Brain Notes Part 1
The forebrain contains the cerebral cortex and a number of other structures that lie beneath the cortex (called subcortical structures): thalamus, hypothalamus, pituitary gland, and the limbic system (collection of structures).
Lobes of the brain
Frontal lobe- involved in reasoning, motor control, emotion, and language and contains the motor cortex
The motor cortex involves planning/ coordinating movement
Prefrontal cortex responsible for higher level cognitive functioning and Broca’s area
Parietal lobe involves processing info from the body’s system, also contains somatosensory cortex, which processes sensory info across the body (touch temp, pain)
Temporal lobe- hearing memory emotion and some aspects of language
The auditory cortex, which is the main area responsible for speech comprehension is located within the temporal lobe
Wernicke’s area is important for speech comprehension which is also in the temporal area
Occipital lobe is the primary visual cortex
Other areas of the forebrain BENEATH the cerebral cortex
Thalamus and limbic system
Thalamus is as sensory relay for the brain, all of our senses except for smell, are routed through the thalamus before being directed to other areas of the brain for processing
The limbic system is involved of processing emotions and memories along with the sense of smell
Smell can evoke emotional responses in ways senses can’t
The limbic system is made up of different structures, the three most important are hippocampus, amygdala, and hypothalamus
Hippocampus- essential for learning and memory
Amygdala- involved in our experience of emotion and in tying in emotional meaning to memories
Hypothalamus- regulates a number of homeostatic processes, regulation of body temp, appetite, and blood pressure The hypothalamus also serves as an interface between the nervous system and the endocrine system and in the regulation of sexual motivation and behavior.
Mid/HindBrain Structures
Reticular formation is centered in the midbrain but extends into the forebrain and down into the hindbrain
Reticular formation is important for regulating the sleep/wake cycle, arousal, alertness, and motor activity
The substantia nigra and the Ventral tegmental area (VTA) are located in the midbrain both regions contain cell bodies that produce dopamine and both are critical for movement. Degeneration of these two areas are involved in Parkinson’s disease. Also involved in mood,reward, and addiction
Hindbrain contains medulla,pons, and cerebellum and controls autonomic nervous system
Pons connects the brain and spinal cord and regulates brain activity during sleep
Cerebellum receives messages from pretty much the rest of the body and important for processing memories such as procedural memory, or memory involved in learning and remembering how to perform tasks,
The neuron is surrounded by extracellular fluid and contains an intracellular fluid (cytoplasm) Two fluid are kept separate
The electrical signal that passes through the neuron depends on the intra and extra floods being electrically different . The Difference is the charge across the membrane(membrane potential) provides energy for the signal, Electrical charge of the fluids are caused by molecules (ions) dissolved in the fluid. The SEMIPERMEABLE NATURE OF THE MEMBRANE RESTRICT THE MOVEMENT OF THESE CHARGED MOLECULES AND SOME OF THE PARTICLES TEND TO BECOME MORE CONCENTRATED EITHER INSIDE OR OUTSIDE THE CELL
The nervous system has two main sub categories; central nervous system(brain and spinal cord) and peripheral nervous system
Parts of the nervous system vocab:
Autonomic nervous system- controls our internal organs and glands
Fight or flight response- activation of the sympathetic division of the autonomic nervous system, allowing access to energy reserves and heightened sensory capacity so that we might fight off a given threat or run away to safety
Parasympathetic nervous system- associated with routine, day to day operations of the body
Peripheral nervous system- connects the brain and spinal cord to the muscles, organs and senses in the periphery of the body
Somatic nervous system-relays sensory and motor info to and from the CNS
Sympathetic nervous system- involved in stress-related activities
Peripheral nervous system
Made up of thick bundles of axons, which are called nerves, they carry messages between CNS and muscles,organs and senses
PNS has two major subdivisions; somatic nervous system and autonomic nervous system
Somatic nervous system- conscious/voluntary activities
Relay of sensory and motor info to and from the CNS
Motor Neurons(efferent fibers) and Sensory Neurons (afferent fibers)
Autonomic Nervous System
Outside the realm of voluntary control
Sub categories; sympathetic and parasympathetic work together to maintain homeostasis
Endocrine Vocab
Adrenal gland- sits atop our kidneys and secretes hormones involved in stress response
Diabetes- disease related to insufficient insulin production
Endocrine system- series of glands that produce chemical substances known as hormones
Gonad- secretes sexual hormones, which are important for successful reproduction and mediate both sexual motivation and behavior
Hormone chemical messenger released by endocrine glands
Pancreas- secretes hormones that regulate blood sugar
Pituitary gland- secretes a number of key hormones, which regulate fluid levels in the body, and a number of messenger hormone, which direct the activity of other glands in the endocrine system
Thyroid- secretes hormones that regulate growth, metabolism, and appetite
hormones are secreted into the bloodstream and travel throughout the body, affecting any cells that contain receptors for them.
Effects of hormone are widespread while neurotransmitters are more localized
Hormone are controlled through interactions between hypothalamus and pituitary gland
Hormone imbalance can lead to a number of disorders
Major glands
The pituitary gland sends out messenger control all the other glands in the system, mostly carries out instructions from the hypothalamus
Also secretes growth hormones, endorphins for pain relief, and a number of the hormones that regulate fluid levels in the body
Thyroid gland releases hormones that regulate growth, metabolism, and appetite.
Adrenal glands secrete hormones involved in stress response, such as adrenaline and noradrenaline. Pancreas secretes hormones that regulate blood sugar levels; insulin and glucagon
These hormones are essential for maintaining stable blood sugar levels.