FINAL EXAM STUDY Flashcards
what is epithelial tissue made of
Epithelial tissue is made mostly of
cells with minimal amounts of
extracellular material
is epithelial tissue vascular or avascular
avascular but innervated
is epthelial tissue regenerative
yes highly which is good as often damaged
what is the basal lamina
Noncellular sheet made of
proteins
* Functions * Selective filter * Scaffolding for new, migrating
epithelial cells
what is the basement membrane made of
basal lamnia and reticular fibers
what are microvili
Folds of plasma membrane * Increase surface area to
increase absorption or
secretion
* Don’t move; smaller than cilia
what are cilia
Whip
-like, highly motile
extensions of plasma
membrane
* Moves fluid/substances in one
direction
what is celiac
Genetic autoimmune disease
* Body attacks and destroys the villi and
microvilli of the small intestine in
response to gluten
* Nutrients are not absorbed well
what is an example of an epithelium that protects
skin
what is an example of an epithelium that secretes
glands
what is an example of an epithelium that absorbs
small intestine
what is an example of an epithelium that diffuses
kidney
what is an example of an epithelium that filters
kidney
where is simple squamous found
diffusion in LUNGS
filtration in KIDNEY
secretion in SEROUS MEMBRANE
where is simple cuboidal found
absorption in KIDNEY
secretion in GLANDS
where is simple columnar found
absorption in GI
movement in BRONCHI
secretion of mucus
where is pseudostratified found
mucus in respirory tract
stratified squamous is found where
Protection: epidermis of skin
(keratinized); oral cavity and
esophagus (nonkeratinized)
stratified cuboidal is what
- Two layers of cube-shaped
cells - Protection and secretion:
salivary glands
where is stratified cuboidal found
protection in MALE URETHRA
some ducts and glands
where is transitional epithelium
in bladder
what is Membranous
- Membranous: majority of body coverings and linings (our focus)
what is Glandular
Glandular: specialized epithelial tissue that produces glandular secretions
difference between glandular and membranous
LOCATION
what are Endocrine glands
- Lack ducts
- Produce hormones which pass into
surrounding tissues/blood vessels
what are Exocrine glands
- Secrete via ducts into body cavities or onto
a body surface
what is an example of an exocrine gland unicellular
Unicellular glands
* Example: Goblet cell
* Shaped like a goblet
* Produce mucus
* Found in respiratory and digestive tracts
what is an example of an exocrine gland multicellular
Multicellular glands
* Two names
* Classified by the structure of their ducts
* Simple (duct is unbranched)
* Compound (duct is branched)
* And the shape of their secretory units
* Tubular (tube shaped)
* Alveolar (spherical)
what is connective tissue
- Abundant; found in every organ
- Many diverse types
- Performs variety of important functions
what does cT do
Connects other tissues and organs together
* Ex. Ligaments, and tendons
* Forms skeleton
* Bone and cartilage
* Carries and stores nutrients
* Blood, bone, adipose
* Supports blood vessels and nerves
* Loose areolar CT
what is EM made of
ground substance
protein fibers
what are the types of protien fibers
Provide strength and flexibility
* Types:
* Collagen fibers
* Strongest
* Most abundant
* Elastic fibers
* Ability to stretch and recoil
* Reticular fibers
* Short
* Support network
mesenchyme
- All originate from common embryonic tissue: mesenchyme (CT)
what is CT proper
- Loose CT
- Dense CT
what is areolar CT
Most widespread of CTs
* Functions:
* Ground substance holds fluid
* Called interstitial fluid (tissue fluid)
* Serves as “packing material” around organs
* Involved in immunity and inflammation
* Often the first line of defense against
invading microorganisms
where is areolar ct
Underlies most epithelia
* Surrounds nerves and blood vessels
what is adipose
- Little EC matrix * MANY adipocytes filled with lipids * Well vascularized * Allows access to lipids for energy * Functions * Protection of organs * Energy source
where is adipose
Hypodermis * Visceral fat * Around highly active organs (ex.
Heart and kidneys)
what is white adipose
Most fat is white (turns yellow over time
because of pigment carotene)
* Stores lipids as nutrients
what is brown adipose
- Brown adipose produces heat and is a
nutrient consumer
what is reticular loose ct
Only contain reticular fibers
* Form a 3-dimensional
network filled with cells
* Functions
* Forms soft internal skeleton
(stroma)
in lymphoid organs
where is dense regular ct
Collagen fibers run parallel to each other
* Function
* Provides strength in one direction
where is dense regular ct
Collagen fibers run parallel to each other
* Function
* Provides strength in one direction
* Locations
* Tendons
* Ligaments
what is dense irregular ct
Collagen fibers run in many
different directions to each
other * Not parallel
* Function * Able to resist strong tensions
from different directions
where is dense irregular ct
Locations * Dermis * Joint capsules * Overlying capsules of kidney and
spleen
where is dense elastic ct
aorta
what is dense elastic ct
- Elastic fibers dominate
- Function
- Withstand stretch and
capable of recoil
what is cartilage
- Firm, flexible tissue; found in many
parts of the skeleton - Characteristics: * The abundant matrix is mostly water * Allows for cartilage to spring back after
compression - Cells (chondrocytes, chondroblasts,
chondroclasts
) - Collagen fibers are thin
Fibrodysplasia Ossificans Progressiva is a real
disorder. Which of the following do you think is
the best literal translation of the name?
Fibers are replaced by bone tissue
Name two features that are used to classify epithelial tissue
the shape of the cells and the number of cell layers present
Which of these is not a primary tissue type (there may be more than one correct answer)?
* Muscle
* Bone
* Connective tissue
* Skin
* Nervous
Bone
Skin
What are the four primary tissue types?
epithelial tissue, connective tissue, muscle tissue, and nervous tissue
What level of structure is just below tissue?
cellular
- What level of structure is immediately above tissue?
an organ
- What kinds of cell junctions connect epithelial cells?
tight junctions, adherens junctions (also called zonula adherens), and desmosomes;
- An example of epithelial tissue is the outer layer of your skin
epidermis
A gastroenterologist performs a colonoscopy. Is the doctor seeing the apical or basal surface of the large intestine when looking
through the scope?
apical
Epithelial tissue is avascular yet highly regenerative. Explain how regeneration can take place with a tissue that is avascular
it relies on a population of stem cells located in its basal layer, which continuously divide and differentiate to replace older, damaged cells, with nutrients reaching them through diffusion from the underlying connective tissue that is well-vascularized
Describe 2 ways in which epithelial tissue differs with connective tissue.
cell arrangement and cell function
If you were designing a tissue that could resist tension in one direction, what protein fiber(s)
would you choose and how would you orient the fibers?
Dense CT
- Name two cells that are found in connective tissues that are involved in defense
mast cells
macrophages
Identify locations for the following connective tissues:
* Reticular
found in the bone marrow, lymph nodes, spleen, liver, and kidney
Identify locations for the following connective tissues:
* Loose areolar
beneath the epidermis of the skin, surrounding blood vessels and nerves, filling spaces between organs
Identify locations for the following connective tissues:
* Adipose
found under the skin (subcutaneous layer), between muscles, around organs like the kidneys and heart, and within bone marrow
- What kind of tissue forms tendons?
dense regular ct
The lower layer of the dermis is made of this tissue:
reticular ct
The upper layer of the dermis is this tissue:
papillary dermis
The epidermis is made of this tissue:
stratified squamous epithelium
Describe the protein fibers and their arrangement for dense regular CT
collagen, which is arranged in tightly packed, parallel bundles, meaning all the fibers run in the same direction
Why is blood considered a connective tissue?
it has the same embryonic origin as other connective tissues and connects the body’s systems together
What cells produce cartilage?
chondrocytes
The skin is the _____________ membrane
the cutaneous
The respiratory system is lined with this type of membrane:
mucous
Describe the structure of a serous membrane
a single layer of flat, squamous epithelial cells called “mesothelium” which rests on a thin layer of underlying connective tissue
What kind of membrane surrounds the heart?
pericardium
Identify the part of the membrane that is closest to the heart
visceral pericardium, also known as the epicardium.
- What fills the cavity between these two layers?
viceral and pericardium
pericardial fluid
A ruptured bowel (large intestine) could cause inflammation of this serous membrane:
____________ and is called ___________.
peritoneum and peritonitis
What kind of tissue is the epidermis?
stratified squamous
A strong protein is found in the epidermis. What is it?
Keritin
What kind of tissue is the dermis?
connective tissue
What kind of tissue is the hypodermis?
Connective tissue
Describe how and where melanin is distributed in keratinocytes
in the basal layer of the epidermis, specifically forming a “cap” or concentrated area around the nucleus, where it is transferred from melanocytes via melanosomes, protecting the cell’s genetic material from UV damage
If the number of melanocytes is consistent between light-skinned and dark-skinned people,
explain why light-skinned people are lighter than dark-skinned people
people with lighter skin produce less melanin
What are two other pigments that contribute to skin color?
carotene and hemoglobin
List the epidermal layers from deep to superficial in thick skin
stratum basale (germinatum),
followed by the stratum spinosum,
stratum granulosum,
stratum lucidum (when present),
and ending with the outermost layer, the stratum corneum
Which layer is found in thick skin but not thin skin?
stratum lucidum
what is the stratum basale
Stratum basale:
Single layer of actively dividing cuboidal cells (keratinocytes) with melanocytes producing melanin for skin color; attached to the dermis.
what is the stratum spinosum:
Several layers of cells with “spiny” projections due to desmosomes connecting them; keratinocytes continue to divide and produce keratin.
what is Stratum granulosum:
Cells start to flatten and develop granules containing keratin and lipids, preparing for keratinization.
What is Stratum lucidum:
Thin, translucent layer only found in thick skin (palms, soles) composed of very flat, dead keratinocytes.
what is Stratum corneum
The outermost layer, consisting of many layers of dead, flattened keratinocytes that constantly shed from the skin surface
- Why is stratum granulosum called stratum granulosum
The stratum granulosum is called “granular layer” because it contains large, visible granules called keratohyalin granules within the keratinocytes, which are primarily composed of proteins like profilaggrin, and their function is to bind keratin filaments together, helping to form the tough, waterproof barrier of the skin’s stratum corneum; essentially, these granules play a key role in the process of keratinization
Which epidermal layers are made of completely dead cells?
stratum corneum
Tommy slammed his finger with a hammer and lost his fingernail. His doctor warned that his
nail might not ever grow back. Why?
damage to nail root
Jenny says she is going to paint her eponichia with fingernail polish. Is this a smart choice?
Explain
no as this is the skin around the nail not the actual nail and it may cause irritation
Nurse Jim examines Al’s fingernails and notices his nailbeds have a blueish tint. This concerns
Nurse Jim. Why?
poor oxygen flow in blood
Alex did not need deodorant until the age of 13. Explain.
hormone changes causes pores to open releasing oder filled sweat
What is occurring with A pimple
a sebaceous gland, also known as an oil gland, becomes clogged with excess oil (sebum) and dead skin cells, leading to inflammation and a visible red bump on the skin surface
What is occurring with a blackhead
the sebaceous gland associated with that follicle; when the clogged pore opens to the skin’s surface, exposure to air causes the trapped material to oxidize and appear black.
what is occurring with acne
sebaceous glands, which are small oil glands connected to hair follicles, become clogged with a buildup of excess oil (sebum) and dead skin cells, leading to the formation of pimples and cysts on the skin,
what is a whitehead
sebaceous gland, which produces oil for the skin, becomes clogged with a buildup of dead skin cells and sebum (oil), resulting in a small, white bump beneath the skin’s surface; essentially, the pore is plugged, preventing the oil from properly exiting the gland and creating a visible bump
why the treatment of acne is often a multi-pronged approach? What are the common
treatments?
because the condition has multiple contributing factors, like bacteria, excess oil production, and clogged pores, so addressing it effectively requires a combination of strategies
I stepped on a tack while walking and said, “Ouch! My stratum lucidum!” Was I (partly) correct
or not?
yes
Megan is delighted to be pregnant but not delighted at the stretch marks developing on her
abdomen. She read that using a cream to help heal the epidermis will help. Is this
advertisement correct or not? Explain.
No because stretch marks are in the dermis this product will not work since it is made to heal the epidermis.
what is the rule of 9s
to quickly estimate the percentage of body surface area affected by a burn injury,
Rank the 3 main types of skin cancer from least likely to metastasize to most likely to
metastasize.
Basal cell carcinoma (least likely), squamous cell carcinoma (intermediate), and melanoma (most likely)
All of these skin appendages are said to be “epidermal derivatives”. What does that tell you
about these structures?
structures that originate from the epidermis, the outermost layer of the skin
List and describe the functions of the skeleton.
gives your body its shape, allows movement, makes blood cells, provides protection for your organs and stores minerals
Compare and contrast spongy and compact bone.
Spongy bone, also called cancellous bone, is a lighter, less dense bone tissue with a porous, honeycomb-like structure made up of trabeculae,
compact bone, also known as cortical bone, is a denser, solid outer layer of bone that provides significant strength and is composed of tightly packed osteons, making it the primary weight-bearing tissue in the skeleton
Imagine a skeleton made only of solid compact bone. What consequences might there be?
too heavy and easy to break bone
How do osteocytes receive nutrients?
through the caniculi
Identify the classification of the Sphenoid
cranial bone
Identify the classification of the Humerous
long bone
Identify the classification of the Talus
short bone
Identify the classification of the Cervical vertebra
irregular bone
Identify the classification of the Frontal bone
flat bone
Identify the classification of the tibia
long bone
Identify the classification of the metacarpal
long bone
Identify the classification of the lunate
carpal bone
Identify where periosteum is located with a long bone. How is the periosteum attached to the
bone?
on the outer surface of a long bone, covering the entire bone except for the joint surfaces (articular cartilage) at the ends;
it is essentially a tough, fibrous membrane that tightly adheres to the bone through strong collagen fibers called “Sharpey’s fibers” which extend from the periosteum into the bone matrix
Identify the location(s) of endosteum.
inner surface of all bones
Both the periosteum and endosteum are said to be osteogenic meaning what
both these membrane-like tissues have the ability to produce new bone cells
using osteoblasts
How are osteons positioned in compact bone (i.e., how does their positioning relate to each
other?
parallel to each other, running along the length of the bone, aligning with the direction of typical stress to help resist bending and fracturing
There are 3 kinds of lamellae. Name them
concentric lamellae interstitial lamellae and circumferential lamellae
what is concentric lamellae
concentric lamellae (forming the rings within an osteon)
what is interstitial lamellae
interstitial lamellae (filling the spaces between osteons)
what is circumferential lamellae
circumferential lamellae (located at the outer and inner edges of the compact bone, running around the entire bone circumference)
Differentiate between the epiphyseal plate and epiphyseal line.
The epiphyseal plate is a cartilaginous growth plate present in children and adolescents, allowing bones to lengthen during development
the epiphyseal line is a bony structure that forms once the growth plate has fused and signifies the end of bone growth
List and briefly describe the different zones associated with an epiphyseal plate.
Resting Zone:
This is the layer of cartilage closest to the epiphysis, where the cells are relatively inactive and maintain the cartilage structure.
Proliferative Zone:
Cells rapidly divide and multiply, creating new cartilage cells that contribute to the lengthening of the bone.
Hypertrophic Zone:
Cartilage cells enlarge and mature, forming large lacunae within the cartilage matrix.
Calcified Cartilage Zone:
The cartilage matrix calcifies, preparing the cartilage to be replaced by bone tissue.
Ossification Zone:
New bone tissue is formed by osteoblasts, replacing the calcified cartilage and connecting the epiphysis to the diaphysis.
Where, in relation to the diaphysis and epiphysis is new bone added?
the epiphysis within the growth plate
what is the resting zone
This is the layer of cartilage closest to the epiphysis, where the cells are relatively inactive and maintain the cartilage structure.
what is the Proliferative Zone:
Cells rapidly divide and multiply, creating new cartilage cells that contribute to the lengthening of the bone
what is the Hypertrophic Zone
Cartilage cells enlarge and mature, forming large lacunae within the cartilage matrix.
what is the Calcified Cartilage Zone:
The cartilage matrix calcifies, preparing the cartilage to be replaced by bone tissue.
what is the Ossification Zone:
New bone tissue is formed by osteoblasts, replacing the calcified cartilage and connecting the epiphysis to the diaphysis.
Why is the epiphyseal plate considered a remnant of the fetal skeleton
closes in babys head
What kind of tissue is remodeled during intramembranous ossification?
bony or mesenchymal connective tissue
What kind of tissue is remodeled during endochondral ossification?
hyaline
Which bones are formed by intramembranous ossification?
Cranial bones, flat bones of the face and clavicals
Which bones are formed by endochondral ossification?
femur, humerus, tibia, fibula, radius, ulna, as well as the vertebrae, ribs, and the base of the skull
When does intramembranous and endochondral ossification take place (roughly)?
during early embryonic development, roughly around six weeks after fertilization
List the general steps of intramembranous ossification.
Mesenchymal condensation:
Osteoblast differentiation:
Osteoid secretion:
Calcification:
Trabecular formation:
Vascularization:
Periosteum formation:
Remodeling:
what is Mesenchymal condensation:
Mesenchymal cells gather and condense at the site of future bone formation, forming an “ossification center.
what is Osteoblast differentiation:
Mesenchymal cells differentiate into osteoblasts, cells responsible for bone matrix production.
what is Osteoid secretion:
Osteoblasts secrete osteoid, a protein-rich substance that forms the bone matrix.
what is Calcification:
Calcium salts deposit within the osteoid, causing it to harden and mineralize.
what is Trabecular formation:
Bone spicules called trabeculae begin to form, creating a network of spongy bone.
what is Vascularization
Blood vessels invade the developing bone, bringing nutrients and supporting further development.
what is Periosteum formation
A layer of connective tissue, the periosteum, develops around the bone.
what is Remodeling
Woven bone is gradually replaced by more organized lamellar bone.
List the general steps of endochondral ossification.
Formation of a cartilage model:
Development of a bone collar:
Cartilage calcification:
Blood vessel invasion:
Medullary cavity formation:
Epiphyseal plate formation:
what is the Primary ossification center
Located in the center of the diaphysis (shaft) of the long bone.
what is the Secondary ossification center
Secondary ossification center: Located in the epiphyses (ends) of the long bone.
Which cells are involved in bone remodeling?
osteoblast and osteoclast
Does bone remodeling occur only during fetal development?
No, bone remodeling does not only occur during fetal development; it is a continuous process that happens throughout a person’s life, allowing bones to adapt to stress, repair damage, and maintain their structural integrity even after skeletal maturity is reached
List, in order, the steps of bone healing after a fracture.
- Hematoma formation (blood clot),
- Soft callus formation (fibrocartilage),
- Hard callus formation (bony tissue),
- Bone remodeling
what is Osteoporosis
a bone disease that weakens bones, making them more likely to break
what is Osteomalacia (rickets)
Rickets and osteomalacia are both conditions that cause bones to become soft and weak, but affect children and adults differently
what is Paget’s disease
a chronic disorder that causes bones to grow abnormally, becoming larger, weaker, and more likely to break
Where is vitamin D made? What is its significance to the skeletal system?
The skin produces vitamin D when exposed to sunlight
it helps the body absorb calcium, which is crucial for building and maintaining strong bones
Why are weight-bearing exercises suggested as a prevention to osteoporosis?
they put stress on the bones, stimulating them to produce more bone tissue, thus increasing bone density and reducing the risk of fractures
Frank is learning the bones of the appendicular and axial skeletons and suggests that the clavicle
and scapula are part of the axial skeleton. Is he correct? Explain.
No, Frank is incorrect; the clavicle and scapula are considered part of the appendicular skeleton, not the axial skeleton, as they make up the pectoral girdle which connects the upper limbs to the central axial skeleton
Why are blood vessels, nerves, and epithelial tissue included in the components of the skeletal
system (versus just bones and cartilage?
they are essential for the proper functioning of bones and cartilage, supplying them with nutrients, oxygen, and innervation necessary for growth, repair, and sensation
What type of tissue is cartilage?
connective tissue
Why is it significant that chondroblasts are positioned between the perichondrium and
cartilage?
allows them to directly access the necessary components to produce new cartilage matrix, allow growth
What significance is the high percentage of water in cartilage? How do you think this differs
with age?
as we age, the water content in cartilage tends to decrease, leading to a stiffer and less flexible joint due to changes in the structure of the proteoglycans that hold water within the cartilage matrix
what is an example of Contractility
the action of your biceps muscle contracting when you bend your elbow
what is an example of Extensibility
the ability of a muscle to stretch without tearing, like when you extend your knee fully, the hamstring muscles in the back of your leg need to stretch to accommodate the movement; this stretching capability is considered extensibility
what is an example of Excitability
a muscle cell contracting rapidly in response to a nerve signal, like when you quickly jerk your hand away from a hot stove
what is an example of Elasticity
a rubber band; when you stretch it, it returns to its original shape once the force is released, demonstrating the property of elasticity where a material can deform under stress and then bounce back to its original form.
List the 3 primary muscle types
Skeletal Cardiac and Smooth
what is smooth muscle
Smooth muscle is located in the walls of internal organs like the stomach, intestines, bladder, blood vessels, and uterus; it is under involuntary control; has no striations; is uninucleated; and has a spindle-shaped cell structure
what is cardiac muscle
Location: Heart walls
Control: Involuntary
Striations: Present
Nucleus: Uninucleated (single nucleus per cell)
Cell Shape: Branched
what is skeletal muscle
attached to bones throughout the body, is under voluntary control, has striations, is multinucleated, and has a cylindrical cell shape
What type of muscle would you expect to find within the walls of blood vessels?
smooth muscle
Identify the levels of organization of a skeletal muscle from whole muscle to muscle cell.
whole muscle (covered by epimysium) > fascicle (covered by perimysium) > muscle fiber (covered by endomysium) > myofibril > sarcomere
Identify the levels of organization of a skeletal muscle from whole muscle to myofilament.
whole muscle, fascicle, muscle fiber (or muscle cell), myofibril, and myofilament
What protein makes up the thick filament?
myosin
What proteins make up the thin filament?
(1) actin, (2) troponin, and (3) tropomyosin
Put these in order from largest to smallest:
* Sarcomere
* Muscle fiber
* Whole muscle
* Myofibril
* Myofilament
* Fascicle
Whole muscle, Fascicle, Muscle fiber, Myofibril, Sarcomere, Myofilament
Does the thick filament shorten?
no
Does the thin filament shorten?
yes
Does the sarcomere shorten? How does this lead to a whole muscle shortening?
yes fiber contraction=muscle shortening
motor unit is what
a single motor neuron and all the muscle fibers it innervates
What is the neuromuscular junction? What occurs here and how is it related to muscle
contraction?
the specialized point where a motor neuron connects to a muscle fiber, allowing the nerve to transmit a signal that triggers muscle contraction by releasing a chemical messenger called acetylcholine onto the muscle membrane, essentially initiating the process of muscle movement
What is the neurotransmitter released at the neuromuscular junction?
ACH
List in order, from strongest to weakest, the following shapes of muscles:
* Convergent
* Parallel
* Pennate
Pennate
Convergent
Parallel
List in order, from the most ability to shorten to the least ability to shorten the following
muscles:
* Convergent
* Parallel
* Pennate
Pennate
Parallel
Convergent
what is the urinary system
- Excretory system
that filters blood and
removes excess
fluids, metabolic
wastes, and ions
where are the kidneys
The kidneys are retroperitoneal
* Located behind the parietal
peritoneum
what protects the kidneys
the ribs
what is the function of the kidneys
Filter blood, removing metabolic
wastes, toxins, and ions
* Regulate volume and chemical
makeup of blood
what surrounds the kidneys
Kidney is surrounded by a tough, fibrous capsule (dense irregular CT)
* Around this capsule is the perirenal fat capsule
what is the Renal cortex (outer layer)
part of the kidney
Lighter in color
* Has extensions into renal
medulla called renal columns
what is the Renal medulla (inner layer)
- Divided into renal pyramids
- Darker in color
- Separated by renal columns
T or F Urine that is produced in the
pyramids drains into a minor calyx
TRUE
where do Multiple minor calices drain into
a major calyx
The major calices drain into ….
pelvis which drains into …..
the renal pelvis, the ureter
The main structural and functional unit of the kidney is
the nephron
what is the Uriniferous tubule
- = nephron + collecting duct
what is a nephron
Each nephron is composed of a
renal corpuscle and a renal
tubule
what is the Renal corpuscle
= glomerular
capsule + glomerulus (a tuft of
capillaries)
The renal tubule is subdivided into
- Proximal convoluted tubule
- Nephron loop (loop of Henle)
- Distal tubule
what does the Distal tubule do
drains into the
collecting duct
* Many nephrons drain into one
collecting duct
* Help concentrate the urine
Cortical nephrons are
- Make up 85% of all nephrons
- Are located almost entirely within the
cortex - Nephron loops dip into medulla only a
short distance
Juxtamedullary nephrons are
- Make up 15% of nephrons
- Are called juxtamedullary because the
renal corpuscle is near the cortexmedullary border - Nephron loops dip deeply into medulla
- Long loops help produce concentrated
urine
what are Peritubular capillaries
- Surround renal tubules
- Branch from efferent arteriole
- Designed for absorption and secretion
- Very porous
T or F Cortical nephrons have only
peritubular capillaries
TRUE
what is the Vasa Recta
- Surround only tubules of juxtamedullary nephrons
- Branch from efferent arteriole of these
nephrons - Descend deep into the medulla of kidney
- Involved with concentrating urine
what are the steps of Steps of urine formation
- Filtration
* Blood is filtered, filtrate is formed - Resorption
* Substances to keep in the body are
returned to blood - Secretion
* Substances to be removed from the
body enter into filtrate
what is the Renal Corpuscle
- Site of all filtration
- Made of glomerulus
surrounded by
glomerular capsule
the Glomerulus is
- Ball of fenestrated capillaries
- Afferent arteriole leads into
glomerulus - Efferent arteriole leads out of
glomerulus
Glomerular capsule is
- Two layers
- Parietal layer forms outer layer of
capsule - Visceral layer surrounds capillaries
what are podocytes
The visceral layer is made of
unusual, branching epithelial cells
filtration slits do what
Filtrate passes into capsule space
through
what is the Proximal Convoluted Tubule
Involved with resorption and
secretion
* Na+
/K+ pump (sodium resorbed,
potassium secreted)
* Cuboidal cells resorb salt, vitamins,
water
* Confined to renal cortex
* Made of simple cuboidal
epithelium with microvilli
* Lots of microvilli that increase
resorption of water, ions, solutes
from filtrate
Thin Segment Descending Nephron Loop is
- Resorption and secretion
- Water can leave filtrate by osmosis
- Walls made of simple squamous
epithelium
what is the ascending nephron loop
Resorption and secretion
* Walls made of simple cuboidal
epithelium
what is the Distal Convoluted Tubule
Resorption and secretion (less so
than the proximal convoluted
tubule)
* Walls made of simple cuboidal
epithelium
Collecting Duct does what
Several nephrons empty into one
collecting duct
* Urine can be concentrated here
* Walls made of simple cuboidal
epithelium
what are kidney stones
Can precipitate out of urine → most commonly from calcium
* If they block ureter, urine can collect w/in renal pelvis
* Drugs & ultrasound (lithotripsy) most common treatments
* HYDRATE→ difficult to form if urine is rich in water
what does the Ureter do
- Drains urine from renal pelvis * Lined with transitional
epithelium * Able to stretch and recoil (as
urine moves through) with
help of smooth muscle
Urinary Bladder is
Muscular sac that collects
and stores urine
Detrusor muscle is
- Under parasympathetic control →
signals contraction when bladder is
stretched
- Internal urethral sphincter is
Smooth muscle
Under sympathetic control →
signals contraction when bladder is
filling
External urethral sphincter is
- Skeletal muscle
- Under voluntary control (somatic
motor NS)
the urethra female is
urethra drains the urinary bladder
* Is made of transitional epithelium close
to bladder and changes to stratified
squamous as it nears opening to body
* 3-4 cm in length (females)
* Internal urethral sphincter
* Smooth muscle
* Keeps urethra closed when urine not
passing through
the urethra male is
The male urethra is approx. 20 cm in length
* Carries both urine and semen
* Has different regions
List the three types of fibrous joints, including an example for each.
sutures, gomphoses, and syndesmoses
Which kind of structural joint is a synchondrosis? Describe this joint type and give an example.
cartilaginous joint where two bones are connected by a rigid bridge of hyaline cartilage, making it an immovable joint
Which kind of a structural joint is a symphysis? Describe this joint type and give an example.
cartilaginous joint
Synovial joints are considered diarthrotic. What does this mean?
means that all synovial joints are freely movable joints, as “diarthrosis” refers to a joint that allows for a full range of motion, making it the functional classification for synovial joints which are the most mobile type of joint in the body.
Describe the types of movement(s) of Hinge joints
flexion (bending) and extension (straightening) movements
Describe the types of movement(s) of Ball-and-socket
A ball-and-socket joint allows for a wide range of movements including flexion, extension, abduction, adduction, internal rotation, external rotation, and circumduction, essentially enabling movement in all directions due to its multiaxial design; this means you can move the joint forward, backward, sideways, and rotate it around its axis
Describe the types of movement(s) of Plane joint
A plane joint, also called a gliding joint, only allows for gliding movements
Describe the types of movement(s) of saddle joint
A saddle joint allows for movements in two planes, primarily enabling flexion/extension and abduction/adduction movements
Describe the types of movement(s) of condylar joint
A condyloid joint allows for flexion, extension, adduction, abduction, and circumduction movements
Describe the types of movement(s) of pivot joint
A pivot joint only allows for rotational movement, meaning the only type of movement possible at a pivot joint is rotation,
Where is the fibrous layer of articular capsule located?
The fibrous layer of the articular capsule is located on the outermost part of a synovial joint, completely surrounding the joint cavity and attaching to the articular surfaces of the bones that form the joint;
essentially, it forms the external layer of the joint capsule, with the synovial membrane lying on its inner surface
Where is the synovial membrane
A layer of connective tissue that lines the cavities of joints, tendon sheaths, and bursae (fluid-filled sacs between tendons and bones).
What produces synovial fluid?
The synovium, or synovial membrane, is the tissue that produces synovial fluid. The synovium is a soft tissue that lines the spaces of joints, tendon sheaths, and bursae.
Describe the structure and location of synovial fluid. Which structure produces it?
Synovial fluid is a thick, lubricating fluid found within the joint cavity of synovial joints, located between the articulating ends of bones; it is produced by the synovial membrane, a thin layer of connective tissue that lines the inside of the joint capsule
Describe “weeping lubrication” and include its significance.
allows joints to function effectively under load by maintaining a fluid layer between the articulating surfaces
What is an articular disc?
a thin, plate-like structure made of fibrocartilage that sits between the articulating surfaces of a joint
What is a bursa? What is its function?
a closed, fluid-filled sac that works as a cushion and gliding surface to reduce friction between tissues of the body
Where would you find a tendon sheath? What is its function?
around tendons, particularly in areas where they pass over joints or through narrow tunnels in the body, like the wrist and ankle; its primary function is to reduce friction and allow tendons to move smoothly by secreting a lubricating fluid called synovial fluid.
What are the names of the two joints that form the knee? Which bones form the knee joint?
The two joints that form the knee are the tibiofemoral joint and the patellofemoral joint
these joints are formed by the articulation of the femur (thigh bone), tibia (shin bone), and patella (kneecap)
What kind of movement is found with the joint formed between the patella and the femur?
flexion and extension movements
Why do you think a bursa is found in this joint?
it acts as a fluid-filled cushion, reducing friction between moving parts like bones, tendons, and muscles
Describe the type of joint that is the tibiofemoral joint
hinge type synovial joint
What are some structures that help improve the stability of this joint?
ligaments, joint capsule, cartilage, friction, and the bony geometry of the articulation.
A common injury to the knee is called the “triad of 3.” Describe what happens in this situation.
all three structures are damaged at once
Differentiate between a sprain and a strain
A sprain is an injury to a ligament, the tissue that connects bones to bones at a joint, while a strain is an injury to a muscle or tendon, the tissue that connects muscle to bone
Rheumatoid arthritis is
a chronic autoimmune disease that causes the body’s immune system to attack its own tissues, primarily affecting the joints
Osteoarthritis’ arthritis is
a degenerative joint disease where the cartilage within joints breaks down over time, leading to pain, stiffness, and swelling
Gout is
a type of arthritis that causes sudden, severe pain and swelling in the joints
Where is the carpal tunnel, and what is carpal tunnel syndrome?
Carpal tunnel syndrome is when the median nerve is compressed as it passes through the carpal tunnel
Differentiate between segmentation and peristalsis. Where does segmentation take place?
Segmentation is a type of muscle contraction in the digestive tract that involves the rhythmic contraction of circular muscles, primarily occurring in the small intestine, which mixes food with digestive juices by moving it back and forth, while peristalsis is a wave-like contraction of longitudinal muscles that propels food forward through the digestive tract, starting in the esophagus and continuing throughout the gastrointestinal system
List and briefly describe the 6 events that occur during digestion.
The digestive processes are ingestion, propulsion, mechanical digestion, chemical digestion, absorption, and defecation
Differentiate between mechanical and chemical digestion
Mechanical digestion involves the physical breakdown of food into smaller pieces through actions like chewing, while chemical digestion uses enzymes to break down the complex molecules within food into smaller, absorbable units
The alimentary canal is made of multiple layers of tissues
typically including the mucosa (inner lining), submucosa, muscularis externa (muscle layer), and serosa (outer layer)
List from lumen to outermost layer, the 4 main layers of this canal
mucosa, submucosa, muscularis externa (or muscularis), and serosa
Name one organ lined with adventitia. Explain why this is the case.
The esophagus is an organ lined with adventitia because it is located retroperitoneally
Compare the nerve plexuses of the enteric nervous system.
the myenteric plexus (Auerbach’s plexus), located between the longitudinal and circular muscle layers of the gut wall, primarily controlling gut motility, and the submucosal plexus (Meissner’s plexus), situated within the submucosa, mainly regulating local blood flow, secretion, and absorption within the intestinal lining
Describe the reflex arc that occurs in the enteric nervous system.
involves sensory neurons within the gut wall detecting a stimulus (like distension from food), sending signals to interneurons located in the myenteric or submucosal plexus, which then integrate the information and activate motor neurons to trigger a response like muscle contractions to propel food along the digestive tract
What kind(s) of digestion occur in the mouth?
chemical and mechanical
What kind of epithelium lines the oral cavity? The lips?
non-keratinized stratified squamous epithelium
Which layer(s) of tissues common to the alimentary canal is/are missing from the oral cavity?
“muscularis mucosae” and “submucosa” layers, which are typically found in the alimentary canal, are usually missing or significantly reduced, meaning these are the layers most likely to be absent in the mouth compared to the rest of the digestive tract
What kind of epithelial tissue covers the anterior surface of the tongue?
The anterior surface of the tongue is covered by stratified squamous epithelium
Describe the structure of the 3 types of papillae on the tongue. Which one(s) have taste buds?
fungiform, circumvallate, and foliate papillae
What is another term for “tongue-tie”? What is a potential consequence of this condition?
a congenital anomaly that occurs predominantly in males and is characterized by an abnormally short lingual frenulum
What are some functions of saliva?
kickstarts digestion, helps you chew and swallow food, and protects your teeth
What macromolecule does saliva start to chemically digest? What is the name of this enzyme?
Saliva begins the chemical digestion of carbohydrates (starch), specifically through the enzyme called amylase
What kind(s) of digestion take place in the mouth?
mechanical digestion (chewing) and chemical digestion (through saliva enzymes)
What are the four main types of human teeth?
incisors, canines, premolars, and molars
Follow a piece of food in the alimentary canal from the entrance of the oropharynx to the
esophagus
the swallowing reflex is triggered, causing the soft palate to rise and the epiglottis to flip down, directing the food bolus towards the esophagus; the upper esophageal sphincter then relaxes, allowing the food to enter the esophagus where muscular contractions called peristalsis propel it down to the stomach
Describe the types of epithelial tissue that the food passes.
stratified squamous epithelium in the esophagus, transitioning to simple columnar epithelium in the stomach and intestines, which are specialized for absorption and secretion functions due to their shape and microvilli lining
Describe the muscularis externa in the esophagus from superior to inferior (the muscle type).
What is the significance of this arrangement?
allows for voluntary control of swallowing in the upper esophagus while relying on involuntary smooth muscle contractions for peristalsis in the lower esophagus to move food efficiently towards the stomach
What kind of digestion occurs in the stomach?
In the stomach, primarily chemical digestion of proteins occurs, where stomach acid and enzymes break down protein molecules into smaller peptides, alongside some mechanical digestion through churning movements that mix the food with digestive juices, creating a thick liquid called chyme
What is a function of the rugae?
allow the stomach to expand and increase its surface area for digestion by stretching out when filled with food
What is the significance of 3 layers to the muscularis externa for the stomach?
allows for efficient churning and mixing of food
Identify the layers of the stomach from stomach wall to lumen
serosa, muscularis externa (muscularis), submucosa, and mucosa
Identify the steps involved in pepsin formation. What does pepsin do?
the inactive precursor protein, pepsinogen, secreted by the chief cells in the stomach lining, comes into contact with hydrochloric acid (gastric acid) which then activates pepsinogen into active pepsin
What does gastric lipase do?
breaks down dietary fats in the stomach
Differentiate between segmentation and peristalsis.
peristalsis is a wave-like movement that propels food forward through the digestive system, segmentation involves localized contractions that primarily mix and churn food within a specific section of the intestine, allowing for better absorption of nutrients
What are 4 features of the small intestine that contribute to its large surface area?
circular folds (plicae circulares), villi, microvilli, and its long length
What structures are found within a villus? What foods enter which of these structures?
carbohydrates and proteins
What kind of epithelium lines the small intestine?
The small intestine is lined with simple columnar epithelium
List, from stomach to large intestine, the segments of the small intestine.
From the stomach to the large intestine, the segments of the small intestine are: duodenum, jejunum, and ileum
What is the material called that enters the small intestine?
chyme
Describe a lacteal
lymphatic vessels in the small intestine that absorb nutrients and transport them into the lymphatic system
Into what structure(s) do/does carbohydrates enter? Proteins? Fats?
Carbohydrates, proteins, and fats primarily enter the small intestine during digestion, where they are broken down into their basic units (sugars, amino acids, and fatty acids respectively) and absorbed into the bloodstream for further use in the body
what do absorptive cells do
specialized epithelial cells that line the intestinal wall and are primarily responsible for absorbing nutrients from digested food into the bloodstream
Goblet cells functions
Goblet cells are epithelial cells that secrete mucus, which protects and lubricates the lining of the respiratory and gastrointestinal tracts
Enteroendocrine cells function
specialized cells in the gastrointestinal (GI) tract that produce hormones and peptides in response to food and other stimuli
What is the significance of the intestinal crypts?
they house the stem cells responsible for continuously regenerating the intestinal epithelium, which is crucial for maintaining gut health by facilitating nutrient absorption and protecting against pathogens through the constant renewal of the lining of the small intestine and colon
Describe the cells found in the intestinal crypts (include their functions).
absorptive enterocytes (responsible for nutrient absorption), goblet cells (secrete mucus), enteroendocrine cells (secrete hormones), and Paneth cells
Where do duodenal glands empty? What product do they produce?
Duodenal glands, also called Brunner’s glands, empty directly into the intestinal lumen
What does MALT stand for? What is it involved with?
MALT stands for mucosa-associated lymphoid tissue, which is a part of the body’s immune system that’s involved with mucosal defense
Where is bile produced? Where is it stored? What does bile do?
Bile is produced in the liver, stored in the gallbladder, and helps with digestion
Where does bile get released into?
the duodenum, the first part of the small intestine
Describe the exocrine function of pancreas. Where do these sections get released?
are released into the duodenum (the first part of the small intestine) through a system of ducts, helping to break down carbohydrates, fats, and proteins in food
What structure is the final control valve that regulates pancreatic and bile release?
The sphincter of Oddi
Describe the influence of fats and acids on hormone secretion. What are the effects of these
hormones?
acting as precursors for certain hormones (like sex hormones), affecting the cell membranes where receptors are located, and impacting the body’s sensitivity to hormones
What do colonocytes do? What do they absorb?
water, electrolytes, and short-chain fatty acids (SCFAs) produced by gut bacteria from the intestinal lumen
What is the significance of intestinal crypts in the large intestine?
they act as the primary site for stem cell renewal, continuously generating new epithelial cells that line the colon, thus maintaining the integrity of the gut lining and facilitating the absorption of nutrients by constantly replenishing the intestinal epithelium
What is the difference between the external and internal anal sphincters?
the internal sphincter is involuntary muscle, meaning you cannot consciously control it, while the external sphincter is voluntary muscle, allowing you to consciously control the closure of the anus
What are hemorrhoids?
swollen veins in the anus or lower rectum that can cause discomfort and bleeding
Where is bile produced and what does it do?
Bile is produced in the liver and its primary function is to help break down fats during digestion by emulsifying them into smaller particles, making it easier for the body to absorb them; it is stored in the gallbladder until needed for digestion
What are some functions of the liver?
producing bile to aid digestion, filtering blood by removing toxins and waste products, regulating blood sugar levels by storing glucose as glycogen, synthesizing proteins necessary for blood clotting, metabolizing drugs and other substances, and storing essential vitamins and minerals like iron and vitamin K
What is the microscopic shape of a liver lobule?
a hexagon
What is the relationship between liver and gallbladder?
The liver and gallbladder are both located in the upper right abdomen and are connected by ducts called the biliary tract
What are most gallstones made of?
cholesteral
What controls the release of bile into the duodenum?
The sphincter of Oddi, a muscular valve, controls the release of bile into the duodenum
What causes most ulcers?
bacteria
Describe two forms of inflammatory bowel disease.
The two most common types of inflammatory bowel disease (IBD) are Crohn’s disease and ulcerative colitis
What are symptoms of IBS?
sharp pain, cramping, bloating, distention, fullness or even burning
Describe celiac disease.
a chronic digestive and immune disorder that occurs when the body’s immune system reacts abnormally to gluten, a protein found in wheat, rye, barley, and sometimes oats
Which types of receptors are in both special and general senses, but not receptors in the special
senses?
The type of receptor found in both special and general senses, but not exclusively in special senses, is the mechanoreceptor
Describe the sensory pathway from receptor to brain.
involves a chain of neurons, starting with a sensory receptor detecting a stimulus, sending signals along a primary sensory neuron (first-order neuron) to the spinal cord or brainstem, then relayed by secondary sensory neurons to the thalamus, and finally reaching the specific sensory area of the cerebral cortex via a tertiary sensory neuron where the signal is interpreted as a sensation
How are receptor potentials different than action potentials
a receptor potential is graded (meaning its amplitude varies with stimulus strength) and can decay with distance, whereas an action potential is all-or-none and maintains its amplitude as it travels along the axon
What do the different receptors respond to?
chemoreceptors to chemicals, mechanoreceptors to physical pressure or distortion, photoreceptors to light, thermoreceptors to temperature changes, and nociceptors to pain signals from tissue damage
Where are the special senses located
The special senses are located in the head and are associated with specific organs that detect stimul
What kind of receptor senses taste?
The type of receptor that senses taste is called a gustatory receptor; these are specialized cells located in taste buds on the tongue that detect chemical compounds in food, allowing us to perceive taste
What kind of papillae have taste buds?
Fungiform, circumvallate, and foliate papillae contain taste buds, while filiform papillae do not
Detail the pathway from receptor to cortex for gustation.
taste information traveling through the facial, glossopharyngeal, and vagus cranial nerves to the nucleus of the solitary tract in the medulla oblongata, then projecting to the ventral posterior medial nucleus of the thalamus, and finally reaching the gustatory cortex in the cerebral cortex where taste is perceived
What contributes to the flavor of a substance?
a combination of its chemical compounds that interact with taste receptors on the tongue (taste) and olfactory receptors in the nose (smell)
Detail the transmission of taste stimulus from receptor to cortex
signal is transmitted via the facial (cranial nerve VII), glossopharyngeal (cranial nerve IX), and vagus (cranial nerve X) nerves to the brainstem, specifically the nucleus of the solitary tract in the medulla oblongata; from there, the information travels to the ventral posterior medial nucleus of the thalamus, and finally reaches the gustatory cortex located in the insular cortex and frontal operculum
What kind of receptor is involved with olfaction?
The type of receptor involved with olfaction (sense of smell) is called an olfactory receptor
What bone do the olfactory receptor cells pass through as they enter the brain?
Olfactory receptor cells pass through the cribriform plate of the ethmoid bone as they enter the brain; this plate contains small holes that allow the olfactory nerve fibers to pass through and reach the olfactory bulb
Detail the paths from receptor to brain for olfaction.
starts with odorant molecules binding to olfactory receptor neurons located in the nasal cavity, which then send signals via their axons (forming the olfactory nerve) through the cribriform plate to the olfactory bulb in the brain
What are some disorders of smell?
Anosmia. Loss of sense of smell.
Ageusia. Loss of sense of taste.
Hyposmia. Reduced ability to smell.
Hypogeusia. Reduced ability to taste sweet, sour, bitter, or salty things.
Follow the flow of tears from production to drainage into the nose
Tears are produced by the lacrimal glands located above the eye, then flow across the eye surface, draining through tiny openings called puncta on the inner corners of the eyelids; these puncta lead to small canals (canaliculi) which funnel the tears into the lacrimal sac, situated on the side of the nose, and finally down the nasolacrimal duct to drain into the nasal cavity
What type of muscles help the eyeballs move?
The extraocular muscles control the movement of the eyes
What is strabismus? What is amblyopia?
a condition where the eyes are misaligned and do not look at the same point at the same time
How does eye positioning influence 3D vision?
allowing each eye to capture a slightly different perspective of an object due to their physical separation on the face, which the brain then combines to create a perception of depth
List from the outermost to the innermost layers (tunics) of the eye.
fibrous tunic (sclera and cornea), vascular tunic (choroid, ciliary body, and iris), and nervous tunic (retina)
What are the structures covered that make up the fibrous tunic?
The fibrous tunic is the outermost layer of the eye and is made up of the cornea and the sclera
What is a difference between the sclera and the cornea?
the sclera is the white, opaque outer layer of the eye, while the cornea is the clear, transparent front part of the eye that allows light to enter and helps focus it on the retina
What are structures covered that make up the vascular tunic?
the iris, the ciliary body, and the choroid
How are blue and brown eyes different?
The main difference between blue and brown eyes is the amount of melanin in the iris
What makes up the ciliary body?
The ciliary body contains smooth muscle fibers called ciliary muscles that help to control the shape of the lens.
What happens to the ciliary muscle and suspensory ligaments when looking at close objects?
Distant objects?
the ciliary muscle relaxes which tightens the suspensory ligaments, making the lens thinner and flatter
What is the innermost tunic of the eye? What two layers make up this tunic?
the neural retina (containing the light-sensitive nerve cells) and the retinal pigment epithelium
Describe how the cells that make up the neural layer are oriented to each other. How does light
entering the eyes travel through these layers? Which cells respond to light?
light must travel through the entire neural layer to reach the photoreceptors that actually respond to light
What cells form the optic nerve?
The optic nerve is formed by the axons of retinal ganglion cells
Compare rods and cones.
rods are highly sensitive to low light levels and primarily responsible for night vision, while cones are active in brighter light and enable color perception by detecting different wavelengths of light
What is the blind spot?
a small area in your visual field where you cannot see because it corresponds to the point on your retina where the optic nerve leaves the eye, lacking light-sensitive cells needed to detect vision in that spot
How does the lens change shape?
The lens of the eye changes shape through the action of the ciliary muscle, a ring of muscle that surrounds the lens
What is the optic disc? What kind of photoreceptors are found there?
The optic disc, also called the optic nerve head, is the area on the retina where the optic nerve leaves the eye, and no photoreceptors (rods or cones) are found there
What is glaucoma?
a group of eye diseases that can damage the optic nerve, which connects the eye to the brain
What is another term for nearsightedness? What can cause this?
myopia
What is presbyopia?
a common, age-related eye condition that makes it difficult to see objects up close
What happens with astigmatism?
blurry or distorted vision
What is a cataract?
a cloudy area in the lens of the eye that can cause blurred or hazy vision, and eventually blindness
What is the structure of the ear that is easily seen?
outer ear
What are the glands that produce ear wax?
The ceruminous glands in the ear produce earwax, also known as cerumen
The middle ear lies between what two structures?
the tympanic membrane (eardrum) and the inner ear
What are the ossicles, in order, as you move deep into the ear?
malleus, incus, and stapes
What connects the middle ear with the pharynx?
The Eustachian tube, also known as the auditory tube, connects the middle ear to the pharynx
What are the muscles that dampen loud noises? What are they attached to?
The tensor tympani and stapedius are two muscles in the middle ear that dampen loud noises
What is a myringotomy?
a surgical procedure that involves making a small incision in the eardrum to drain fluid from the middle ear
What are differences between the bony and membranous labyrinths?
the bony labyrinth is a solid bone structure while the membranous labyrinth is a flexible, fluid-filled system of canals and sacs responsible for sensory perception
What are differences between inner hair cells and outer hair cells?
sensory transduction for inner hair cells and mechanical amplification for outer hair cells
Where in the cochlea do high pitched sounds deflect the basilar membrane? Low pitched
sounds?
In the cochlea, high-pitched sounds cause the basilar membrane to deflect most significantly near the base
Which structure (utricle or saccule) is involved to vertical movements?
The saccule
What are otoliths and how are they involved with equilibrium?
tiny calcium carbonate crystals located in the inner ear, specifically within the utricle and saccule, which are part of the vestibular system; they act as sensors to detect linear acceleration and head tilt relative to gravity, playing a crucial role in maintaining balance and equilibrium by sending signals to the brain about the body’s position and movement in a straight line
What kind of stimuli do the semicircular canals respond to?
rotational head movements or angular acceleration
What structure in the semicircular canals has receptors?
The structure in the semicircular canals that houses the receptors for balance is called the ampulla
What is vertigo and what can cause it?
a type of dizziness that makes you feel like you or the world around you is spinning, even when you’re still
What is the vomeronasal organ? What does it respond to?
The vomeronasal organ (VNO) is a small, tubular cavity in the nasal septum that responds to pheromones and other chemical signals
what is a receptor
something to receive the information
T or F :Special senses are localized and
confined to the head region
TRUE
Taste buds are
found on tongue
posterior palate, pharynx, inside of
cheeks, posterior wall of pharynx,
and the epiglottis
Taste is
Dissolved molecules in saliva enter taste pore
* Molecules bind to receptors on gustatory
hair cells
* Action potentials are generated, sensory
neurons stimulated, signals sent to CNS
What is flavor
- Flavor = combination of taste,
smell, and texture - Smell and taste work hand-in
hand
what is the gustatory pathway
Taste receptors on
gustatory hair cells →
sensory nerve fibers in
cranial nerves →
brainstem → thalamus
→ gustatory cortex
(insula)
what is olfaction
Olfactory receptors are in the
olfactory epithelium
(pseudostratified columnar) that
covers superior nasal concha and
the superior part of nasal
septum
Olfactory Receptors
have olfactory cilia
Extensions of sensory
neurons =
filaments of
olfactory nerve
T or F Synapse with mitral cells
in olfactory bulb at
glomeruli
TRUE
what are some chemical sense disorders
- Anosmia = absence of smell
- Blow to head/whiplash
- Colds/allergies
- Zinc deficiency
- Uncinate fits = olfactory hallucinations
- Brain disorders
Eyebrows do what
- Shade eyes from sunlight
- Prevent sweat from running into eyes
palpebrae are
- Have eyelashes at free margin
- Keep foreign objects out of eye
- Very sensitive→ blinking reflex
Palpebral fissure
- Space between eyelids
Lacrimal caruncles
Pink raised portion; medial
angle
Conjunctiva is
- Transparent mucous
membrane - Covers inner surface of
eyelids and anterior
surface of eyeball (except
cornea)
Lacrimal apparatus is what
made
of the lacrimal gland and
ducts that drain lacrimal fluid
tears go where
Tears move across eye, enter
puncta
* Drain into lacrimal canaliculi, then
* Lacrimal sac →
* Nasolacrimal duct →
Extrinsic Eye Muscles
Movement of each eye is controlled by 6 extrinsic eye muscles
* Skeletal muscles
* Attach to outer surface of the eyeball (sclera)
Strabismus =
misaligned eyes (cross-eyed)
3 tunics of the eye
Fibrous tunic (outermost) * Vascular tunic * Sensory tunic (innermost)
what is the Fibrous Tunic
Outermost layer
* Extension of dura mater
* Provides protection and mechanical
support
* Avascular
* Parts
* Sclera (dense irregular CT→ opaque)
* Cornea (dense regular CT→
vascular tunic
Middle tunic * Parts * Choroid: vascular, dark surface
absorbs excess light
* Iris is made of smooth muscle * Contracts and enlarges to
regulate light entry to eyeball → pupil changes size
* Melanocytes (brown
pigment, eye color)
what is the Ciliary body
Ciliary muscle
* Smooth muscle
* Suspensory ligaments
* Controls the shape of the
lens (which focuses light
onto the back surface of
the eye)
* Capillaries within produce
aqueous humor
Accommodation is
The lens changes shape when looking
at things up close = accommodation
With age, the lens becomes less
elastic →
presbyopia
what is the innermost tunic
sensory tunic
Pigmented layer (next to choroid) is
- Single epithelial layer, contains melanin
granules - Absorbs light * Nourishes neural layer
Neural layer (in contact with lumen
of eye)
- Three types of neural cells * Photoreceptor cells * Bipolar cells * Ganglion cells
rods cells are
Most numerous (~120 million
per eye)
* Responds light intensity * Most sensitive to light (good
for night vision)
* Most numerous in periphery
of retina (sides)
bipolar cells
activated by rods and cones
ganglion cells
Activated by bipolar cells
* Axons of ganglion cells transmit
impulse to brain through optic
nerve
Photoreceptors activate bipolar
cells →
bipolar cells activate
ganglion cells → axons of ganglion
cells form optic nerve → brain
Circadian Photoreception
Some cells in the retina are not involved with vision
* They contain a protein called melanopsin
Visual Pathway
Optic nerve → optic chiasma
→ optic tract→ thalamus →
optic radiations→ occipital
lobe (primary visual cortex)
Optic disc is what
- Location at back of eye where axons of ganglion cells leave eye
- Called blind spot
- No photoreceptors
Fovea centralis is located in
the center of the macula
lutea
* Only cones
* Greatest visual acuity here
* Why central vision is sharpest
Age-related macular
degeneration (AMD) is
Progressive deterioration of
macula lutea portion of the
retina
The fovea centralis is in
the middle
of the macula lutea
Ciliary body changes
shape to
focus light on fovea centralis
Anterior segment is
- Anterior 1/3 of eye
(cornea to lens) - Filled with aqueous
humor - Has two chambers:
- Anterior chamber
- Anterior to iris
- Posterior chamber
- Between iris and
lens
Anterior segment is filled
with
aqueous humor
Glaucoma is
Condition where aqueous
humor is drained slower
than it is produced
posterior segment is what
Poster 2/3 of eyeball
* Behind lens
* Contains vitreous humor
Emmetropic eye
is
- Normal vision
- Light focuses on retina (fovea centralis)
Myopic eye
- Nearsighted (can see things up close, not far)
- Eye may be too long, image focuses in front of retina
- Correction: concave lens
Hyperopic Eye
Farsighted (can see things far away, not close)
* Eye may be too short, image focuses behind retina
* Correction: convex lens
Presbyopia
- Lens becomes less elastic with age—need bifocals
Astigmatism is
Abnormal shape of corneal surface causes light rays to diffract differently
* Result: two or more focal points
Detached Retina
A hole or small tear in the retina allows vitreous humor to leak
between the pigmented and neural layers of retina
* Photoreceptor cells will eventually die if neural layer is not reattached
to the nourishing underlying layer
cataract is
- Lens becomes cloudy
- Most commonly due to age-related damage to the internal part of lens
- Excessive sunlight, smoking, oral steroids can contribute
- Treatment: lens replacement
ear regions are
External ear
* Collects and directs sound
waves
* Middle ear
* Amplifies and transmits sound
waves
* Internal (inner) ear
* Location for sensory organs for
hearing and equilibrium
what is the auricle
Auricle (pinna)
* Outer fleshy portion; provides
protection
* Helps funnel sounds into the
external acoustic meatus
* Made of elastic cartilage
* Ridges and cavities help the
brain to locate where sounds
are coming from
* Earlobe = lobule (no cartilage)
External acoustic meatus
is
- Air-filled canal
- Stratified squamous epithelium
lines canal - Hairs keep insects and foreign
material out
Ceruminous glands and sebaceous
glands
- Secrete cerumen (wax) which
inhibits microorganism growth,
traps dust, repels insect
middle ear
The middle ear extends from the
tympanic membrane to oval
window
* Contains the auditory ossicles
* Malleus
* Attached to tympanic membrane
* Incus
* Stapes
* Attached to oval window
what is the pharyngotympanic tube
(eustachian tube) connects
middle ear with pharynx
* This allows for throat infections to
move to the middle ear (= otitis
media)
* A myringotomy may be needed to
drain excess pus
what is the internal ear made of
- The bony labyrinth
* Cavity in the petrous
portion of temporal
bone
* Parts are:
* Semicircular canals
* Vestibule
* Cochlea
The membranous labyrinth is
Continuous series of
membrane-walled sacs
and ducts that fit loosely within
bony labyrinth
* The membrane is thin layer CT
lined with simple squamous
epithelium
The membranous labyrinth
structures are filled with clear
liquid that is called
endolymph
The cochlea is a very small (size of a
split pea), spiraling chamber
- The coiling is around a central pillar of
bone = modiolus - The cochlear nerve is located in the
modiolus - The cochlear duct (scala media) is
within the cochlea
Cochlear duct (also called
scala media) is filled with
endolymph
what is the spiral organ
Organ of Corti = spiral organ
the spiral organ is inside the
cochlear duct, has
- One row of inner hair cells and
- Three rows of outer hair cells
Stereocilia at the tips of hair cells
are embedded in tectorial
membrane
T or F :
inner versus Outer Hair Cells Both are located in spiral organ
TRUE
Structures of maculae:
– Hair cells
* Mechanoreceptor cells that respond
to movement
* Stereocilia
– Extensions of hair cells that are
embedded in otolithic membrane;
initiate an impulse when bent
Otolith membrane
* Jelly like disc that sits atop sensory
epithelium & shifts in response to
movement (bend stereocilia)
– Otoliths
* Calcium carbonate crystals that add
weight to membrane and cause more
dramatic shift
The membranous
semicircular ducts
are
within the bony
semicircular canals
what is vertigo
feeling of motion when aren’t moving
what are the male primary repordutive organs
testes that produce sperm
what are the primary reproductive organs for women
ovaries produce eggs
what are the accessory reproductive organs in males (EDSEPBUP)
- Epididymis
- Ductus deferens
- Seminal vesicle
- Ejaculatory duct
- Prostate
- Bulbourethral gland
- Urethra
- Penis
what are the accessory reproductive organ in women (VVUU)
- Vulva
- Vagina
- Uterus
- Uterine tube
what is spermatogenesis
sperm production
what is the scrotum
pouch) is outside
the body; contains
* Testis: sperm production
* Epididymis: sperm
storage and maturation
Two muscles control
placement of scrotum:
- Dartos muscle
- Smooth muscle that wrinkles
scrotal skin to increase thickness
for warmth - Cremaster muscle
- Bands of skeletal muscle that
elevates testes for warmth
Testicular Descent is
The testes descends through
the inguinal canal
* This occurs throughout
pregnancy and ends shortly
before birth
The testes are made of
seminiferous
tubules which produce sperm (=
spermatogenesis)
Sperm will finish maturation in
epididymis
With ejaculation, sperm travels from epididymis to
ductus deferens
what is the pathway of sperm movement
Seminiferous tubules
(spermatogenesis) →
epididymis → ductus
deferens → ejaculatory
duct → prosthetic
urethra →
membranous urethra
→ spongy urethra
the male urethra has three segments
- Prostatic urethra: passes through
prostate gland - Membranous/intermediate part of the
urethra: passes through pelvic floor - Spongy urethra: passes through penile
tissue
Urethra ends at
external urethral
orifice
what is the penis made of
erectile tissue
* Smooth muscle and connective tissue surrounded by dense CT
* Vascular spaces fill with blood
what is the Corpus cavernosa
- Paired, primary erectile bodies
what is the Corpus spongiosum:
- Keeps urethra open during ejaculation
vasectamy is what
Ductus deferens is cut and each end is tied off or cauterized
semen formation order is
Seminal vesicle
* Seminal vesicle produces about 60% seminal fluid
* Ejaculatory duct
* Prostate gland
* Bulbourethral gland
the glans penis is
- Extension of corpus
spongiosum at end of penis
what is circumcision
Is surgical removal of the foreskin
(typically performed shortly after birth)
* Is controversial
what is the Labia majora
outer folds
what is the Labia minora
inner folds
what is the clitoris
erectile tissue
what are mammary glands
breasts
where does milk drain into
Milk drains into lactiferous ducts
* Lactiferous ducts drain into lactiferous
sinus
* Milk empties via nipple
* Nipple is in center of areola
what is oogenesis
process of egg formation
where is an oocyte is released from a
follice
Empty follicle becomes the
corpus luteum
* This is an endocrine structure
* Releases progesterone and estrogens which signal uterus to prepare for
possible fertilized egg
An oocyte is released from
the ovary into the pelvic cavity
* Opening of uterine tube in close proximity to capture released oocyte
Fimbriae is what
- Ciliated edges of uterine tube that create
a current to draw oocyte up into tube
what are the regions of the uterus
Regions
* Fundus
* Body
* Cervix
what are the layeres of the uterine wall
Perimetrium
* Outer layer; visceral peritoneum
(serous membrane)
* Myometrium
* Smooth muscle layer
* Endometrium
what is the cervix
Lower portion of uterus that
opens into vagina
what is the vagina
- External opening of female
reproductive system - Lined with stratified squamous
epithelium
