What are meninges?
CT surrounding the CNS
The dura mater means what? and is what?
- tough mother
- The outer most layer of tough fibrous connective tissue. In direct contact with skull.
The dura mater is seperated from he vertebrae by what?
The epidural space which is a layer of fat.
What are the dural sinuses?
Cavities between the two layers of Dura Mater where blood and CSF drain into and then are returned to venous blood flow.
What is the arachnoid mater?
The middle layer that sends down tiny "weblike" projections of CT to the bottom layer.
What is the subarachnoid space?
The space created by the tiny weblike projections of the arachnoid mater and is where our CSF circulates.
What are arachnoid villi?
tiny one way valves that drain excess csf into the dural sinuses to be returned to the blood.
What is the pia mater?
inner layer of delicate CT that is in direct contact with the CNS
What is CSF?
formed as a filtrate of the blood-very similar to blood plasma nourishes and cushions CNS.
How many ventricles of the brain are there? what are they?
4 chambers of the brain that are filled with CSF
What are the choroid plexus?
areas of ventricles that are specialized capillary networks that filter the blood
How is CSF circulated?
New CSF is constantly being produced and circulates in the subarachnoid space. Old CSF is constantly draining into dural sinuses,removing wastes and reenters the blood stream from the dural sinuses.
Nmae the 4 parts of the brain
- Brain stem
How large is the cerebrum in relation to the rest of the brain?
Name the three parts of the Diencephalon
Name the three parts of the Brain Stem
- Medulla oblongata
How large is the crebellum in relation to the rest of the brain?
The 2nd largest part of the brain
What is the cerebrum divided into and what is it connected by?
Divided into the Lt and Rt hemispheres connected by the corpus callosum
Each hemisphere of the cerebrum is divided into 2 regions, what are they?
Cerebral cortex and white matter tracts
What color is the cerebral cortex and why?
It is grey and it is b/c it in unmyelinated
What color is the white matter tracts and why?
It is white and it is because it is myelinated
What is the cerebral cortex?
Outer layer of grey matter of the cerebrum
What are gyri?
folds in the cerebral cortex
What are sulci?
fissures between folds in the cerebral cortex
What part of the brain makes us "human"? Give examples
The cerebral cortex-thought,reasoning,language etc
Name the five lobes of the cerebral cortex
What is the central sulcus?
fissure that seperates frontal and parietal lobes
What is the precentral gyrus? AKA and what does it do?
- gyrus of frontal lobe next to central sulcus
- AKA motor cortex
- initiates voluntary movement
What is the post central gyrus? AKA and what does it do?
- gyrus of parietal lobe next to central sulcus
- AKA sensory cortex
- primary sensory area
What is the homunculus?
imaginary projection of the body on our motor and sensory cortexes.
What are white matter tracts and what do they do?
Inner part of cerebrum..they are myelinated nerve fibers that connect different parts of the brain.
What are basal ganglia?
- groups of neuron cell bodies within the white matter of the cerebrum.
- Relay stations from the motor cortex which decrease muscle tone and inhibits muscular activity. Inhibits antagonist muscle
Where is the dopamine in our body produced?
In the basal ganglia
What is the main function of the hypothalamus and how does it connect to the pituitary gland
It maintains homeostasis ie RELATIVE CONSTANCY, and is connected to the pituitary gland via the infundibulum
What does the Cerebellum control?
MOTOR AREA. controls subconscious skeletal muscle contractions necessary for coordination,posture and balance--essential for smooth coordinated movement
What are the ASCENDING nerve fiber bundles in the spinal cord involved in?
What are the DESCENDING nerve fiber bundles in the spinal cord involved in?
What is the cauda equina?
when the spinal cord ends at L1 it is a bundle of spinal nerves that continues down the vertebral canal and continues to exit between the TVP below L1
Name the 5 types of nerve receptors and what they are sensitive to
- Chemo-changes in chemical environment
- Mechanoreceptors-physical movement of tissue
- Thermoreceptors-changes in temp
- Photoreceptors-changes in light
- Nociceptors-pain receptors (tissue damage)
What is sensory adaptation?
- when receptors are continuously stimulated there is a decrease in sensitivity at the receptor level.Different than the brain filtering out extra info
How many senses do we have?
more than 5
What are special senses? Give examples
Receptors are localized (sight,smell,taste,hearing)
What are general senses? give examples
- Receptors are widespread through out the body.
Name the three types of mechanoreceptors involved with touch/pressure(name,CT covering,what they are responsible for)
1)Free Nerve endings-no CT covering-responsible for VERY light touch (most sensitive)
2)Meissners corpuscles-has ct covering-responsible for light-mod touch
3)Pacinean corpuscles-many layers of CT covering-responsible for deep pressure-(least sensitive)
What is proprioception?
sense of awareness of our bodies position relative to itself
What are Golgi tendon organs?
- mechanoreceptors responsible for proprioception
- measures length of muscle
How many types of thermoreceptors are there? Which are there more of?
- 2 types- hot and cold
- 10 times more cold
What do extremes in hot or cold temperature do?
Damage tissue and stimulate pain receptors
T or F
Pain receptors do not have sensory adaptation.
TRUE. Nociceptors do NOT engage in sensory adaptation and are widely distributed