TELENCEPHALON & RECEPTORS

I.   INTRODUCTION
-- telencephalon: the cerebrum
* higher brain functions

II. TELENCEPHALON (= cerebrum)
-- consists of an outer gray matter (cerebral cortex)

and an inner white matter

-- In general, each hemisphere controls the opposite side of the body
-- Structure:

1.  two cerebral hemispheres

2.  longitudinal fissure:

 

 

3.  corpus callosum:

 

 

4.  Cortex is highly convoluted

* raised area/elevation: gyrus
* depression or groove: sulcus

-- Lobes - 5 pairs:

1.  Frontal:
* ends at the central sulcus:

A.  Motor speech area (Broca’s area): on left frontal
** controls motor functions involved with speech

B.  Primary Motor Cortex:
**  located in precentral gyrus of each frontal lobe
** controls voluntary skeletal muscle movement

2.  Parietal:
* ends anteriorly at central sulcus
* lateral limits at a lateral sulcus

A.  Primary Somatosensory Cortex:
**  located in postcentral gyrus of each parietal lobe
** receives sensory input from skin, muscles, joints        

B.  Wernicke’s Area:
** overlaps both parietal and temporal lobes
**  helps us understand written/spoken language

3.  Temporal:

A.  Primary Auditory Cortex:
*  interprets/distinguishes sounds

B.  Wernicke’s area:        

 

 
C.  Primary Olfactory Cortex: processes smell information and provides conscious awareness of smells

4.  Occipital: 

                        
A.  Primary Visual Cortex:
*  works with other areas in the occipital lobe to distinguish and interpret visual images

 

 

5. Insula: deep to the lateral sulcus
* involved w/memory

A.  Primary Gustatory Cortex: involved in processing taste information

 

 

III.  RECEPTORS

-- Def: a receptor is a structure that converts a sensory stimulus to a nerve impulse.

-- different ways to classify receptors (see Table 19.1 in your text - by stimulus location, receptor distribution (body location), or type of stimulating agent

-- 3 kinds, based on location:

1.  Exteroceptors: near surface of body
* stimuli from outside environment
* some are cutaneous receptors
* special senses (sight, smell, taste, hearing, balance)

 

 

 

2.  Interoceptors (visceroceptors, enteroceptors)
* primarily stretch receptors in smooth muscle of blood vessels and viscera

 

 

 

 

 

3.  Proprioceptors: provide information about muscles, joints and tendons

The primary motor cortex, which controls voluntary skeletal muscle movement, is located in the:

a. central sulcus

b. precentral sulcus

c. postcentral sulcus

d. precentral gyrus

e. postcentral gyrus

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