Phyl 141L Exam 3, part 3

What does the brain develop from?

The neural tube.

What are the 3 primary brain regions formed during week 4?

Forebrain, midbrain, and hindbrain.

What are the 4 major regions of the adult brain?

Cerebral hemispheres, diencephalon, brain stem, and cerebellum.

What is the cerebrum?

The most superior portion of the brain.

What are gyri?

Ridges or raised folds of the cerebral cortex.

What are sulci?

Shallow grooves between gyri.

What are fissures?

Deep grooves in the brain.

What does the longitudinal fissure separate?

The right and left cerebral hemispheres.

What does the central sulcus separate?

Frontal and parietal lobes.

What does the lateral sulcus separate?

The temporal lobe from the frontal and parietal lobes.

What does the parieto-occipital sulcus separate?

Parietal and occipital lobes.

What are the main functions of the frontal lobe?

Voluntary movement, speech production, decision-making, memory, and personality.

What is the primary motor cortex responsible for?

Controlling voluntary skeletal muscle movements.

Where is the primary motor cortex located?

Frontal lobe.

What is Broca's area responsible for?

Controlling speech production.

Where is Broca's area located?

Frontal lobe.

What are the main functions of the parietal lobe?

Proprioception, skin sensation, and sensory integration.

What is proprioception?

Awareness of body position and movement.

What are the main functions of the temporal lobe?

Hearing, smell, and understanding speech.

Which lobe contains the auditory cortex?

Temporal lobe.

Which lobe contains the olfactory cortex?

Temporal lobe.

Which lobe is responsible for understanding speech?

Temporal lobe.

What is the main function of the occipital lobe?

Visual processing and sight.

Which lobe contains the visual cortex?

Occipital lobe.

What are the 3 parts of the brain stem?

Midbrain, pons, and medulla oblongata.

What is the function of the midbrain?

Organizes visual and auditory information.

What is the function of the pons?

Helps regulate autonomic functions, including breathing.

Which cranial nerves are associated with the pons?

Cranial nerves V–VIII. (triggerman, abducens, facial, vestibularcocchlear)

What is the function of the medulla oblongata?

Controls autonomic functions such as heart rate and reflexes.

What are examples of medulla-controlled reflexes?

Gagging, swallowing, and coughing.

What is the main function of the cerebellum?

Coordinates muscle movements, balance, and posture.

What is the olfactory bulb?

Extension of the olfactory nerve located above the ethmoid bone.

What is the function of the olfactory bulb?

Processes information related to smell.

What is the optic nerve?

Cranial nerve II

What is the optic chiasma?

The crossing point of the optic nerves.

What is the function of the pituitary gland?

Secretes hormones that regulate body functions.

What are the mammillary bodies responsible for?

Memory processing, especially involving smell.

What is the function of the corpus callosum?

Connects the right and left cerebral hemispheres.

What is the function of the basal ganglia?

Controls voluntary movement and contributes to habit learning.

What is the function of the thalamus?

Relays sensory and motor signals to the cerebral cortex.

How does the thalamus contribute to consciousness?

Helps maintain alertness and regulates sleep-wake states.

What is the function of the hypothalamus?

Coordinates the autonomic nervous system and maintains homeostasis.

What does the hypothalamus regulate?

Body temperature and other involuntary body functions.

What are the meninges?

Connective tissue membranes that cover and protect the brain.

What are the 3 layers of the meninges from outermost to innermost?

Dura mater → arachnoid mater → pia mater.

What is the outermost meningeal layer?

Dura mater.

What are the characteristics of the dura mater?

Thick, tough, and leathery outer layer.

What is the middle meningeal layer?

Arachnoid mater.

What is the innermost meningeal layer?

Pia mater.

What are the characteristics of the pia mater?

Thin, delicate layer closely attached to the brain.

What is the subdural space?

Potential space between the dura mater and arachnoid mater.

What is the subarachnoid space?

Space between the arachnoid and pia mater containing CSF.

What is the falx cerebri?

Meningeal fold located in the longitudinal fissure between cerebral hemispheres.

What is the falx cerebelli?

Meningeal fold between the two cerebellar hemispheres.

What is the tentorium cerebelli?

Meningeal fold separating the cerebrum from the cerebellum.

What are arachnoid villi?

Projections that extend into dural venous sinuses and allow CSF drainage.

What is cerebrospinal fluid (CSF)?

Fluid that cushions the brain and transports nutrients.

Where is CSF located?

In the ventricles and spaces surrounding the brain and spinal cord.

What produces cerebrospinal fluid?

The choroid plexus.

What is the function of CSF?

Cushions the brain, provides protection, and transports nutrients and wastes.

How does CSF drain from the brain?

Through arachnoid villi into dural venous sinuses.

What are the 3 lateral eye-turning muscles?

Lateral rectus, superior oblique, and inferior oblique.

What are the 3 medial eye-turning muscles?

Medial rectus, superior rectus, and inferior rectus.

Which muscle abducts the eye?

Lateral rectus.

Which muscle adducts the eye?

Medial rectus.

What is the general function of the oblique eye muscles?

Rotate the eye and assist with vertical movements.

Where is the lacrimal gland located?

Superior lateral portion of the eye.

What is the function of the lacrimal gland?

Produces tears.

What is the pathway of tear drainage?

Lacrimal caruncle → lacrimal canaliculi → lacrimal sac → nasolacrimal duct.

What is the lacrimal caruncle?

Small structure at the medial corner of the eye where eye debris collects.

What are the 3 layers of the eye from outermost to innermost?

Fibrous layer → vascular layer → inner neural layer.

What are the 2 structures of the fibrous layer?

Sclera and cornea.

What is the function of the sclera?

Maintains eye shape and provides attachment for eye muscles.

What is the function of the cornea?

Transparent external window that bends (refracts) light.

What are the main structures of the vascular layer?

Ciliary body, iris, and pupil.

What is the function of the ciliary body?

Changes lens shape and produces aqueous humor.

What is accommodation?

Changing lens shape to focus on objects at different distances.

What is the function of the iris?

Controls pupil diameter.

What is the function of the pupil?

Allows light to enter the eye.

What are the 2 layers of the retina?

Pigmented layer and neural layer.

What is the function of the pigmented layer?

Absorbs excess light and contains melanocytes.

What cells are found in the neural layer?

Photoreceptors, bipolar cells, and ganglion cells.

What are the 2 types of photoreceptors?

Rods and cones.

What is the function of rods?

Detect low light and shades of gray.

What is the function of cones?

Detect color and function best in bright light.

What type of image forms on the retina?

A real, smaller, inverted, and reversed image.

What is refraction?

The bending of light as it passes through different materials.

What is accommodation?

Changing the shape of the lens to focus clearly on objects at different distances.

What is presbyopia?

Age-related loss of lens elasticity that reduces near focusing ability.

How can presbyopia be tested?

Near-point accommodation test.

What is myopia?

Nearsightedness

Where does light focus in a myopic eye?

In front of the retina.

What is hyperopia?

Farsightedness

Where does light focus in a hyperopic eye?

Behind the retina.

How many types of cones detect color?

Three types.

What colors do the three cone types detect?

Red, green, and blue.

What causes color blindness?

Deficiency or dysfunction of one or more cone types.

Which photoreceptors work best in dim lighting?

Rods.

Which photoreceptors are responsible for color vision?

Cones.