Immunology . Quiz!. Covering of the body (skin, mucous membrane) Innate Adaptive (acquired) . What are the three lines of host defenses ?. Skin and mucous membranes . Physical barrier Epidermis, cilia movement, low of air/fluid Chemical pH, enzymes, other antibacterial peptides
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What are the three lines of host defenses?
What are the organs of the immune system?
After macrophage does its job, it returns to regional lymph nodes and calls for
What are Lipopolysacchides (LPS)?
I. Humoral Immunity
II. Cell-mediated Immunity
cell under threat grew additional side-chains to bind the toxin, and that these additional side chains broke off to become the antibodies that are circulated through the body
Who is Paul Ehrlich and what was his theory?
In each class, molecules have two chains
- alpha and beta
How many alpha chain does MHC I has?
False, it is a life long phenomenon
(T/F) Deletion of T-cells (selection for reactivity to MHC-peptide tolerance) stops at the age of 6 month
CD 4 becomes helper T-cell: target for HIV
CD 8 becomes what cell?
Then you have dendritic cells that moves in between B and T cells
Interacts with both
T cells are found in the superficial cortex of the lymph nodes
1st specific reaction
Binding of MHCII (dendritic cell) to T-cell
Genetically programmed to recognizes one epitope
What make sure that T-cell are not attacking “self”?
(T/F) B-cell becomes a plasma cell and start to make antibodies
2 identical light chains
2 identical heavy chains
(T/F) Both intra and inter chains are held together by disulfide bound
– determined by the Heavy (H)
– determined by the Light (L)
Which Ig is monomeric?
Antibody can’t do anything until it borrows complements from the innate system
It’s a cascade, each amplifies the “waterfall”
C3 and C5 calls for neutrophilphagocytosis
Later molecules in the sequence – C9 – punches a hole in the bacterial membrane
True: Class switch can occur in the apical light zone
IgM often switches class
(T/F) B-cell can change the class of Ig it produces
(T/F) B-cells need T-cell to activate and produce antigens.
Foramen of Monro
Foramens of Lushka & Magendie
Internal carotid artery
External carotid artery
Strongest in the middle
Smaller RF = increase acuity
Overlapping receptive fields: the one that respond the loudest determines location
Lateral inhibition further sharpens acuity
Signal from the brain can decrease the pain from a paper cut
Sensation is shaped by both:
Bottom up – mechanical stimulation on the skin
Top down – CNS signals
Cutaneousmecanoreceptor nerve ending are all the same, the only difference is the types of tissue surrounding them and there they are located
- light touch, texture
- stronger deformations of the skin deep pressure, shape
Inflammatory molecules increase the threshold of nociceptors, causing hyperalgesia
Hyperalgesia: sensitive to pain
Increase threshold: more AP to actually cause pain
Hyperalgesia is associated with decrease threshold – less AP to cause pain
This leads to release of substance P at both spinal cord and the site of injury
Activation of nociceptors leads to release of substance P (for pain) in the spinal cord and afferent feedback onto mast cells
Mast cells then secrete histamine, further sensitize the nerve ending
PAG – periaqueductal gray matter
Both are from medulla
Decends in dorsalateralfuniculus
Presynaptic or post synaptic inhibition
The foviacentralis is where all optic nerves are leaving the retina, therefore it has the highest visual acuity
Optic disk is where the optic nerve are exiting the eye
Foviacentralis is the highest visual acuity area, that is true
The cornia refracts light more than the lens
If the eye is myopic, then the image is formed behind the retina
This condition can be corrected with concave lens
First part is false – myopic = nearsighted, image is formed before the retina
Second part is true – myopia is corrected with concave lens
In fovea centralis, the circuitry is shifted out of the way
Nourishes rods and cone – detached retina: separation of retinal from pigmented epithelium
Bipolar / Amacrine /
Horizontal cells : process, compress, converge raw data from rods and cones
send info to brain
In the dark, the cell is depolarizing, transmitter always released by the inner segment
Light hits rhodopsin/opsin molecule (outer segment) change in configuration
Reaction via G-protein cascade
cGMP is converted to GMP
Closes the cGMP gated channel
Na+ can no longer flow in
Hyperpolarization– stops release of transmitter by the inner segment
Deflection of basilar membrane produces shearing of hair cell stereocilia
Auditory information is carried by the 8th cranial nerve, it synapses with a 2nd order neuron in the medulla, crosses over, and is sent to the contralateral Primary auditory cortex
Detects angular acceleration
Otoliths lags behind and pulls on the hair cells
- direct effect on sodium channel
- direct effect on sodium channel, can interfere with Na+
Molecules dissolved in mucus, detected by olfactory receptor cells
G-protein cascade leading to opening of ion channel
Synapse at the olfactory bulb
The only sensory modality that does not have synapse at medulla or thalamus
Olfactory bulb has direct connection with the limbic system –strong effect on emotion and memory
As you fall deeper asleep (stage 1-4) amplitude increases and frequency decreases
Circadian rhythm is controlled by what structures of the brain (3)
Reticular activating system
Dopamine is produced
Dopamine – reward pathway (Locus ceruleus, midbrain, prefrontal cortex)
Mrs. D has undergone an aggressive surgery to treat glioma (tumor). A large part of her hippocampus and basal ganglia are removed. What type of memory deficit do you anticipate for Mrs D?
Mr. W had a left middle cerebral artery stroke 2 m.o. ago. When asked how he is doing he responds
“Well I eat grasshoppers and boy does that shin look chipy bog”
Which area is affected? Broca or Wernicke?
Agonist excitation: THERE IS NO INTERNEURONS!!
Touch something hot
Sensory fiber transmit pain
Activate ipsilateral flexors (via excitatory interneuron)
Inhibit ipsilateral extensors (via inhibitory interneuron)
Result in removal of arm from the stove – whole process does not require cortical input
Just remember: the interneuron that crosses to the contralateral side is always excitative.
Therefore to inhibit contralateral side, you need a 2nd interneuron to do this
Increase in rate and magnitude of withdrawal response with increased stimulus strength
The more it hurts, the stronger your reaction is going to be
When a muscle is lengthened, there is no problem
When a muscle is in shortened position, muscle spindle collapse and sensitivity is reduced
Decrease in force production
ALPHA GAMMA CO-ACTIVATION
Golgi Tendon Organs
GTO is the main underlying mechanism for stretch reflex
N.B: The stretch reflex (knee jerk) is usually considered to be the same thing as GTO reflex.
Paralysis and weakness (?)
Made of multiple precursors called myoblast
Skeletal muscle fibers consist of cylindrical bundles called myofibrils.
The striations within each myofibril are caused by alternating light I-bands and dark A-bands. In the center of each light band is a dark line called the Z-line. These structures delineate the sarcomere, the contractile unit of skeletal muscle.
Each sarcomere consists of two sets of parallel and partially overlapping protein filaments: thick filaments extending from one end of the A band to the other, and thin filaments, attached to the Z lines and extending across the I band and part way into the A band.
Two views of actin thin filaments and myosin thick filaments in a sarcomere.
The cross-bridge cycle is driven by ATP binding and hydrolosys by the myosin head groups.
ADP + Pi
ADP + Pi
ADP + Pi
What is included in a motor unit?
Muscle fiber surface
Muscle contraction is possible even if T-tubules are blocked
Ability of muscle to contract is coupled with Ca release by SR
T-tubules are more signal detectors, not very important for contraction of skeletal muscles
Cadmium – Ca+ blocker
Spinal cord injury after an accident on Dr. Penfield
Duchene Muscular Dystrophy
Carpal Tunnel syndrom
Is autonomic system sensory or motor?
What is main purpose of autonomic system?
What are the divisions of autonomic system?
Sympathetic, parasympathetic, enteric
Where are automatic motor neuron located?
Outside the spinal cord, in groups called autonomic ganglia
Ach Nicotinic receptor
NE alpha/beta adrenergic
Ach Nicotinic receptor
Nucleus of the solitary tract
The nucleus of the solitary tract integrates visceral sensory inputs and autonomic outputs and project to higher brain centers involved in homeostasis.
Homeostasis is maintained through what type of feedback?
What is a Nucleus?
Collection of neuron body in CNS
What is equivalent of nucleus in the PNS?
Enteric system depends on sympathetic and parasympathetic system to function
No, it receives input from them but can function alone