Physiology Chapter 2

Corpus callosum

Connects hemispheres of the brain and allows them to communicate

Stroke

Damage to a region of brain tissue that results from blockage or rupture of vessels that supply blood to that region

Limbic system

1. Amygdala-emotional regulation, odor perception 2. Hippocampus- learning and memory 3. Fornix- learning and memory 4. Cingulate gyrus- direction of attention 5. Olfactory bulb- sense of smell

Types of glial cells

1. Astrocyte- star-shaped cell with numerous processes extending in all directions. Some regulate blood flow to provide more supplies to active neurons. They communicate among themselves and with other neighboring neurons. involved in formation of new synapses. 2. Microglial cell- very small cells that remove debris from injured or dead cells. May be key component of neural pain systems. Maintain synapses (interference with this associated with Alzheimer's). 3. Ogliodendrocytes- forms myelin in the central nervous system. Provide myelin sheath beads to axon. 4. Schwann cells- also form myelin in the peripheral nervous system but ensheaths the axon

Basal ganglia

1. Caudate nucleus- 2. Putamen- 3. Globus pallidus-in the telencephalon under cerebral cortex 4. Substantia nigra- in the midbrain, motor center releases dopamine

Spinal cord (top to bottom)

1. Cervical- (top 8) ventral(front motor) and dorsal(back sensory) 2. Thoracic- (next 12) trunk 3. Lumbar- (5) lower back 4. Sacral- (5) pelvic 5. Coccygeal- (1) bottom

Major parts of neuron

1. Dendrites- serve as an input zone where they receive info from other neurons. Branch to accommodate synapses from other neurons. 2. Cell body (soma[ta]- contains the cell's nucleus, may receive additional synaptic contacts. Acts as an intgeration zone where inputs are transformed in cell body. 3. Axon- leads away from the cell body and serves as a conduction zone, transmitting cell's output info in the form of electrical impulses away from cell body. 4. Axon terminals (synaptic boutons)- functional output zone where they transmit neuron's activity to other cell's synapses.

Diencephalon "between brain"

1. Hypothalamus- hunger, thirst, temperature, sex 2. Thalamus- directs almost all incoming sensory info to appropriate regions of the cortex for further processing and receiving instructions from cortex to control what sensory info is transmitted

Neuron classification

1. Multipolar neurons- many dendrites and a single axon, most common type 2. Bipolar neurons- single dendrite at one end of the cell and a single axon at the other. Common in sensory systems such as vision. 3. Unipolar neurons (monopolar)- have a single extension thought of as an axon that branches in two directions away from the cell body. Ones end is the input zone with branches like dendrites. The other end is the output zone.

3 principal components of synapse

1. Presynaptic membrane- (on axon terminal) transmits info by releasing NT 2. Post synaptic membrane-(on surface or dendrite or cell body) receives info by responding to NT from presynaptic neuron 3. Synaptic cleft- (gap between pre/postsynaptic membranes)

3 parts of ANS

1. Sympathetic nervous system-(thoracic and lumbar spinal cord) inner area sympathetic chain of autonomic ganglia. Prepares body for action "fight or flight"-- uses norepinephrine to accelerate activity 2. Parasympathetic nervous system- "rest and digest response" help body relax and prepare for future action-- uses acetylcholine to slow down activity 3. Enteric nervous system- regulates functioning of the gut, maintains fluid and nutrient balance

Meninges

3 protective sheets of tissue that surround the brain and spine; dura mater, pia mater, arachnoid

Angiography

A brain imaging technique in which a specialized x-ray image of the head is taken shortly after the cerebral blood vessels have been filled with a radiopaque dye by means of catheter

Computerized axial tomography CAT OR CT

A non visual technique from examining brain structure in humans through computer analysis of x ray absorption at several positions around the head

Magnetic resonance imaging MRI

A noninvasive technique that uses magnetic energy to generate images that reveal som structural details in the living brain

Circle of willis

A structure at the base of the brain that is formed by the joining of the carotid and the basilar arteries

Peripheral nervous system

All nerves and neurons outside CNS 1. Cranial nerves- connected directly to the brain 2. Spinal nerves- connected at regular intervals to the spine 3. Autonomic nervous system- nerves that control internal organs (viscera) --these 3 components communicate sensory info to CNS and commands from CNS

Basilar artery

An artery formed by the fusion of the vertebral arteries that supplies blood to the brainstem and to the posterior cerebral arteries

Dyadic functional MRI dfMRI

An fmri technique that observes the brain while two individuals are interacting

Vertebral arteries

Arteries that ascend the vertebrae enter the base of the skull and join together to form the basilar artery

Temporal lobe

Auditory info, sense of smell, some aspects of learning and memory

Central nervous system

Brain and spinal cord

Cerebral cortex

Complex cognition, outer covering of cerebral hemispheres

Nodes of ranvier

Gaps between myelin sheath beads where axon is exposed

Cranial nerves III, IV, VI, V, VII, IX, X= Motor

I. Olfactory-smell II. Optic-vision III. Oculomotor-move eye IV. Trochlear-move eye VI. Abducens-move eye V. Trigeminal-face, sinuses, teeth, jaw VII. Facial-tongue, soft palate, facial glands, tear glands VIII. Vestibulocochlear-inner ear: hearing, balance IX. Glossopharyngeal-taste, throat muscles, mouth sensations X. Vagus-info from internal organs XI. Spinal accessory-neck muscles XII. Hypoglossal-tongue muscles

Functional MRI fMRI

Magnetic resonance imaging that detects change in blood flow and therefore identifies regions of the brain that are particularly active during a given task (live)

Carotid arteries

Major arteries that ascend from the left and right sides of the neck to the brain, supplying blood to the anterior and middle cerebral hemispheres

Frontal lobe

Movement and high level cognition, Includes precentral gyrus which is crucial for motor control

Gray matter

On exterior of cortex are nerve cell bodies and dendrites--processes info

Autonomic nervous system

Part of PNS that supplies neural connections to glands and to smooth muscles of the internal organs

Magnetoebcephalography MEG

Passive and noninvasive functional brain imaging technique that measures the tiny magnetic fields produced by active neurons, in order to identify regions of the brain that are particularly active during a given task

Occipital lobe

Receive and process info from the eyes

Lesions

Regions of damage within the brain

Parietal lobe

Spatial cognition, Includes postcentral gyrus that mediates sense of touch

Receptors

Specialized protein molecules that capture and react to molecules of the NT after they cross the cleft

Synaptic vesicle

Spherical structure that contains molecules of NT. Vesicles fuse with presynaptic membrane and release NT into cleft

Middle cerebral arteries

Two large arteries arising from the carotids that provide blood to most of the lateral surfaces of the cerebral hemispheres

Anterior cerebral arteries

Two large arteries arising from the carotids that provide blood to the anterior poles and medial surfaces of the cerebral hemispheres

Edema

Swelling of tissue, in brain, in response to injury

Positron emission tomography PET

Technique for examining brain function by combining tomography with injections of radioactive substances used by the brain

Blood-brain barrier

The mechanisms that make the movement of substances from blood vessels into brain cells more difficult than exchanges in other body organs, thus affording the brain greater protection from exposure to some substances found in the blood

White matter

Underneath layer of cortex that consists or axons with white myelin sheaths--transmits info

Posterior cerebral arteries

Two large arteries arising from the basilar artery that provides blood to posterior aspects of the cerebral hemispheres

Nerves

collection of axons bundled together

Motor nerves

transmit info from the spinal cord and brain to the muscles, organs, and glands