Kin 131 brain review (midterm 2) Flashcards
What’s the difference between a nerve and a neuron? where are they found?
Nerve:
-bundle of nerves including the connective tissue and the blood vessels
- Found only in the PNS
Neuron:
- Base unit of the nervous system
- Found in both the CNS and the PNS
What are found in the CNS instead of nerves?
pathways/tracts and commissures
Pathways/tracts: Group of axons together in the CNS
Commisures: Group of axons that connect the hemispheres of the brain
What 3 parts is the brain divided into? What sub parts make up these larger sections?
- Forebrain
- Cerebrum
- Diencephalon - Midbrain
- Hindbrain
- Pons
- Medula oblongata
- Cerebellum
Explain what the cerebrum is
It’s a part of the forbrain that is the biggest part of the brain. The outer layer of the cerebrum is called the cerebral cortex and is made up of the different lobes
What are the lobes that make up the cerebral cortex? What are their main functions?
- Frontal lobe
- Voluntary movement
- Executive decision making
- Personality - Parietal lobe
- Sensory perception
- language processing - Temporal
- Auditory preception
- memory retreival - Occipital lobe
- Vision perception
- facial and object perception - Insular lobe
- Location: Between the frontal and temporal lobe\
- Regulates taste and smell
What’s the primary area vs the secondary area do?
primary area: receives stimulus and is aware of stimulus
Secondary areas: Applies meaning to the information
What are the primary and secondary areas in the frontal lobe?
primary motor area: Sends out signals to the muscles
Secondary motor area: Plans movement and sends it to primary motor area
What are the primary and secondary areas called in the different lobes?
Frontal: primary/secondary Motor area
Parietal: primary/secondary Somatosensory area
Occipital: primary/secondary visual area
Temporal: primary/secondary Auditory area
Insular:
- Smell: primary/secondary olfactory area
- taste: primary/secondary gustatory area
Brain structure nomenclature
Gyri: peaks in the folds of the brain
Sulci: trouves between folds
Fissures: Long deep grooves
What divides the left and right hemisphere?
The longitudinal fissure
What are the boundaries for the frontal lobe
-Central sulcus: sulcus that separates the frontal lobe from the parietal lobe
latteral sulcus: Sulcus that separates the frontal lobe from the temporal lobe
What are the boundaries for the parietal lobe
-Central sulcus: sulcus that separates the frontal lobe from the parietal lobe
lateral sulcus: Sulcus that separates the parietal lobe from the temporal lobe
Parieto-occipital sulcus: Sulcus that separates the parietal lobe and the occipital lobe
What are the boundaries for the occipital lobe
Parieto-occipital sulcus: Sulcus that separates the parietal lobe and the occipital lobe
What are the boundaries for the temporal lobe
lateral sulcus: Sulcus that separates the parietal lobe from the temporal lobe
Explain the homunculus
Map of the frontal and parietal lobe and shows the parts of the brain that are dedicated to sensory and motor functions for different body parts
Sensory Homunculus: shows how much of the cortex is dedicated to processing sensory information from different body parts. Body parts that are more sensitive, like the fingers and lips, are represented larger.
Motor Homunculus: Found in the primary motor cortex, it indicates how much brain area is devoted to controlling voluntary movements of various body parts. Again, areas requiring finer motor control, like the hands and face, are depicted as larger.
What and where is the diencephalon
Its located under the cerebrum and its where the limbic system if found
What are the 4 parts of the limbic system and what they do?
- Hippocampus
- Turning short term memory into long term memory - Hypothalamus
- Controls hormone production and release. - - Regulates sleep/wake cycle, temperature and hunger
- controles auntonomic funtion of body - Amygdala
- Emoption processing especialy that of fear
4.Thalamus
- Decides if a stimulus should be ignored or not
What’s the main function of the brain stem
To relay info from the spinal cord to the brain and control Important bodily functions such as breathing, heartbeat
What are the 4 parts of the brain stem and their functions? ASK
- Medula oblongata
- Responsible for regulating life’s basic functions such as heart rate, breathing, vomiting, sneezing, swallowing - Pons
- Bridges the cerebellum to the rest of the brain
- Sleep/wake cycle - midbrain
- Pupile light reflex, blink reflex - reticular formation:
- Neurons all through the brainstem
- When turned on it wakes us up. When inhibited we fall asleep
- 5 major senses turn it on exept for smell
What are the 3 parts of the hindbrain?
- Pons
- Bridges the cerebellum to the rest of the brain - Medulla oblongata
- Responsible for regulating life’s basic functions such as heart rate, breathing, vomiting, sneezing, swallowing - cerebellum
- Balance and courdination
Name the parts of the brain stem in order from spinal cord up
- Medulla oblongata
- Pons
- Midbrain
- reticular formation
What’s the difference between a nucleus and a ganglia?
Nucleus: group of cell bodies in the CNS
Ganglia: Group of cell bodies in the PNS
What are basil nuclei and what do they do? What are their 3 main functions and what diseases affect those 3?
They are a group of cell bodies (AKA grey matter) in white matter.
Their main function are:
- Plan and execute voluntary movement
- Parkensins disease causes decrease in movement - Help inhibit unessisary movement
- Huntingtons disease is when the basil nuclei that regulate unwanted movement is damaged causing a increase in movement - Subconscious movements
What’s the difference between akinesia vs brady kinesia?
Akenesia: Loss of movement
Bradykinesia: Slower movement
What part of the limbic system is not enclosed by the blood brain barrier? Why?
The Hypothalamus so it can accurately read the content of the blood in order to know what hormones to release
What part of the brain contains the most neurons?
The cerebellum
What 3 things can damage to the cerebellum lead to? What can cause this damage?
Can be caused by: severe concussion, stroke and results in movement errors
Dysmetria: Error in the range of movement causing bad accuracy
Dysdiadochokinesia: Inability to perform a rapid alternating movement
Ataxia: Unsteady gate (Walking patterns)
What are the 3 ways the CNS is protected. What do each of them do?
- Cerebral spinal fluid
- Protects brain by suspending it in CSF
- Nutrient supply - Blood brain barrier
- Controls what can enter the brain from the blood stream - Meningies
- 3 layer protection of the brain that surrounds it - Pia mater
- Arachnoid mater
- Dura mater
What are the 3 layers of meningitis from closest to the brain and spinal cord out (PAD)
- Pia mater
- Thin layer of connective tissue
- Contains blood vessels - Arachnoid mater
- middle layer
- spider web like structure that let CSF flow through it - Dura matter
- Tough outter layers of connective tissue
- Actually made of 2 layers
What is the purpose of the spinal cord
Top relay information from the PNS to the CNS
Where does the spinal cord attach to on the brain?
The brain stem
What 5 sections is the spinal cord separated into?
- Cervicle
- Thoracic
- Lumbar
- Sacral
- Coccygeal
How many spinal nerve pairs are their?
31 pairs
How many spinal nerve pairs are on the cervicle region?
8
Are the spinal nerves part of the CNS or the PNS
PNS
The spinal nerves are broken up into two pieces. What are they called and do they carry afferent or efferent info?
Posterior ramus: carries afferent info
Anterior ramus: carries efferent info
What is the conus medullaris, Filum terminals, and the caudal equina?
conus medullaris: End of the spinal cord
Filum terminals: Anchors the spinal chord to the coccyx
caudal equina: Extention of nerves past the end of the spinal cord enervating the lower limbs
What is a dermatome and a myotome?
Dermatome: Area of skin supplied by the same spinal nerve that detects sensory stimulus
Myotome: Group of muscles that is supplied by the same spinal nerve
What’s the main purpose of the limbic system?
Basic emotional and behavioural responses needed for survival
What part of the brain decides wether a stimulus is important enough to send to the brain?
Thalamus
What is the subarachnoid space?
space between the Pia mater and the arachnoid mater that’s filled with CSF
Explain where brain bleeds can happen what their results
Epideural hematoma:
- bleeding in the epidural space (between skull and dura mater)
- usually caused by bone fracture
- causes a increase in pressure
Subdural hematoma:
- Bleeding in the subdural space (between dura mater and arachnoid matter)
- Increases pressure in brain
Subarachnoid hematoma:
- Bleeding in the subarachnoid space (between arachnoid matter and Pia mater)
What is meningitis?
The inflammation of the meningitis causing a increase in pressure
Where is cerebrospinal fluid produced?
CSF is produced by the choroid plexus which is made of ependymal cells
Explain the flow of CSF swell as its drainage back into the blood stream. ASK ABOUT THIS
- CSF is produced in the lateral ventricles
- Flows to the third ventricle through the inter ventricular Forman
- Flows the the fourth ventricle through the cerebral aqueduct
- CSF then goes to the subarachnoid space via the medial and latter apeture
- CSF gets drained from the subarachnoid space into the superior sagittal sinus via arachnoid villi
What is the purpose of a spinal tap?
To obtain a sample of cerebral spinal fluid from the spine in order to determine for infections
What is hydrocephalus?
A condition where the production of CSP is greater than what we can drain. Results in a enlarged head which is more dangerous for adults than kids.
What do the astrocytes create to form the blood brain barrier?
Tight junctions
What are the different types of receptors in the PNS and what stimulus are they made for?
1.Thermoreceptors:
- Detects temperature change
- Photoreceptors
- React to light - Chemoreceptors
- React with certain molicules - Mechanoreceptors
- Pay attention to [pressure, touch vibration - Nociceptors
- Fire to indicate pain
What 3 afferent pathways can the PNS be divided into?
Somatic sensory:
- Physical feelings from the skin
Visceral sensory
- Feelings from inside the body (eg. heart lungs)
Special sensory
- Stimulus from the 5 senses
What are the two efferent pathways in the PNS?
Somatic motor: Controles voluntary movement
Autonomic motor: Controles involentary movement
- Sympathetic: Flight or fight
- Parasympathetic: rest and digest
Enteric: Regulates GI function
Where are the sensory receptors located?
Ends of sensory dendrites
What are the two ways sensory receptors can be categorized?
Mode of detection and where their detected from
Name the 3 sources of stimulus (Where the stimulus is from)
Extroceptors: Stimulus from outside the body (eg. Sight, sound, touch)
Proprioceptors: Stimulus from joints
Enteroceptors: sense things in the gut
What’s are the two types of adaptation receptors and what do they do?
fast adapting receptors: Activated when a stimulus is first encountered, but fall silent if a stimulus stays present
Slow adapting receptors: Keep responding to a continuously present stimulus
Explain the sensory unit
Sensory unit: Single afferent neurin and all of its sensory receptors attached to it
Receptive feild: The area under one sensory unit
What is sensory coding?
How the brain understands what’s happening by anylizing the type, location and intensity of a stimulus
What determines the intensity of a stimulus?
Frequency coding: The amount of stimulus coming in
Population coding: Amount of neurons being activated
What determines the type of stimulus?
Each receptor has a specific type of stimulus it detects for
What determines the location of a stimulus?
When overlapping receptor fields receive a stimulus that stimulates them both, lateral inhibition occurs. This is when the sensory unit that is sending the most AP inhibits its neiboring neurons via axon collaterals. This centralizes the location of the stimulus
What are the things called that perform lateral inhibition?
Axon collaterals
Is a smaller or larger receptor field more accurate?
Smaller
There are two types of mechanoreceptors. What are they and what do they sense?
Touch receptors: Provides info about shape and texture of a object
Pressure receptors: How intense is the stimulus
What are the 6 types of touch/pressure receptors? are they fast or slow adapting?
- Root hair plexuses: Gives info about stimulus of hairs. Fast adapting
- Pacinian corpuscles: Gives info about deep pressure. Fast adapting
- Meisseners corpuscles: Detect light touch and low frequency vibration. Good at detecting movement. Fast adapting
- Merkel cells: Detect light touch. Slow adapting. Good at detecting shape
- Ruffini corpuscles: Detect stretch in skin. Slow adapting
- Free nerve endings
What kind of receptors are a type of free nerve endings?
- Nociceptors
- Thermoceptors
- Mechanoceptors
What are the two types of nociceptors? Are they mylenated or not?
Type A: Mylenated, provide info on quick sharp pain
Type C: Unmylenated, provide info on deep aching pain
What ways can thermoreceptors be activated?
Heat/cold as well as chemicals which can trick them
What is referred pain
Pain is felt on a different part of the body because the sensory neuron connects into the same place on the spinal cord
What are the two types of proprioceptors?
Muscle spinal stretch receptors: Info about the change of length in a muscle
Golgi tendon organs: Information about the compression in tendons
What is a spinal reflex?
A automatic reflex arc that doesn’t require the brain to happen.
