Mid Semester Exam Flashcards
What does the afferent division do?
Brings information from periphery to CNS
What does the CNS do?
- Subconsciously regulate homeostatic responses
- experience emotions
- voluntarily control your movements
- be aware of your body and surroundings
- engage in other higher cognitive processes
What does the efferent division do?
Conveys CNS ‘orders’ to the effector organs to respond
What do interneurons do?
Connect afferent neutrons with efferent neutrons within CNS
What are the major parts of the brain?
Cerebral cortex Basal nuclei Thalamus Hypothalamus Cerebellum Brain stem
What does the cerebrum do?
• Makes up 80% of total brain weight
• Divided into right and left cerebral hemispheres
• Each hemisphere divided into lobes
• Outer surface is the convoluted cerebral cortex:
-covers inner core that houses basal nuclei
-most complex integrating area of the brain
What is the cerebral cortex?
- the cerebral cortex is gray matter; the core is white matter.
- gray matter is organised into 6 well-defined layers
- integration of neural input and initiation of neural output take place within gray matter
- the white matter consists of bundles of nerve fibers that interconnect brain areas.
What are the four major lobes
Occipital
Temporal
Parietal
Frontal
What are the basic lobe functions
- Occipital lobes house the visual cortex
- temporal lobes house the auditory cortex
- parietal lobes are responsible for reception and perception of somatosensory input
- frontal lobes are responsible for voluntary motor movement
What is the somatosensory cortex?
- Located in the front portion of each parietal lobe behind the central sulcus.
- site for initial processing and perception of both somesthetic and proprioceptive input
- someosthetic sensations are from the surface of the body (touch, pressure, heat, cold and pain)
- proprioception is the awareness of body position
- receives input from the opposite side of the body
What is the primary motor cortex?
- Controls voluntary movement produced by skeletal muscles
- motor cortex on each side of the brain primarily controls muscles on the opposite side of the body
- contains motor homunculus
- body parts needing fine control of movement occupy larger area of motor homunculus
What are the secondary motor areas?
Supplementary motor area
Premotor cortex
Posterior parietal cortex
Cerebellum and basal nuclei also influence motor function
What and where is Broca’s area?
Located in left frontal lobe near motor areas
Controls speaking ability
What and where is wernike’s area?
Located in the left cortex at the juncture of the parietal, temporal and occipital lobes
Associated with language comprehension of both spoken and written messages
What is basal nuclei?
Consists of several masses of Gray matter located deep within white matter.
Primary functions:
Inhibiting muscle tone throughout the body
Selecting, maintaining purposeful motor activity
Suppressing unwanted patterns of movement
Coordinates slow, sustained contractions
What is the thalamus?
Reinforces voluntary motor behaviour initiated by motor cortex
Serves as ‘relay station’ and synaptic integrating centre for sensory input
Helps direct attention to stimuli of interest
Capable of crude awareness of sensations but cannot distinguish their location or intensity
What is the hypothalamus?
Collection of nuclei and associated fibers that lie beneath the thalamus
Integrating enter for homeostatic functions
An important link between the autonomic nervous system and the endocrine system
Brain area most involved in directly regulating internal environment
What are the hypothalamic functions?
- Controls body temperature and food intake
- Controls thirst and urine output
- Controls anterior pituitary hormone secretion
- Produces posterior pituitary hormones
- Controls uterine contractions and milk ejection
- Serves as a major autonomic coordinating center
- Plays role in emotional and behavioural patterns
- Participates in sleep-wake cycle
What is the limbic system?
Includes portions of cerebral lobes, the basal nuclei, the thalamus and the hypothalamus
Utilises the neurotransmitters norepinephrine, dopamine and serotonin
Associated with emotions, basic survival, sociosexual behavioural patterns, motivation and learning
What are some of the limbic system functions?
Emotion Basic behavioural patterns Motivation Learning Memory
What types of memory are there?
Long term, retained for day to years
Short term, lasts seconds to hours
Consolidation is the transfer of short term memory traces into long term memory stores
What is declarative memories?
“What-type memories” processed in the hippocampus and associated structures
What is procedural memories?
“How to memories” processed in the cerebellum.
What does the prefrontal cortex serve as?
Temporary storage area associated with planning, problem solving, organising and inhibiting impulses
What is the cerebellums 3 functionally distinct parts?
Vestibulocerebellum- balance and eye movements
Spinocerebellum- enhances muscle tone and coordinates skilled movements
Cerebrocerebellum- planning and initiating voluntary activity and stores procedural memories
What does the brain stem consist of?
Midbrain, pons and medulla
What are the brain stem functions?
- Links spinal cord and higher brain levels
- contains centres that control cardiovascular, respiratory and digestive function
- regulates postural muscle reflexes
- controls the overall degree of cortical alertness
- plays a role in the sleep-wake cycle
What is EEG?
EEG is the special equipment that determines any changes in brain activity
What is consciousness?
The subjective awareness of the external world and self
What are the states of consciousness?
Maximum alertness
Wakefulness
Sleep
Coma
Why do we need sleep?
Restoration, recovery and memory consolidation
What are the 2 different kinds of sleep?
Slow wave sleep and paradoxical (REM) sleep
What is slow wave sleep?
Characterised by slow waves on EEG
What is REM sleep?
Characterised by an EEG pattern similar to that of an alert, awake individual
Where is the spinal cord located?
Extends from the brain stem, descends through canal formed by vertebrae.
What are the 2 spinal cord functions?
Serves as the neuronal link between the brain and the peripheral nervous system
Is the integrating centre for spinal reflexes
What is white matter tracts?
White matter is organised into nerve tracts- bundles of nerve fibers with a similar function
Each tract begins or ends within a particular area of the brain
What do ascending and descending white matter tracts do?
Ascending- transmit afferent sensory input
Descending- relay efferent motor output
What are the the horns in Gray matter? And what is there function
Dorsal horn- contains cell bodies of interneurons on which afferent neutrons terminate
Ventral horn- contains cell bodies of efferent motor neutrons supplying skeletal muscles
Lateral horn- contains cell bodies of autonomic sympathetic nerve fibers
What types of fibers do spinal nerves contain?
Afferent and efferent
How many pair of nerves emerge from spinal cord through spaces between adjacent vertebrae? What kind of nerves are these?
31 pairs 8 pairs cervical (neck) 12 pairs thoracic (chest) 5 pairs lumbar (abdominal) 5 pairs sacral (pelvic) 1 pair coccygeal (tailbone)
What is a reflex?
Any response that occurs automatically without conscious effort
What are the two types of reflexes?
Simple , basic reflexes- built in, unlearned responses
Acquired, conditioned reflexes- result of practice and learning
What is the reflex arc?
The neural pathway involved in accomplishing reflex activity
What are the five basic components of the reflex arc?
Receptor Afferent pathway Integrating centre Efferent pathway Effector
The nervous system consists of
Central nervous system
Peripheral nervous system
Enteric nervous system
What is pain?
Primarily a protective mechanism to bring awareness that tissue damage is occurring
How does pain begin?
Stimulation of nociceptors
What are the 3 categories of pain receptors?
Mechanical, thermal and polymodal
What is the pain pathway?
Afferent pain fibers terminate in spinal cord on ascending pathways that transmit the signal to the brain
Descending pathways use endogenous opiates to suppress the release of substance P.
Descending pathways serve as a built in analgesic system.
What are the two different afferent pathways and what is the difference?
Fast pathways- carries sharp,prickling pain signals
Slow pathways- carries dull, aching, persistent pain signals
What is the eye? LMAO EASY AF BUT
GO ON JAZ U GOT THIS
Sensory organ for vision
What are the three tissue layers in the eye?
Sclera/cornea
Choroid/ ciliary body/ iris
Retina
What is choroid?
Middle layer underneath sclera, contains blood vessels that nourish retina.
What does the choroid layer form?
Ciliary body- controls lens shape
Iris- controls amount of light entering eye
What is the pupil?
Opening through which light enters the eye
Size is adjusted by iris muscles
What is sclera?
Tough outer layer of connective tissue
Forms visible white part of eye
What is cornea?
Anterior, transparent outer layer
Light rays pass through it before entering interior of eye
What is the retina?
Innermost coat under choroid
Consists of inner nervous tissue layer and outer pigmented layer
What is the refraction of light
The bending of a light ray is known as refraction
What is the difference between convex and concave light rays?
Convex surfaces converge light rays
Concave surfaces diverge light rays
What is the function of the cornea and lens?
They are the primary refractive structures that bend incoming light rays
What is accommodation?
Ability to adjust strength of lens by changing its shape, shape is regulated by ciliary muscle.
What is the names for nearsightedness and farsightedness?
Near- myopia
Far- hyperia
What is the neural retinas 3 layers of editable cells?
Outermost layer contains rods and cones
Middle layer contains bipolar cells
Inner layer contains ganglion cells
Axons of ganglion cells join to form?
Optic nerve
Where is the optic disc?
It is point on the retina where the optic nerve leaves. This region is the blind spot
What is the function of the optic disc?
No image can be detected in this area because it has no rods or cones
Explain fovea?
Small depression in centre of retina
Has only cones, no bipolar or ganglion cells.
Point of most distinct vision
Explain macula lutea?
Area immediately surrounding fovea
Has cones, bipolar and ganglion cells
Fairly high acuity
Rods and cones consist of three parts, list and explain there function
Outer segment: detects the light stimulus
Inner segment: contains metabolic structures
Synaptic terminal: releases neurotransmitter depending on dark or light exposure detected by the outer segment
What 2 components does a photo pigment contain?
Opsin- an integral protein in the plasma membrane
Retinal- a derivative of vitamin A that absorbs light
What happens when a photo pigment is activated?
It causes a receptor potential in the rod or cone
Through a series of steps this leads to an action potential in ganglion cells
What is phototransduction?
The process of converting light stimuli into electrical signals
What is visual field?
It is the field of view that can be seen without moving the head
What are the three parts in the ear?
External and middle portions transmit and amplify airborne sound waves to the fluid filled inner ear
Inner ear contains neural receptor cells for two sensory systems:
• cochlea for hearing
• vestibular apparatus for equilibrium
what are sound waves?
travelling vibrations of air
