Quizlet Midterm Flashcards
Muscle insertion
Place where the muscle ends
Deltoid (Origin, insertion, and action)
Triangle shaped, covers shoulder
Origin: acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral fibers) and spine of scapula (posterior fibers)
Insertion: deltoid tuberosity of humerus
Action: lateral fibers abduct arm at shoulder joint; anterior fibers flex and medially rotate arm at shoulder joint, posterior fibers extend and laterally rotate arm at shoulder joint.
Gluteus maximus (origin, insertion, and action)
Sacrum to beneath greater trochanter of femur
Origin: iliac crest, sacrum, coccyx, and aponeurosis of sacrospinalis
Insertion: iliotibial tract of fascia lata and superior lateral part of linea aspera (gluteal tuberosity) under greater trochanter of femur
Action: extends thigh at hip joint and laterally rotates thigh; helps lock knee in extension
Quadriceps femoris
Covers most of anterior surface and sides of the thigh: rectus femoris, vastus laterlais, vastus medialis, vastus intermedius.
Rectus femoris (origin, insertion, and action)
Anterior aspect of thigh
Origin: anterior inferior iliac spine
Insertion: patella via quadriceps tendon and then tibial tuberosity via patellar ligament
Action: Quads together extend leg at knee joint; acting alone, flexes thigh at hip joint
Vastus laterlais (action)
Lateral aspect of thigh
Action: extend leg at knee joint
Vastus medialis (action)
Medial aspect of thigh
Action: extend leg at knee joint
Five ion channels
- Electrochemical
- Leak channels
- Ligand gated channels
- Mechanical gated channels
- Voltage gated channels
Electrochemical gradient
A concentration difference + an electrical difference = ions move from higher concentration to lower concentration 9chemical part of the gradient) and negative anions move toward a positive area (electrical part of the gradient)
Leak channels
Gates randomly alternate between open and closed positions. Typically, plasma membranes have far more K+ leak channels than Na+ leak channels, and the K+ leak channels are leakier than the Na+ leak channels. Therefore, the membranes permeability to K+ is much higher than Na+. Leak channels are found in nearly all cells, incl. dendrites, cell bodies, and axons of all neurons.
Ligand gated channels
Opens and closes in response to the binding of a ligand (chemical) stimulus. Ex. NTs, hormones, ions. Ex. Ach opens cation channels that allow Na+ and Ca+ to flow in and K+ to flow out. Located in the dendrites of some sensory neurons, such as pain receptors, and in dendrites and cell bodies of interneurons and motor neurons.
Mechanical gated channels
Opens or closes in response to mechanical stimulation in the form of vibration (such as sound waves), touch, pressure, or tissue stretching. The force distorts the channel from resting position, opening the gate.
Voltage gated channels
Opens in response to a change in membrane potential. Participate in the generation and conduction of action potentials in the axons of all types of neurons.
Resting membrane potential
Exists because of a small buildup of negative ions in the cytosol along the inside of the membrane, and an equal buildup of positive ions in the ECF outside the membrane. The separation of + and – charge is a form of potential energy, measured in volts or millivolts. The greater the difference in charge across the membrane, the larger the membrane potential (voltage). The buildup in charge occurs only very close to the membrane.
How to measure resting membrane potential?
- The tip of the recording micro electrode is inserted inside the neuron
- The reference electrode is placed in the ECF
- The electrodes (conduct charge) are connected to a voltmeter (detects voltage/change in charge) that measures the difference in charge across the plasma membrane
What does ‘polarized’ mean?
Electrically charged, negative inside and positive outside.
What are the three factors that a negative resting membrane potential arises from?
- Unequal distribution of ions in the ECF and cytosol
- Inability of most anions to leave the cell
- Electrogenic nature of the Na+/K+ ATpases
Negative resting membrane potential factor - unequal distribution of ions in the extracellular fluid and cytosol
Extracellular fluid if rich in sodium and chloride. Cytosol is rich in potassium (cation) and three phosphate groups attached to ATP and amino acids (anions). more potassium diffuse down their concentration gradient towards extracellular fluid, making the ECF (outside) more positive and the cytosol (inside) more negative.
Negative resting membrane potential - inability of most anions to leave the cell
Most anions inside the cell cannot leave and follow potassium out of the cell because they are attached to non-diffusible molecules like ATP and large proteins.
Negative resting membrane potential - electrogenic nature of sodium/potassium ATPase
Three sodium and two potassium in. ATPase = since the pumps removes more positive charges from the cell than bringing it into the cell = makes it electrogenic (contribute to the negative resting membrane potential)
What are the six types of small molecules NTs?
- Acetylcholine
- Amino acids
- Biogenic amines
- ATP and other purines
- Nitric oxide
- Carbon monoxide
Acetylcholine (ACh)
Excitatory (ACh binds to ionotropic and open cation channels)
Inhibitory (bind to metabotropic + G protein and opens potassium channels)
Three types of Amino acids
- Glutamate (excitatory)
- GABA (gaba/aminobutyric/inhibitory)
- Glycine (inhibitory)
Three types of Biogenic amines
- Norepinephrine
- Epinephrine
- Dopamine
Effects of Norepinephrine
Arousal, dreaming, and mood
Effects of Dopamine
- Emotional responses
- Addiction
- Pleasure
- Regulate skeletal muscle tone
Catecholamines include?
- Epinephrine
- Norepinephrine
- Dopamine
Serotonin
(Biogenic amine) aka 5-hydroxytryptamine (5-HT): in raphe nucleus:
- Sensory perception
- Temperature regulation
- Control of mood
- Appetite
- Induction of sleep
Nitric oxide (NO)
Excitatory: brain, spinal cord, adrenal glands, nerves to penis
Cervical plexus
C1-C5
Brachial plexus
C5-T1
Lumbar plexus
L1-L4
Sacral plexus
L4-S4
Coccygeal plexus
S4, S5, and CO1 (coccygeal nerve)
Direct motor pathways
- Collections of upper motor neurons with cell
bodies in the motor cortex that project axons into
the spinal cord, where they synapse with lower
motor neurons or interneurons in the anterior
horns. AKA pyramidal pathways. - Include lateral corticospinal, anterior
corticospinal, and corticobulbar tracts - Convey nerve impulses that originate in the
cerebral cortex and are destined to cause
voluntary movements of skeletal muscles
Indirect motor pathways
- Motor tracts that convey info from the brain
down the spinal cord for automatic movements,
coordination of body movements with visual
stimuli, skeletal muscle tones and posture, and
balance. AKA extrapyramidal pathways. - Include rubrospinal, tectospinal, vestibulospinal,
lateral reticulospinal, and medial reticulospinal
tracts - Convey nerve impulses from the brain stem to
cause automatic movements and help coordinate
body movements with visual stimuli. - Also maintain skeletal muscle tone, sustain
contraction of postural muscles, and play a major
role in equilibrium by regulating muscle tone in
response to movements of the head.
Spinal reflex
Simple, when integration takes place in the spinal cord grey matter. (Ex: Patellar reflex (knee jerk))
Reflex arc
Sensory receptor, sensory neuron, integration, motor neuron, and effector that are involved in a quick response to a stimulus.
Sensory receptor
The distal end of a sensory neuron (dendrite) or an associated sensory structure = responds to a specific stimulus by producing a graded potential called a generator (or receptor) potential.
If a generator potential reaches the threshold level of depolarization, it will trigger one or more nerve impulses in the sensory neuron.
Sensory neuron
The nerve impulses propagate from the sensory receptor along the axon of the sensory neuron to the axon terminals, which are located in the gray matter of the spinal cord or brain stem.
From here, relay neurons send nerve impulses to the area of the brain that allows conscious awareness that the reflex has occurred.
Stimulus
A change in the internal or external environment that excites a sensory receptor, a neuron, or muscle fibers. Any stress that changes a controlled condition.
Integrating center
Interneurons in the CNS; one or more regions of grey matter within the CNS = a single synapse between a sensory neuron and a motor neuron.
Motor neuron
Impulses triggered by the integrating center propagate out of the CNS along a motor neuron to the part of the body that will respond.
Effector
The part of the body that responds to the motor nerve impulse, such as a muscle or gland.
Its action is called a reflex.
If the effector is skeletal muscle the reflex is a somatic reflex, if the effector is smoother muscle, cardiac muscle, or a gland, the reflex is an autonomic reflex
Monosynaptic reflex arc
The sensory (afferent, presynaptic) neuron fires directly onto the motor neuron (efferent, postsynaptic); only one synapse in the CNS. Less common type.
Polysynaptic reflex arc
Pathway in which signals travel over many synapses on their way back to the muscle; involves more than two types of neurons and more than one CNS synapse. The integrating center consists of one or more interneurons, which may relay impulses to other interneurons as well as to a motor neuron.
Stretch reflex
- stimulation muscle spindle
- generate impulse by muscle spindle
- propagation of impulse along sensory neuron
- integration of impulse at synapse in gray matter of spinal cord
- activation of motor neuron in anterior gray horn
- propagation of motor impulse
- release of ACh from motor neuron
- stimulation of muscle contraction
Patellar reflex (knee jerk reflex):
Involves extension of the leg at the knee joint by contraction of the quadriceps femoris muscle in response to tapping the patellar ligament (stretch reflex).
Blocked by damage to the sensory or motor nerves supplying the muscle or to the integrating centers in the 2nd, 3rd, or 4th lumbar segments of spinal cord.
Often absent in people with chronic DM or neurosyphilis which cause degeneration of nerves.
Exaggerated in disease or injury involving certain motor tracts descending from the higher centers of the brain to the spinal cord.
Babinski reflex
Results from gentle stroking of the lateral outer margin of the sole.
Great toe extends, with or without a lateral fanning of the other toes.
Normally occurs in children under 1.5 years old due to incomplete myelination of fibers in the corticospinal tract.
Positive Babinski sign after age 1.5 is abnormal and indicates an interruption of the corticospinal tract as the result of a lesion of the tract, usually in the upper portion
The normal response after age 1.5 is the plantar flexion reflex, curling of the toes.
Cranial dura mater
Outermost meningeal matter: lies tightly agains cranial bones and consists of two layers
- Periosteal layer (external)
- Meningeal layer (internal)
Ventricles of the brain
Canals in the brain that contain cerebrospinal fluid
Lateral ventricles (Ventricles 1 and 2) – one in each hemisphere of the cerebrum separated anteriorly by a thin membrane: septum pellucidum – the thin membrane that separates the lateral ventricles of the brain anteriorly
(Ventricle 3) – a narrow slitlike cavity along the midline, superior to the hypothalamus and between the R and L halves of the thalamus
(Ventricle 4) – lies between the brain stem (medulla oblongata and pons) and the cerebellum
Hypothalamus functions
- Body temperature
- Sleep
- Appetite
- Emotions
- Control of the pituitary glands
Epithalamus
A small region of the diencephalon, superior and posterior to the thalamus, composed of pineal gland and associated structures.
- Pineal gland – Small pea-sized cone shaped gland located in the roof of the third ventricle. Secretes melatonin. Part of the endocrine system.
- Melatonin – a hormone secreted by the pineal gland that helps set the timing of the body’s biological clock. More melatonin is produced in darkness than in light.
- Habenular nuclei – involved in olfaction, especially emotional responses to odors.
White matter tracts (column)
Conduct nerve impulses to and from the brain;
a. anterior (ventral) white column – front
b. posterior (dorsal) white column – rear
c. lateral white column – out to the side.
Somatosensory area
A region of the cerebral cortex posterior to the central sulcus in the postcentral gyrus of the parietal lobe of the cerebrum that localizes exactly the points of the body where somatic sensations originate - nerve impulses for touch, pressure, vibration, itch, tickle, temp, pain, and proprioception (joint and muscle position), and is involved in the perception
Brain waves
Patterns of neuron electrical activity; electrical signals that can be recorded form the skin of the head.
Alpha waves
Rhythmic waves about 8-13 per second.
Frequency unit = hertz Hz. One hertz is one cycle per second. Alpha waves are present in EEGs of nearly all normal individuals when awake and relaxed with eyes closed. Disappear entirely during sleep.
Beta waves
14-30 Hz. Generally appears when nervous system is active, during periods of sensory input and mental activity. Awake and alert
Theta waves
4-7 Hz. normally occur in children and adults experiencing emotional stress, and also in many disorders of the brain; reduced consciousness, deep meditation, REM sleep.
Delta waves
1-5 Hz. occur during deep sleep in adults, but normal in awake infants. When produced by an wake adult, indicate brain damage, long, slow waves that indicate the deepest stage os sleep.
Cranial nerve VIII
Vestibulocochlear (hearing and balance/equilibrium)
Sympathetic motor pathways
Called thoracolumbar due to the fact that the preganglionic neurons begins in the thoracic and lumbar regions of spinal cord (from T1-L2).
Preganglionic neuron is short, postganglionic neuron is long (generally)
Most ganglia are located near the spinal cord
Autonomic plexus
A network of both sympathetic and parasympathetic neurons that serve a specific body region: cardiac, pulmonary, celiac, superior ad inferior mesenteric; hypogastric, renal.
Many of which lie along major arteries and named for same.
May also contain sympathetic ganglion and axons of autonomic sensory neurons.
Cholinergic neuron
Referring to cells that use acetylcholine (ACh) as their synaptic transmitter.
Cholinergic receptr
A nerve receptor stimulated by acetylcholine (nictoinic and muscarinic)
Adrenergic neuron
Releases epinephrine (adrenaline) or norepinephrine (in ANS) as its neurotransmitter
Adrenergic receptors
Bind both to norepinephrine and epinephrine.
Alpha 1 (vasoconstriction
Alpha 2 (inhibits norepinephrine)
Beta 1 (increase heart rate)
Beta 2 (vasodilation)
Sympathetic division of ANS
Fight or flight: pupils dilate, heart rate increases, and BP increases, airway dilate.Kidney and GI tract blood vessels constrict, skeletal, cardiac, liver, and adipose tissue blood vessels dilate, release of glucose by liver, non essential processes inhibited.
Parasympathetic division of ANS
Rest and digest: tends to calm the body by slowing the heart and breathing and by allowing the body to recover from the activities that the sympathetic system causes:
S - Salivation
L - Lacrimation
U - Urination
D - Digestion
D - Defecation
Sleep
A state of altered consciousness or partial unconsciousness form which you can be aroused. It is essential by the exact functions of sleep are unclear. Sleep deprivation impairs attention, learning, and performance. consists of two components. NREM and REM.
NREM sleep
Non rapid eye movement sleep; encompasses all sleep stages except for REM sleep.
REM sleep
Rapid eye movement sleep, a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active.
Reticular formation
A network of small groups of neuronal cell bodies (grey matter) scattered among bundles of myelinated axons (white matter) beginning in the medulla oblongata and extending superiorly through the central part of the brain stem.
Neurons within the reticular formation have both ascending and descending function.
Odor threshold and adaptation
Low threshold, only a few molecules need to be present. Adaptation occurs rapidly
Taste thresholds and adaptation
Complete adaptation to specific taste can occur in 1-5 mins of continues stimulation.
Bitter threshold is the lowest: toxic substances are usually bitter, maybe a protective function.
Light adaptation
Visual system adjusts in seconds to the brighter environment by decreasing its sensitivity
Dark adaptation
Visual systems sensitivity increases slowly over several minutes
Anatomy of taste buds
Oval body consisting of 50 receptor cells surrounded by supporting cells
- Single gustatory hair projects upwards through
the taste pores
- Basal cells develop into new receptor cells every
10 days
Anatomy of papillae
Elevations on the tonuge in which taste buds are found. They increase the surface area and provide a tough texture to the upper surface of the tongue.
Three types of papillae
- Vallate
- Fungiform
- Foliate
Pupil
The hole in the center of the iris, the area though which light enters the posterior cavity of the eyeball
Iris
Regulate the amount of light entering the eyeball through the pupil.
Red eye in photos
When light is directed into the pupil, the reflected light is red because of the blood vessels on the surface of the retina.
Autonomic reflexes regulate pupil diameter in response to light levels
When stimulated by bright light, parasympathetic fibers of the oculomotor (III) nerve stimulate the circular muscles of the iris to contract, causing decrease in size of the pupil.
Circular muscles (constriction) or sphincter pupillae - iris muscles
Contract in bright light in response to stimulation by parasympathetic fibers of the oculomotor (III) nerve.
Radial muscles (dilator) or pupillae - other iris muscles
In dim light, sympathetic neurons stimulate these muscles to contract, causing an increase in the pupils size
Rods
Allow sight in dim light. Do not provide color vision so in dim light we see only black, white, and all shades of grey,
Cones
Stimulated by brighter light. Produce color vision.
Three types of cones
- Blue cones: sensitive to blue light
- Green cones: sensitive to green light
- Red cones: sensitive to red light
Refraction of light rays
Bending of light rays as it passes through the cornea and lens to that they come into exact focus on the central fovea of the retina.
As light rays enter the eye they are refracted at:
The anterior and posterior surfaces of the cornea
Anatomy of ear
- Outer ear
- Middle ear
- Inner ear
External ear (outer ear)
- Auricle or Pinna: the projecting part of the external ear, composed of elastic cartilage and covered by skin.
- External auditory canal: a curved tube in the temporal bone that leads to the middle ear. AKA meatus.
- Ceruminous glands: specialized sudoriferous (sweat) gland in the external auditory canal/meatus that secretes cerumen.
- Cerumen: earwax.
- Eardrum or tympanic membrane: thin, semitransparent partition of fibrous connective tissue between the external auditory meatus and the middle ear.
Middle ear
Small, air-filled cavity in the petrous portion of the temporal bone lined by epithelium. Separated from the external ear by the tympanic membrane and internal ear by a thin bony partition with two small openings.
- Auditory ossicles: the three smallest bones in the body, connected by synovial joints, attached to middle ear by ligaments
- Malleus – “hammer”: attaches to the internal surface of the tympanic membrane. Head of malleus articulates with the body of the incus
- Incus – “anvil”: middle bone in the series. Articulates with the head of the stapes.
- Stapes – “stirrup”: the base or footplate of the stapes fits into the oval window.
- Oval window: a small, membrane covered opening between the middle ear and inner ear into which the footplate of the stapes fits
- Round window: a small opening between the middle and internal ear, directly inferior to the
- Oval window: covered by the secondary tympanic membrane.
- Auditory tube or eustachian tube: the tube that connects the middle ear with the nose and nasopharynx region of the throat. AKA pharyngotympanic tube. Consists of both bone and elastic cartilage Connects the middle ear with the nasopharynx Normally closed at the medial end. During swallowing and yawning, it opens allowing air to enter or leave the middle ear until the pressure in the middle ear equals the atmospheric pressure.
Internal ear
hearing and equilibrium;
- Bony labyrinth: a series of cavities within the petrous portion of the temporal bone forming the vestibule, cochlear, and semicircular canals of the inner ear
- Perilymph: the fluid contained between the bony and membranous labyrinths of the inner ear
- Membranous labyrinth: the part of the labyrinth of the internal ear that is located inside the bony labyrinth and separated from it by the perilymph; made up of the semicircular ducts, the saccule and utricle, and the cochlear duct.
- Endolymph: the fluid within the membranous labyrinth of the internal ear.
- Vestibule: the oval central portion of the bony labyrinth.
- Utricle: the larger of the two divisions of the membranous labyrinth located inside the vestibule of the inner ear, containing a receptor organ for static equilibrium.
- Saccule: the inferior and smaller of the two chambers in the membranous labyrinth inside the vestibule of the internaear containing a receptor organ for static equilibrium.
- Semicircular canals: three bony channels (anterior, posterior, lateral), filled with perilymph, in which lie the membranous semicircular canals filled with endolymph. Contain receptors for equilibrium.
- Ampulla: a saclike dilation at one end of each semicircular canal.
- Semicircular ducts: the portions of the membranous labyrinth that lie inside the bony semicircular canals. Connect with the utricle of the vestibule.
- Cochlea: anterior to the vestibule, a winding, cone-shaped tube forming a portion of the inner ear and containing the spiral organ (organ of Corti)
- Cochlear duct or scala media: continuation of the membranous labyrinth into the cochlea, filled with endolymph.
- Scala vestibuli: the channel above the cochlear duct in the bony cochlea, filled with perilymph, ends at the oval window
- Scala tympani: inferior spiral shaped channel of the bony cochlea, filled with perilymph, ends at the round window.
-Helicotrema: an opening at the apex of the cochlea where the scala vestibuli and the scala tympani are not completely separated.
- Vestibular membrane: the membrane that separates the cochlear duct from the scala vestibuli.
- Basilar membrane: separates the cochlear duct from the scala tympani and on which the spiral organ rests.
- Spiral organ or organ of Corti: the organ of hearing, consisting of supporting cells and hair cells that rest on the basilar membrane and extend into the endolymph of the cochlear duct.
- Hair cells: about 16,000, which are the receptors for hearing. 2 groups of hair cells: inner hair (arranged in a single row) and outer hair cells (arranged in three rows)
- Stereocilia: at the apical tip of each hair cell; 40-80 that extend into the endolymph of the cochlear duct (Long, hair-like microvilli arranged in several rows of graded height.)
- Tectorial membrane: a flexible gelatinous membrane covering the hair cells of the spiral organ
Equilibrium
Static and dynamic
Static equilibrium
The maintenance of posture in response to changes in orientation of the body, mainly the head, relative to the ground. Body movements that stimulate the receptors for static equilibrium include tilting the head and linear acceleration or deceleration, such as when the body is being moved in an elevator or a car that is speeding up or slowing down (vestibules)
Dynamic equilibrium
The maintenance of body position, mainly the head, in response to sudden movements such as rotation (semicircular canals).
Physiology of hearing
- The auricle directs sound waves into the external auditory canal.
- When sound waves strike the eardrum, the alternating high- and low-pressure of the air causes the eardrum to vibrate back and forth. The distance it moves, which is very small, depends on the intensity and frequency of the sound waves. The eardrum vibrates slowly in response to low-frequency (low-pitched) sounds and rapidly in response to high-frequency (high-pitched) sounds.
- The central area of the eardrum connects to the malleus, which also starts to vibrate. The vibration is transmitted from the malleus to the incus and then to the stapes.
- As the stapes moves back and forth, it pushes the membrane of the oval window in and out. The oval window vibrates about 20 times more vigorously than the eardrum because the ossicles efficiently transmit small vibrations spread over a large surface area (eardrum) into larger vibrations of a smaller surface (oval window).
- The movement of the oval window sets up fluid pressure waves in the perilymph of the cochlea. As the oval window bulges inward, it pushes on the perilymph of the scala vestibuli.
- Pressure waves are transmitted from the scala vestibuli to the scala tympani and eventually to the round window, causing it to bulge outward into the middle ear.
- As the pressure waves deform the walls of the scala vestibuli and scala tympani, they also push the vestibular membrane back and forth, creating pressure waves in the endolymph inside the cochlear duct.
- The pressure waves in the endolymph cause the basilar membrane to vibrate, which moves the hair cells of the spiral organ against the tectorial membrane. Bending of the hair cell stereocilia produces receptor potentials that ultimately lead to the generation of nerve impulses.
Posterior pituitary
AKA neurohypophysis
a. Composed of neural tissue
b. Consists of two parts: pars nervosa (larger bulbar portion) and the infundibulum
Posterior pituitary hormone
Oxytocin and ADH
Thyroid stimulating hormone (TSH) or thyrotropin
Stimulates the synthesis and secretion of the two thyroid hormones: triiodothyronine (T3) and thyroxine (T4) TRH – thyrotropin-releasing hormone.
From the hypothalamus. Control TSH secretion. Release of TRH depends on blood levels of T3 and T4 (high levels inhibit secretion of TRH via negative feedback). There is no thyrotropin-inhibiting hormone.
Thyroixine or tetraiodothyronine or T4
Contains four atoms of iodine. hormone secreted by the thyroid gland that regulates metabolism, growth and development, and the activity of the nervous system.
Triiodothyronine or T3
Thyroid hormone that stimulates cellular metabolism. Of the two thyroid hormones it is the more potent and considered by physiologists to be the principal thyroid hormone. One molecule contains three iodine atoms.
Actions of thyroid hormones
- Increase basal metabolic rate
- Stimulate synthesis of Na+/K+ ATPase
Increase body temperature (calorigenic effect)
- Stimulate protein synthesis
- Increase the use of glucose and fatty acids for ATP production
- Stimulate lipolysis
- Enhance some actions of catecholamines
- Regulate development and growth of nervous tissue and bones
Adrenal gland
A pair of endocrine glands that sit just above the kidneys and secrete hormones that help arouse the body in times of stress (flattened pyramidal shape- During embryonic development, the adrenal glands differentiate into two distinct regions: large peripheral adrenal cortex (80-90% of the gland) and a small centrally located adrenal medulla.
Connective tissue capsule covers the gland.
The adrenal glands are highly vascularized)
Cushings syndrome (adrenal gland)
Caused by prolonged exposure to high levels of cortisol
Addisons disease (adrenal gland)
Occurs when the adrenal glands do not produce enough of the hormones cortisol or aldosterone.
Pituitary dwarfism
Lack of growth hormone, normal proportions with short stature
Gigantism (pituitary)
Hyper secretion of growth hormone during childhood, resulting in abnormal increase in the length of long bones and extreme height but with body proportions remaining about normal.
Acromegaly (pituitary)
Abnormal enlargement of the extremeties
Diabetes insipidus (pituitary)
Antidiuretic hormone is not secreted adequately, or the kidney is resistant to its effect (hypo secretion).
Congenital hypothyroidism (cretinism)
Hypo secretion of thyroid hormone during youth. Low metabolic rate, retarded growth and sexual development, possible mental retardation.
Myxedema (thyroid)
Caused by extreme deficiency of thyroid secretion, also known as adult hypothyroidism (common in females)
Graves disease (thyroid)
An autoimmune disorder that is caused by hyperthyroidism and is characterized by goitre and/or exophthalmos.
Goitre (thyroid)
Enlargement of the thyroid gland.
Diabetes mellitus (pancrease)
Inability to use or produce insulin
Two types of diabetes mellitus
Type 1: autoimmune disease in which the persons pancreatic beta cells are destroyed
Type 2: most common, usually occurs in obese people
Adrenal cortex hormone
Aldosterone, cortisol, androgens
Aldosterone
‘Salt retaining hormone’ which promotes the retention of sodium by the kidneys, sodium retention promotes water retention, which promotes a higher blood volume and pressure.
Androgens
Male sex hormones (in females = libido, estrogen)
Cortisol
Stress hormone released by the adrenal cortex (glucocorticoids influence glucose metabolism)
Adrenal cortex neurotransmitters
Epinephrine, norepinephrine, and dopamine
Inhibin
Inhibits secretion of FSH in gonads by anterior pituitary glands
Neuroglia
Cells that support and protect neurons
Four types of neuroglia
- Oligodendrocytes
- Astrocytes
- Microglia
- Ependymal cells
Olygodendrocytes
Produce myelin sheath around nerve fibers in the central nervous system
Astrocytes
Form blood brain barrier
Microglia
Phagocytes
Ependymal cells
Produce cerebrospinal fluid
What does the cochlea contain?
Fluid, organ of corti (receptor for hearing)
Subarachnoid space contains
Cerebrospinal fluid
Which part of the spinal cord contains cell bodies of somatic motor neurons and motor nuclei?
Anterior
Dermatone characteristics
- Used to determine area of spinal cord damage
- Anesthesia requires blocking 3 adjacent spinal
nerves - Designated based on cranial or spinal nerve that
serves an area of the skin - The dermatome serving the face is supplied by the trigeminal nerve
Is each dermatome served by multiple spinal nerve?
No
Rami communicantes
‘Connecting branch’ contain autonomic nerve fibers that controls vital functions
What two forces is a lever acted on?
Effort and load
The origin of a muscle on a limb is usually ___ to its insertion
Proximal
Gluteus maximus
Extends thigh at hip joint an laterally rotates thigh
Prime mover
Muscle with the major responsibility for a certain movement
Antagonists
The muscle opposite the agonist, which must relax and lengthen during contraction of the agonist
From superficial to deep, describe the abdominal muscles
External oblique, internal oblique, transverse abdominis
Deltoid action
Abducts arms
What muscles are used in forceful breathing?
Intercostals and diaphragm
The sensory nervous system
Detects stimuli and transmits information from receptors to the CNS
The integrative nervous system
Analyzes and stores data, makes decisions which stimuli are important. Perception
The motor nervous system
Stimulates muscles to contract or glands to secrete. Response system
Which neuroglial cell produces and assists in the circulation of cerebrospinal fluid (letter F)?
Ependymal cells
A synapse is where two neurons or a neuron and an ___ meet
Effector
Unipolar neuron
A neuron with one process extending from its cell body
Bipolar neuron
A neuron with one axon and one dendrite attached to its soma
Multipolar neuron
A neuron with one axon and many dendrites attached to its soma
A polarized cell
Has a charge imbalance, includes most cells of the body, contains membrane potential.
Light touch
Perceive touch through light pressure or use of a cotton ball
Heavy touch
Joints, muscles, palms
How does the nervous system distinguish between a light touch and a heavier touch?
Changing frequency of impulses sent to sensory centers
Three ways to remove a neurotransmitter
- Diffusion
- Enzymatic degration
- Uptake by cells
External ear components
- Auricle
- External acoustic meatus
- Tympanic membrane
Middle ear components
The chamber between the eardrum and cochlea containing three tiny bones (hammer, anvil, and stirrup)
Inner ear components
Vestibule, semicircular canals, and cochlea
What does the external ear do?
Collects sound waves
What does the middle ear do?
Amplifies sound
What does the inner ear do?
Hearing and balance
Basilar membrane
Membrane supporting the organ of corti and hair cells in the conchlea
Outer hair cell funnction
Amplify sound
Inner hair cell
The primary transducer of sound into an electrochemical signal
Papillae and gustatory cells
Found on the tongue
Filiform papillae
No taste buds
Muscarinic receptors (parasympathetic)
Are normally activated by acetylcholine (ACh)
Where does the biceps brachii insert?
Radial ruberosity
Adrenal medulla secretes
Epinephrine and norepinephrine
The pituitary gland
The endocrine systems most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands
Cerebral cortex
The intricate fabric of interconnected neural cells that covers the cerebral hemispheres, the bodys ultimate control and information processing center.
Adipose tissue
Tissue that stores fat
Spina cord segments
8 Cervial
12 thoraci
5 Lumbar
5 Sacral
1 coccygeal
Depolarization
The process during the action potential when sodium is rushing into the cell causing the interior to become more positive
Proprioceptors
Sensory receptors, located in the muscles and joints, that provide information about body position and movement. Monitor the position and movement of skeletal muscles and joints.
Zygomaticus major
Smiling
Fascicle arrangement
Determines the range of motion and power of a skeletal muscle. Pennate are stronger than parallel, and parallel are stronger than circular.
Dermatome C6
Thumb
Process of hearing
Pinna –> Ear canal –> Eardrum –> Ossicles (hammer, anvil and stirrup) –> Oval window –> Cochlea –> Cochlear fluid –> Cilia –> Organ of Corti
How does light enter the eye?
Cornea –> Pupil –> Iris –> Lens –> Retina
Thyroid hormones
T3, T4, calcitonin. Responsible for regulation of metabolism
Alpha cells
Glucagon
Beta cells
Insulin
Brain ventricles
Cerebrospinal fluid filled cavities within the brain
Bladder receptors
Sympathetic:
- Bladder wall (detrusor B1 + B2) relax
- Sphincter (trigone) contract (alpha 1)
Parasympathetic activation
- Bladder wall (detrusor) contacts
- Sphincter (and trigone relax)
Water soluble hormone action
1st messenger: Causes production of second messenger inside the cell
2nd messenger: cyclic AMP (cAMP)
Neurotransmitters, neuropeptides, and several sensory transduction mechanism (vision) also act via second messenger systems.
Lipid soluble action
Bind to receptors on the surface of the target cell, while fat soluble hormones bind to receptors inside the target cell.
Folia
Folds of cerebral cortex
Chromaffin cells
The cells in the adrenal medulla that secrete epinephrine and norepinephrine
Hemispheric lateralization
Split brain theory (one side controls the other, similar patterns but carries per individual, less pronounced in females than males, observable in 32-week fetus).
Sodium gated channels
Open when a local region is depolarized and have an inactivation gate- this limits the flux of sodium ions by blocking the channel shortly after depolarization opens it: when there is repolarization the inactivation gate is released back out of the pore and the channel can return to the closed state.
Astigmatism
Defective curvature of the cornea or lens of the eye
Near sightedness
Myopia. A condition in which nearby objects are seen more clearly than distant objects because distant objects focus of the retina.
Far sightedness
Hyperopia. A condition in which far away objects are seem more clearly than near objects because the image of near objects is focused behind the retina.
Calcium channels
Axon terminals. Release of neurotransmitter.
Trigger zone of neuron
Axon hillock. Where action potential is initiated.
Diverging circuits
A type of neural circuit in which a single input neuron contacts several output neurons.
Reciprocal innervation
When a reflex stimulates one muscle to contract and one inhibits the antagonistic muscle (vital for coordinating body movements)
Blood brain barrier (BBB)
Physiological barrier between the circulatory system and the central nervous system that establishes a privileged blood supply, restricting the flow of substances in to the CNS.
What type of junction seals endothelial cells of capillaries in the brain for the blood brain barrier to work?
Tight junctions
Lateral ventricles of the brain.
Ventricles found in each cerebral hemisphere. Containing cerebral spinal fluid (choroid plexus)
How does blood flow in the brain?
Via the vertebral and carotid arteries and flows back to the heart via the jugular veins.
Arachnoid vili (granulation)
Help recycle cerebrospinal fluid to blood; look like little warts; allow CSF to general circulation
CSF circulation
- CSF is produced by choroid plexus in each ventricle
- CSF flows from lateral ventricles and 3rd ventricle through the cerebral aqueduct into the 4th ventricle.
- CSF in 4th flows into subarachnoid space by passing through openings in the roof of the 4th ventricle. These openings are the paired lateral apertures and the single median aperture. CSF also fills the central canal of the spinal cord.
- As it travels through the subarachnoid space, CSF removes waste products and provides buoyancy for the brain and spinal cord.
5.CSF accumulates w/i the subarachnoid space, it exerts pressure w/i the arachnoid villi. This pressure exceeds the pressure in the venous sinuses. Thus, the arachnoid villi extending into the dural venous sinuses provide a conduit for a one-way flow of excess CSF to be returned into the blood within the dural venous sinuses.
Pyramids (brain)
Paired white matter structures of the brainstems medulla oblongata that contain motor fibers of the corticospinal and corticbulbar tracts.
Cerebellum
This part of the brain monitors movements initiated by the motor areas of the cerebrum
Thalamus
The brains sensory replay center, located on top of the brainstem. It directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.
Longitudinal fissure
Separates left and right hemispheres
Basal ganglia
Structures in the forebrain that help to control movements (attention, laughing, yawning, regulate muscle tone)
Vagus nerve
The 10th cranial nerve that innervates visceral activities (digestive organs, heart and other areas)
Optic nerve
Carries neural impulses form the eye to the brain (for vision/location)
Vestibular nerve
Nerve conducts impulses related to maintaining balance to the brain.
Trigeminal nerve
Sensory for the face. Motor fibers to chewing muscles.
Oculomotor nerve
Eye movement
Dual innervation of ANS
Some organs receive motor impulses from both the parasympathetic and sympathetic system. Interact to control the level of visceral activity to maintain homeostasis.
Preganglionic neuron
The first neuron in a series that transmits impulses form the CNS, cell body with thin lightly myelinated axon extending to ganglion, its axons exit the CNS in a cranial or spinal nerve.
Postganglionic neuron
The second neuron in a series that transmits impulses form the CNS, form synapses directly with their target organ.
Parasympathetic preganglionic neuron
Exits the brain stem or sacral region and meets the postganglionic neuron at the terminal ganglia. ALWAYS releases ACh and is long and myelinated.
Sympathetic preganglionic neurons
Have dendrites and cell bodies in the grey matter of the thoracic and upper lumbar segments of the spinal cord. Short
A1 adrenergic receptor
Norepinephrine receptor responsible for peripheral vasoconstriction
A2 adrenergic receptor
Inhibits norepinephrine, contracts smooth muscle
B1 adrenergic receptors
Heart rate and strength increases, found in cardiac muscle fibers.
B2 adrenergic receptors
Causes vasodilation and bronchodilation.
Adrenal medullae secretes epinephrine and norepinephrine causing ___
Intense sympathetic response in tissue with both alpha or beta receptors.
Somatic reflexes activate ___
Skeletal muscles
Autonomic reflexes activate ___
Smooth and cardiac muscles and glands
Corpuscle of touch
Also called Meissner corpuscle. Rapid adapting. Touch receptors located at the dermis
Type 1 cutaneous mechanoreceptors
Also called Merkel discs. Slow adapting nerve endings. Light touch
Specialized sensory receptors (separate cells)
- Vision: photoreceptors (rods and cones)
- Audition/equilibrium: specialized mechanoreceptors
- Smell: olfactory receptors
- Taste: taste receptors; ion channels
Lamellated (pacinian) corpuscles
Deep pressure, and high frequency vibration
Tickle and itch receptors
Free nerve endings attached to small diameter unmyelinated C fibers
Where do axons decussate (cross over)?
Spinal cord
Narcolepsy
A condition characterized by involuntary falling asleep or feeling very sleepy during the day.
Special senses receptors
Specialized receptors in more complex sense organs in specific locations of the head.
Five special senses
- Olfaction
- Gustation
- Vision
- Auditory
- Equilibrium
Fungiform papillae
Mushroom like containing about five tastebuds and located on the sides and tip of the tongue.
Foliate papillae
On side walls of tongue and contain taste buds during childhood
Order of flow of tears
- Lacrimal gland
- Lacrimal duct
- Superior or inferior lacrimal canal
- Lacrimal sac
- Nasolacrimal duct
- Nasal cavity
Hyperpolarization in photoreceptors
When light rays strike its photopigments, the photoreceptor cell undergoes hyper polarization.
Where will a nerve impulse that arose in the ganglion cells terminate?
Thalamus
What does the organ of corti do?
Converts mechanical vibrations into action potentials
Where is the organ of corti located?
Cochlea
What happens when a facial nerve is damaged?
Inability to make facial expressions, increased sensitivity to sound
First order neuron
Conducts impulses from cutaneous receptors and proprioceptors (branches diffusely as it enters ipsilateral cochlear nuclei or spinal cord or medulla).
Second order neuron
Continues as far as a ‘gateway’ called the thalamus at the upper end of the brainstem.
Third order neuron
Carries the signal the rest of the way to the sensory regions of the cerebral cortex.
Exocrine glands
Secretes chemical substances into ducts that lead either to other organs or out of the body
Are exocrine glands carried by body fluids?
No, it is secreted through ducts
Cyclic AMP
A second messenger derived form ATP and triggers specific cellular changes in metabolic regulation.
First messenger
A water soluble hormone that binds to it receptor at the outer surface of the plasma membrane
Water soluble hormones
(All amino acid based hormones except thyroid hormones)
Act on plasma membrane receptors
Act via G protein second messengers
Cannot enter cells
Lipid soluble hormones
Steroid and thyroid hormones (act on intercellular receptors that directly activates genes and can enter cells)
Methods of stimulating hormone secretion from an endocrine cell
Signals form nervous system, chemical changes in blood, releasing hormones.
What does the thyroid gland do?
Regulates metabolism and blood calcium levels.
Hyper secretion of aldosterone symptom
Dehydration (Addison disease)
hCG (human chorionic gonadotropin)
Pregnancy hormone, produced by the placenta
Long term stress hormones
Cortisol, hGH, and thyroid hormone
The stretch reflex is initiated by
Muscle spindles
Stretch reflex arc
Components:
- Receptor
- Sensory receptor
- Motor neuron
- Effector (muscle)
Central sulcus
Separates frontal and parietal lobes
Root words that describe size of muscle
Maximus (largest)
Minimus (smallest)
Major (larger)
Minor (smaller)
Longus (long)
Brevis (short)
Vastus (great, large, vast)
Sphenoid
Single, irregular, bat shaped bone, forming part of the cranial floor
What does the sphenoid bone house?
Pituitary gland
Medulla oblongata
Part of the brainstem that controls vital life sustaining autonomic functions such as heart beat, breathing, blood pressure, and digestion
Retina
The light sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information
What does the hypothalamus control?
Pituitary gland (hormone system)
How does a postsynaptic membrane respond to a neurotransmitter?
Either excitatory (positive charge) or inhibitory (negative charge)
Excitatory postsynaptic potentials (EPSP)
A slight depolarization of a postsynaptic cell, bringing the membrane potential of that cell closer to the threshold for an action potential
Inhibitory postsynaptic potential (IPSP)
An inhibitory hyperpolarization of the postsynaptic membrane of a synapse caused by the liberation of a neutransmitter by the terminal button.
Spatial summation occurs when ___
Multiple local potentials occur at different places on the same cell at the same time
What are monosynaptic reflexes?
Stretch (patellar reflex and achilles reflex)
What are the polysynaptic reflexes?
Withdrawal - afferent and efferent connected via interneurons (all reflexes except stretch reflexes)
Ipsilateral reflex
Stimulus and response are on the same side of the body (acoustic reflex test)
Contralateral reflex
Starts on one side of the body and travels to opposite side
Pituitary dwarfism
Lack of growth hormone, normal proportions with short stature
Thoracic nerves
T1-T12 (they do not form a spinal plexus, part of the brachial plexus)
Stroke volume
Depends on the strength of contraction and the pressure in the arteries
Afterload
Arterial pressure.
A high pressure in the arteries decreases in the stroke volume (hypertension)
Preload
The ventricular end diastolic pressure
End diastolic pressure
As the end diastolic volume or venous return increases, the pressure in the ventricles increases
Frank starling mechanism
The stroke volume of the heart increases in response to an increase in the volume of blood in the ventricles, before contraction, when all other factors remain constant.
Maintaining left and right ventricular output equality
Importance of calcium in cardiac muscles
In contrast to skeletal muscle, it requires extracellular calcium ions for contraction to occur.
SA node
Pacemaker
Structure of artery
Thick walls and thick layers of muscle and elastic fibers
Structure of vein
Thinner walls and thinner layers of muscle and elastic fibers. One way valves to prevent blood form flowing in the wrong direction
Venous pressure
Pressure in veins drives blood into the heart. Pressure in beings lower than pressure in arteries. Veins have higher compliance.
Venous return
The rate of blood flow back to the heart. It normally limits cardiac output
Valve between left atrium and left ventricle
Bicuspid valve or mitral valve
Valve between right atrium and right ventricle
Tricuspid valve
Arteries
Carries deoxygenated blood
Veins
Carries oxygenated blood
