Chapter 3 Human Anatomy Flashcards
4 Ways To Study Brain Functioning
- Examine the effects of brain damage (how does someone with a left temporal stroke act?)
- Examine the effects of stimulating some part of the brain (what happens if I put some electricity in the amygdala?)
- During some kind of behavior, record what happens in the brain (hook someone up to an EEG while they are sleeping)
4.Correlate brain anatomy with behavior (compare ADHD kids’ brains with non-ADHD kids)
What Causes Brain Damage?
Stroke, disease, genetic impairments, toxins, nutritional deficiencies
How do you tell what area of the brain was damaged?
Post-mortem autopsy or through brain scan techniques if living
Intentional brain damage in animals
- electrodes or chemicals used to damage specific area
- but, brain damage may not solely produce behavior; impairment may be due to many factors
Structural Imaging (MRI)
- A Still photograph, a moment in time
- Considered safer
- fMRI (functional magnetic resonance imaging) detects release of oxygen in active cell without radioactivity- replaces PET and rCBF
Functional Imaging (PET Scan)
- Gives information about what the brain is doing
- Uses color to do so
- PET (positron emission tomography) makes glucose radioactive. When an area of a brain is really active, it uses up a lot of glucose, so you can see which areas are absorbing it the fastest
Recording Brain Activity
- identifies area of brain associated with behavior
CBF or rCBF
- (regional cerebral blood flow) measures increased blood flow by monitoring inert radioactive chemicals (active areas receive more blood)
Sympathetic
- arousal, “fight or flight”, expends energy during an emergency
- prepares the body for arousal, fight or flight
increased breathing, increased heart rate, decreased digestive activity - axons of this system typically release norepinephrine, which is aka noradrenaline (adrenaline – what does that do?)
Parasympathetic
- “relax and digest”, conserves energy during non-emergency times
- increases digestive activity, activities opposing sympathetic system
- Axons of this system typically release acetylcholine
Central Nervous System
The brain and the spinal cord
Peripheral Nervous System
the nerves outside the brain and spinal cord. Has 2 parts:
Somatic Nervous System
the nerves that convey messages from the sense organs to the CNS and from the CNS to the voluntary muscles
Autonomic Nervous System
a set of neurons that control involuntary muscles (heart, intestines, and other organs)
Anatomical Terms
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Ventral
Toward the stomach
Dorsal
Toward the back
Lateral
away from the spinal cord (to the side)
Medial
toward the middle close to the spinal cord
Anterior
toward the front (think of how your nose sticks out in front of you, that type of front)
Posterior
toward the back (backside)
Superior
above
Inferior
below
Ipsilateral
On the same side
Contralateral
on opposite sides
Coronal cut
Cut the face side off
Sagittal cut
Cut right down the nose and looking at the brain from the side
Horizontal/Transverse Cut
Exactly what it sounds like
Bell-Magendie Law
Dorsal roots - carry sensory information to the brain; they are afferent to the brain
Ventral roots - carry motor information to the muscles and glands; they are efferent to the brain
A root - is a bundle of axons
Dorsal root ganglia
- clusters of somata outside, but near, the spinal cord on the dorsal roots carrying sensory information
- Motor neuron somata are located inside the spinal cord
- Cut the spinal cord and brain loses motor control over and sensation from parts of body served by that segment and below
Grey Matter
- In the spinal cord grey matter is on the inside
- In the brain grey matter is on the outside
- A cluster of soma and dendrites
White Matter
- In the spinal cord white matter is on the outside
- In the brain white matter is on the inside
- A cluster of myelinated axons which are white in color
Central Canal
- A narrow tube that runs the length of the spinal cord
- Filled with cerebral spinal fluid
Layers of Protection [placeholder]
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Bone
Outtermost layer
Fat tissue
Inside bone layer
3 meninges
Inside of the fat
- Dura mater - the outermost layer and the toughest layer
- Arachnoid membrane - layer #2, spider webby
- Pia mater - Thin and delicate and clings to every surface
Cerebral Spinal Fluid (CSF) - (Between all of those layers fluid is in everything)
Also covers your brain
Cerebral Spinal Fluid
Fills the spaces between the meninges
- fills the central canal
- Fills the ventricles, four fluid-filled cavities within the brain
Job of CSF
- To cushion the brain and also to provide buoyancy – the brain is heavy. Without the CSF the top of the brain would put too much pressure on the bottom of the brain and damage it.
- If the flow of CSF gets blocked, the fluid, which is continuously produced, builds up and puts tremendous pressure on the brain. It can be fatal. In kids, whose bones are more malleable, it can cause the skull bones to spread = hydrocephalus, which usually leads to MR
