Chapter 3 Human Anatomy Continued Flashcards
Medulla
- just above spinal cord, controls vital reflexes, e.g., breathing, heartbeat, coughing, vomiting. Damage here typically fatal. Most cranial nerves (nerves for senses and movement above the spinal cord) are centered here.
Pons
- in humans, in front and on top of medulla
Function
where many axons cross from one side of the brain to the other before they go down the spinal cord – why the left hemisphere controls right side muscles and vice versa
Reticular Formation
- the medulla and pons contain this
Function
- (controls motor areas of the spinal cord and arousal and attention)
raphe system
- medulla and pons contain this
- (increases or decreases the brain’s readiness to respond)
Cerebellum
- controls movement, balance, and coordination
- damage impairs coordination, rhythm and timing, and difficulty shifting attention between auditory and visual stimuli
The Midbrain (mesencephalon)
.
Tectum
(“roof”): includes superior colliculi and inferior colliculi, important routes for sensory information
Top for sight, Bottom for hearing
Tegmentum
- (“carpet” - under the tectum)
- nuclei for third and fourth cranial nerves (eye movements)
- parts of the reticular formation
- extensions of the pathways between the forebrain and the spinal cord or hindbrain
Substantia nigra
- dopamine path that is involved in movement. This path deteriorates in Parkinson’s disease, a movement disorder
The Forebrain (prosencephalon)
.
Cerebral cortex
- outer portion of brain. Covered with bumps (gyrus or gyri) and grooves (sulcus or sulci) to increase surface area
Contains grey matter (dendrites and somata), the outer surface of cerebral hemispheres
White matter is formed by axons extending inward from cortex (what makes it white?)
Broken down into 2 hemispheres – left and right
Neurons from each hemisphere communicate with each other through pathways of nerve bundles called the corpus callosum and the anterior commissure
Gyrus
The bumps in the cerebral cortex
Sulci
grooves in the cerebral cortex
Fissure
Very deep grooves in the cerebral cortex
Subcortical
The parts of the brain below the cortex
Thalmus
center of forebrain and relay station for sensory information to/from cerebral cortex (except olfactory)
Basal Ganglia
plays a big role in movement
Limbic System
emotion (more on next slide)
Basal forebrain
- Includes the nucleus basalis
Nucleus basalis
- which is a key part of brain’s system for arousal, wakefulness, and attention
Limbic system
- borders the brain stem and mediates eating, drinking, sexual activity, and emotions like anxiety and aggression. This system includes the hypothalamus, hippocampus, and amygdala
- four f’s fighting, fleeing, feeding and fornicating
Hypothalamus
small area under thalamus with widespread connections
- damage here affects sexual behavior, temperature regulation, fighting, feeding, activity level
- sends messages to attached pituitary gland, altering release of hormones into bloodstream
Hippocampus
- located between thalamus and cerebral cortex
- critical for the formation of new memories
Amygdala
- implicated in emotions
diencephalon
The thalamus and hypothalamus
telencephalon
The rest of the forebrain
Lobes of Cortex
.
Occipital Lobe
- posterior end of cortex
- contains primary visual cortex
- damage in one hemisphere causes blindness in opposite visual field
Parietal Lobe
between occipital lobe and the central sulcus
- contains the postcentral gyrus which houses the primary somatosensory cortex which receives touch sensation, muscle-stretch and joint position information
- It’s also organized so each area of your body has a corresponding spot in the postcentral gyrus (page 99)
- Involved in spatial things – where am I, where are you, and which way do I need to go if I want to approach or avoid you
Somatosensory
- Sense of touch
Primary Somatosensory Cortex (postcentral gyrus)
- The primary place where you experience touch
- Sense of touch
- Based on the location of where it is (spacial awareness)
Temporal Lobe
- the left temporal lobe is the language side
- lateral portion of each hemisphere, near the temples
- essential for understanding spoken language
- contributes to perception of movement and face recognition and other complex visual processes
- Also plays a role in emotion and motivation - damage may lead to Klüver-Bucy syndrome
Frontal Lobe (precentral gyrus)
- Movement and executive functioning
- extends from the central sulcus to the anterior limit of the brain
- The precentral gyrus houses the primary motor cortex which controls movements. Again, different areas of the PMC correspond to different parts of the body (pg 99)
- prefrontal cortex important for working memory, delayed response tasks, planning of appropriate behavior for context. Stuff that goes on here is called “executive functioning” (planning, organizing, analyzing, recognition of appropriate social behavior)
