Anatomy & Physiology: Brain Functions and Systems

Vocabulary-style flashcards covering cerebrospinal fluid, the blood-brain barrier, functional brain regions, the limbic system, reticular formation, and higher-order brain functions based on the McKinley Anatomy & Physiology transcript.

Cerebrospinal fluid (CSF)

A clear, colorless liquid that surrounds the CNS, circulates in ventricles and the subarachnoid space, and provides buoyancy, protection, and environmental stability.

Buoyancy

A function of CSF that reduces the brain's apparent weight by $95\,\%$.

Choroid plexus

Located in each ventricle and composed of ependymal cells and blood capillaries; it filters and modifies blood plasma to form CSF.

CSF Composition

Compared to plasma, this fluid contains more $Na^+$ and $Cl^-$ and less $K^+$, $Ca^{2+}$, and glucose.

Arachnoid villi

Structures through which excess CSF flows to drain into dural venous sinuses; a collection of these is called an arachnoid granulation.

Blood-brain barrier (BBB)

A structure composed of specialized capillaries with tight junctions and a thick basement membrane that regulates which substances enter the brain's interstitial fluid.

Perivascular feet

Extensions of astrocytes that wrap around capillaries to help form the blood-brain barrier.

Prefrontal cortex

Located rostral to the premotor cortex in the frontal lobe; it is responsible for complex thought, judgment, personality, planning, and deciding.

Wernicke area

A functional brain region, typically in the left hemisphere, involved in language comprehension.

Primary motor cortex

Located in the precentral gyrus of the frontal lobe; it controls skeletal muscle activity on the opposite side of the body.

Motor homunculus

A map of the body on the primary motor cortex where distorted proportions reflect the amount of cortex dedicated to the precise movements of each part.

Motor speech area (Broca area)

Located in the inferolateral portion of the left frontal lobe; it controls the movements necessary for vocalization.

Primary somatosensory cortex

Located in the postcentral gyrus of the parietal lobes; it receives somatic sensory information from proprioceptors, touch, pressure, pain, and temperature receptors.

Somatosensory association area

Located posterior to the postcentral gyrus; it integrates touch information to allow for the identification of objects by feel.

Gnostic area

A common integrative area that converges information from variety of sensory association areas to make the brain aware of a situation.

Limbic system

Known as the 'emotional brain,' it is composed of multiple cerebral and diencephalic structures that process and experience emotions.

Hippocampus

A component of the limbic system located in the temporal lobe that helps form long-term memories.

Amygdaloid body

A limbic system structure involved in many aspects of emotion and emotional memory, especially fear.

Fornix

A thin white tract that connects the hippocampus with other limbic structures.

Reticular formation

Loosely organized gray matter of the brainstem that regulates muscle tone and assists in autonomic functions.

Reticular activating system (RAS)

The sensory component of the reticular formation that processes sensory information to bring about alertness and awareness.

Cognition

Mental processes of awareness, knowledge, memory, perception, and thinking for which the association areas of the cerebrum are responsible.

Agnosia

The inability to recognize or understand the meaning of stimuli, often resulting from lesions in specific brain lobes.

Sensory memory

Associations based on sensory input, such as smells, that last for only seconds.

Short-term memory (STM)

Memory with a limited capacity of about $7$ bits of information and a brief duration of seconds to hours.

Long-term memory (LTM)

Memory encoded from short-term memory through repetition that may exist indefinitely.

Encoding

Also known as memory consolidation; it is the process of forming long-term memories and requires the amygdala and hippocampus.

Aprosodia

Dull, emotionless speech caused by a lesion to the right hemisphere in the area opposite the Wernicke area.

Apraxia of speech

A motor disorder where a person is aware of what they want to say but cannot speak properly.

Aphasia

Difficulty understanding or producing speech, often due to head injury or stroke.