Lab Exam 2 Flashcards
Cerebral Cortex (Cerebrum)
- the largest part of the human brain associated with higher brain function (thought and action)
- has two halves or hemispheres
- intentions, consciousness
- 4 lobes
Tapetum lucidum
- “bright carpet”, part of choroid layer
- iridescent or metallic luster that reflects some light back to the retina improving light in low light conditions
- animals with good night vision (cats and cows but not humans or pigs)
- reason for eyes shining in light during SCOTOPHASE
Fovea
- the center of the macula that only contains cones (humans)
- this is where all critical vision occurs
Sclerotic coat
- tough, white outer layer that protects and gives shape to the eyeball
Two principle cells in the brain
1) neuron- white and gray matter
2) glia
Accommodation
- adjustment in the shape of the lens primarily through the action of suspensory ligaments and ciliary muscles (focusing on retina)
- ability of the eye to change its focus from distant to near objects, and vice versa
- the posterior surface of the lens changes little due to the pressure of the vitreous humor
Ciliary body
- thickening of the choroid layer
- have ciliary muscles
- eye fluids are produced here
Gray matter
- primarily nerve cell bodies(NCB) and support cells
- the more of this, the more nerve cells, the more complex
4 lobes of the cerebral cortex
1) Frontal lobe- REASONING, planning, parts of speech, movement, problem solving
2) parietal lobe- MOVEMENT, orientation, recognition, perception of stimuli
3) occipital lobe- VISUAL processing
4) temporal lobe- perception and recognition of AUDITORY/OLFACTORY stimuli, memory and speech
Cross section of spinal chord
White vs gray matter
- white on outside
- gray on inside
How do horses view objects that are close up or further away? Accommodation
- their eyes are located in the sides of their heads so they have limited binocular vision
- they reposition their heads to aid in focusing images on the macula
Z line
- boundary line for a sarcomere
- gives skeletal muscle the striated(striped) look
Ganglion
- a cluster of cell bodies outside the CNS
Actin
- the thin mylofilament of sarcomeres
- contains troponin and tropomyosin
Macula lutea
- area of retina that has the most acute vision
- has highest concentration of rods and cones, so can focus image easier
- where the eye tries to focus the image
Brain stem
- medulla oblongata
- pons
Why do albinos eyes lack color?
- bc there is no pigment in the choroid, so the Iris will also have no color
- but you will be able to see pink/red eye color from their blood vessels
Ventral, dorsal, superior, inferior
1) Ventral- toward the belly (front)
2) dorsal- toward the back
3) superior- toward the top of the head/body
4) inferior- beneath
Optic disk
- where the optic nerve leaves the retina, there are no rods or cones
- causes a blind spot
- blind spot in horses is straight down, so of they wanna see the ground they must tilt their head
During muscle contraction what occurs?
- the A band does not change because the myosin does not change sizes
- the I band and M line will decrease
Pituitary gland
- endocrine organ
- behind the optic chiasma
- a tumor results in blindness
White matter
- (MYELINATED) axons, or fibers, portion of the nerve cell (communication)
Lens
- used to FOCUS THE IMAGE on the retina, “fine tuning” of the image
- are biconvex and transparent
- dehydrated compared to most body organs, high protein content (33%) and 66% water
- can undergo accommodation
Cornea
- the transparent outer covering of the eye, FOCUSES THE LIGHT RAYS on the retina
- astigmatism is an abnormality in the shape of the cornea which results in improper focusing of light rays and blurry or out of focus images
Epimysium
- the skeletal connective tissue around the whole muscle
Rods
- function in dim light
- contain rhodopsin, retinal an aldehyde of retinol (vitamin A)
- has more photopigment than cones, more sensitive to light
- vitamin A not synthesized in humans so definition u in diet will create night blindness
- if shift focus off of macula and on to rods you can see better in late or early hours
Vitreous humor
- semigelatinous fluid
Olfactory bulbs
- cranial nerve #1
- control the sense of smell
Ex: sheep vs beagle - beagle larger than sheets
Emmetropia
- 20/20 vision
- retina is in complete focus of the eye
Ciliary muscles
- used for changing lens shape for focusing on near objects
- get weaker with age
- they relax when the eye is at rest, when the eye is focused on distant objects
Nerve
- a bundle of axons outside of the CNS
Hyperopia
- far sighted vision
- focus is behind the retina
- to fix this need to be closer to object
What spinal chord did we talk about in lab
- cow spinal chord
Thalamus
- between cerebrum and midbrain
- relay center to and from the cerebrum
Hypothalamus
- involved in thermoregulation, rage, satiety, osmolarity and thirst
- controls anterior and posterior pituitary glands
Anterior chamber
- between cornea and iris
- filled with aqueous humor
Cerebellum
- MOTOR FUNCTION and movements
- rate and gait (how fast/smoothly you move)
- does what the cerebrum says to do
- distinctive ARBOR VITAE (tree of life), “little brain”
- gray and white matter
Sclera
- a place for muscle attachment to move the eye
- “white of the eye”
What animals have a tapetum and what do not?
- cows and cats have it
- humans and pigs do not
Pupil
- opening in the center of the iris
Posterior chamber
- between Iris and lens
- filled with aqueous humor
Medulla oblongata
- extension of the spinal chord
- vegetative/reflex functions such as cardiovascular, respiratory, sneezing, crying, vomiting
H zone
- only contains the thick mylofilament(myosin), not including the part that overlaps the actin
Ventricles
- chambers around thalamus filled with cerebrospinal fluid (CSF) essentially cushioning the entire CNS in a fluid filled protective layer
- infections of the CSF is meningitis
- can also cause hydrocephalus if CSF buildup
Corpus callosum
- above ventricle
- COORDINATES functions between right and left hemispheres
- consists of white axons going from one side of brain to the other
Skeletal muscle cells
- long multinucleated cylinders separated by connective tissue
- striated appearance
- peripheral nuclei (multinucleated cells)
- differential staining (light and dark cells)
Meninges
- outermost covering of the CNS, covers entire brain
3 layers
1) dura mater- outermost and toughest layer
2) arachnoid- fluid filled space, middle layer
3) piameter- blood vessels, most inner layer
- meningitis=infection
Endomysium
- the skeletal connective tissue for individual cells
- each muscle cell (fiber) is isolated from its neighbors by this layer
Midbrain
- mesencephalon
- involved in vision, hearing, motor control, sleep/wake, arousal, temperature regulation
What two proteins are involved in muscle contraction
- troponin and tropomyosin
Vitreous Body
- large cavity behind the lens
- filled with a vitreous humor
Skeletal muscle connective tissue layers
1) endomysium
2) perimysium
3) epimysium
Sarcomeres
- alternating mylofilaments
- multiple nuclei, banding and striations
1) myosin (thick)
2) actin (thin)
Cross section of brain
White matter vs gray matter
- gray on outside
- white on inside
Myosin
- thick mylofilament of sarcomeres
Cataracts
- a clouding of the lens, decrease in light receptors on the retina
Optic Chiasma
- cranial nerve #2
- connects nerves to your eyes
- fat behind the eye socket, when people are sick eyes become sunken bc they lose fat behind eye
- occipital lobe (birds have a very large one)
Retina
- innermost layer of the eye, contains rods and cones
- if detached eye will not work
What animal eyes did you study in lab?
- Primarily cow eyes, but also pig eyes
Interoreceptors and proprioceptors
- internal sensations such as hunger, thirst and muscle position
A band
- contains ALL of the thick mylofilament (myosin) and overlaps the thin mylofilament (actin)
Limbic system
- emotions and memory
Gyri and sulci
- Raised Ridges and grooves
- increase the surface area of the brain, the more conjugated (more nerve cell bodies, NCB) -> the more complex
Ex: sheep vs human vs chicken
- sheep semi conjugated
- humans very conjugated
- chicken smooth
Hippocampus
- memory functions
- looks like a sea horse
Suspensory ligament
- fibers arising from the ciliary body and attaching to the lens
- keeps the lens in place
- causes flattening of the lens when the choroid layer and ciliary body exert tension
What brain did we dissect in class
- sheep brain
Dura Mater
- tough outermost layer of spinal chord
Iris
- extension of choroid layer
- regulates the amount of light passing through the lens
- contains pupil
What happens when you focus on closer objects? Accommodation
- CILIARY MUSCLES CONTRACT pulling the choroid layer forward decreasing the tension on the suspensory ligaments and allows the LENS to be more ROUND
Cones
- function in bright light and color perception
- have 3 visual pigments that absorb red, green and blue wavelengths
- are in the retina
Conjunctiva
- a thin membrane continuous with the inner surface of the eyelid and adhering to the cornea
Pons
- bridge from spinal chord to the rest of the brain
- involved in sleep, respiration, swallowing, hearing, equilibrium, taste
Rhodopsin
- in the rods
- it is visual purple (turns purple after green and blue wavelengths are absorbed)
Exteroreceptors
- external sense organs
Denticulate ligaments
- bilateral thickenings of pia mater that suspend the spinal chord within the dura mater
Pig eye
- has a fat deposit behind the bony socket
- if becomes ill will lose the fat and the eye will become sunken
Conjunctivitis or pink eye
- an infection of the conjunctiva
I band
- stretches over 2 sarcomeres adjacent to eachother
- contains only the thin filament (actin)
Pineal gland
- small endocrine gland (melatonin)
- responsible for seasonal effects (breeding, coat color, texture changes) and our response to daily photoperiodic rhythms (jet lag)
Myopia
- near sighted
- focus is in front of the retina
- to fix this need to move further away
Choroid
- pigmented (black), vascular layer that prevents internal reflection of light rays
Optic nerve
- sensory afferent from the eye
- carries rods and cones from macula to the brain
Nucleus
- a cluster of cell bodies inside the CNS
What happens when you focus on distant objects? Accommodation
- the eye is at rest, therefore the CILIARY MUSCLES RELAX
- the choroid layer exerts tension on the suspensory ligaments and the FLATTENING of the LENS
Aqueous humor
- clean, watery fluid over the eye, but under the cornea
- constantly being produced and reabsorbed
What animals can see UV light?
- birds
Perimysium
- the skeletal connective tissue for separate groups of cells
- isolates groups of muscle cells
- blood vessels and nerves
Glaucoma
- a buildup of aqueous humor
- increase in intraocular pression result in constant headaches
- can result in decreased blood flow to the retina and permanent vision loss
Astigmatism
- an abnormality in the shape of the cornea that results in improper focusing of the light rays and blurry or out of focus images
Tract
- a bundle of axons inside the CNS
Meningitis
- infection of the cerebral spinal fluid
Hydrocephalus
- buildup of cerebral spinal fluid
