The Brain Pt. 2 Flashcards
What two parts of the brain does the diencephalon connect?
The brain stem and cerebrum.
What surrounds the diencephalon?
The third ventricle.
What are the three parts of the diencephalon?
- Thalamus.
- Hypothalamus.
- Epithalamus.
What are the functions of the thalamus?
- Relay almost all sensory input to cerebral cortex.
- Provides crude pain, pressure, temperature, and touch perception.
- Hormone production.
- Nuclei for movement planning and control.
What part of the brain is the major regulator of homeostasis?
Hypothalamus.
How many nuclei compose the hypothalamus?
A dozen.
What ANS functions is the hypothalamus engaged in?
- Smooth and cardiac muscle contractions.
- Gland secretion.
- Axons extend to the sympathetic and parasympathetic nuclei in the brain and spinal cord.
- Major regulator of visceral activities (HR, GIT motility, urinary bladder contraction).
What are the two types of connections with the pituitary gland?
- Hypothalamic hormones released into capillary networks.
- Axons extend to posterior pituitary lobe.
How does the hypothalamic hormone connection work?
The bloodstream carries them to anterior lobe of pituitary gland, which stimulates or inhibits the secretion of hormones.
How does the nervous hormone connection work?
Cell bodies of neurons make OT and ADH.
What system does the hypothalamus work with to regulate emotional/behavioral patterns?
Limbic system.
*Aggression, pain, pleasure, rage.
How does the hypothalamus regulate thirst and temperature?
By monitoring rising osmotic pressure in the ECF and rising blood temperature.
What does it mean if the hypothalamus controls circadian rhythm and states of consciousness?
It controls patterns of wakefulness and sleep in conjunction with input from the eyes.
What are the 2 parts of the epithalamus?
- Habenular nuclei.
- Pineal gland.
What is the function of the habenular nucleus?
- Emotional response.
- Olfaction.
*ex: Smelling your grandmother’s favorite candle.
How big is the pineal gland?
Size of a small pea.
What does the pineal gland secrete?
Melatonin.
What triggers the release of melatonin?
Decreasing daylight.
What does melatonin promote?
Sleepiness, which helps set the body’s biological clock.
What is the cerebrum?
The seat of intelligence.
What are the functions of the cerebrum?
- Calculating.
- Composing.
- Memory.
- Moving.
- Perception.
- Personality.
- Planning.
- Reading.
- Remembering.
- Speaking.
- Writing.
What is the outer portion of the cerebral cortex composed of?
Gray matter.
What is the inner portion of the cerebral cortex composed of?
White matter.
Why does the brain have folds in it?
From gray matter enlarging faster than white matter during embryonic development.
What are the regular sized folds in the brain called?
Gyrus or gyri. Also, convolutions.
What is the deepest groove between folds?
Fissures.
What is the most prominent fissure?
The longitudinal fissure.
What does the longitudinal fissure separate?
The cerebrum into R and L halves.
What are shallower grooves called?
Sulci.
What is the corpus callosum?
A broad band of white matter that contains axons extending between hemispheres.
How many lobes does the cerebrum have?
4.
What are the lobes of the cerebrum?
- Frontal, parietal, occipital, temporal.
What are the lobes of the cerebrum named after?
The bones that cover them.
What type of axons does the cerebral white matter contain?
Myelinated and unmyelinated axons.
What are the three tract types that are found in the white matter?
- Association.
- Commissural.
- Projection.
What are association tracts?
Axons that conduct nerve impulses between gyri in the same hemisphere.
What are commissural tracts?
Axons that conduct nerve impulses from gyri in one hemisphere to corresponding gyri in another hemisphere.
ex: Corpus callosum.
What are projection tracts?
Axons that conduct nerve impulses from the cerebrum to the lower parts of the CNS and visa versa.
Where is the basal ganglia located?
Deep within the cerebrum.
What are the 3 parts of the basal ganglia?
- Caudate nucleus.
- Globus pallidus.
- Putamen.
*2 and 3 are collectively called the Lentiform nucleus.
What does the basal ganglia receive input from?
The cerebral cortex.
What does the basal ganglia provide output to?
The motor portions of the cerebral cortex.
What are the major functions of the basal ganglia?
- Regulates initiation and termination of movement.
- Subconscious contraction of skeletal muscles.
What are minor functions of the basal ganglia?
- Attention.
- Memory.
- Planning.
- Regulation of emotional behavior with limbic system.
What 3 diseases result from dysfunction of the basal ganglia-limbic system connection?
- Chronic anxiety.
- OCD.
- Schizophrenia.
Where is the limbic system located?
Encircling the upper part of the brain stem and corpus callosum.
*Forms the inner border of the cerebrum and floor of diencephalon.
What is the limbic system colloquially referred to as?
The emotional brain.
What are the functions of the limbic system?
- Affection, anger, docility, pain, and pleasure (primarily).
- Memory.
- Olfaction.
What is the function of the hippocampus?
Memory.
