Lab #13 - Identifying External Brain Structures - Lab 1, eye anatomy , Nervous System Study Guide, 12 Cranial Nerves , Parts of the Ear , Lab 13: Activity 2 - Identifying Internal Brain Structures , Parietal Lobes Function, Occipital Lobe Functions,…

Frontal Lobe

A region of the cerebral cortex that has specialized areas for movement, abstract thinking, planning, memory, and judgment

Temporal Lobe

A region of the cerebral cortex responsible for hearing and language.

Occipital Lobe

A region of the cerebral cortex that processes visual information

Cerebellum

the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance

Pons

A brain structure that relays information from the cerebellum to the rest of the brain

Medulla Oblongata

Part of the brainstem that controls vital life-sustaining functions such as heartbeat, breathing, blood pressure, and digestion.

Gyrus

A ridged or raised portion of a convoluted brain surface.

Cortex (gray matter)

The outer layer (approximately one-fourth to one-half inch) of brain tissue containing nerve cell bodies (neurons)

Pituitary Gland

The endocrine system's most influential gland. Under the influence of the hypothalamus, the pituitary regulates growth and controls other endocrine glands.

Optic Chiasma

The crossing of the optic nerves from the two eyes at the base of the brain

Optic Nerve

The nerve that carries neural impulses from the eye to the brain

Olfactory Bulb and Tract

Sense of smell

Lateral Sulcus

Separates temporal lobe from parietal and frontal lobes

Central Sulcus

Separates frontal lobe from parietal lobe

Sulcus

Narrow groove

White Matter

Whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths.

longitudinal fissure

separates left and right hemispheres

precentral gyrus

the strip of frontal cortex, just in front of the central sulcus, that is crucial for motor control

postcentral gyrus

the strip of parietal cortex, just behind the central sulcus, that receives somatosensory information from the entire body

cornea

the transparent layer forming the front of the eye.

palpebral fissure

space between eyelids

conjunctiva

Delicate membrane lining the eyelids and covering the eyeball

conjunctivitis

inflammation of the conjunctiva (pink eye)

Astigmatism

Can cause blurred or distorted vision at near and far distances

superior oblique muscle

Depresses eye and turns it laterally and is controlled by the trochlear nerve.

superior oblique tendon

What is B?

superior rectus muscle

elevates eye and turns it medially

inferior rectus muscle

Depresses the eyes (downward movement of the eyes)

medial rectus muscle

moves eye medially

lateral rectus muscle

moves eye laterally

ciliary body

ring of tissue behind the peripheral iris that is composed of ciliary muscle and ciliary processes

sclera

white of the eye

lens

the transparent structure behind the pupil that changes shape to help focus images on the retina

pupil

the adjustable opening in the center of the eye through which light enters

iris

a ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening

optic nerve

the nerve that carries neural impulses from the eye to the brain

optic chiasma

the crossing of the optic nerves from the two eyes at the base of the brain

optic tract

How information from the optic nerve travels to the thalamus.

retina

the light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information

cataracts

clouding of the lens

glaucoma

increased intraocular pressure results in damage to the retina and optic nerve with loss of vision

accomadation

the process by which the eye's lens changes shape to focus near or far objects on the retina

visual acuity

the ability to see fine detail

binocular

pertaining to two or both eyes

panoramic

a view of an area in all directions

convergence

A binocular cue for perceiving depth; the extent to which the eyes converge inward when looking at an object

depth perception

the ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance

CNS

-Central Nervous System

-Brain and spinal cord of dorsal body cavity

-Integration and control center

-Interprets sensory input and dictates motor output

PNS

-Peripheral Nervous System

-Provides links from and to world outside body

-All neural structures outside brain

-Sensory receptors

-Peripheral nerves and associated ganglia

-Efferent motor endings

-The portion of the nervous system outside CNS

-Consists mainly of nerves that extend from brain and spinal cord

-Spinal nerves to and from spinal cord

-Cranial nerves to and from brain

-Sensory and Motor DIvision

Sensory (afferent)

-transmit impulses toward the CNS

-Somatic sensory fibers = convey impulses from skin, skeletal muscles, and joints to CNS

-Visceral sensory fibers = convey impulses from visceral organs to CNS

Motor (efferent)

-carry impulses away from the CNS

-Transmits impulses from CNS to effector organs

-Muscles and glands

Somatic Nervous System

-Division of the PNS that controls the body's skeletal muscles.

-Somatic motor nerve fibers

-Conducts impulses from CNS to skeletal muscle

-Voluntary nervous system

-Conscious control of skeletal muscles

Autonomic Nervous System

-ANS consists of motor neurons that

-Innervate smooth and cardiac muscle, and glands

-Make adjustments to ensure optimal support for body activities

-Operate via subconscious control

-Also called involuntary nervous system or general visceral motor system

-Sympathetic and Parasympathetic

Sympathetic

-Mobilizes body during activity; "fight-or-flight" system

-Exercise, excitement, emergency, embarrassment

-Increased heart rate; dry mouth; cold, sweaty skin; dilated pupils

-During vigorous physical activity

-Shunts blood to skeletal muscles and heart

-Dilates bronchioles

-Causes liver to release glucose

Parasympathetic

-Promotes maintenance activities and conserves body energy

-Directs digestion, diuresis, defecation

-As in person relaxing and reading after a meal

-Blood pressure, heart rate, and respiratory rates are low

-Gastrointestinal tract activity high

-Pupils constricted; lenses accommodated for close vision

Sympathetic and Parasympathetic maintain

homeostasis

Sensation

-the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment

-The awareness of changes in the internal and external environment

Perception

-the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events

-The conscious interpretation of those stimuli

Afferent

Impulses only toward the CNS

Efferent

Impulses only away from the CNS

Integrative

Analyze incoming sensory information, store some aspects, and make decisions regarding appropriate behaviors

Neuron Body

Biosynthetic center of neuron

Synthesizes proteins, membranes, and other chemicals

Rough ER (chromatophilic substance or nissl bodies)

Most active and best developed in body

Spherical nucleus with nucleolus

Some contain pigments

In most, plasma membrane part of receptive region

Most neuron cell bodies in CNS

Nuclei- clusters of neuron cell bodies in CNS

Ganglia- lie along nerves in PNS

Axon

One axon per cell

In some axon short or absent

In others most of length of cell

Some 1 meter long

Long axons called nerve fibers

Conducting region of neuron

Generates nerve impulses

Neurotransmitters released into extracellular space

Either excite or inhibit neurons with which axons in close contact

Carries on many conversations with different neurons at same time

Lacks rough ER and Golgi apparatus

Relies on cell body to renew proteins and membranes

Efficient transport mechanisms

Quickly decay if cut or damaged

Dendrites

In motor neurons

100s of short, tapering, diffusely branched processes

Same organelles as in body

Receptive (input) region of neuron

Convey incoming messages toward cell body as graded potentials (short distance signals)

In many brain areas fine dendrites specialized

Collect information with dendritic spines

Appendages with bulbous or spiky ends

Amitotic

relating to or denoting the division of a cell nucleus into two parts by constriction without the involvement of a mitotic apparatus.

neurons are

amitotic

Life span of neurons

Neurons have an extreme longevity of more than 100 years

Metabolism of neuron

Neurons have a high metabloc rate which requires a continuous supply of oxygen and glucose

synapse

the junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron

synaptic cleft

The narrow gap that separates the presynaptic neuron from the postsynaptic cell.

chemical impulse

between the neurons or between neuron and effector

electrical impulse

A sudden surge of energy in one direction.

Acetylcholine (ACh)

-A neurotransmitter that enables learning and memory and also triggers muscle contraction

-First identified; best understood

-Released at neuromuscular junctions ,by some ANS neurons, by some CNS neurons

-Synthesized from acetic and choline by enzyme choline acetyltransferase

-Degraded by enzyme acetylcholinesterase (AChE)

-Aids in memory formation

-Less produced as Alzheimer's progresses

Norepinephrine (Catecholamines)

A neurotransmitter involved in arousal, as well as in learning and mood regulation

Epinephrine (Catecholamines)

Neurotransmitter secreted by the adrenal medulla in response to stress. Also known as adrenaline.

Dopamine (Catecholamines)

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system.

Seretonin

a neurotransmitter that affects mood, hunger, sleep, and arousal; undersupply linked to depression.

Melatonin

A hormone manufactured by the pineal gland that produces sleepiness.

endoneurium

loose connective tissue that encloses axons and their myelin sheaths

perineurium

coarse connective tissue that bundles fibers into fascicles

epineurium

tough fibrous sheath around a nerve

fiber tracts

axons in the central nervous system that travel together in bundles

association fiber

horizontal; connect different parts of same hemisphere

commisural

horizontal; connect gray matter of two hemispheres

projection fibers

vertical; connect hemispheres with lower brain or spinal cord

left hemisphere

Controls language, math, and logic

right hemisphere

Visual-spatial skills, intuition, emotion, and artistic and musical skills

Hemispheres communicate

almost instantaneously via fiber tracts and functional integration

transverse cerebral fissure

separates cerebrum and cerebellum

insula lobe

found deep beneath the lateral sulcus, associated with memory and interpretation of taste

mechanoreceptor

respond to touch, pressure, vibration, and stretch (movement)

thermoreceptor

sensitive to changes in temperature (temperature)

exteroceptor

Respond to stimuli arising outside body

Receptors in skin for touch, pressure, pain, and temperature

Most special sense organs

(external)

internoreceptor

(visceroceptors)

Respond to stimuli arising in internal viscera and blood vessels

Sensitive to chemical changes, tissue stretch, and temperature changes

Sometimes cause discomfort but usually unaware of their workings

(internal)

proprioreceptor

Respond to stretch in skeletal muscles, tendons, joints, ligaments, and connective tissue coverings of bones and muscles

Inform brain of one's movements

(touch)

CNS neuron regeneration

CNS oligodendrocytes bear growth-inhibiting proteins that prevent CNS fiber regeneration

PNS neuron regeneration

Axon fragments (Wallerian degeneration); spreads distally from injury

Macrophages clean dead axon; myelin sheath intact

Axon filaments grow through regeneration tube

Axon regenerates; new myelin sheath forms

pupillary autonomic reflex

The automatic process by which the iris contracts and relaxes to control the size of the pupil, in response to the relative brightness of light entering the eye

parasympathetic

ciliospinal reflex (autonomic)

-Dilation of the pupil caused by pain in the neck, face and upper trunk

-Sympathetic nervous system response

Salivary reflex (autonomic)

secretion of saliva in response to reflex activation

food odor detection causes salivation