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314 Biology

" Brain "

Bipedal – method of moving by using two feet. It’s different than other animals, like the horse, spiders, and things with wings.

Humans are consistently bipedal.

Look at the human skeletons. What do you see? S-curved spin –gives support

Upright position. What does this mean? Standing on two feet and up-straight. Frees hands to perform other skills.

Human Foot structure – heel is rounded, arch is curved at mid-foot, or flat feet that causes some problems, shorter toes than a primate.

 

BRAIN: Humans have a thinking brain.

Not the largest, but it functions are : reasoning, controls abstract thinking, - surpasses all other living organisms.

 

Cerebrum – has two distinct parts, or sides, left and right hemispheres. Individually controlled in reference to certain behaviors: sensory and movement – left side of body controlled by right hemisphere of brain, of the cerebrum. So the right side of the body is controlled the left hemisphere of the cerebrum.

Left hemisphere controls language and speech, mathematical and other analytical abilities.

Right hemisphere – responsible for visual and spatial processing

 

 

Epilepsy human condition that causes seizures, fibers of corpus callosum are surgically severed, separating the two hemispheres. Reduces severity of seizures.

 

Cerebellum – structure at the back of the brain, which in certain views looks like a clamshell, controls posture and balance.

Motor cortex – controls the movements of the body.

 

Sensory cortex – lets you feel sensations from your body.

 

Corpus callosum – bundle of nerves that allows communication between the brain hemispheres.

 

Neurons – nerve cells, brain contains 1 trillion cells with trillions of potential associations.

Dendrites – branch extensions that act like antennae to receive incoming messages

Axons – at the other end of a dendrite is an extension which sends outgoing messages.

Nervous system – an organized network of interconnected neurons that extends throughout the brain and body that provides a link between the outside world and the inner world of the body.

Stimulus - incoming information that causes the body to respond.

Neurotransmitters – chemicals that are released by electrical impulses. They act as messengers that transmit the signal across the gap between neurons.

Synapse – is the gap between neurons.

Reflex – a simple and quick response to a stimulus

 

Reflex arc – a pathway that neurons travel after responding to a stimulus.

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