Lectures 4 & 5 Flashcards
Occipital Lobe (Structural Overview)
Calcarine Sulcus
Lingual Gyrus
Primary Visual Cortex
Lingual Gyrus
Important for color perception
Primary Visual Cortex
Area above and below the Calcarine Sulcus
Responsible for visual functioning
This area receives half of the visual input from each eye
Motor vs. Sensory
Parts of the cortex are involved in either motor processing or sensory processing
There are some parts of the cortex that aren’t specifically sensory or motor processing
Called Association Areas
Association Areas
Parts of the cortex that aren’t specifically sensory or motor processing
Limbic Lobe (General Overview)
Can be seen with a midsaggital
A strip of cortex that lies between the corpus callosum and the frontal, parietal, and occipital lobes
Generally, the limbic lobe is believed to be the center of emotions; emotional processing
Limbic Lobe (Structural Overview)
Amygdala Hippocampus Parahippocampal Gyrus Uncus Cingulate Gyrus Fornix
Hippocampus & Amygdala
Important for processing drives, emotions, and memory
Fornix
Near the front tip of the corpus callosum
Insula
Important for language communication
Patients with damage to the insula have been reported to have speech production problems such as apraxia of speech
Has both long and short gyro
Located near the transverse lateral gyri/Heschl’s gyri
Heschl’s Gyri
Involved in hearing
Secular Sulcus
The sulcus that surrounds the insula
Other divisions of the brain
Forebrain
Midbrain
Hindbrain
Forebrain
In a midsaggital view its the outer circumference
Midbrain
The region that connects the pons
Hindbrain
Includes everything not already included in the forebrain and midbrain, including parts of the brain stem and the cerebellum
Diencephalon (General Info)
Means: between brain
Lies between 2 brain regions:
Cerebrum
Brainstem
Diencephalon (Structural Overview)
4 Major Divisions: Thalamus Hypothalamus Subthalamus Epithalamus
Parahippocampal Gyrus
Posterior portion of the limbic system
Limbic Lobe (Function)
Believed to be the center of emotions, emotional processing
Thalamus (Function)
Largest component of the diencephalon
Serves as a relay station where sensory and motor information are processed before the information is sent to its destination
Receives input from many sources and projects to many parts of the cortex
Plays a role in: Consciousness, alertness, attention, audition, vision
Patients with thalamic lesions have language problems, specifically aphasia
Medial Geniculate Body
One of 2 main nuclei of the thalamus
Found on the posterior surface of the thalamus - looks like a swelling
Involved in auditory processing, forms part of the auditory pathway
Receives info from the inferior colliculus (another nuclei
Lateral Geniculate Body
One of 2 main nuclei of the thalamus
Forms part of the visual pathway
Hypothalamus (General)
Lies below the thalamus
Forms a small part of the diencephalon
Forms part of the floor of the lateral wall of the third ventricle
Related to a number of structures: optic chasm, mamillary body, tuber cinereum
Hypothalamus (Function)
Any aspect of physiology of the body is influenced by the hypothalamus
Primary function is processing visceral info : hunger, thirst, controls hormones, regulates body temp, homeostasis,
Phagic Center (nucleus)
Lateral portion of the hypothalamus
Controls hunger or phagia
Patients with lesions in the part of the hypothalamus exhibit symptoms of anorexia nervosa
Satiety Center
Ventral medial portion of the hypothalamus
Patients with lesions here eat too much, relates to obesity
Can also cause aggressive behavior
Homeostasis
Regulation of the pituitary gland
maintains equilibrium in the body
Pituitary Gland
AKA Hypophysis
Pea-sized swelling at base of hypothalamus
Has two main areas:
Adenohypophysis - anterior
Neurophypophysis - posterior
Sellar Turcica
Bony cavity in which the pituitary gland sits
Covered by a dural fold called the Sellar Diaphragm
Sellar Diaphragm
A dural fold that covers the sellar turcica (the bony cavity where the pituitary gland sits)
Adenohypophysis
Relatively large portion of the pituitary gland located on its anterior portion
This is where hormones are produced
The hypothalamus controls endocrine cells located here - due to this the hypothalamus is able to influence the release of the hormones that these cells produce
Controls the parasympathetic nervous system
Neurophypophysis
The posterior portion of the pituitary gland
Controls the sympathetic nervous system - heart rate, breathing, sweating
Adipsia
Lack of desire to drink
Caused by a lesion to the phagic center of the hypothalamus (lateral portion) - if the lesion is small enough
Supraoptic Nucleus
Located in the anterior portion of the hypothalamus
Involved in regulating water balance in the body
Allows us to feel thirsty if there’s an insufficient amount of water in the body
If there is too much water in your system the hypothalamus creates the urge to urinate
A lesion is the supraoptic nucleus will cause polydipsia and polyuria
Polydipsia
Increased water intake - Due to a lesion of the supraoptic nucleus
Polyuria
Increased urination due to a lesion of the supraoptic nucleus
Vasoconstriction
Muscles are signaled to shiver in order to generate heat
Hyperthermia
Increased body temperature caused by a lesion to the anterior portion of the hypothalamus
Hypothermia
Decreased body temperature due to a lesion in the posterior hypothalamus
Hypothalamus on Emotion
Hypothalamus is involved in the physical expression of emotion
ex: increased heart rate due to fear, sweating due to fear
In animals stimulation of the dorsomedial nucleus of they hypothalamus causes the animal to behave aggressively and with rage
Epithalamus
Lies above the thalamus
Has 3 substructures:
Pineal Body/Gland
Stria Medullares
Habenulae
Pineal Body/Gland
Portion of the epithalamus
Receives visual information about light and darkness
Secretes its chemicals into the bloodstream - these chemicals are associated with sleep/wake cycles
Stria Medullares
Portion of the epithalamus
Carries the circadian rhythm
Habenulae
Portion of the epithalamus
Subthalamus
A structure found in the caudal portion of the diencephalon
Has 3 main structures:
Fields of Forel
Zona Incerta
Subthalamic Nucleus
Fields of Forel
Structure in the subthalamus
Zona Incerta
Structure in the sub thalamus
Subthalamic Nucleus
Conntected to a structure called Globus Pallidus
Receives fibers from the motor cortices
Damage to the subthalamic nucleus results in involuntary movements, especially in the upper limbs
Globus Pallidus
Structure connected to the subthalamic nucleus
