The senses Flashcards

Question

The hairs of the body are what?

Answer 1

rapidly adapting and low threshold

Answer 2

For Touch , slow adapting and low threshold for pleasant contact

Answer 3

they are used for injurious force Slow adapting , High thereshold

Answer 4

only nerve fibers from muscle spindles (1a afferents) synapse directly with motoneurons

Answer 5

The corticospinal pathway carries the motor commands from the motor cortex to the muscles needed for the grip.

Answer 6

Muscle Spindles and Golgi Tendon Organs in the muscles provide feedback about the muscle length and tension

Answer 7

The lemniscal pathway carries information to brain about touch, pressure, and proprioception (the sense of where your hand is in space).

Answer 8

Based on this feedback, the brain sends adjustment signals back through the motor cortex, via the corticospinal pathway, to fine-tune the grip

Answer 9

where the brain processes the sensory input (e.g., texture, pressure, and proprioception).

Answer 10

When sensory information (e.g., touch, temperature, pressure) is gathered from receptors in the skin or muscles, it travels up the spinal cord. The thalamus, located in the brainstem, acts as a relay station that filters and relays the sensory signals to the somatosensory cortex in the parietal lobe of the brain.

Answer 11

Area 3,1,2 : Primary Somatosensory cortex Area 4: Primary Motor Cortex

Answer 12

Penfield's most famous achievement was creating a map of the somatosensory and motor cortices of the brain, called the "motor homunculus" and "sensory homunculus"

Answer 13

Is not static through life but modifiable through changing input and learning

Answer 14

He is particularly known for his groundbreaking work on how the brain is capable of reorganizing itself.Progressive change in cortical representation after transection of the median nerve

Answer 15

the brain suppresses some information in order to focus on other stimuli or avoid overwhelming sensory information eg Humans: Why can’t we tickle ourselves? Brain cancels out predictable touches

Answer 16

When you move your eyes or head, the image on your retina changes. To keep your vision stable, your brain sends a signal (corollary discharge) that tells your visual system, “Hey, this movement is coming from me!” This prevents you from feeling like everything is shifting around randomly. It's like the brain is saying, "I moved, so the shift in what I see is normal, not something that should surprise me."

Answer 17

Primary endings are type Ia afferent fibers that wrap around the central part of the muscle spindle fibers. They are responsible for detecting changes in muscle length and how fast those changes are happening.

Answer 18

Ia afferent fibers carry sensory information from muscle spindles to the brain, specifically about how much a muscle is stretched and how fast it's changing

Answer 19

Are a crucial part of the nervous system that are responsible for controlling voluntary muscle contraction.

Answer 20

are a crucial part of the nervous system that are responsible for controlling voluntary muscle contraction.

Answer 21

that integrates sensory input (information from the environment and body) and translates it into motor output (muscle movements).

Answer 22

Primary motor cortex M1 Premotor cortex Supplementary motor area S-I and S-II PPC

Answer 23

Cerebellum Basal Ganglia

Answer 24

Corticospinal Tract (Pyramidal Tract), Extrapyramidal Tracts, Rubrospinal Tract, Reticulospinal Tract,

Answer 25

Origin: The red nucleus in the midbrain. Function: It plays a role in controlling muscle tone and coordination of limb movements, especially in the upper limbs. Decussation: It crosses over in the midbrain

Answer 26

Vestibulospinal Tract: Origin: The vestibular nuclei in the medulla (brainstem). Function: This pathway is important for maintaining balance and posture. It helps coordinate movements that keep the body upright, especially in response to changes in head position (like when you're balancing or walking). Decussation: The lateral vestibulospinal tract does not cross (uncrossed), while the medial vestibulospinal tract does cross over at the level of the brainstem.

Answer 27

Origin: The superior colliculus (a part of the midbrain involved in visual processing). Function: It helps coordinate movements in response to visual stimuli, especially head and neck movements in response to visual cues (like turning your head to look at something). Decussation: It crosses over at the level of the midbrain

Answer 28

The ability of the CNS to anticipate the consequences of action is critical for the control of voluntary action

Answer 29

Term introduced by Wiersma (1964), When stimulated these neurons evoked a movement, the pattern of which was NOT coded in their sequence of spikes Neural decision-making cells

Answer 30

Prefrontal Cortex (PFC), Motor cortex, cerebellum

Answer 31

Brainstem neurons were found to be responsible for stopping locomotion * The neurons could ‘command’ the rhythmic neural circuits (the CPG) to stop locomotion

Answer 32

the basal ganglia

Answer 33

Brainstem neurons were found to be responsible for stopping locomotion * The neurons could ‘command’ the rhythmic neural circuits (the CPG) to stop locomotion

Answer 34

motor cortex--> patamen--> lateral GPi ---> ventral lateral neuculas

Answer 35

Dorsolateral prefrountal cortex ---> Dorsolateral coaudate ----> Medial GPi ---> medial dorsal and ventral anterior neucai

Answer 36

Anterior cingulate cortex ---> ventral striatum ---> ventral pallidum ----> medial dorsal nucleas

Answer 37

Results in the activation of the supplementary motor area (SMA) before and during movement. * SMA activity prior to movement: the ‘readiness potential’ * Function: sequencing of serial order actions for the execution of learned motor programs. * Direct and Indirect pathways: Go v No Go

Answer 38

excites the motor cortex, 5 neurons- 1. Corticostriate fibres from sensorimotor cortex activate GABAergic spiny neurons in the striatum with D1 class dopamine receptors. These neurons are receiving nigrostriatal input 2. Activated GABAergic striatal neurons inhibit internal pallidal GPi neurons 4. Activation of the supplementary motor area (SMA) 5. Modification of corticostriate activity and initiation of movement via corticospinal (CST) and corticoreticulospinal tracts (CRT)

Answer 39

7 neurons 1. Corticostriate fibres from sensorimotor cortex activate GABAergic spiny neurons in the striatum with D2 class dopamine receptors. These neurons are receiving nigrostriatal input. 2. Activated striatal neurons inhibit external pallidal GPe neurons. 3. The subthalamic nucleus (STN) receives input from the GPe neurons 4. The STN excites the internal pallidal neurons (GPi) 5. Inhibition of ventral lateral nucleus (VLN) thalamocortical neurons 6. Activation of the SMA (reduced due to 5) 7. Modification of corticostriate activity and initiation of movement via corticospinal (CST) and corticoreticulospinal tracts (CRT)

Answer 40

dysfunction in 2 circuits the basal ganglia and the cerebello-thalamo-cortical pathway

Answer 41

Lead Pipe’ rigidity, Co-contraction of prime movers and agonists, dysfunction related to golgi tendon organs (1b) autogenic inhibition

Answer 42

Weakened contribution of the SMA prior to movement

Answer 43

Impaired in anticipatory postural adjustments

Answer 44

Basal Ganglia direct and indirect pathways compete to either facilitate or inhibit movement * Disinhibition of the thalamus (Direct pathway) is opposed by inhibition of the thalamus by additional excitatory circuitry from the STN to the GPi)

Answer 45

chorea- excessive movements- Overactivity of the Direct Pathway Parkinson's disease-Overactivity of the Indirect Pathway

Answer 46

Mirror neurons are a special type of brain cell that fires both when you perform an action and when you observe someone else performing the same action. This means that the same neural circuits are active whether you're doing something yourself or just watching another person do it.