-brain

-spinal cord

afferent-sensory

efferent-motor

     somatic-skeletal

     autonomic-smooth muscle, glands, heart

           sympathetic-thoracolumbar outflow

           parasympathetic-craniosacral outflow

functional unit of nervous system

-sensory

-motor,

-interneuron (99.9%)

• multipolar-1 axon, 2 or more dendrites
• bipolar-1 axon, 1 dendrite
• unipolar (pseudounipolar) 1 axon-divides close to cell body forming 2 branches

• neuroglia-glial cells in CNS
• Schwan cells and satellite cells in ggl of PNS

• astrocytes
• oligodendroctes
• microglia
• ependyma

-myelinate neurons in PNS

-node of Ranvier

-Clefts of Schmidt Lanterman

-saltatory conduction

contains nerve fibers and clusters of neuron cell bodies

*cell bodies-perikaryon-cyton

*ggl are outside the CNS

31 segments

31 pairs of spinal nerves

8 cervical

12 thoracic

5 lumbar

5 sacral

1 coccygeal

epineurium

perineurium

endoneurium

• innervates skeletal muscle
• one neuron system

• innervates smooth muscle, glands, heart
• 2 neuron system

• short pre, long postsynaptic
• synapse in paravertebral or symathetic chain ggl
• fight or flight

• long pre, short post synaptic
• synapse in or near organ of innervation
• conservation functions

*SNS and PSNS often innervate same organ, have antagonistic effects

Connective tissue of CNS: Meninges 

3 layers?

• Dura mater-connected to bone=periosteum of bone
• Arachnoid-trabecular arrangement
• Pia mater-surface of nervous tissue

• outer molecular layer
• Purkinje layer-purkinje cells diagnostic
• inner granuar layer

Cerebrum-cerebral cortex

6 layers

• molecular
• external granular
• medium sixe pyramidal layer
• internal grnular
• larger pyramidal layer
• multiform layer

*Pyramidal cells diagnostic

Regeneration

nerve cells cannot divide- is some regeneration

ii.     Longer the section of axon cute – more likely for cell death, if shorter axon section cut – less nuclear disruption

 iii.     Chromatolysis peaks within 2 weeks of injury

 iv.     Schwann cells multiply and form cord of cells along damaged fiber

v.     Axon sprouts grow from cut end of proximal stump

 vi.     Sprout may follow Schwann cell cord – 3 mm/day

• produce myelin within CNS
• (smaller dark round nucleus)

• microglia-macrophages of the CNS
• (small, dark, elongated)

• cuboidal to columnar cells lining the central canal and ventricles of the brain
• cilia and microvilli

Flow of blood through the heart

right atrium

right ventricle

pulmonary artery

pulmonary vein

right atrium

right ventricle

aorta

• heart-pump creates pressure gradient
• Circulatory system-pipeline to deliver blood throughout body
• systemic system- heart to tissue and back (120/80)
• pulmonary-heart to lungs and back (25/8)

arteries->arterioles->capillaries->venules->vein

vein btwn 2 capillary beds

ex: hepatic portal system, hypophyseal portal system

• aorta and major branches
• elastic recoil during diastole keeps blood moving

• thick
• lining endothelium (intimate with blood)
• basal lmina
• subendothelial CT with smooth muscle
• internal elastic membrane

• thickest layer*
• sheets of elastic material and smooth muscle (fenestrated) that secretes collagen
• no fibroblasts present*

• thin <1/2 thickness of t. media
• most closely associated with C.T.
• main component collagen fibers from fibroblasts
• vaso vasorum
• nervi vascularis (unmyelinated neurons)

• less elastic tissue and more smooth muscle
• "distributing artery"

• endothelial lining +basal lamina
• very little subendothelial CT
• prominent internal elastic membrane*

• smooth muscle + collagen fibers
• litle elastic material
• smooth muscle produces collagen and some elastic fibers
• no fibroblasts present

• CT with collagen fibers main tissue
• same thickness as t. media *
• external elastic membrane next to t. media

small arteries and arterioles

(distinguished by different amounts of smooth muscle in t. media)

• small artery has internal elastic membrane which is not present in arteriole
• only 1 smooth muscle layer in arteriole
• endothelium-contains no junctions between endothelial cells nor between smooth muscle cells in t. media
• tunica adventitia-thin not well defined sheath

• 3 layers are not as well defined as in arteries
• thinner walls than comparable arteries
• vein lumen>artery lumen
• veins contain valves

• tunica intima
• endothelium
• basal lamina
• small amt of subendothelial CT w/ smooth muscle
• tunica media
• thin; circular smooth muscle cells, collagen fibers, fibroblasts*
• tunica adventitia
• thick; longitiudinal smooth muscle cells, collagen fibroblasts, some elastic fibers

• tunica intima- may have thin internal elastic membrane
• tunica media-thinner than medium artery, circular smooth muscle w/ collagen fibers
• tunica adventitia-thickest layer, longitudinal smooth muscle w/ collagen and elastic fibers

• post capillary venules-endothelium, basal lamina, pericytes,no tunica media*
• muscular venules- 1 or 2 layers of tunica media with t. adventitia surrounding

• single layer of endothelial cells and basal lamina
• cells joined by tight junctions
• enodtothelial cell nucleus bulges into lumen*
• pericytes may surround some=myoepithelial cells=nucleus bulges away from lumen

• continuous capillaries
• fenestrated capillaries
• sinusoidal capillaries (discontinuous capillaries)

• presence of pinocytotic vesicles for transepithelial transport
• material exchange is restricted

• contains circular fenestrae or pores allowing exchange of materials

• specialized vessels in liver, spleen, bone marrow, adrenal cortex, anterior pituitary gland
• larger diameter than other capillaries (50micron) 
• lining cells to specific function
• incomplete basal lamina

• direct route btwn arteriole and venule (bypass capillary)
• smooth muscle contraction closes this anatomoses
• widespread but most common in skin (thermoregulation)
• ANS innervated
• fingertips-specialized a-v anatomoses=glomus body

lymphatics

• carry fluid that drains from intercellular space of tissues
• prominent flap-like valves (unidirectional flow)
• some areas have fenestrated endothelium & discontinuousbasement membrane (entrance of lrg proteins, triglycerides, and some cells)
• btwn smaller & larger lymphatic vessels, fluid passes through lymph nodes
• found clearly in blind ending channels (lacteals) of intestinal villi

• antigens processed by immune system; activated lymphocytes are added to lymph
• larger lymph vessels pump lymph into2 main lymphatic vessels:
• thoracic duct: empties to left internal jugular and left subclavian vein
• right main lymphatic duct: empties into right internal jugular and right subclavian vein

• epicardium (visceral pericardium)- outer flat mesothelial cells
• myocardium-bulk of heart wall-cardiac muscle cells *myocytes seen only here
• endocardium-thin inner lining of endothelial cells

• atrioventricular valves
• mitral (bicuspid) -left
• tricuspid-right
• semilunar valves-aortic and pulmonary valves

Functions of integumentary system

(the skin and its derivatives)

• protection
• prevent water loss
• receptors for pain, pressure, touch, temperature
• Cholesterol - vit. D
• heat regulation
• excretion

• straitified squamous epithelium
• Stratum disjunctum
• Stratum corneum - keratin - no nuclei
• Stratum lucidum - not found in thin skin - refractile eosinophilic cells
• Stratum granulosum - numerous keratohyalin granules
• Stratum spinosum - desmosomes - dividing cells
• Stratum basale - dividing cells - hemidesmosomes attach to anchoring filaments
• Dumb Cancer Likes Giving Sun Burn

• connective tissue
• papillary layer
• reticular layer

• dermal papillae
• epidermal ridges
• in thick skin
• dermal ridges+dermal papillae=fingerprint

• deep dense irregular CT
• anchors basal lamina to dermis

• "superficial fascia"
• loose CT
• layer of adipose tissue
•  panniculus adiposus

• epidermal derivatives
• sweat glands
• hairs
• sebaceous gland
• nails

1. karatinocytes
2. melanocytes
3. langerhans cell
4. merkle cell
5. free nerve endings
6. Encapsulated nerve endings

• all skin cells in epidermal layers
• keratinohyaline granules from free ribosomes
• eosinophilia due to tonofilaments in cytoplasm 
• as you move toward basal regions there is a shift toward basophilia due to more rough ER, mitochondria, and golgi

• rounded cells in stratum basale
• skin color
• need special stain to identify
• produces melanin granules-melanosomes (tyrosine-DOPA-melanin)
• in caucasion-melanin degraded by lysosomes in keratinocytes
• dark races-melanosomes more stable

skin color

• dermal vascular bed-oxyhemoglobin
• carotenes-concentrated in fat tissue
• minerals absorbed into skin or by digestion
• endogenous pigments-end products of hemoglobin breakdown if not removed by liver will cause yellow skin (jaundice) 
• pigments in epidermis-melanin

• located in stratum spinosum
• immune responses-present antigens to T lymphocytes, phagocytic

• in stratum basale
• mechanoreceptor

• nociceptors
• mechanoreceptors

• pacinian corpuscle-pressoreceptrs
• meissner's corpuscle-in dermal papillae in fingertips
• Ruffini endings-fusiform structures in skin and joints
• end bulbs of Krause

• keratinized filaments
• develop from invaination of epidermis known as hair follicle
• internal root sheath
• external root sheath
• arrector pilli
• sebaceous gland-sebum-holocrine gland

1. medulla
2. cortex
3. cuticle

3 layers of internal root sheath

produces keratin

1. cuticle

2.Huxley's layer

3. Henle's layer

• merocrine- not associated with hiar; entre body surface; watery secretion; temp regulation
• apocrine-axilla regions, areola of nipple, associated with external genitalia; proteinaceous sweat; body odor

• nasal cavities
• pharynx
• larynx
• trachea
• extrapulmonary bronchi
• intrapulmonary bronchi and bronchioles
• terminal bronchioles

• where gas exchange occurs
• respiratory bronchioles
• alveolar ducts, sacs, alveoli

• mucous membrane=mucosa: ciliated pseudostratified culumnar and lamina propria
• Submucosa: CT, blood vessels, nerves
• Cartilage and Smooth Muscle Layer
• Adventitia

• walls and roof lined with olfactory mucosa
• no goblet cells*
• 3 cell types
• bowmans glands: mucousy secretion-lubricates surface
• olfactory neurons :Fila Olfactoria: small circular nerve

1. olfactory cells:bipolar primary olfactory neurons, nucleus low in nuclear layer,long non-motile cila
2. sustentacular cells:tall columnar, provide support, most numerous,nuclei in upper region
3. basal cells: rounded, nuclei close to basal lamina, germinal?

• ciliated pseudostratified columnar epithelium
• 3 cell types

1. ciliated cells (pseudostratified columnar to cuboidal-can vary in lab animals)
2. goblet cells
3. basal cells

• trachealis muscle
• cartilage rings (hyalin)

• clara cells: non ciliated, dome-shaped surface, secretes lipoprotein component of surfactant, secrete protective proteins, stem cells
• goblet cells

1. type I alveolar cell or neumocyte
2. type II alveolar cell or pneumocyte
3. Brush cell
4. pulmonary macrophage

• 95% of alveolar surface area
• simple squamous

• "great alveolar cell" or "septal cell"
• 2-5% of alveolar surface area
• cuboidal, granular
• produce/secrete pulmonary surfactant
• stem cells for type I

• "dust cell"
• phagocytize invading microrganisms and particulate
• monocytes that have entered pulmonary CT and alveoli