Physiology 2 Flashcards
After 4 and 5 weeks after conceptions what structures are formed from the neural tube
forebrain, midbrain, hindbrain
What does the forebrain consist of
Diencephalon(thalamus, hypothalamus) and cerebral hemispheres
mesencephalon
midbrain
Hindbrain
pons, cerebellum, medulla oblongata
CSF travels freely through
subarachnoid space, central canal, and ventricles of brain
Largest portion of the brain~ 80% of mass
Cerebrum
The right/left cerebral hemispheres are connected by
corpus callosum
Raised folds are called… these folds are separated by depressed grooves called…. together called….
gyri, sulci, convolutions
Each hemisphere is divided deep sulci or fissures making up…
5 lobes
5 lobes
frontal, parietal, temporal, occipital, insula
Frontal and parietal lobes are separated by what sulcus
central sulcus
pre central gyrus (also called) is located… and is responsible for ….. neurons here are called…
(Primary motor cortex)-frontal lobe, motor control, upper motor neurons
Involved with control of voluntary muscles
postcentral gyrus is located in… and is responsible for… also called the…
parietal lobe, somatesthetic sensation (coming from receptors in skin, muscles, tendons, joints), somatosensory cortex
cutaneous and proprioceptive senses
Auditory center
temporal lobe
vision and coordination of eyes
occipital lobe
insula function
memory and integration of sensory responses with visceral responses: receives olfactory, gustatory, auditory, and pain information
What hemisphere is dominant and what is its function
left: language and analytical ability
right hemisphere is specialized for
spatial comprehension
Motor speech area is …. located where….
broca’s area; left inferior frontal gyrus
understanding language area is…. located where…..
wernickes area; m left superior temporal gyrus
information about written words is sent by
occipital lobe; visual cortex
werickes aphasia destroys
spoken and written language comprehension
Describe how speech works ( include brocas and wernickes areas)
Auditory and visual info is sent to wernickes area that will then send a signal to brocas area along the arcuate fasciculus. brocas area sends information to primary motor cortex to direct movement of appropriate muscles
Diencephalon includes and is surrounded by
it is part of forebrain that includes epithalamus, thalamus, hypothalamus, part of pituitary gland, and the third ventricle. Surrounded by cerebral hemispheres.
Thalamus is… it acts as…. for …
paired masses of gray matter, relay center, for all sensory information except smell and sends to cerebrum
Epithalamus
contains choroid plexus and pineal gland
Hypothalamus
maintains homeostasis and regulates ANS; contains centers for hunger/satiety and thirst, regulation of body temp, regulation of sleep and wake, sexual arousal/performance, emotions of fear, anger, and pleasure, control of the endocrine system, controls hormone secretion from the pituitary gland
Regions of hypothalamus (5)
lateral: hunger Medial:satiety
per optic-anterior: shivering, hyperventilation, vasodilation, sweating
supraoptic: ADH production
paraventricular: oxytocin
cerebellum
gray matter outside, white matter inside. receive input from procioceptors in joints tendons and muscles. Needed for motor learning and proper timing and force required to move limbs in a specific task.
medulla oblongata
Has vital centers:
vasomotor center- controls blood vessel diameter
cardiac control center- controls heart rate
respiratory(rhythmicity) center- works with areas in pons to control breathing
white matter is composed of… arranged in…
ascending and descending fiber tracts; funiculi (6 columns)
ascending tracts
carry sensory impulses, given the prefix spino- and suffix of where it synapses
spinothalamic is what type of tract
ascending tract
anterior corticospinal tract is what type of tract
descending tract
descending tracts
carry motor impulses, given the suffix -spinal and the prefix of where they come from
pituitary gland is connection between
nervous system and endocrine system
somatic motor neurons have their cell bodies within the… and send axons to…
CNS, skeletal muscles
The stretch reflex does not depend on activation of
upper motor neurons
upper motor neurons vs lower motor neurons
upper motor neurons originate in the cerebral cortex and travel down to the brain stem or spinal cord, while the lower motor neurons begin in the spinal cord and go on to innervate muscles and glands throughout the body
Muscle stretch reflex
has only one synapse-monosynaptic reflex. Sensory neuron directly synapses with motor neuron(no interneuron)
Monosynaptic reflex arc
streching stimulation of muscle-sensory receptor- sensory neuron (dorsal root)- motor neuron (ventral horn)- muscular effector(contraction)
streching stimulation
sensory receptor-sensory neuron (dorsal root)- interneuron in CNS(inhibitory)- motor neuron (ventral horn)- muscular effect (antagonistic muscle relax)
What passes to the brain that allows conscious awareness that reflex has occurred
action potential
Reciprocal Innervation
stimulation of motor neurons to agonist muscle and inhibition of motor neurons to antagonist muscle
Reflexes that do not send to or receive signals from the brain
spinal reflexes
somatic motor neurons have cell bodies in the … and #? neuron(s) traveling from …. to ….
spinal cord, 1, spinal cord to effector
The ANS has how many sets of neurons in PNS
2
Preganglionic vs postganglionic neurons
pre- cell bodies in brain or spinal cord and synapses in an autonomic ganglion
post- cell bodies in autonomic ganglion and synapses on effector
Preganglionic neurons of sympathetic division come from _____ division of spinal cord
T1-L2 or thoracolumbar division
Preganglionic neurons of sympathetic division synapse in _____ that run ____ to spinal cord
sympathetic ganglia that run parallel to spinal cord also called paravertebral ganglia
paravertebral ganglia are connected and form a
sympathetic chain of ganglia
Divergence vs Convergence
Divergence is when one preganglionic neuron synapse on several postganglionic neurons at different levels
convergence is when several preganglionic neurons at different levels synapse at one postganglionic neuron
Preganglionic fibers that exit the spinal cord below the diaphragm pass through the sympathetic trunk without synapsing. Beyond the sympathetic chain these fibers are called
splanchnic nerves
preganglionic fibers in splanchnic nerves synapse in
collateral ganglia
collateral ganglia include
celiac, superior mesenteric, and inferior mesenteric ganglia
Postganglionic fibers that arise from the collateral ganglia innervate what
organs of the digestive, urinary, and reproductive systems
The adrenal _____ secretes _____ and _____ when stimulated by the sympathetic nervous system as part of mass activation
medulla, epinephrine and norepinephrine
mass activation
divergence and convergence can activates the entire sympathetic division for flight or flight responses in response to visceral stimuli
The adrenal medulla is a ____ _____ and is innervated directly by ____ _____ ____
modified ganglion, preganglionic sympathetic neurons
adrenal glands are apart of what division
sympathetic
preganglionic neurons of parasympathetic division come from the _____ or ______ of the spinal cord
brain or sacral region of spinal cord or together craniosacral regions
PS preganglionic neurons synapse on ____ located near or in _____ called _____
ganglia, effector organs, terminal ganglia
terminal ganglia supply very ____ postganglionic neurons to the ____
short, effectors
sympathetic function
activates fight or flight through release or norepinephrine from postganglionic neurons and secretes epinephrine from adrenal medulla, prepares body for intense physical activity by increasing heart rate and glucose and diverting blood to skeletal muscles, tonically regulates heart, blood vessels, and other organs
parasympathetic functions
rest and digest through release of Ash from postganglionic neurons, slows hear rate and increases digestive activities
What is the neurotransmitter of ALL preganglionic axons
ACh
Cholinergic
nerve endings that when stimulated release ACh, released by most parasympathetic post ganglionic neurons
Adrenergic
nerve endings that release epinephrine, norepinephrine, released by most sympathetic postganglionic neurons
Response to adrenergic stimulation
can be epinephrine in blood or norepinephrine from sympathetic nerves;
stimulation: heart, dilatory muscles of iris, vasoconstriction of blood vessels ( contracts smooth muscle)
inhibition: bronchioles of lungs, other blood vessels; inhibits contraction and dilation
Types of adrenergic receptors and functions
alpha and beta
Alpha receptors are more sensitive to norepinephrine
Beta receptors are more sensitive to blood epinephrine
Response to cholinergic stimulation
ACh from all preganglionic neurons is stimulatory
ACh from postganglionic neurons in PS is stimulatory usually but some are inhibitory
cholinergic receptors
Nicotinic- found in autonomic ganglia and skeletal muscle, stimulated by ACh from preganglionic neurons, serve as ligand gated Channels for Na and K
Muscarinic- found in visceral organs and stimulated by release of ACh from postganglionic neurons, can by stimulatory or inhibitory (opening Ca Na, or K channels), use G proteins and second messenger system
nicotinic receptors in skeletal muscle cause _____ producing ____ its mechanism is
depolarization, action potentials and muscle contraction, ACh opens cation channels in receptor
nicotinic receptors in autonomic ganglia respond by ______ and causing _____ the mechanism is ____
depolarization, postganglionic neuron activation, ACh opens cation channels in receptor
Musarinic receptors in smooth muscles and gland vs heart
response in smooth muscle and glands is depolarization causing contraction and secretion
response in heart is hyper polarization, slowing rate of spontaneous depolarization
Mechanisms- ACh activates g-protein coupled receptors opening Ca channels in smooth muscles and glands while K channels open in heart
preganglionic fibers of the parasympathetic division originate from
the brain (midbrain, pons, medulla) and in the sacral region
What fibers occur in spinal nerves
sympathetic
which fibers innervate the structures of the skin and why
Only sympathetic fibers occur in spinal nerves; therefore they are the only type to innervate blood vessels, sweat glands, and arrector pili muscles of the skin.
cholinergic neurons
all preganglionic neurons, all somatic motor neurons, and parasympathetic postganglionic neurons
Functions of circulatory system
transportation (respiratory gases, nutrients, and wastes), regulation (temperature and hormones), protection (clotting and immunity)
Components of circulatory system
cardiovascular system- heart and blood vessels
lymphatic system- lymphatic vessels, lymphoid tissues, lymphatic organs (spleen, thymus, lymph nodes)
Lub Dub sounds caused by
closing of AV valves (ventricular systole), closing of semilunar valves (ventricular diastole)
heart mumur
abnormal heart sound due to abnormal blood flow may be caused by defective valves
mitral stenosis
mitral valve calcifies and impairs flow between left atrium and ventricle, may result in thick RV and pulmonary hypertension
Isovolumetric contraction
ventricles begin contraction, pressure rises, AV valves close (lub)
ejection
pressure builds, semilunar valves open, and blood is ejected into arteries
isovolumetric relaxation
pressure in ventricles falls, semilunar valves close (dub)
rapid fill
pressure in ventricles is less than atria, AV valves open, ventricles fill
atrial contraction
atria contract, sending last of blood to ventricles
cardiac output
(stroke volume x cardiac rate) the volume of blood pumped each minute by each ventricle
average heart rate, stroke volume, and cardiac output
70 bpm, 70 to 80 ml/beat, 5500 ml/min
what neurotransmitters and cardiac center affect heart beat
medulla oblongata;
sympathetic norepinephrine increase heart beat
parasympathetic (vagus nerve) acetylcholine slows heart rate
End-diastolic volume
total volume of blood in the ventricles at the end of diastole
End-systolic volume
total volume of blood left in ventricles after systole (1/3 of end-diastolic volume)
Stroke volume is affected by what three things
preload, contractility, and afterload
Preload also known as EDV
the tension on the ventricular walls produced by their filling with the end diastolic volume of blood (the load ion a muscle before it contracts)
contractility
strength of ventricular contraction
afterload
the total peripheral resistance, presents an impedance to the ejection of blood from the ventricles at systole
Frank-Starling law of the heart
the relationship between EDV, contraction strength, and stroke volume is an intrinsic property of a heart muscle. If one variable increase then so do the others
venous pressure/return
draining of blood into the atria
external vs internal respiration
external- ventilation/gas exchange in lungs
internal- oxygen utilization/ gas exchange in tissues
conducting zone
transports air to lungs. humidifies, warms, filters, and cleans air, voice production
External intercostal muscles
raises rib cage during inspiration
internal intercostal muscles
lowers rib cage during forced expiration
parasternal intercostal muscle
works with external intercostal
quiet expiration
relaxation of inspiratory muscles (passive) external and parasternal muscles relax
forced expiration
internal intercostal muscles contract to lower ribs
spirometry
records volume/frequency of air movement, measures lung volumes/ capacities
can diagnose restrictive/ obstructive Lung disorders
Tidal volume (movement like a calm waves)
amount of air exhaled or inhaled in quiet breathing
Expiratory reserve volume
air that can be forced out after tidal volume
inspiratory reserve volume
amount of air that can be forced in after tidal volume
residual volume
amount of air left in lungs after max expiration
Vital capacity
max amount of air that can be forcefully exhaled after max inhalation
total lung capacity
amount of gas in lungs after max inspiration
inspiratory capacity
amount of gas that can be inspired after normal expiration
Functional residual capacity
amount of air left in lungs after normal expiration
IRV+ERV+TV=?
Vital Capacity
RV+ERV=
Functional residual capacity
vital capacity+residual volume
total lung capacity
Inspiratory capacity
total lung - functional residual capacity (RV+ ERV)
IRV+TV
glutamate
major excitatory neurotransmitter in brain
80% of EPSPs in the cerebral cortex produced by glutamate
Energy needed for all of EPSPs constitutes major brain energy usage
GABA
inhibitory, opens Cl channels when it binds to receptors
most common neurotransmitter in brain
involved with motor control
glycine
produced IPSPs, opens Cl channels
makes it harder to reach threshold
spinal cord
In the heart, acetylcholine (opens/closes) K+ channels producing ______ that increase/decrease heart rate while in smooth muscle it opens/closes K+ channels, producing ________ that relax/contract these muscles
opens (by beta-gamma complex), IPSPs, decrease
closes(by alpha subunit), EPSPs, contract
