CNS, ANS, CN Flashcards
what does the human brain consist of
cerebrum (cerebral cortex)
diencephalon (thalamus, hypothalamus, pineal gland)
midbrain (also called the mesencephalon, a part of the brainstem)
pons (connects to the cerebellum and medulla and is part of the brainstem)
medulla oblongata (connects to the spinal cord and is part of the brainstem)
cerebellum
what are the lobes of the cerebral cortex
frontal lobe parietal lobe occipital lobe temporal lobe insula
what is the major fiber pathway that interconnects the two hemispheres
corpus callosum
where is the gray and white matter in the brain
the convulated surface of the cerebral hemispheres containing the cortical neurons comprises the gray matter and lies above the deeper situated white matter, which comprises the fiber connections that course from deeper brain regions or the interconnections that permit communication between the two hemispheres
what is the thalamus
the “Executive secretary” of the cortex, because it is reciprocally connected to the cortex and conveys motor, sensory, and autonomic information from the brainstem and spinal cord.
what is the hypothalamus
it lies beneath the thalamus, and its connections with the pituitary gland reflect its important role in neuroendocrine function
what is the pineal gland
an endocrine organ that secretes melatonin and is important in regulation circadian rhythms
what are the colliculi
superior and inferior culliculi are sensory nuclei associated with visual reflexes and auditory reflexes, respectively. Are also part of the midbrain
what is the function of the basal ganglia and what does it include
provide subconscious control of skeletal muscle tone and coordination of learned movements. Once a voluntary movement is initiated cortically, the natural rhythm and patterns that we take for granted in walking or reaching for objects are controlled subconsciously by the basal ganglia.
it includes:
- caudate nucleus
- putamen
- globus pallidus
what are some disorders affecting the basal ganglia
Huntington’s disease: results in a hereditary loss of basal ganglia and cortical neurons that leads to a hyperactive state of involuntary movements. The jerky movements of this disease almost resemble a dancer out of control, and the term chorea (“dance”) aptly characterizes this fatal condition. In its late states, mental disorientation is common.
Parkinson’s disease: resulting from the degeneration of the dopamine-secreting neurons of the substantia nigra, this progressive disease results in bradykinesia (slow movements), resting rhythmic muscular tremor, muscular rigidity, stooped posture, a masked or expressionless face, and a shuffling gait.
what is the limbic system
it is a functional group of structures that form a ring (“limbus”) around the diencephalon. The limbic system participates in emotional behaviors (fear, rage, pleasure, and sexual arousal) and in the interpretation of internal and external stimuli (linking conscious functions with autonomic functions, and aspects of memory and retrieval)
functions of the hippocampus and amygdala
functionally, the hippocampus and amygdala are important in memory consolidation and access. Moreover, the hippocampus plays a role in spatial relationships, whereas the amygdala associates a variety of sensory memories and links them to our emotional responses, especially fear and aversion.
Name some characteristics of the thalamus
The right and left thalamus are seperated by the 3rd ventricle and form the major portion of the diencephalon (about 80%)
The central location of the thalamus is representative of its importance; essentially, no sensory information, except olfactory information, passes to the higher cortical regions without synapsing in the thalamus. Thus the thalamus has been characterized as the “executive secretary” of the brain because it sorts and edits information.
Sensory, motor, and autonomic information from the spinal cord and brainstem is conveyed to the cortex via the thalamus. Likewise, the thalamic nuclei are reciprocally interconnected with the cortex. A white matter tract, the medullary laminae, runs through the thalamus and relays information to the cortex.
Characteristics and function of the hypothalamus
the hypothalamus lies below the thalamus and the 3rd ventricle, it is part of the diencephalon.
Functionally, the hypothalamus is very important in visceral control and homeostasis and possesses extensive connections with other brain regions.
Its main functions include:
- regulation of the autonomic nervous system (hear rate, blood pressure, respiration, and digestion)
- expression and regulation of emotional responses
- water balance and thirst
- sleep and wakefulness related to our daily biological cycles
- temperature regulation
- food intake and apetite regulation
- reproductive and sexual behaviors
- endocrine control
major functions of the preoptic and anterior hypothalamic area
heat loss center: cutaneous vasodilation and sweating
major functions of the posterior hypothalamic area
heat conservation center: cutaneous vasoconsctriction and shivering
major functions of the lateral hypothalamic area
feeding center: eating behavior
major functions of the ventromedial hypothalamic area
satiety center: inhibits eating behavior
major functions of the supraoptic (subfornical organ and organum vasculosum) hypothalamic area
ADH and oxytocin secretion
major functions of the paraventricular hypothalamic area
ADH and oxytocin secretion
major functions of the periventricular hypothalamic area
secretion or releasing hormones for the anterior pituitary
General functions of the cerebellum
- Regulate the postural muscles of the body to maintain balance and stereotyped movements associated with walking
- Adjust limb movements initiated by the cerebral mortor cortex
- paticipate in the planning and programming of voluntary, learned, skilled movements
- play a role in the eye movement
- play a role in cognition
