Anatomy: Final Review Topics

Absorption

Active uptake of molecules

Secretion

Active release of molecules

Absorbtion and secretion...

Usually involve microvilli= extensions to increase surface area

Diffusion

Molecules move down the concentration gradient
Passive (no energy used by cell)

Filtration

Plasma (fluid component of blood) leaks across capillary walls
Passive (no energy used by cell)

Propulsion

Cilia drive fluid along surface of epithelium

Functions of epithelium

Absorbtion
Secretion
Diffusion
Filtration
Propulsion
Sliding
Protection
Sensory reception

Protection

Stratified= multiple cell layers

Sensory reception (not nerves)

Epithelial cell generates sensory signal
Ear and tongue have special epithelial tissue

Classification by layering

Simple vs stratified

Classification by shape

Squamous vs cubodial vs columnar
Named for the shape of the apical layer

Simple squamous

Thinnest kind
No surface projections (cilia,microvilli)
Lining air sacs in lungs (aveoli)
Glomerular capsule in kidney (where filtration occurs)

Mesothelium

Simple squamus
Lining of closed body cavities

Endothelium

Simple squamous
Inner lining of heart & blood vessels

Simple cuboidal

Kidney tubules
Most glands
Larger cells provide more space for organelles

Simple columnar (nonciliated)

Lines most of digestive tract
Provides more room for organelles than cubodial
Ex: goblet cells=secrete mucus (digestive and respiratory tracts)

Simple columnar (ciliated)

Lines small bronchi (air tubes in lungs)= sweeps away debris
Also lining of uterine tube

Psuedostratified columnar

All cells attached to basement membrane, so not truly stratified
Undifferentiated cells don't reach apical surface
Nuclei occur at different levels so tissue looks "stratified"

Simple squamous major functions

Diffusion/filtration
Sliding

Simple cuboidal/columnar/pseudostratified major functions

Absorbtion/secretion
Propulsion

Stratified squamous

Thickest
Function= protection
Keratinized= skin
Nonkeratinized= ends of digestive & reproductive tracts

Stratified cuboidal

Large ducts of glands (not common)
Function= Protection and secretion

Stratified columnar

In urethra
Function= Protection and secretion

Transitional

Found in urinary bladdar
Apical cells change shape when tissue stretches
The shape of epithelium changes shape through the layers
Function= stretchable and protection

Connective tissue proper

Relatively unspecialized- "classic" CT
Cells: fibroblasts (secrete matrix) – become fibrocytes (maintain the matrix), and other cells
Six types, varying and density and types of fibers:
Loose connective tissue: lots of ground substance, fewer fibers
Dense connective tissue: lots of collagen fibers, good at resisting tension (pulling) forces

Connective tissue proper: areolar

Loose connective tissue
Most widespread, "generic" CT
Gel like matrix, lots of tissue fluid
Adjoins all epithelia
All three fiber types
Has defense cells to fight infections
Has fat cells to store energy

Connective tissue proper: adipose

Loose connective tissue
Matrix composition as in areolar CT
Less matrix than any other CT
Mostly fat cells
In hypodermis (superficial fascia)- deep to skin
Also "visceral fat" around internal organs
Energy storage, protection, insulation

Connective tissue proper: Reticular CT

Loose connective tissue
The only fibers are reticular fibers
Exclusively in lymphoid structures (parts of the immune system, e.g. spleen, lymph nodes, red bone marrow)
Labyrinth used by defense cells

Connective tissue proper: Dense regular CT

Dense connective tissue
All collagen fibers run in one direction (axis)
Resist tension in one direction (axis)
Tendons and ligaments
Fascia (deep fascia)

Connective tissue proper: Dense irregular CT

Dense connective tissue
Collagen fibers oriented in various directions
Resists tension in various directions
In dermis, and fibrous capsules of organs/joints

Connective tissue proper: elastic CT

Dense connective tissue
Most fibers are elastic fibers (also has collagen fibers)
Able to recoil after stretching
Bronchial tubes in lungs; artery walls; some intervertebral ligaments

Body cavities

Open body cavities (continuous with the outside world), E.g., respiratory, digestive, reproductive, urinary tracts
Closed body cavities (not continuous with the outside world)

Dorsal body cavity

Cranial cavity (brain)
Vertebral cavity (spinal cord)

Ventral body cavity

Visceral organs (viscera)
Thoratic cavity (heart, lungs)
Abdominopelvic cavity (mainly organs of digestive, urinary, reproductive systems)

Membrane

Membrane= it's thin, pliable layer that covers or separates, E.g. plasma membrane, basement membrane
Concerned with multi cellular membranes that line the bodies cavities and surfaces
Membrane composed of epithelium layer + connective tissue layer

Membrane Functions (SPESS)

Protection
Exchange
Support
Sliding
Sensation
etc.

Mucous membrane (mucosa)

Produces mucus, enzymes, etc., by secretion (Active process)
Lines the lumen (internal space) of open body cavities, e.g., respiratory, digestive, reproductive, and urinary tracts

Tissue layers (deep to superficial): Mucous membrane

Lumen
Epithelium (mucous membrane)
Lamina propria (connective tissue) (mucous membrane)
Muscle

Serous Membrane

Lines the spaces between and around the organs in the ventral body cavity (a closed body cavity)
Lines outer surface of visceral organs
Lines inner surface of body wall
Produces watery fluid, mainly by filtration (passive process)- for lubrication
Mesothelium- simple squamous

Tissue layers (deep to superficial): Serous membrane

Muscle
Connective tissue (visceral serosa)
Mesothelium (visceral serosa)
Serous cavity (fluid filled)
Mesothelium (parietal serosa)
Connective tissue (parietal serosa)
Muscle

Serous membrane continued

Organs can have mucus membrane, serous membrane, both, or neither
Ventral body cavity (an internal body region) contains: visceral organs; serous cavity (a slit like space)

Cutaneous membrane= the skin

Directly exposed to outside world
Has glands that secrete (active process)

Tissue layers (deep to superficial): Cutaneous membrane

Muscle
Dermis (connective tissue) (cutaneous membrane)
Epidermis (epithelium) (cutaneous membrane)

Internal and external lining of G.I. Tract

Membrane= two layers (epithelium lines space; connective tissue nourishes epithelium)
mucosa (mucous membrane)
Serosa (serous membrane)

mucosa (mucous membrane)

Lines lumen (interior space) of the G.I. tract
Has simple columnar epithelium throughout most of its length
Connective tissue layer called lamina propria

Serosa (serous membrane)

Called the peritoneum in abdominopelvic cavity
lines the peritoneal cavity (space between organs)
Epithelium (mesothelium) is simple squamous
CT layer
Deep (inner) lining of cavity= Visceral peritoneum= outer layer of organ wall
Superficial (outer) lining of cavity= Parietal peritoneum= inner layer of body wall

Serosa (serous membrane) (Continued)

Mesentery= double layer of peritoneum connecting parietal and visceral peritoneum
Supports G.I. tract, carries vessels and nerves, stores fat
During development, some organs in abdominopelvic cavity become buried in body wall= Secondarily retroperitoneal (e.g. pancreas)
Still has peritoneum on one side, has adventitia on the other side
Organs that keep their mesentery are called intraperitoneal (e.g. stomach)

Respiration function

Respiration= exchange of gases (oxygen and carbon dioxide) with the environment
Consists of 4 processes:
1. Ventilation= move air in/out of lungs
2. External respiration= gas diffuses between lungs and blood
3. Gas transport via blood
4. Internal respiration= gas diffuses between blood and cells
Steps 1 & 2 are functions of respiratory system
Steps 3 & 4 are functions of cardiovascular system

Zones

Conducting zone (passageways for air; no diffusion) (process=ventilation)
-external nose through most tubes in lungs
Respiratory zone= the anatomical zone where oxygen diffuses into blood (process= External respiration)
-pulmonary alveoli
-respiratory bronchioles

Circulatory routes

Pulmonary circuit= delivers blood to and from the lungs= for external respiration
Systemic circuit= delivers blood to and from the rest of the body= For internal respiration

General circulatory principles

Capillary beds- where exchange takes place
Artery- delivers blood from the heart to capillary beds (oxygenated blood- most arteries not all)
Vein- delivers blood from capillary beds
Back to the heart (most veins)
Or to another capillary bed (these veins are portal veins)
Deoxygenated blood- most veins (not all)

Hepatic portal system

Chambers and vessels overview

Chambers and vessels

Atria (receive blood from veins)
Right atrium: receives deoxygenated blood from: inferior and superior vena cava; coronary sinus- returns blood from heart tissue
Left atrium: receives oxygenated blood from: pulmonary veins
Ventricles (eject blood from heart)
Right ventricle: pumps deoxygenated blood to: pulmonary trunk -> pulmonary arteries
Left ventricle: pumps oxygenated blood to:
aorta- coronary arteries (supplying blood to heart tissues) are branches of aorta

Heart valves

Prevent backflow of blood
Atrioventricular valves
Semilunar valves
Mnemonic: tri before you bi

Atrioventricular valves (AV valves)

Between atrium and ventricle
Tricuspid (R AV) valve- between the right atrium and ventricle
Bicuspid (mitral, L AV) valve- between left atrium and ventricle
These valves held in place by chordae tendinae, which are anchored to papillary muscles- prevents eversion (prolapse)

Semilunar valves (SL valves)

Between great arteries and ventricles
Aortic SL valve- between left ventricle and aorta
Pulmonary SL valve- between right ventricle and pulmonary trunk

Heart sounds in each heartbeat

First heart sound (“lub”)= closing of both AV valves when L and R ventricles begin contracting
Second heart sound (“dup”)= closing of both SL valves when L and R ventricles begin relaxing

Lymphatic system function

A system of vessels and nodes that returns excess tissue fluid to the blood
Needed because plasma tends to leak out of blood capillaries
Note: most cells get oxygen and nutrients directly from interstitial fluid
Filters pathogens to be targeted by immune system

Lymphatic system: Pathway of flow

Throughout most of the body, tissue fluid (interstitial fluid) enters lymphatic capillaries- The fluid is now called lymph
Moves through lymph vessels and lymph nodes
Returned to the blood at veins at base of the neck

lympahtic system: Structures

Very low pressure system- uses valves to maintain flow direction
Lymphatic capillaries: Wall= Endothelium (simple squamous epithelium); Minivalves formed by loose edges of cells
Larger lymph vessels- has valves (similar to those of veins)
Lymph nodes- contains reticular CT (with reticular fibers); lymph flows through; pathogens are filtered out by immune cells

lymphatic system Pathology

Lymphedema= accumulation of interstitial fluid due to poor lymphatic drainage
Example (extreme): elephantitis- caused by parasitic worm

Functional classification

Sensory (afferent) neurons
Carries signal to CNS
Make up the sensory division of PNS
Note- axon terminal is (typically) in CNS
Motor (efferent) neurons
Carries signal from CNS to effector
Make up the motor division of PNS
Note- cell body is (typically) in CNS
Interneurons- between sensory and motor neurons- found entirely within CNS

Structural classification

Multipolar: many processes (many dendrites, 1 axon), most neurons (“typical”)
Bipolar: One axon, One fused dendrite, found in some sensory organs
Unipolar (pseudounipolar): typical sensory neurons, receptive endings; no dendrites
Axon with peripheral and central processes

Nervous system: Gross anatomy

Nerve= group of axons traveling together in PNS
Endoneurium= surrounds axon
Perineurium= surrounds each subgroup of axons
Epineurium= wraps around outside of nerve
Fascicle= subgroup of axons

Nerves versus neurons

Each nerve contains the axons of many neurons
Axons are also called nerve fibers
Axons carry signals toward the axon terminals
Most nerves carry signals in both directions- because contain neurons oriented in both directions
The only exception are some cranial nerves

Ganglion

Collection of neuron cell bodies in the PNS

Gray and white matter

Two general types of nervous tissue in the CNS
White matter= myelinated axons
Gray matter= everything else (Unmyelinated axons, dendrites, cell bodies)

Tract

Collection of axons traveling together inside the CNS
White matter

Nucleus

Collection of neuron cell bodies inside the CNS
Gray matter

Diagram of Blood and CSF flow through the brain