The Brain and Special Senses (Structures of the Eye (Retina- translucent…
The Brain and Special Senses
- most complex region of the brain and is involved in higher thought process.
function in motor activities.
Primary motor cortex
, initiates voluntary skeletal muscle activity
, plans and coordinates learned, skilled motor activity
Frontal eye field
, regulates the skeletal muscles that perform movement for binocular vision
Motor speech area
, regulates skeletal muscle movement involved with speech
function in general sensation.
Primary somatosensory cortex
, receives and interprets somatic information from receptors for touch and pain.
functions in hearing
Primary auditory cortex
, processes and interprets sounds, stores auditory memories.
Primary olfactory cortex
, provides conscious awareness of taste.
functions in vision
Primary visual cortex
, process, stores and integrates visual information.
Primary gustatory cortex
, located in the insula, processes taste information and provides conscious awareness of taste.
, involved in higher intellectual functions, like concentration, decision making and planning. Gives you your personality.
, helps understand written and spoken language.
, integrates all information being processed to give understanding of a current activity.
- provides the relay center for some sensory and motor pathways and is used for the control of visceral activities
, composed of two halves that sit around the third ventricle. It is the final relay point for sensory relay to the cerebellum
, floor of the third ventricle. Has many important functions including control of the autonomic nervous system, the endocrine system and many aspects of homeostasis.
, posterior roof of the diencephalon and covers the third ventricle.
endocrine gland that is responsible for the secretion of the hormone melatonin
- connects the cerebrum, diencephalon and cerebellum to the spinal cord.
- the superior portion of the brainstem. Functions in optic and auditory reflexes.
- superior to Medulla Oblongata and inferior to Midbrain, houses autonomic nuclei. Functions as a reflex center, which helps in the control of respiration.
- the most inferior part of the brain stem. All communication between the brain and spinal cord travel through the medulla oblongata. Vital reflex center for control of heartbeat, respiration and vasomotor activity.
- main function is to carry out learned movement, responsible for "muscle memory."
Structures of the Spinal Cord
- spinal cord tissue composed of neuron cell bodies, dendrites and unmyelinated axons. Centrally located, surrounds the central canal and its shape resembles a butterfly.
- spinal cord tissue that derives its color from myelin in myelinated axons. External to gray matter.
- a small hole in gray matter that runs the entire length of the spinal cord. Contains cerebrospinal fluid
- Connects to the posterior side of the spinal cord, contains unipolar neurons that are bringing sensory input to the spinal cord.
Dorsal root ganglia
- holds the cell bodies of the sensory neurons.
- Connects to the anterior side of the spinal cord. Contains multipolar motor neurons that are sending output signals to muscles.
Structures of the Eye
- the white outermost layer for protection and maintenance of shape
- the anterior part of the scelera through which light enters the eye.
- dark middle layer which absorbs light to prevent reflection.
- translucent inner layer that contains rods and cones
- produce sharp color vision in bright light
- specialize in black and white peripheral vision.
-produces tears and lubricate the eye
- colored part of eye, constricts and dilates to control the amount of light let into the eye.
- behind the iris; focuses light on the retina
- circular muscle that changes the shape of the lens to focus.
- viscous fluid occupying the posterior cavity. Functions to maintain the shape of the eye and support the internal parts.
- the central opening of the iris, in which light passes through.
Structures of the Ear
or pinna- on the outside of the head; functions to collect sound waves
External auditory canal
- carries sound waves from auricle to tympanic membrane
or eardrum- boundary between external and middle ear.
or tympanic cavity
- conduct vibrations to the inner ear
or hammer- vibrations of tympanic membrane cause malleus to vibrate
or anvil- vibration of malleus cause incus to vibrate
or stirrup- vibration of incus causes stapes to vibrate and press against the oval window.
- membrane covered opening into the inner ear; vibrations of this membrane cause waves in the fluid of the inner ear.
- waves of the inner ear fluid press against this structure causing it to bulge into the middle ear cavity
- connects the middle ear with the nasopharynx to equalize the air pressure of the ear
- responsible for the sense of equilibrium
- a spiral bony chamber contains fluid that is set in motion by sound waves picked up by the tympanic membrane.
Organ of Corti
- hair cells that are moved against a membrane as the cochlear fluid vibrates. Initiate the nerve impulses that are transmitted to the temporal lobe for auditory perception