Ex. #1: Functional Anatomy Flashcards
Functional Anatomy --> CNS and PNS
What are the 3 anatomical planes the brain is divided into?
- Coronal (“frontal”)
- Sagittal
- Horizontal (“axial”)
How does the “coronal (frontal) plane” split the brain?
- Splits it into front and back pieces
How does the “sagittal plane” split the brain?
- Splits it in half (think from a bird eye’s view)
How does the “horizontal (axial) plane” split the brain?
- Splits into top and bottom halves
Anterior means …
- Front or in front of
Posterior means …
- Back or behind
Superior means …
- Above
Inferior means …
- Below
In terms of the brain, “rostral” means …
- towards your nose
In terms of the brain, “caudal” means …
- towards back of your head
In terms of the brain, “dorsal” means …
- Top of the brain and back of your spinal cord (think on your butt side)
In terms of the brain, “ventral” means …
- Bottom of the brain and front of your spinal cord (think on your boobs side, lol)
The central nervous system consists of .. (2 things)
- Brain
- Spinal Cord
How many parts is the brain split up into and what are they?
3
1. Forebrain aka Cerebrum aka Cerebral Cortex
2. Brainstem
3. Cerebellum
What is the Cerebral Cortex? (forebrain)
- outer brain
- layer on top of the cerebrum (they basically are the same thing)
How many hemispheres is the brain split into?
- 2
How many cortexes does the brain have and what are they called?
-2
1. Motor Cortex
2. Sensory Cortex
What does the “motor cortex” do?
- helps with movement
What does the “sensory cortex” do?
- helps with sensations
How many lobes does the brain have and what are they called?
- 4
1. Frontal Lobe
2. Parietal Lobe
3. Temporal Lobe
4. Occipital Lobe
What is the function of the “Frontal Lobe”?
- executive functions like thinking, planning, organizing, problem solving, emotions and behavioral control, and responsible for personality
What is the function of the “Parietal Lobe”?
- perception
- making sense of the world
- helps with spelling
- arithmetic
What is the function of the “Temporal Lobe”?
- memory
- understanding
- language
What is the function of the “Occipital Lobe”?
- vision
What are the two cortexes separated by?
- central sulcus
Describe a “sulcus”.
- depression or fissure on the surface of the brain
- VALLEY
Describe a “gyrus”.
- ridge on cerebral cortex surrounded by sulci
- MOUNTAIN
How many layers does the cerebral cortex have? What are they?
- 6 layers
- Supragranular (layers 1-3)
- Internal granular (4th layer)
- Infragranular (layers 5-6)
In what layer of the cerebral cortex are most of the neurons located?
- supragranular layer
What type of cells/neurons does the “supragranular” layer have?
- Pyramidal cells
(cell body or soma is in the shape of a pyramid)
What matter are “pyramidal” cells in and are they excitatory or inhibitory?
- grey matter
- excitatory (+)
- activate downward neurons
True of False: Pyramidal Cells activate DOWNWARD neurons
- True
True or False : Pyramidal cells have direct connections with muscles due to their long axons
- True
What type of cells/neurons does the “internal granular” layer have?
- densely packed “stellate” cells only
Are “stellate” cells/ neurons excitatory or inhibitory?
- inhibitory (-)
The more neural density, the more ______ you are. (think humans vs animals)
- intelligent
Where is the “white matter” in the brain?
- inner brain
True or False: Myelin and myelinate axons are gray.
- False, due to them being in the white matter because they are white
Areas with “axonal tracts” are called _____ matter.
- white
Where is the “gray matter” in the brain?
- outer brain
Areas with cells, dendrites, and unmyelinated axons appear ____.
- gray
What is the function of the “corpus collosum”? Processes what signals?
- integrate and transfer info. from both cerebral hemispheres
- commissural region of the brain that has tracts that connect the left and right sides of the brain
- made of 200 mil fibers
- sensory, motor, and cognitive signals (how the hems. communicate)
What is the function of the “basal ganglia”?
- gets input signals from the cerebral cortex
- sends signals to the limbic and prefrontal cortex
- associated with reward, and cognition, but mostly involved in motor control
Parkinson’s Disease and Huntingdon’s disease comes from affects in what part of the brain?
- Basal Ganglia
—-> motor dysfunction
What is the role of the “thalamus”?
- serves as a relay station filtering information between the brain and body
- composed of different nuclei that serve a unique role
—> relaying sensory and motor signals from outside to the inside structures
—> regulation of consciousness and alertness
“Afferent” means …
- “ascending” from spinal cord To brain
- ‘sensory’ neurons that bring info. from the outside world TO the brain
- from the PNS to the CNS
–> senses like vision, hearing, smell, taste, touch (pain, temp.)
example: hand on a hot stove –> up spinal cord –> brain then communicate with efferent neurons ..
“Efferent” means …
- “descending” from brain to spinal cord
- ‘motor’ neurons that carry info AWAY from the brain
- from the CNS to the PNS (muscles)
example: this then initiates the action- nerves tell bodies to perform the
action of taking a hand off the
stove
- nerves tell bodies to perform the
(“E” for ‘exit’)
True of False: ‘Afferent” sensory neurons have long dendrites, short axons, and cell bodies are OUTSIDE spinal cord in dorsal root ganglion
- True
True or False: ‘ Efferent’ motor neurons have short dendrites, long axons, and cell bodies are IN ventral horn of the spinal cord
- True
- Afferent consists of a single axon the divided into how many distinct branches?
- One is connected to the ______ organ.
- The other carries sensory info. to _____ via dorsal root.
- 2
- sensory
- spinal cord
Efferent axons leave the ____ through ventral root through spinal nerves and then synapse with skeletal muscle in neuromuscular junction.
- spinal cord
How many regions are in the “brain stem” and what are thy called?
- 3
1. midbrain
2. pons
3. medulla
What is the function of the “brain stem”?
- midbrain: relay system for sending info. necessary for vision and hearing
- role in motor movement, fear, anxiety, pain, sleep/wake cycle, arousal, coordination (body regulations/unconscious things)
- rostral continuation of the spinal cord
–> one of the main areas of the brainstem is reticular formation that is involved in coordinating reflexes and simple motor actions
What is the function of the “cerebellum”?
- important role in motor control and coordination of complex movements
The brainstem connects the brain to the ____.
- spinal cord
True or False: Within the spinal cord, the gray and white matter in terms of their locations are the same as in the brain.
- False
—> in spinal cord, gray matter is closer to the center vs. brain its away from center
—> in S.C., white matter is further from center vs. brain its close to the center
What brain structure for inter-hemisphere info transfer?
- corpus callosum
What brain structure is responsible for relaying sensory and motor info. between brain and body?
- thalamus
Abnormalities in what brain structure will lead to Parkinson’s Disease?
- basal ganglia
What brain structure coordinates complex movements?
- cerebellum
True or False: The PNS consists of the somatic and autonomic nervous systems. Includes all nerves that enter or exit from the brain and spinal cord.
- True
What is the role of the “autonomic” nervous system?
- has nerves that connect the CNS to the visceral organs (heart, stomach)
- mediates unconscious activities
–> think ““auto-matic”, don’t have to think about it
What is the role of the “somatic” nervous system?
- consists of nerves that go to the skin and muscles and is involved in conscious activates
–> think “ SO-conscious rn”
The PNS consists of what two types of nerves?
- cranial
- spinal
INFO CARD!!!!! :)
–> Within the PNS, the 12 cranial nerves emerge directly from the brain and provide both afferent (sensory) and efferent (motor and autonomic) innervation to the structures of the head and neck
What 2 sources does the brain get blood from and their function?
- Internal carotid arteries
- vertebral arteries
–> blood supplies’ oxygen and nutrients
INFO. CARD!!!! :)
The two arteries in the brain branch off from the dorsal aorta to supply the brain and spinal cord.
What is the “circle of willis”?
- ring of vessels connecting the anterior and posterior circulations of the brain
The “anterior cerebral artery” supplies blood to which parts of the brain?
- the frontal lobe
The “middle cerebral artery” supplies blood to which parts of the brain?
- parts of the lateral and inferior frontal lobe and the anterior lateral parts of the parietal lobe
The “posterior cerebral artery” supplies blood to which parts of the brain?
- occipital lobe
- inferior part of the temporal lobe and various deep structures
The “anterior choroidal artery” supplies blood to which parts of the brain?
- visual pathways, limbic system, basal ganglia, diencephalon, midbrain, temporal lobe
What is the “blood brain barrier?”
- barrier between cerebral capillary blood and interstitial fluid of the brain
–> maintains a homeostatic environment in which the CNS structures can function without disruption from other bodily functions
—> primarily regulates composition and volume of the cerebrospinal fluid (CSF)
The blood brain barrier has what kind of support/protection?
- chemical ONLY
–> no mechanical
The BBB has a tight junction that does what?
- open and closes and can allow the filtering of bad stuff
The ventricular system is an interconnected series of cavities with CSF that cushions the brain and spinal cord, serves as a nutrient delivery and waste removal system…. and provides ______ support/protection.
- mechanical protection
Where is the CSF produced?
- choroid plexus and flows from the lateral ventricles
INFO. CARD!!!! :) The cerebral ventricular system is made up of 4 ventricles
- 2 lateral ventricles (one in each cerebral hemisphere)
- 3rd ventricle in the diencephalon
- 4th ventricle in the hindbrain
INFO. CARD!!! :)
The CSF is critical to the functioning of the CNS.
The brain and spinal cord are enveloped within 3 layers of membrane collectively called the _____.
- meninges
The meninges provide _____ support/protection.
-mechanical ONLY
INFO CARD!!:)
Cranial meninges specifically referring to the structure that covers the brain.
What is the chief function of the “meninges”?
- protect the contents of the brain and spinal cord
How many layers of the “meninges” called?
- superficial –> dura
- middle –> arachnoid
- deep –> pia mater
What is the “dura maters” function?
- drainage system – allows blood to leave brain and allows CSF to re-enter circulation
- means “hard”
- composed of dense connective tissue and adheres to inner surface of the skull and vertebrae
What is the “arachnoid maters” function?
- contains CSF which acts like a cushion
- it has small projections that allow CSF to re-enter the circulation via the dual venous sinuses
- thin wispy membrane that lies just deep to the dura
What is the “pia maters” function?
- protect the CNS by helping containing CSF
- very thin, clear membrane that directly adheres to the surface of the brain and spinal cord
True or False: Cranial nerves CANNOT be both motor or sensory
- False, can be either or both
True or False: PNS includes nerves that enter or exist from the CNS
- True
True or False: Cranial nerves DO NOT regulate autonomic functions like internal organ function.
- False, they do
Neurons are the ____ of the nervous system.
- building blocks
Neurons help ____ information to the surroundings.
- spread
True of False: Axon MUST connect to another neurons dendrites to send a signal
- True
Within a neuron what is the function of a “dendrite”?
- receives signals from other neurons
Within a neuron what is the function of a “cell body/soma”?
- contains nucleus and regulates gene expression
- stores organelles of cell and regulates production of proteins and lipids needed by the rest of neuron
Within a neuron what is the function of a “myelin sheath”?
- insulates
- prevents current flow across the axonal membrane
- made of protein and fatty acids
- allows electrical impulses to transmit quickly and efficiently along nerve cells
—-> increases speed of action potential propagation and the distance a current can passively spread
—-> the thicker the myelin the faster conduction and greater chances of AP propagation
— prevent AP from decaying so things/ responses to stimuli (pain) are quicker
Within a neuron what is the function of a “nucleus”?
- where RNA is produced in neurons
Within a neuron what is the function of a “axon terminal”?
- transmit info between neurons and away from muscles and glands via neurotransmitters at synapses
Retinal amacrine (large) cells are inhibitory OR excitatory?
- inhibitory (-)
- STOP downstream neuron signals
Are “cerebellar purkinje cells” inhibitory OR excitatory?
- inhibitory (-)
- play a crucial part in motor control
- receives largest # of synapses from opposite neurons
INFO CARD!!!:)
- Glial cells are a type of cell that provides physical and chemical support to neurons and maintain their environment
- In CNS and PNS
What are the 2 main types of “glial cells”?
- Macroglia: big
- Microglia: small
What are the 3 types of “macroglia” cells?
- astrocytes
- oligodendrocytes
- schwann cells
What is the type of “microglia” cell?
- scavenger cells
What do macroglia, “astrocytes” do?
- in CNS can provide immune
defense - form BBB
- modulating fluid
- CNS development
What do macroglia, “oligodendrocytes” do?
- provide myelin sheaths in CNS
What do macroglia, “schwann cells” do?
- provide myelin sheaths in the PNS
What does the microglia, “scavenger cells” do?
- primary immune defense for CNS (produce antibodies)
- support neuron regeneration
- work with globulin barrier
- when extra pathogens come in the scavenger cells come and clean/ get rid of them
Myelin is made of _____ cells in the CNS.
- “oligodendrocytes” (macro)
Myelin is made of _____ cells in the PNS.
- “schwann cells”
INFO CARD!!!! :)
- Myelin sheath is a sheath of proteins and fats surrounding an axon.
True of False: You can only find sodium channels at the nodes of Ranvier in myelinated axons.
- True
What is “saltatory conduction”?
- AP’s jumping across nodes
- myelin causes “jumps” instead of passing through
True of False: Nodes of Ranvier DO NOT have myelinated sheath but have Na+ channels.
- True
Membranes do what in cells?
- surround cells and separate the inside (intracellular) from the outside (extracellular)
“Intracellular” means…
- inside
“Extracellular” means…
- outside
True or False: The plasma membrane IS NOT impermeable to ions.
- False, IS
“Impermeable” means…
- not permitting passage of fluid through its substance
True of False: Multiple layers of closely opposed glial membranes wrap the axon and serve as an electrical insulator
- True
True or False: Sodium channels are clustered at the Nodes of Ranvier
- True
Membrane Channels:
What are the 3 types of ion exchange?
- active transporters
- ion channels
- gap junction or leak channels
Active transporter channels are ___ pumps and requires ____?
- ion pumps
- ATP
Active transporters actively move selected ions AGAINST or TOWARDS concentration gradient?
- AGAINST
- they create ion concentration gradients
–> steps: ion binds then ion is transported across membrane q
Ion channels are voltage gated and are ion ____?
- specific
Ion channels allow or don’t allow ions to diffuse down concentration gradient?
- allow
True or False: Ion channels are selectively permeable to certain ions.
- True
INFO CARD!!!! :)
- The “electrochemical gradient”, determines the direction that ions will flow through an open ion channel. Is the gradient of electrochemical potential for an ion that can move across a membrane
Which ion permeability is most responsible for “resting membrane potential”?
- K+ (potassium)
Which ion permeability is most responsible for “depolarization/action potential”?
- Na+ (sodium)
