week 4

Question 1

What are the 2 divisions of the nervous system?

Answer 1

CNS: brain and spinal cord
PNS: nerves and peripheral ganglia

Question 2

What is the Neuraxis?

Answer 2

an imaginary line that is drawn through the spinal cord, all the way up to the front of the brain

Question 3

With respect to Directionality, desribe what the terms Rostral or Anterior/Caudal or Posterior, Ventral, Dorsal, Lateral and Medial and reffering to in the CNS ans Neuraxis.

Answer 3

Dorsal = back, above(when talk abt brain)
ventral = front, below(brain)
Rosteral or Anterior = front
Caudal or Posterior = back
Lateral = away from neuraxis
Medial = towards neuraxis
* view picture to get a better understanding

Question 4

What are Ipsilateral and Contralateral, when referring to directionality.

Answer 4

Ipsilateral + structured located on the same side of the body/Neuraxis
Contralateral + Structured located on opposite side of the body/Neuraxis

When touching something with the right hand, it send signals to the left side of the brain, vice versa with left hand and right side of brain

Question 5

Give an example of Evidence of Contralateral Function when corpus callosum has been cut.

Answer 5

Joe’s left hand was able to draw the picture on the right side of the screen even though he could not see it.

Question 6

What is Broca Aphasia?

Answer 6

Non-fluent aphasia
Damage to the frontal lobe of the brain called the broca’s area.
“tono.. tono”

Question 7

What is Wernicke’s Aphasia?

Answer 7

fluent aphasia; lateralized to the left hemisphere, posterior portion of superior temporal gyrus.

Sounds like their speech is fluent, but the words are meaningless
Lack of comprehension, trouble understanding
And their speech has lack of meaning

Question 8

What are the 4 divisions of the brain?

Answer 8

Forebrain(Telencephalon)
Forebrain (dienceohalon)
Midbrain
Hindbrain

Question 9

What is the Telencephalon: Cerebral Cortex?

Answer 9

Most prominent part of the brain
Convoluted (smooshed together to fit in the skull) by sulci/fissure and gyri
- Gyri - raised parts of brain
- Sulci - crevasses of the brain
- Sulci can be used to localized parts of the brain

Made up of neurons and glia (gray matter)

• Gray matter all of the cell bodies
• White matter the axons of those neurons

Question 10

What are the 4 lobes of the cerebral cortex?

Answer 10

Frontal: Abstract reasoning, emotion, personality, decision making, executive function, motor movement

Parietal: Numerical information, and integrates spatial information, processes sensory information (postcentral gyrus/primary sensory cortex)

Occipital: vision perception (striate cortex/primary visual cortex damage and cortical blindness

Temporal: auditory information processing, memory and learning, language, facial recognition, emotion and motivation

Question 11

What are Somatosensory Strip and Motor Strip?

Answer 11

Somatosensory Strip: placed between the parietal lobes and our frontal lobes. coordinates the sensory data that comes up from all over the body.

Motor Strip: placed between the parietal lobes and our frontal lobes. it helps to control movement

Question 12

What is Cortical Homunculus?

Answer 12

How our bodies are represented in the brain

Sensory Homunculi; lips, tongue, hands
Motor Homunculi: hands, not ears b/c not everyone can move their ears

*view picture in notes for better understanding

Question 13

What is Telencephalon: Limbic System?

Answer 13

Limbic System: Structures that form the epicenter of emotion and behavioural expression
Limbic System is implicated in fear, depression, anxiety and alzheimer’s disease
Includes olfactory bulb, amygdala(fear), Hippocampus, Cingulate Gyrus, (portion of nucleus accumbens and Hypothalamus)

Question 14

What is Telencephalon: Basal Ganglia?

Answer 14

Basal Ganglia: Bundles of subcortical nuclei that lie beneath the lateral ventricle, lateral to Thalamus
Basal ganglia is implicated in OCD, parkinson, schizophrenia

Question 15

What is the Forebrain: Diencephalon?

Answer 15

Smaller portion of the forebrain that surround the third ventricle (Thalamus and Hypothalamus)

Thalamus: Projection fibers connect to the cortical surface to relay sensation,spatial and motor signal information

Acts as a gateway to higher cortical function
Regulates consciousness, sleep, alertness

Question 16

What is the Diencephalon: Hypothalamus?

Answer 16

Controls the autonomic nervous system and endocrine system
Fighting, feeding, feeling, mating, sleeping, drinking (motivational behaviours)
Releases it’s neurohormone via the pituitary gland
- The anterior pituitary is the master gland - releases tropic hormones that control secretion and production of hormones in other glands of the endocrine system

Question 17

What is the Midbrain: Mesencephalon?

Answer 17

Tectum

• “Roof” of the midbrain
• Dorsal portion of the midbrain
• Swelling on each side are superior and inferior colliculus
  
  • Superior = visual processing and eye movements
  • Inferior = auditory processing

Tegmentum

• “floor “ of the midbrain
• Includes periaqueductal gray matter (PGM), ventral tegmental area (VTA) and substantia nigra
  
  • PGM: Important for species-specific behaviour (e.g., freezing [flight, fight .. or freeze], mating behaviour)
  • VTA: projections of DA neurons from VTA to nucleus accumbens (Mesolibic; moticationa dn reward) and from VTA to PFC (Mesocorical; cognitive function)
  • Substantia nigra: Da projections from substantia nigra to striatum (Nigrostriatal; movement)

Question 18

What is the Hindbrain: Metencephalon?

Answer 18

Cerebellum “little brain”

• Vital for standing, walking, coordination, and sense of timing of external stimuli
• Integrates info, from various sense
• Important for attentional control and some forms of memory

Pons “Bridge”

• Relays info between the cerebral cortex and the cerebellum and spinal cord
• Connected to cranial nerves that control sensations and movement of head )skin, eye movement, face, hearing)

Question 19

what is the Hindbrain: Myelencephalon?

Answer 19

Medulla Oblongata

• Most caudal (posterior) part of the brain stem, sitting above the spinal cord
• fatal if damaged
• Important for the cardiac, respiratory, vomiting, sneezing, salivation, coughing, and vasomotor function
• Connected to cranial nerves that controls sensations and movement of head (taste, tongue, neck; vagus nerve)

Question 20

What is the structure of the Spinal Cord?

Answer 20

the spinal cord is the cord of nervous tissue within the spinal column

Segmented structure - with sensory nerve (Dorsal) and motor nerve (ventral) on the left and right side

Question 21

What is the Bell-Magendie Law within the Spinal cord?

Answer 21

afferent(sensory) dorsal fibers and efferent(motor) ventral fibers

Question 22

what is the vertebral column?

Answer 22

It protects the spinal cord

there are 24 vertebrae

Question 23

what are the vertebral column and spinal cord segmented into?

Answer 23

Cervical vertebrae
Thoracic Vertebrae
Lumbar vertebrae
Sacral vertebrae
Coccyx

Question 24

how many pairs of spinal nerves are formed along the spinal cord?

Answer 24

Spinal nerves are formed at 31 places along spinal cord

8 in the Cervical vertebrae
12 pairs in the Thoratec vertebrae
5 in Lumbar vertebrae
5 in Sacral vertebrae
1 in Coccyx

each pair connects the spinal cord with a specific region of the body connecting CNS with PNS

Question 25

Where does the spinal cord pass through?

Answer 25

Spinal cord passes through the hole of the spinal foramen

Question 26

Describe the purpose of the Cervical Nerves

Answer 26

“C”: (nerves in the neck) supply movement and feeling to the arms, neck and upper trunk. Also controls breathing

Question 27

Describe the purpose of the Thoracic nerves

Answer 27

“T” : (Nerves in the upper back) supply movement and sensation to the trunk and abdomen

Question 28

Describe the purpose of the Lumbar nerves snd Sacral nerves

Answer 28

“L” and “s”: (nerves in the lower back) supply movement and sensation to the legs, the bladder, bowel and sexual organs

Question 29

Are the spinal nerve fibers part of the CNS or PNS?

Answer 29

the nerve fibres are extending from the spinal cord so they are actually part of the PNS

Question 30

Describe the PNS. (The 2 nervous systems)

Answer 30

Somatic Nervous System
The part of the peripheral nervous system that controls the movement of skeletal muscles or transmits somatosensory information to the central nervous system from the skin and sense organs
Spinal nerves and cranial nerves

Autonomic nervous system
Portion of the peripheral nervous system that controls the body’s vegetative functions (smooth muscle, cardiac muscle and glands)
Sympathetic and parasympathetic nervous system

Question 31

Describe the PNS Somatic nervous system.

Answer 31

Spinal nerves
Front he vertebral column, fibers travel to muscles or from sensory receptors
Afferent axons (to CNS) and efferent axons (from CNS)
Dorsal Root Ganglion = neuron bundle along dorsal root

Cranial nerves
12 paris attached to ventral surface of brain
sensory/motor function of head and neck
Vagus nerve (x) regulates thoracic and abdominal cavities

Question 32

Describe the The PNS: Autonomic nervous system.

Answer 32

Sympathetic Nervous System
Activation associated with energy expenditure and mobilization (e.g., increased blood pressure, heart rate, epinephrine release)
Via preganglionic neurons in spinal nerves at thoracic and lumbar regions (thoracolumbar) of the CNS to postganglionic neurons that stimulate target tissue = sympathetic ganglion chain

Parasympathetic nervous system
Processes associated with conserving and restoring energy (e.g., salivation, blood flow to gastrointestinal tract, digestion
Preganglionic axons stem from cranial and sacral region (craniosacral) and connect to postganglionic cells in intermediate vicinity of target cells

Question 33

What are the 3 protections of the brain?

Answer 33

Blood Brain Barrier
Meninges
Cerebral Spinal Fluid

Question 34

Describe the protective layer: Meninges.

Answer 34

Meninges: layers of connective tissues that protect the CNS
3 layers that enclose the CNS that protect the bain and principal cord
Dura Mater: tough, flexible
Arachnoid membrane: soft, spongy
Pia Mater: thin, delticate

Question 35

Describe The Ventricular System and Production of Cerebrospinal Fluid

Answer 35

Lateral Ventricle: Largest ventricle located in the center of the telencephalon
Third ventricle: located in the center of the diencephalon
Fourth ventricle: locates between cerebellum and dorsal pons in the center of the metencephalon
Interventricular foramen: connects the lateral and the third ventricle; located anterior to massa intermedia
Cerebral aqueduct: a narrow tube connecting the third and fourth ventricle
Choroid plexus: special tissue that manufacture CSF(Cerebrospinal Fluid) and protrudes into all 2 ventricles (ependymal cells)

Question 36

Why is CSF important?

Answer 36

• Provides a protective buoyancy for the brain which effectively makes the weight of the brain 1/30th of its actual weight
• Cushions the brain against mechanical shock (TBI)
• Maintaining the chemical environment of the central nervous system (role in communication)
• The one-way flow of CSF from the ventricular system, around the spinal cord, into the subarachnoid space and into the venous sinuses is a way in which potentially harmful metabolites are removed

Question 37

What happens if CSF does not flow properly, if it does not drain properly?

Answer 37

Hydrocephalus, CSF is building up and not draining. Creating a larger head. We know the skull is quite malleable so excess CSF enlarges the ventricular system and enlarges the CNS and the surface of the brain.
Not stopping this soon enough can lead to sever brain damage and deaths in children

Normal pressure hydrocephalus, again CSF is not draining properly and causing a build up in the cerebral spinal fluid. difficult to diagnose b/c when measuring the CSF it would show as if the pressure was normal

Question 38

What are the symptoms and misdiagnosis of Normal Pressure Hydrocephalus?

Answer 38

characterized by symptoms of dementia, memory loss, difficulty speaking and changes in behaviour
shuffling when they walk, having trouble moving their feet and maintaining balance, these are also signs of parkinson’s disease

Question 39

How is Normal Pressure Hydrocephalus alleviated?

Answer 39

Manually draining the CSF