Anatomy & Physiology Exam 2

epidermis, dermis, subQ

three layers of the skin

epidermis

outer layer

dermis

nerves, blood vessels, composed of connective tissue containing collagen and elastic fibers

hypodermis or subQ

fat, blood vessels, attaches skin to underlying tissues and organs, separates the dermis and epidermis from everything else, mostly adipose tissue

keratinocytes

makes keratin

Malanocytes

makes melanin; number and amount produced determines skin color

Intraepidermal macrophages

immune system

Tactile epithelial cells

modified nervous system cells (sensory neurons)

stratum basale

stem cells, 1 row

stratum spinosum

spinal layer, stratified, 8-10 rows, immune cells

stratum granulosum

granular layer, lots of keratin, stratified, 3-5 layers

stratum lucidum

only present in thick skin; dead cells, still connected through desmosomes

stratum corneum

outermost layer, dead cells filled with keratin, still connected through desmosomes

thin skin

covers all body regions except the palms, palmar surfaces of digits, and soles

thick skin

covers the palms, palmar surfaces of digits, and soles (on the hands and feet because we frequently use them)

mole

a grouping of melanocytes that broke free from where they were supposed to be

papillary layer

closest to the epidermis, thin collagen fibers, elastic fibers

reticular layer

deeper, more dense, thicker mesh work, thicker collagen & elastic fibers

lanugo

protects epidermis

terminal

longer, thicker hair (on head)

vellus

short, pale, thin (peach fuzz)

arrector pili muscle

adjust the position of the hair

hair shaft

dead highly keratinized epidermal cells

sebaceous (oil) glands

connected to the hair follicles, produces sebum

eccrine (merocrine) sweat glands

the most numerous, watery sweat, electrolytes, used to maintain temp, palms and soles

apocrine sweat glands

located mainly in hairy skin, start around puberty

ceruminous glands

modified sweat glands located in the ear canal, ear canal, makes earwax

Six functions of the skin

blood reservoir, protection, excretion and absorption, synthesis of vitamin D, thermoregulation, cutaneous sensations

sensory receptors

superficially, deep

deep wound healing

occurs when an injury extends to the dermis and subQ

basal cell carcinoma

most common form of skin cancer

squamous cell carcinoma

second most common, higher risk for metastisis

malignant melanoma

most serious and most rare

first degree burn

only epidermis

second degree burn

down to the dermis

third degree burn

down to the subQ

Functions of the Nervous System

sense changes through sensory neurons, respond to stimuli, analyze incoming sensory information, store some aspects, and make decisions regarding appropriate behaviors

PNS

sensory neuron and motor neuron

CNS

interneuron

neuroglia

not electrically excitable, make up about half the volume of the nervous system, can multiply and divide, 6 kinds total

phagocyte

cell that eats other cells

protoplasmic astrocyte

trash compactorsand form blood brain barrier

microglial cell

immune system of the brain “phagocytic”

fibrous and protoplasmic astrocytes

regulate “stuff” in interstitial fluid

ependymal cell

form a lining, produce CSF

schwann cell

only one neuron

oligodendrocyte

multiple neurons

myelin sheath

produced by Schwann cells and oligodendrocytes and surrounds the axons of most neurons

gray matter

cell bodies and synapse

white matter

has a myelin sheath, axons

action potentials

allow communication over short and long distances

graded potentials

allow communication over short distances only

Resting membrane potential

the membrane of a non-conducting neuron is positive outside and negative inside, production of AP and GP depends on this and the existence of certain ion channels

sensory afferents

towards CNS

motor efferent

towards organ or muscle

leakage channels

alternate between open and closed

ligand-gated channels

respond to chemical stimuli (ligand binds to receptor), chemicals control channel opening

mechanically-gated channels

respond to mechanical vibration or pressure stimuli, stretch, in sensory neurons and smooth muscle

voltage-gated channels

responds to direct changes in membrane potential, in axons, drive action potentials

graded potentials

small deviations in resting membrane potential, depends on stimulus strength, can be added together to become larger in amplitude

action potentials

a sequence of rapidly occurring events that decrease and eventually reverse the membrane potential (depolarization) and eventually restore it to the resting state (repolarization), can only occur of the membrane potential reaches threshold

spatial summation

from different places

temporal summation

at different times

plasticity

the capability to change based on experience (more plasticity when we’re younger)

regenerate

the capability to replicate or repair

prosencephalon

forebrain

mesencephalon

midbrain

rhombencephalon

hindbrain

telencephalon

cerebrum

diencephalon

thalamus, hypothalamus, and epithalamus

metencephalon

pons and cerebrellum

myelencephalon

medulla oblongata

cranial meninges

dura mater, arachnoid mater, pia mater

Blood Brain Barrier

protects brain cells from harmful substances and pathogens by serving as a selective barrier to prevent passage of many substances from the blood into the brain

gyrus

bump of brain

sulcus

groove of brain

fissure

very deep groove of the brain

frontal lobe

thought and planning

parietal lobe

sensory (touch)

occipital lobe

vision

temporal lobe

hearing

insula

5th lobe

nuclei

groups of cell bodies that have specific functions

corpus callosum

junction between R&L side of the brain, damage to this causes split-brain syndrome, 4 billion nerve impulses per second

olfactory bulb

sense of smell

amygdala

fight or flight

hippocampus

creating memories

pons

located superior to the medulla oblongata and links parts of the brain with one another by way of tracts

medulla oblongata

continuous with the superior aspect of the spinal cord and contains portions of both motor and sensory tracts

reticular formation

helps regulate muscle tone, alerts the cortex to incoming sensory signals, and is responsible for maintaining consciousness and awakening from sleep

Olfactory I

sensory - sense of smell, signals are sent up to the olfactory bulb to pick up on those signals and process our sense of smell

Optic II

sensory - sense of vision, sending signals out

Oculomotor III

motor - moves the eyeball, controls eyelids and most of the movement of the eyeball through the muscles above and below it

Trochlear IV

motor - controls the superior oblique muscle

Abducens

motor - controls the lateral rectus muscle

Trigeminal V

mixed motor and sensory - picks up on stuff with our lips, tongue, pallet; chewing; opthalmic branch, maxillary branch, mandibular branch

Facial VII

mixed motor and sensory - sense of taste, causes saliva and tears to be formed, controls facial expression

Glossopharyngeal IX

motor and sensory - picks up on taste in the back part of the tongue, a little bit about where food is when it’s in the back of the mouth, regulates the pharynx, controls the parotid salivary gland

Hypoglossal XII

motor - controls your tongue, right below the glossopharyngeal

Vestibulocochlear VIII

balance and head positioning, sense of hearing