PSIO 241 CH 5 cont..

Broca’s area

**transmits program to primary motor cortex** for commands to the motor neurons that supply relevant muscles of the **larynx, tongue, cheeks, and lips for speaking** (motor activity)

* near primary cortex

Wernicke’s area

permits recognition of spoken and written language

* when we intent to speak, area **formulates phrases and transmits plan of speech** to Broca’s area

basal nuclei

Functions:

* inhibiting muscle tone throughout the body
* selecting and maintaining purposeful motor activity
* suppressing unwanted patterns of movement
* coordinate slow, sustained contractions

\- consists of several masses of gray matter **located deep within white matter**

\- act by **modifying** ongoing activity in motor pathways

Parkinson’s disease

**cause**: loss of dopamine producing neurons in basal ganglia

**symptoms**: tremors, rigidity, lack of motor initiation, bradykinesia, impaired balance, speech issues

somatotopy

body mapped on brain

thalamus

**reinforces voluntary motor** **behavior** initiated by motor cortex

* serves as **“relay station” and synaptic integrating** center for sensory input
* helps **direct attention** to stimuli of interest
* capable of **crude awareness** of sensations but cannot distinguish their location or intensity

hypothalamus

important link between the autonomic nervous system and endocrine system

* collection of nuclei and associated fibers that lie beneath the thalamus
* integrating center for homeostatic functions
* brain area most involved in **directly regulating internal environment**

hypothalamic functions

* controls body temperature and food intake
* controls thirst and urine output
* serves as a major **autonomic coordinating** center
* plays role in emotional and behavioral patterns
* participates in sleep-wake cycle
* has many endocrine and reproductive functions

cerebellum

integrates balance and eye movements

* receives inputs from many CNS structures including the vestibular apparatus of the inner ear, the spinal cord, and the cerebral cortex

brain stem

* it contains centers that control cardiovascular, respiratory, and digestive function
* regulates postural muscle reflexes
* controls the overall degree of cortical alertness
* plays a role in the sleep-wake cycle

\- the brain stem is link between the spinal cord and higher brain levels

\- consists of bid rain, pons, and medulla oblongata

medulla

controls sympathetic and parasympathetic activity

reticular formation

* acts as a somatosensory filter
* sends output to cerebral cortex for spousal and activation (reticular activating system)

\- originates in the brain stem

limbic system

includes portions of the cerebral lobes, the basal nuclei, the thalamus, and the hypothalamus

emotion (limbic system)

subjective feelings and moods and the physical responses associated with these feelings

basic behavioral patterns (limbic system)

aimed at survival and perpetuation of the species. (ex: human instinct scared of snakes)

motivation (limbic system)

directing behavior toward goals.

learning (limbic system)

acquiring knowledge or skills as a result of experience and/or instruction.

memory (limbic system)

storage of acquired knowledge later use.

short term memory

lasts for seconds to hours

long term memory

retained for days to years

consolidation

the transfer of short-term memory traces into long-term memory stores (hippocampus)

declarative memories

“What-type memories,” processed in the hippocampus and associated structures

procedural memories

“How to memories,” processed in the cerebellum

prefrontal cortex

The _ serves as a temporary storage  area associated with planning, problem solving, organizing, and inhibiting impulses.

spinal cord

serves as the link between the brain and peripheral nervous system

* integrating center for spinal reflexes
* **31 pairs of spinal nerves** emerge from spinal cord through spaces between adjacent vertebrae

spinal nerves

contain both afferent and efferent fibers

dorsal root

carries afferent/sensory information

ventral root

carries efferent/motor information

white matter tracts

• White matter is organized into **nerve tracts**.

• Tracts are bundles of nerve fibers with a similar function.

• Each tracts begins or ends within a particular area of the brain

ascending tracts

transmit afferent, **sensory** input (up to brain)

\- white matter

descending tracts

relay efferent, **motor** output (down brain)

\- white matter

dorsal horn

cell bodies of **neurons for sensory** processing

\- gray matter

ventral horn

cell bodies of **alpha motor neurons** supplying skeletal muscles

\- gray matter

reflexes

Any response that occurs automatically without conscious effort

\- can be **somatic** (skeletal muscle) or **visceral** (organs, glands, smooth  muscle)

simple or basic reflexes

Built-in, unlearned responses

acquired or conditioned reflexes

Result of practice and learning

reflex arc

the neural pathway involved in accomplishing reflex activity

**basic components**:

–Receptor

–Afferent pathway

–Integrating center

–Efferent pathway

–Effector

somatic reflex

skeletal muscle

visceral reflex

organs, glands, and smooth muscle

secondary motor areas

\- supplementary motor area

\- premotor cortex

\- posterior parietal cortex

* cerebellum and basal nuclei also influence motor function