - protein
Define amine hormones
derived from amino acid tyrosine
secreted from thyroid and adrenal medulla
Define steroid hormones
neutral lipids derived from cholesterol
What hormones require secondary messenger systems?
peptide and amine
needed as first messenger is hydrophilic and cannot pass through phospholipid bilayer
What hormone requires mode of action?
steroid
enters cell by diffusion
Describe negative feedback and gvive an example
one hormone inhibits release of another
increased insulin decreases blood glucose
Describe positive feedback and give and example
one hormone stimulates release of another
increased estrogen stimulates release of GnRH, LH, FSH
What organs only function in the endocrine system?
pituitary gland
parathyroid gland
thyroid gland
adrenal gland
What organs have a mixed funcion in the endocrine system?
hypothalamus
thymus
heart
stomach
pancreas
duodenum
kidney
skin
ovaries
placenta
testes
What organ has an uncertain function in the endocrine system?
pineal gland
Describe the pineal gland. What hormone does it produce?
tiny, pinecone shaped in the center of the brain
melatonin
Describe melatonin
indoleamine (AMINE) hormone that affects mood and sleep-wake cycle
synthesized from seratonin
hormone of darkness
Describe the circadian rhythm
24 hour cycle in the physiological processes of living beings
can be manipulated
duration of melatonin each day is directly proportional to length of night
What time of day does melatonin peak? At what age does melatonin opeak?
middle of the night
early childhood
Describe seasonal estrus
melatonin is an anti-gonadotrophic hormone
inhibits LH and FSH
hat is an example of a long-day breeder? Short-day breeder?
horse and groundhog
sheep and deer
Describe the hyypothalamus
regulate pituitary
secretes peptide hormones
What hormones are released by the hypothalamus and directed to the pituitary?
thyrotropin-releasing hormone TRH
corticotropin-releasing homrone CRH
gonadotropin-releasing hormone GnRH
growth hormone-releasing homrone GHRH
growth hormone-inhibiting hormone GHIH
prolactin-releasing hormone PRH
prolactin-inhibiting hormone PIH
Describe what the thyrotropin-releasing hormone does
paraventricular nucleus
thyroid stimulating hormone becomes released from the anterior pituitary
Describe what the prolactin-releasing hormone does
paraventricular nucleus
stimulates prolactin release from anterior pituitary
Describe what the prolactin-inhibiting hormone does
dopamine
arcuate nucleus
inhibits release of prolactin from anterior pituitary
Describe what the corticotrophin-releasing
hormone does
paraventricular nucleus
adrenocorticotropic (ACTH) release from anterior pituitary
Describe what the gonadotropin-releasing hormone does
preoptic area
FSH and LH from anterior pituitary
Describe what the growth hormone-releasing hormone does
arcuate nucleus
stimulates growth hormone release from anterior pituitary
Describe what the growth hormone-inhibiting hormone does
somatostatin
periventricular nucleus
inhibits growth hormone release from anterior pituitary
What relationship does the hypothalamus have with the pituitary? Specific linkages for the anterior? Posterior?
regulates the pituitary through a direct connection
anterior pituitary is connected to the hypothalamus via portal blood system
posterior pituitary is connected to the hypothalamus via specialized nerves
What is the pituitary gland?
double lobed gland located just below the hypothalamus
anterior creates and releases hormones
posterior stores and releases oxytocin and ADH
Describe the anterior pituitary. What 6 peptide hormones does it synthesize, store, and release?
growth hormone (somatotropin)
thyroid-stimulating hormone (thyrotropin)
adrenocorticotropic hormone (ACTH)
prolactin
gonadotropins
What are gonadotropins?
follicle stimulating hormone and luteinizing hormone (FSH and LH)
What type of tissue is the anterior pituitary?
glandular epithelial tissue (5 different cell populations)
Describe thyroid stimulating hormones
secreted by thyrotropes
stimulates secretion of thyroid hormone and growth of thyroid
hypothyroidism occurs if absent
regulated by thyroid releasing hormone
What is hypothyroidism
thyroid becomes atrophic
Describe adrenocorticotropic hormone
ACTH
secreted by corticotropes
stimulates cortisol secretion by adrenal cortex and growth of adrenal cortex
absence leads to inability to respond to stressful situations
regulated by external stimuli
Describe the sternum
breastbone
consists of sternebrae
What is the first sternebrae called?
manubrium
What is the last sternebrae called?
xiphoid
Describe the ribs
protect the chest cavity
paired
sternal ribs, asternal ribs, and floating ribs
dorsal contains bone, ventral contains costal cartilage
What does the appendicular skeleton consist of?
thoracic and pelvic limbs
What three bones are fused together to make the pelvic girdle?
ilium
ischium
pubis
What are examples of hooks and pins?
ilium and ischium
What are the parts of the visceral skeleton?
os cordis, os rostin, os penis
What is the os cordis?
bone in heart of cattle and sheep
What is the os rostri?
bone in snout of swine
What are the 3 types of joints?
fibrous
cartilaginous
synovial
What is an example of a fibrous joint?
the joints between the bones of the skull
What is an example of a cartilaginous joint?
intervertebral disks between vertebrae
What is an example of a synovial joint?
knees and elbows
What are the 4 types of synovial joints?
hinge
gliding
pivot
ball and socket
What are the different types of synovial joint movement and their definition?
flexion - decrease angle
extension - increase angle
adduction - move towards median
abduction - move away from median
rotation - twist along own axis
circumduction - distal end moves in circle
Describe hinge joint. Give an example
move on one plane
only capable of flexion and extension
elbow joint
Describe gliding joint. Give an examplke
slight rocking movement
flexion and extension capable
carpal joint
Describe pivot joint. Give an example
rotary movement only
neck; only pivot joint
Describe ball and socket joint. Give an example
extensive movement
capable of all synovial joint movements
hip joint
