I
Name the types of joints and give an example of each and the range of motion of each
Fibrous - ends of fibula and tibia - limited range of motion
Cartilaginous - intervertebral discs - slightly moveable
Synovial - shoulder joints and actually everything else - allow for the most range of motion
Describe the relationship between proximal/distal, superior/inferior, and anterior/posterior and give examples for all three.
p/d - proximal is closer to the axial skeleton, distal is further away (i.e. your hand is distal to your shoulder)
s/i - superior is closer to the cephallic region of and inferior is closer to your feet (i.e. your diaphragm is superior to your pelvis)
a/p - anterior is closer to the front of your body and posterior is closer to the back of your body (i.e. your pectoralis major is more anterior than your lattismus dorsi)
Name the muscles that... (I'm so sorry this is gonna suck)
1. Flexes the spinal column (there are 3)
2. Compresses abdominal muscles
3. Abducts Arm
4. Adducts/Flexes Humerus
5. Extends Humerus
6. Flexes Elbow (there are 3, name 1)
7. Flexes Wrist (there are 3, name 1)
8. Extends Hip (there are 2)
9. Flexes Hip (there are 2)
10. Flex Knee (there are 2)
11. Dorsiflexes the foot
12. Plantar flexes foot
13. Closes jaw
14. Neck flexion
1. Rectus Abdominus, Internal/External Obliques
2. Transverse Abdominus
3. Deltoid
4. Pectoralis Major
5. Latissmus Dorsi
6. Biceps Brachii, Barchialis, Brachioradialis
7. Flexor Carpi Radialis, Flexor Carpi Ulanris, Flexor Digitorum Superficialis
8. Gluteus Maximus, Hamstring Group
9. Iliopsoas, Sartorius
10. Hamstring Group, Sartorius
11. Tibalis Anteriors
12. Soleus
13. Masseter
14. Sternocleidomastoid
What is a receptor potential? What is a receptive field? What is innervation density?
A rececptor potential is the change in membrane potential due to incoming sensory stimulus
A receptive field is the area of sensory space where a stiulus will excite a given nerve fiber
Innervation density is the number of neurons supplying a region of skin per unit area (related to spacial acuity - can you describe that?)
Describe the difference between spatial and temporal summation. Can you relate it to your knowledge of auditory stimuli for the ear?
Spatial summation comes from multiple different input locations, so multiple stimuli added togerther to reach threshold
Temporal summation is from a singular repeated stimulus attempting to reach threshold by repeating itslef over and over again.
In the ear increasing the amount of hair cells to transduce the stimuli vs bending the same one over and over again/extra hrad in order to transduce the stimuli.
Name the 6 synovial joint configurations and the key features of a synovial joint.
Plane (intercarpal joints) - sliding movements, no axial movement
Hinge (elbow joint) - uniaxial rotation
Pivot (radial/ulnar joint) - uniaxial roation
Condylar (knuckle joints) - biaxial hinge movement
Saddle (thumb joint) - biaxial hinge movment
Ball and Socket (shoulder and hip joint) - multiaxial (full rotation)
Key features: Hyaline cartilage covers the ends of bones forming joints allowing for sliding movement (low friction), Articular capsule enclose the joint-- sleeve of fibrous connective tissue, Synovial fluid lubricates the joint, reinforcing ligaments to support the joint
Describe the bone growth (length) process in growing children - be specific.
The process is called ossification. The existing hyaline cartilage get's covered by the osteoblasts and as cartilage breaks down, infiltrates to grow new bone. In children this happend at the epiphyseal plate and new cartilage growns beneath this palte.
Note: this can also happen at the distal end of the epiphysis however the articular cartilage stays on the outside of the bone and the bone fills in beneath a layer of this cartilage.
Name the five types of sensory recptors and what stimulus they respond to
Mechanorecptor - mechanical stimuli (stretching, pressure, vibration)
Thermoreceptors - temperature
Nocioceptors - pain receptors (damage to physical or chemical body)
Chemorecptors - chemical stimuli (taste, smell, bodily osmolality)
Photorecptors - light
What are the two signal pathways for somatic senses and what does each pathway transmit?
The Dorsal Column-Medial Lemniscal (DCML) system - transmits your large, myelinated afferent fibers. So your Aα and your Aβ peripheral neurons are transmited to the spinal cord with this system. Fine touch and proprioceptive sensation and for rapid changes
Anterolateral System - transmits your smaller, myelinated and unmyelinated afferent fibers. So the Aδ and the AC peripheral neurons are transmitted to the spinal cord with this system. Pain, thermal, crude touch, tickle and slower.
There are how many layers in the somatosensory cortex?
Which layer is the most important in this class and what is its responsibility?
How are these layers organized and what does this organization serve?
1. there are 6 layers in the somatosensory cortect
2. the most important layer in this class is layer iv and it is where the incoming sensory signals are recieved and then spread to the other layers
3. Corical columns, each column has all 6 layers and serves one specific sensory modality at a specific location on the body.
What are 3 of the 5 golden rules for skeletal muscle activity?
1. All skeletal muscles cross at least one joint (just go with it)
2. Typically, the bulk of the skeletal muscle lies proximal to the joint it crossed
3. All skeletal muscles have at least two attachments: origin and insertion
4. Skeletal muscles can only pull, never push
5. During contraction, skeletal muscle insertion moves towards the origin point
Name the 5 regions of the spinal column (in order superior to posterior) and the number of vertebrae in each column. Also what lies in between each vertebrae?
Cervical - 7 vertebrae
Thoracic - 12 vertebrae
Lumbar - 5 vertebrae
Sarcum - 5 vertebrae (fused)
Coccyx - 4 vertebrae (fused)
Intervertebral discs made of fibrocartilage to absorb impact.
Divergence - happens all along the DCML, expands the signal to engage more neurons and make a stronger signal spatially and at a higher rate
Lateral Inhibition - aftter divergence happens at the synapse, lateral inhibition ensures that further divergence doesn't occur at neighboring neurons, preventing excessive excitation.
They work in tandem to provide both strong and clear signals.
For the DCML there are dorsal columns and the thalamus. Describe the spatial organization of both and which side of the body is on which side of the dc/thalamus
Thalamus - more inferior portions of the body are more lateral in the the vetrobasal complex, right side of the body is felt by the LEFT side of the thalamus
What is the difference between slow-adapting receptors and fast-adapting receptors? Draw it for us for when you are receiving a touch of consistent pressure on your wrist.
Slow adapting receptors detect continuous stimulus strength versus fast adapting receptors detect changes in stimulus strength.
What ratio defines mechanical advantage?
There are three classes of levers - describe them and state the mechanical advantage of each. If you can give a body example of each (not required for points but show off a little).
MA = load/effort , (distance from effort)/(distance from load)
Class 1 - MA can be either less than or greater than 1, load - fulcrum - effort (nodding your head)
Class 2 - MA is greater than 1, fulcrum - load - effort (tip toes)
Class 3 - MA is less than 1, load - effort - fulcrum (flexing elbow)
Name all of the bones in your arm and describe their palcements. (And if you can how many we have per hand but not required for points)
Humerus - show it
ulna - closer to your body in supine
radius - on the other side of the ulna
carpals - little bones at the base of your wrist (8 per hand)
metacarpals - the little bones that connect your carpals to your phalanges (5 per hand)
phalanges - your finger bones (14 per hand)
When a sensory neuron (Aα or Aβ) enters the spinal cord via the DRG it divides between two pathways, name and describe the two pathways.
There is a 3 neuron chain for one of the pathways, name and describe the 3 parts of this chain.
Lateral branch - enters the dorsal horn grey matter and forms divisions to synapse on local neurons
Three neuron chain from sensory receptor to the cortex
1. First Order Neurons - axons entering the dorsal columns travel uninterrupted to the dorsal medulla
2. Second Order Neurons - originate in the medulla and travel to the thalamus (these neurons decussate in the medulla, travel via the medial lemnisci to the ventrobasal complex in the thalamus)
3. Third Order Neurons - originate in the ventrobasal thalamus and travel to the somatosensory cortex
Define somatic senses.
For mechanoreceptive somatic senses what is the difference between tactile and proprioceptive sensation?
Somatic senses are nervous mechanisms that collect sensory information from all over the body.
Tactile - cutaneous sensation of touch (external information)
Proprioceptive - movement and position sensation of the body (internal information)
Name the three receptors that are responsible for fine touch and describe what they are.
LTMRs (you have to list all 4), Merkel, Ruffini, Meissner, Pacinian - receptor responsible for fine touch
Free nerve endings - neuron is directly activated by deformaiton
Hair end Organ - hair and its basal nerve fiber, detects contact with body
Show dorsi flexion, show plantar flexion, show inversion, show eversion, show supination, show pronation, show opposition
Dorsi flexion - pull toes upwards
plantar felxion - point toes downwards
inversion - turn foot inwards
eversion - turn foot outwards
supination - palms up
pronation - palms down
opposition - thumb to the tips of your other fingers
Name all the bones in your leg and describe their placement. (And if you can how many we have per leg but not required for points)
femur - thigh bone
tibia - the frontal shin bone (bigger of the two)
fibula - behind the tibia (ish) (smaller of the two)
tarsals - the little bones in your ankle (7 per foot)
metatarsals - the long bones connecting your tarsals to your phalanges (5 per foot)
phalanges - your toe bones (14 per foot)
LTMR - low threshold mechano receptor
Merkel Cells (SA - I) - <5Hz, static indentations and very low frequency vibrations, important for determining fine spatial features and textures.
Ruffini endings (SA - II) - no freq range given but it is important for determining skin stretch so like position of your fingers
Meissner Corpuscles (RA - I) - detects medium frequency vibrations 5-50 Hz, important for slip and edge contours
Pacinian Corpuscle (RA - II) - detects high frequecy vibrations 50-300 Hz, important for tool manipulation
What is the primary somatosensory cortex? Name the regions we learned about in class and describe what they process and where they are relative to each other.
The primary somatosensory cortex is the first processing center for somatosensory information in the cortex
3a - where proprioceptive information is processed. between the motor cortex and region 3b
3b - first place somatosensory information enters the brain, "true" cortex. process both touch and proprioceptive information. Between 3a and 1
1 - higher order region, primarily process tactile information, between 3b and 2What are the 4 types of peripheral neurons? Name them and describe their size/what they transmit and where they end up.
Aα - large, myelinated - primary muscles spindles (stretch reflexes) (very fast)
Aβ - relatively large, myelinated - LTMRs, hair receptors (sorta fast)
Aδ - small, myelinated - free nerve endings, deep pressure, some pain (smaller, slower)
AC - very small, unmyelinated - temperature, pain/itch/tickle, (smallest, slowest)
Peripheral nerves enter the spinal cord via the spinal nerves. Sensory neurons enter via the dorsal root and afferent cell bodies reside in the dorsal root ganglion (DRG) THIS IS YOUR AFFERENT PATHWAY FOR PERIPHERAL NERVES