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Flashcards in General Histology Deck (186):
1

Cytoplasm

Site of cell synthesizing activity
Contains organelles, cytoplasmic inclusions (glycogen, pigments, lipids, etc.
Cytoplasmic matrix made of ground substance

2

Membrane bound organelles

Rough endoplasmic reticulum
Smooth endoplasmic reticulum
Golgi apparatus
Mitochondria
Lysosomes
Peroxisomes
Endosomes

3

Non membrane bound organelles

Microtubules
Centrioles
Filaments
Basal bodies
Ribosomes

4

Rough endoplasmic reticulum

Protein synthesis for export outside of cell
Studded with ribosomes

5

Smooth endoplasmic reticulum

Steroid synthesis (adrenal cortex, testes)
Sequesters calcium (muscles)
Lipid and glycogen metabolism (liver)

6

Golgi apparatus

Posttranslational protein modification and packaging
Lysosomes production

Adds oligosaccharides for glycoproteins
Adds sulfate groups for proteoglycans

7

Mitochondria

ATP production via Krebs cycle and oxidative phosphorylation

Contains inner and outer membrane

Have own cyclic DNA

Not present in RBCs

8

Lysosomes

Digestion of microorganisms or other cellular components by hydrolytic enzymes

Produced by Golgi

9

Peroxisomes

Elimination of H2O2 by oxidative enzymes (catalase and peroxidase)

10

Endosomes

Vesicles formed as a result of phagocytosis

11

Microtubules

Provide skeletal support, intracellular transport and cellular movement

Axoneme: specialized micro tubules in cilia and flagella arranged in 9+2 pattern

12

Centrioles

Provide microtubule organization
Form end of mototic spindles

13

Filaments

Microfilaments (actin, myosin): important for muscle contraction and cellular movement/anchorage

Intermediate filaments (vimentin, cytokerrin): cytoskeletal support

14

Basal bodies

Required for development of cilia

15

Ribosomes

Protein synthesis for use within the cell

Composed of rRNA and protein

16

Nucleus

Nuclear membrane: inner and outer plasma membrane
Nucleoplasm: ground substance of nucleus
Chromatin: complex of DNA and proteins
Euchromatin: loose, indicates activity
Heterochromatin: condensed
Nucleolus: site of rRNA synthesis
Barr body: repressed X chromosome found only in cells of females appearing as sense chromatin mass next to nuclear membrane

17

At what week can the sex of an embryo be determined?

8th week by examining presence (female) or absence (make) of a Barr body

18

Cell surface appendages

Microvilli: fingerlike structures on apical surface of most epithelial cells providing increased surface area
Stereocilia: long microvilli only in epididymis and sensory cells of inner ear
Cilia: short structures used for locomotion or movement of substances (require basal bodies for development)
Flagella: long whiplike structures used for locomotion

19

Cell cycle

G0
G1
S
G2
M

20

Mitosis

Produces 2 daughter cells with same chromosome number as parent cell (diploid, 2n)

All somatic cells

21

Interphase

G1: first cell growth period
G0: period outside of cell cycle for terminal differentiation
S: DNA synthesis (7 hours)
G2: second variable period of cellular growth

22

Prophase

Chromatin coils and condenses in nucleus
Mitotic spindle forms

23

Metaphase

Nuclear membrane and nucleoli disappear
Chromosomes line up at equitorial plate of mitotic spindles

24

Anaphase

Chromosomes split to opposite poles

25

Telophase

Nuclear membrane forms around chromosomes at poles
Chromosomes uncoil and nucleoli reappear
Cytoplasm divides into two daughter cells

26

Meiosis

Produces four daughter cells with half the chromosome number (haploid, n)

Only gametes

27

Cell to cell contacts

Tight junction: beltlike junction sealing off intercellular space

Intermediate junction: beltlike junction leaving 15-20nm wide space

Desmosome: strong but localized adhesion sites composed of attachment plaque to which intermediate filaments are anchored

28

Junctional complex

Tight junction
Intermediate junction
Desmosome

29

Cell turnover rate (high to low)

Oral, epidermal, GI

Smooth muscle, vascular endothelial

Skeletal muscle, cardiac

Neurons

30

Hemidesmosomes

Cell to ECM contact
Integrins are principle proteins

Pemphigus: autoimmunity against des isomers
Pemphigoid: autoimmunity against hemidesmosomes

31

Gap junction

Areas of free communication between cells to allow passage of fluids, ions and small molecules

32

Functions of epithelium

Barrier
Diffusion
Absorption
Secretory
Transport
Sensory

33

What is the thinnest epithelium in the oral cavity?

Sublingual mucosa

34

True or false: epithelium is characterized by cell morphology and arrangement as well as function.

False

It is only characterized by morphology and arrangement, not function

35

Epithelium classification by cell layers

Simple: one layer
Stratified: 2 or more layers
Pseudo stratified: one layer but some don't reach to outer surface

36

Epithelium classification by morphology

Squamous: wide and short
Cuboidal: cubic
Columnar: tall and skinny
Transitional: ranges from squamous to cuboidal

37

Epithelium classification by location

Endothelium: lines blood vessels
Mesothelium: lines closed body cavities

38

Functions of basement membrane

Attachment
Separation
Filtration
Scaffolding

39

Components of basement membrane

Lamina lucida: electron clear
Lamina densa: type 4 collagen, proteoglycans, laminin, and fibronectin and anchoring fibrils
Reticular lamina: reticular fibers of type 3 collagen

40

Connective tissue proper

Loose CT: ground substance with sparse divers and cells
Dense CT: greater fiber concentration
Irregular: found in dermis, sub mucosa of GI, fibrous capsules
Regular: ordered arrangement found in tendons, ligaments, and aponeuroses

41

Connective tissue attachments

Ligaments: bone to bone
Tendons: muscle to bone
Aponeurosis: sheet like tendon
Sharpey's fiber: portion of ligament or tendon inserting into bone

42

Where do most CTs derive from?

Mesoderm

CTs of head and neck can derive from neural crest ectoderm

43

Cells of connective tissue

Resident cells: fibroblasts, myofibroblasts, adipocytes, macrophages, mast cells, mesenchymal cells

Transient cells: lymphocytes, neutrophils, monocytes, plasma cells, eosinophils, basophils

44

3 types of glands

Exocrine: secrete through ducts
Endocrine: secrete into blood stream
Paracrine: secrete into extra cellular spaces

45

Structure of salivary glands

Comprised of lobes divided by CT septa
Terminal secretion unit = acini or tubules

Intercalated duct : transports saliva to larger ducts (simple cuboidal)
Striated duct: modifies salivary components
(Low columnar)
Terminal excretory duct: transports saliva to oral cavity (pseudo stratified)

46

Cartilage

Avascular connective tissue
Composed of chondrocytes in lacunae
Chondroblast: initial cartilagenic cells

47

Cartilage matrix

Type 2 collagen
Ground substance
Glycosaminoglycans (hyaluronic acid, chondroitin sulfate, keratin sulfate)
Proteoglycans

48

What type of cartilage is the precursor to bone in endochondrial ossification?

Hyaline cartilage

49

Does cartilage contain calcium salts?

No, it does not contain calcium salts

50

Perichondrium covers cartilage except what three locations?

Fibrocartilage
Articular cartilage of joints
Basal/costal cartilage

51

Perichondrium

Inner cellular layer: produces chondroblasts

Outer fibrous layer: provides protection

52

Growth of cartilage

Appositional: new cartilage forms on surface of existing cartilage

Interstitial: new cartilage forms in existing cartilage, chondrocytes divide

53

Types of cartilage

Hyaline: articular surfaces, nose, trachea, bronchi; thin collagen, pliable and resilient

Elastic: external ear, eustschian tube, epiglottis; collagen and elastin, elastic

Fibrocartilage: intervertebral discs, TMJ, pubic symphysis, meniscus; withstands compression and tension

54

Bone

Osteoblasts: produce osteoid (type 1 collagen); mature bone forms when osteoid calcifies
Osteocytes: osteoblasts that become trapped in lacunae during calcification
Canaliculi channels maintain nourishment

Predominant mineral: hydroxyapatite

55

Functions of bone

Support
Protection
Movement
Mineral storage
Hematopoiesis

56

Bone matrix

Organic: type 1 collagen, osteocalcin, osteonectin, ground substance

Inorganic: hydroxyapatite

57

Intramembranous ossification

Mesenchymal cells differentiate into osteoblasts that secrete matrix in loosely arranged collagen
New matrix calcified to form woven bone
Woven bone is replaced over time to calcified bone

Flat bones of skull, maxilla, mandible body, clavicle

58

Endochondral ossification

Subperiosteal bony cuff forms around hyaline cartilage model
Chondrocytes hypertrophy and die and matrix becomes calcified


Long bones, vertebrae, mandibular condyles

59

Bone growth

Appositional growth: both endochondral and intramembranous at any time

Interstitial growth: endochondral only until epiphyseal plates close

60

Types of bone

Cortical: haversian systems (lamellae surrounding Haversian canal with connecting canaliculi between osteocytes) connected by Volkmann's canals

Cancellous: less dense arrangement with lamellae arranged in thin spicules called trabeculae
Marrow spaces are between trabeculae

61

Bone surfaces

Periosteum: CT capsule around outer surface containing collagen, fibroblasts, and osteoprogenitor cells

Endosteum: one cell thick layer of osteoprogenitor cells inside of bone and contains bone marrow

62

Bone remodeling

Mature bone grows only by appositional growth

Osteoclasts resorb; osteoblasts lay down

63

Osteoclasts

Multinucleated giant cells residing in Howship's lacunae

Produce hydrolytic enzymes from ruffled borders

Protons lower pH at resorption site and collagenases and proteases digest matrix

64

Fracture repair steps

1. Blood clot formation
2. Bridging callus formation
3. Periosteal callus formation
4. New endochondral bone formation

65

Calcium regulation

Parathyroid hormone: stimulates osteoclasts to release calcium

Calcitonin: inhibits osteoclasts to decrease blood calcium levels

66

Classification of joints based on motion

Synarthrosis: immovable
Amphiarthrosis: slightly moveable
Diarthrosis: fully movable

67

Type of joint based on connective tissue

Fibrous: joined by fibrous CT
Suture
Syndesmosis (ex: tibia-fibula
Gomphosis (tooth socket)
Cartilaginous: joined by cartilage
Synchondrosis
Symphysis
Synovial: freely movable lined by synovial membrane
Majority of joints

68

Synovial joint types

Ball and socket
Gliding hinge
Pivot
Ellipsoidal
Saddle

69

Components of synovial joint

Articular capsule
Articular cartilage
Synovial cavity
Synovial membrane
Synovial fluid

70

Nervous tissue components

Perikaryon (cell body)
Axon
Dendrites
Cytoskeleton

71

Neuron classification

By function
Motor (efferent), sensory (afferent), mixed

By processes
Unipolar (sensory)
Bipolar (retina and CN VIII ganglia)
Multipolar (3 or more processes; motor and mixed)

72

Nervous tissue support cells

Astrocytes: regulation of metabolites and BBB

Oligodendrocytes: myelination

Microglia: phagocytosis

Ependymal: epithelium of brain, spinal cord

Choroidal: CSF secretion

Schwann cells (PNS only): myelination

Satellite cels (PNS only): support

73

Functions of blood

Transportation
Buffering
Thermoregulation

74

Hematocrit

Percentage of RBCs in blood

45% men
40% women

75

Components of blood

Plasma (55%): water,proteins, electrolytes

Formed elements (55%): erythrocytes, leukocyte a, and platelets

Serum = blood plasma - fibrinogen and clotting factors

76

Lifespans of formed blood elements

Erythrocytes/ 120 days
Platelets: 5-10 days
Leukocytes: variable

77

Granulocytes vs agranulocytes

Granulocytes
Neutrophils (60%)
Eosinophils (5%)
Basophils (1%)
Agranulocytes
Lymphocytes (30%)
Monocytes (4%)

Note: monocytes became macrophages once they enter tissues

78

Leukocyte S

Neutrophils: phagocytosis, acute inflammation
Eosinophils: phagocytosis, chronic inflammation
Basophils: hypersensitivity
Lymphocyte: immunoregulation
Monocytes: phagocytosis, chronic inflammation

79

Blood vessel layers

Tunica intima (simple squamous )
Tunica media (smooth muscle)
Tunica adventitia (collagen and elastin)

80

Pancreas

Exocrine: digestive enzymes via ducts

Endocrine: glucagon, insulin, somatostatin via bloodstream

81

Exocrine pancreas

Produces digestive enzyme precursors that are activated by trypsin in small intestine

Pancreatic acini

Centroacinar cells

82

Endocrine pancreas

Regulates blood glucose levels

Islets of langerhans

Alpha cells = glucagon
Beta cells = insulin
Delta cells = somatostatin (inhibits alpha and beta cells)

83

What regulates pancreatic enzyme secretion ?

Secretin in the duodenum (increase bicarbonate secretion)

CCK (increase proenzyme secretion)

84

Urinary system components

Kidneys
Ureters
Urinary bladder
Urethra

85

Kidney functions

Remove metabolic waste
Conserve body fluids
Synthesize erythropoietin
Synthesize renin
Hydroxylatea vitamin D

86

Components of kidney

Capsule
Cortex
Renal corpuscles
Glomerulus
Bowman's capsules
Proximal tubules
Distal tubules
Collecting ducts
Medulla
Medullary collecting ducts
Loop of Henle
Vasa recta

87

Pyramids of kidney

Conical structures in medulla composed of medullary straight tubules, collecting ducts, and vasa recta

88

Medullary rays of kidney

Striations in the cortex radiating from medulla composed of cortical straight tubules and collecting ducts

89

Juxtaglomerular apparatus

Macula densa: part of distal convoluted tubule

Juxtaglomerular cells: modified smooth muscle cells that secrete renin

Extraglomerular mesangial cells: phagocytosis cells

90

What does renin do?

Regulates blood pressure

Produced in juxtaglomerular cells

91

Nephron functions

Filtration
Absorption
Secretion
Excretion

92

Nephron components

Glomerulus
Bowman' capsule
Proximal convoluted tubule
Loop of Henle
Distal convoluted tubule

93

Types of nephrons

Cortical: located in outer cortex with short loops of Henle
Intermediate: middle cortex with medium loops is Henle
Juxtamedullary: base of medullary pyramid with long loops of Henle

94

Urethra

Male urethra is 20cm long with 3 segments
Prostatic: widest and dilatable
Membranous: shortest and least dilatable
Penile: longest and narrowest

Female urethra is 3-5cm long

95

Testes

Produce sperm and steroids
Tunica albuginea: thick CT
Composed of seminiferous tubules where spermatogenesis occurs

Epididymis: stores sperm
Seminal fluid: seminal vesicles and prostrate secretions

96

Major cellular components of male reproductive system

Leydig cell: testosterone production in seminiferous tubules

Sertoli cell: testicular fluid production in seminiferous fluid

Sperm cell: sperm in seminiferous tubules but mature in epididymis

97

Layers of the heart

Endocardium (simple squamous)
Myocardium (cardiac muscle)
Pericardium (connective tissue and adipose)

98

Sinusoid

fenestrated or disconinuous capillaries in liver, spleenand endocrine glands

larger and irregular compared to capillaries in order to accommodate phagocytic cells

99

Where does the greatest drop in blood pressure in circulation occur?

From arteries to arterioles

100

Capillaries

Only endothelial layer
one erythrocyte wide
slowest velocity of blood flow
gas and metabolite exchange via diffusion

101

Venules vs Veins

Venules have thick tunica adventitia
Veins have thickest tunica adventitia, some valves, some vasa vasora

102

Cardiac Conduction

Sinoatrial node (SA node): the pacemaker of the heart
Autonomic nerves only regulate the RATE of cardiac impulses, cardiac muscle maintains its own rhythm

SA node -> AV node -> Bundle of His -> Purkinje fibers

103

Tachycardia and Bradycardia

Tachycardia > 100bpm
Bradycardia

104

Lymph

Yellowish, plasma like liquid containing mostly lymphocytes
Lymph is not pumped; it relies on valves, gravity, and skeletl muscle contractions

105

Where is most of the lymph reurned to?

The junction of the left internal jugular and subclavian veins

106

Functions of lymphatic system

Transport tissue fluid to circulation
Tranport fat metabolites to circulation
Filtration of foreign agents in lymph nodes
Immunological surveillance

107

Lymph Drainage

Thoracic duct: majority of the body (left sublcavian vein)
Right lymphatic duct: upper right body (right subclavian vein)

108

Components of Lymphatic System

Bone marrow
Thymus
Spleen
Lymph
Lymphatic vessels
Lymph nodes
Lymphatic nodules (tonsils, appendix, Peyer's patches)

109

Lymph nodes

Small fibrous-encapsulated organs that filter lymph
Macrophages and lymphocytes process lymph in nodal cortical and trabecular sinuses
Consist of
External capsule
Outer cortex (B cells)
Paracortex (T cells)
Inner medulla (B cells and macrophages)
Note: lymph nodes are the only lymph structures wth both efferent and afferent vessels

110

Bone Marrow

Site of B cell maturation
Contains pluripotent stem cells capable of differentiating into lymphocytes or phagocytes

111

Thymus

Site of T cell maturation
Replaced with adipose tissue in adulthood
Consists of
External capsule
Outer cortex (high concentration T cells)
Inner medulla (epitheliorecticular cells)

112

Spleen

Largest lymphatic organ
Develops from mesenchyme of primitive stomach
Sie of lymphocyte proliferation, large antigen scavenging, and damage erythrocytes
Consists of
External capsule
White pulp (B ells) surrounded by Periarterial lymphatic sheath (PALS) containing T cells
Red pulp: erythrocytes, macrophages, lymphocytes

113

Pituitary Gland

Located in sella turcica of sphenoid bone
"Master endocrine gland"
Attached to hypothalamus via infundibulum
Inferior and superior hypophyseal arteries provide blood supply
Contains own portal system (2 capillary beds)
2 different components
1. Adenohypophysis: anterior
2. Neurohypophysis: posterior

114

What is the most abundant of the pituitary hormones?

GH

ADH and oxytocin are synthesized in hypothalamus and stored in posterior pituitary

115

Thyroid gland

Bilobed organ anterolateral to upper trachea in anterior triangle of neck
Surrounded by CT capsule
Secretory follicles surround gel-like colloid composed of thyroglobulin

116

What is the normal T4 to T3 ratio?

20:1

117

Thyroid gland issues

Hypothyroidism: Cretinism (children), Myxedema (adults), Hashimoto's thyroiditis (autoimmune)

Hyperthyroidism: Grave's disease (toxic goiter)

118

Cell components of thyroid follicles

Follicular cells: T4 and T3 secretion

Parafollicular cells: secrete calcitonin

119

Parathyroid Glands

Small ovoid organs in pairs located in thyroid CT
Derive from 3rd and 4th pharyngeal pouches
Regulate blood calcium and phosphate
Innervated by superior cervical ganglion
Blood supply from inferior and superior thyroid arteries

120

Effects of PTH

Increased blood calcium levels
Stimulation of bone resorption
Increased renal calcium resorption
Decreased renal phosphate resorption
Increased intestinal calcium absorption

121

Pineal Gland

Small, cone-shaped gland located at back of 3rd ventricle of brain
Regulates sleep-wake cycle Contains numerous neurotransmitters including melatonin

122

Hormones produced in anterior pituitary (adenohypophysis)

Growth Hormone
Prolactin
Follicle-stimulating hormone (FSH)
Leutinizing hormone (LH)
Adenocorticotropic hormone (ACTH)
Thyroid-stimulating hormone (TSH)
Lipotropic hormone (LPH)

Note: embryological origin is Rathke's pouch

123

Hormones produced in posterior pituitary (neurohypophysis)

Antidiuretic hormone (ADH)
Oxytocin

Note: embryological origin is Infundibulum

124

Major Parathyroid Cells

Chief cells: secrete PTH
Oxyphil cells: unknown function

125

Adrenal Glands

Located superior to kidneys
Provides regulatory feedback to pituitary and hypothalamus

126

Outer cortex of adrenal glands

Developed from mesoderm
Produces mineralcorticoids (aldosterone) in zona glomerulosa
Produces glucocorticoids (hydrocortisone, cortisone) in zona fasiculata
Produces gonadocorticoids in zona reticularis

127

Inner medulla of adrenal glands

Developed from neural crest ectoderm
Produces catecholamines (epinephrine, norepinephrine)

128

Respiratory System Functions

Air filtration
Air conduction
Gas exchange

129

Divisions of respiratory System

Conduction: warms air, moistens, removes particles
Nasal cavities, nasopharynx, oropharynx, larynx, trachea, and bronchi

Respiration: gas exchange
Bronchioles, alveolar ducts, alveolar sacs and alveoli

130

Alveoli

site of gas exchange
aleolar septum separates adjacent alveolar air spaces

131

Types of alveolar epithelial cells

Type 1: 95%; gas exchange, joined by tight junctions

Type 2: 5%: secretion of surfactant

132

What are dust cells?

Alveolar macrophages

133

Functions of the upper digestive system

Barrier
Absorption
Secretion

134

Layers of upper digestion system

Mucosa: epithelium, lamina propria, and muscularis mucosa (smooth muscle)
Submucosa: dense irregular CT, glands, submucosal plexus of unmyelinated nerves
Muscularis externa (smooth muscle)
Serosa: mesothelium, CT
Adventitia

135

Peristalsis

the waves of smooth muscle contraction of the muscularis externa that propels GI contents along

136

Esophagus

Transports food from oropharynx to the stomach
nonkeratinized stratified squamous epithelium
Glands: mucous

137

Stomach

Mixes and partially digests food, producing chyme
Simple columnar epithelium renewing 3-5 days
Lining: Rugae (longitudinal folds for expansion) and Gastric pits (microscopic depressions for gastric glands)
Parts: cardiac, fundic, and pyloric
Glands: mucous, chief cells make pepsinogen, parietal cells make HCl, enteroendocrine cells make gastrin
Innervation: CN X

138

Small Intestine

Digestion of chyme and absorption
Simple columnar epithelium renewing 5-6 days

139

Small Intestine Linings

Plicae circulares (valves of Kerckring): transverse semilunar folds along lumen to provide surface area

Villi: fingerlice projections on plicae

Microvilli: micro fingerlike projections on enterocytes

140

Small Intestine Organization

Duodenum: shortest segment with submucosal (Brunner's glands)

Jejunum: middle segment with more plicae and villi

Ileum: longest segment with lymphoid tissue (Peyer's patches)

141

Muscularis externa

Myenteric (Auerbach's) plexus is located between two layers of smooth muscle

142

Small Intestine Glands

Intestinal glands (Crypts of Lieberkuhn): small intestine at base of villi
Submucosal glands of Brunner: only in duodenum

143

Cells of Small Intestine

Enterocytes: epithelium for absorption and digestion
Goblet cells: mucous secreting cells
M cells: absorption of antigens to lymphatics
Paneth cells: digestion of bacterial cell walls (secrete lysozyme)
Enteroendocrine cells: CCK increases pancreatic and bile secretion, secretin increases pancreatic bicarbonate secretion, GIP decreases gastric acid secretion
Mucosal cells: produce bicarbonate

144

Large Intestine

Reabsorbs water and electrolytes and eliminates waste
Simple columnar epithelium renewing 5-6 days
Smooth surface lining
Muscularis externa: teniae coli (longitudinal bands for peristalsis), haustra (independent contration)
Glands: intestinal glands
Innervation: CN X, pelvic splanchnic nerve

145

Large intestine organization

Cecum: appendix
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum (no teniae coli)
Anal canal

146

Gut-Associated Lymphatic Tissue (GALT)

Lamina propria (GI tract)
Peyer's patches (ileum)
Lymphoid aggregates (large intestine and appendix)

147

Liver

Exocrine: bile
Endocrine: albumin, lipoproteins, alpha/beta globulins, prothrombin, fibronectin

148

Portal Triad

Hepatic artery
Portal vein
Bile duct

149

Liver lobules

Hexagonal stacks of hepatocyte cords separated by anastamosing sinusoid
Surround a central vein (where sinusoids drain)
Portal triads located at each corner

150

Hepatocytes

Nuclei are often binucleate
Acidophilic cytoplasm (peroxisomes contain catalase and alcohol dehydrogenase)
Lysosomes store iron
Glycogen deposits
Lipid droplets
5 month lifespan, capable of regeneration

151

Hepatic sinusoids

Lined by thin, discontinuous epithelium with no basement membrane
Kupffer cells: mononuclear macrophages
Ito cells: adipocytes in space of Disse storing vitamin A
Perisinusoidal space: site of exchange between blood and hepatocytes

152

Biliary flow

Hepatocytes ->
Canaliculi ->
Canals of Hering ->
Inerlobular bile ducts ->
Lobar ducts ->
Common hepatic duct ->
Common bile duct ->
Duodenum

153

What increases biliary flow?

Primarily CCK (produced by enteroendocrine cells)

secretin and gastrin also increase biliary flow

154

Biliary Tree

Ductal system transporting bile from hepatocytes to gall bladder and duodenum
Canaliculi: small canals formed by grooves in adjacent hepatocytes
Ampulla of vater: opening of common bile duct into duodenum
Sphycter of Boyden at common bile duct; Sphyncter of Oddi at ampula of vater

155

True or false: biliary flow is opposite to that of blood flow?

True

Central vein -> portal canal

156

What condition does elevated serum bilirubin result in?

Jaundice

157

Bile composition

Water
Electrolytes
Cholesterol
Lecithin
Bile salts (glycocholic acid, taurocholic acid)
Bile pigments (bilirubin, biliverdin, glucoronide)

158

Gall Bladder

Concentrates and stores bile
Simple columnar epithelium wih microvilli and Rokitansky-Aschoff sinuses
No submucosa in gall bladder and no lymphatic vessels
Mucin-secreting glands

159

Duct system of testes

Seminiferous tubules ->
Rete testis->
Efferent ductules ->
Ductus epididymis->
Ductus (vas) deferens->
Ejaculatory duct

160

Prostate gland

Surrounds proximal urethra
Secretes acid phosphatase, fibrinolysin, citric acid

161

Penis

3 major masses of tissue surrounded by dense fibroelastic capsule (tunica albuginea)
Corpora cavernosa (2): dorsal erectile tissue
Corpus spongiosum: ventral, urethra

162

Ovary

Elliptical organs supported by broad ligament of uterus

Produce ova and steroids (estrogen and progesterone)

Inner medulla: vasculature, nerves, CT
Outer cortex: ovarian follicles (oogenesis)

163

Ovarian follicle development

1. Primordial oocytes
2. Multilayered theca interna (secretes estrogen)
3. Surrounding stromal cells
4. Split in theca interna forms Graafian follicle

164

Oviducts

4 sections from ovary to uterus
1. Infundibulum: contains fimbriae
2. Ampulla: longest, fertilization
3. Isthmus
4. Uterine

165

Uterus

3 layers
1. Endometrium
2. Myometrium
3. Perimetrium

Cervix = lowest section of uterus connecting to vagina

166

Vagina

Lined by nonkeratinized stratified squamous
Does not contain glands

167

Mammary glands

Contain tubuloalveolar glands (produce milk), sebaceous glands, and sweat glands

Merocrine and apocrine secretion produce milk

Lactation is under control of hypothalamus and pituitary

168

Functions of skin

Protection
Sensory
Homeostasis
Synthesis (vit D)
Excretion (sweat)

169

Layers of skin

Epidermis
Basement membrane
Dermis
Hypodermis

170

Layers of epidermis (inner to outer)

Bad Sprinters Get Leg Cramps

Basale: mitotic activity
Spinosum: langerhans cells, prickle layer
Granulosum: keratohyalin granules
Lucidum: only on thick skin
Corneum: flattened cells, few/no organelles

171

Layers of basement membrane

Lamina lucida
Lamina densa (basal lamina)
Type 4 collagen, proteoglycans, laminin, fibronectin, anchoring fibrils
Reticular lamina: type 3 collagen

172

Layers of dermis

Dermis has CT, vasculature, lymphatics, nerves, sweat glands, hair follicles

Papillary layer: thin, rete pegs, blood vessels

Reticular layer: fibrous and thick

173

Specialized epidermal cells

Melanocytes: produce melanin
Keratinocytes: produce keratin
Langerhans cells: APCs
Merkel cells: touch sensation

Concentrated in basal layer

174

Skin nerve endings

Free nerve endings: most abundant; touch, temperature, pain

Pacinian corpuscles: pressure and vibration

Meissner's corpuscles: touch

Ruffini endings: mechanoreceptors

175

Hair

Regulates body temp
Composed of keratinized cells
Produced by hair follicles

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Components of hair follicle

Bulb
Internal root sheath
External root sheath
Arrector pili muscle

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Types of sweat glands

Eccrine: body temp, sweat, located on entire body except lips and genitalia

Apocrine: produces pheromones, odorless serous secretion, located in axilla, areola, nipple, circumanal, external genitalia

Both SNS Innervation

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Sebaceous glands

Sebocytes: secrete sebum (oily substance on skin and hair)

Outgrowths of external root sheaths of hair follicles

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Layers of the eye

Corneoscleral coat
Cornea: "clear anterior portion
Limbus
Sclera: "white portion"
Uvea
Choroid: vascular layer
Ciliary body: smooth muscle
Iris: smooth muscle, pigmentation
Pupil: central aperture of iris
Retina
Pigment epithelium: melanin cells
Neural retina: rods and cones

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What is aqueous humor?

The watery fluid within the anterior and posterior chambers of the eye

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What is vitreous humor?

The transparent watery gel within the vitreous chamber

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Chambers of the eye

Anterior: cornea to iris
Posterior: iris to lens
Vitreous: lens to neural retina

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10 layers of retina

Outermost to innermost
1. Pigment epithelium
2. Photoreceptors cells (rods - light, cones - color)
3. External limiting membrane
4. Outer nuclear layer
5. Outer plexiform layer
6. Inner nuclear layer
7. Inner plexiform layer
8. Ganglion cell layer
9. Optic nerve fibers
10. Internal limiting membrane

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What vitamin is a source of retinal, an essential component of rods?

Vitamin A

Deficiency results in night blindness

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Optic disc

Collection of retinal ganglion cell nerve fibers leaving eye as optic nerve

Right and left nerves meet at optic chiasm
Central artery and vein of retina also edit here

Small blind spot on retina: 3mm to nasal side of macula
Only part of retina without rods or cones

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Macula lutea

Temporal to optic disc

Responsible for detailed central vision (ex: reading)

Fovea: center of macula with no blood vessels but high concentration of cones
Fovea = area of sharpest vision