General Histology Flashcards
Cytoplasm
Site of cell synthesizing activity
Contains organelles, cytoplasmic inclusions (glycogen, pigments, lipids, etc.
Cytoplasmic matrix made of ground substance
Membrane bound organelles
Rough endoplasmic reticulum Smooth endoplasmic reticulum Golgi apparatus Mitochondria Lysosomes Peroxisomes Endosomes
Non membrane bound organelles
Microtubules Centrioles Filaments Basal bodies Ribosomes
Rough endoplasmic reticulum
Protein synthesis for export outside of cell
Studded with ribosomes
Smooth endoplasmic reticulum
Steroid synthesis (adrenal cortex, testes) Sequesters calcium (muscles) Lipid and glycogen metabolism (liver)
Golgi apparatus
Posttranslational protein modification and packaging
Lysosomes production
Adds oligosaccharides for glycoproteins
Adds sulfate groups for proteoglycans
Mitochondria
ATP production via Krebs cycle and oxidative phosphorylation
Contains inner and outer membrane
Have own cyclic DNA
Not present in RBCs
Lysosomes
Digestion of microorganisms or other cellular components by hydrolytic enzymes
Produced by Golgi
Peroxisomes
Elimination of H2O2 by oxidative enzymes (catalase and peroxidase)
Endosomes
Vesicles formed as a result of phagocytosis
Microtubules
Provide skeletal support, intracellular transport and cellular movement
Axoneme: specialized micro tubules in cilia and flagella arranged in 9+2 pattern
Centrioles
Provide microtubule organization
Form end of mototic spindles
Filaments
Microfilaments (actin, myosin): important for muscle contraction and cellular movement/anchorage
Intermediate filaments (vimentin, cytokerrin): cytoskeletal support
Basal bodies
Required for development of cilia
Ribosomes
Protein synthesis for use within the cell
Composed of rRNA and protein
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
At what week can the sex of an embryo be determined?
8th week by examining presence (female) or absence (make) of a Barr body
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
Cell cycle
G0 G1 S G2 M
Mitosis
Produces 2 daughter cells with same chromosome number as parent cell (diploid, 2n)
All somatic cells
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
Prophase
Chromatin coils and condenses in nucleus
Mitotic spindle forms
Metaphase
Nuclear membrane and nucleoli disappear
Chromosomes line up at equitorial plate of mitotic spindles
Anaphase
Chromosomes split to opposite poles
Telophase
Nuclear membrane forms around chromosomes at poles
Chromosomes uncoil and nucleoli reappear
Cytoplasm divides into two daughter cells
Meiosis
Produces four daughter cells with half the chromosome number (haploid, n)
Only gametes
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
Junctional complex
Tight junction
Intermediate junction
Desmosome
Cell turnover rate (high to low)
Oral, epidermal, GI
Smooth muscle, vascular endothelial
Skeletal muscle, cardiac
Neurons
Hemidesmosomes
Cell to ECM contact
Integrins are principle proteins
Pemphigus: autoimmunity against des isomers
Pemphigoid: autoimmunity against hemidesmosomes
Gap junction
Areas of free communication between cells to allow passage of fluids, ions and small molecules
Functions of epithelium
Barrier Diffusion Absorption Secretory Transport Sensory
What is the thinnest epithelium in the oral cavity?
Sublingual mucosa
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
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
Epithelium classification by morphology
Squamous: wide and short
Cuboidal: cubic
Columnar: tall and skinny
Transitional: ranges from squamous to cuboidal
Epithelium classification by location
Endothelium: lines blood vessels
Mesothelium: lines closed body cavities
Functions of basement membrane
Attachment
Separation
Filtration
Scaffolding
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
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
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
Where do most CTs derive from?
Mesoderm
CTs of head and neck can derive from neural crest ectoderm
Cells of connective tissue
Resident cells: fibroblasts, myofibroblasts, adipocytes, macrophages, mast cells, mesenchymal cells
Transient cells: lymphocytes, neutrophils, monocytes, plasma cells, eosinophils, basophils
3 types of glands
Exocrine: secrete through ducts
Endocrine: secrete into blood stream
Paracrine: secrete into extra cellular spaces
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)
Cartilage
Avascular connective tissue
Composed of chondrocytes in lacunae
Chondroblast: initial cartilagenic cells
Cartilage matrix
Type 2 collagen
Ground substance
Glycosaminoglycans (hyaluronic acid, chondroitin sulfate, keratin sulfate)
Proteoglycans
What type of cartilage is the precursor to bone in endochondrial ossification?
Hyaline cartilage
Does cartilage contain calcium salts?
No, it does not contain calcium salts
Perichondrium covers cartilage except what three locations?
Fibrocartilage
Articular cartilage of joints
Basal/costal cartilage
Perichondrium
Inner cellular layer: produces chondroblasts
Outer fibrous layer: provides protection
Growth of cartilage
Appositional: new cartilage forms on surface of existing cartilage
Interstitial: new cartilage forms in existing cartilage, chondrocytes divide
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
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
Functions of bone
Support Protection Movement Mineral storage Hematopoiesis
Bone matrix
Organic: type 1 collagen, osteocalcin, osteonectin, ground substance
Inorganic: hydroxyapatite
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
Endochondral ossification
Subperiosteal bony cuff forms around hyaline cartilage model
Chondrocytes hypertrophy and die and matrix becomes calcified
Long bones, vertebrae, mandibular condyles
Bone growth
Appositional growth: both endochondral and intramembranous at any time
Interstitial growth: endochondral only until epiphyseal plates close
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
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
Bone remodeling
Mature bone grows only by appositional growth
Osteoclasts resorb; osteoblasts lay down
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
Fracture repair steps
- Blood clot formation
- Bridging callus formation
- Periosteal callus formation
- New endochondral bone formation
Calcium regulation
Parathyroid hormone: stimulates osteoclasts to release calcium
Calcitonin: inhibits osteoclasts to decrease blood calcium levels
Classification of joints based on motion
Synarthrosis: immovable
Amphiarthrosis: slightly moveable
Diarthrosis: fully movable
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 jointsSynovial joint types
Ball and socket Gliding hinge Pivot Ellipsoidal Saddle
Components of synovial joint
Articular capsule Articular cartilage Synovial cavity Synovial membrane Synovial fluid
Nervous tissue components
Perikaryon (cell body)
Axon
Dendrites
Cytoskeleton
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)
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
Functions of blood
Transportation
Buffering
Thermoregulation
Hematocrit
Percentage of RBCs in blood
45% men
40% women
Components of blood
Plasma (55%): water,proteins, electrolytes
Formed elements (55%): erythrocytes, leukocyte a, and platelets
Serum = blood plasma - fibrinogen and clotting factors
Lifespans of formed blood elements
Erythrocytes/ 120 days
Platelets: 5-10 days
Leukocytes: variable
Granulocytes vs agranulocytes
Granulocytes
Neutrophils (60%)
Eosinophils (5%)
Basophils (1%)
Agranulocytes
Lymphocytes (30%)
Monocytes (4%)
Note: monocytes became macrophages once they enter tissues
Leukocyte S
Neutrophils: phagocytosis, acute inflammation
Eosinophils: phagocytosis, chronic inflammation
Basophils: hypersensitivity
Lymphocyte: immunoregulation
Monocytes: phagocytosis, chronic inflammation
Blood vessel layers
Tunica intima (simple squamous ) Tunica media (smooth muscle) Tunica adventitia (collagen and elastin)
Pancreas
Exocrine: digestive enzymes via ducts
Endocrine: glucagon, insulin, somatostatin via bloodstream
Exocrine pancreas
Produces digestive enzyme precursors that are activated by trypsin in small intestine
Pancreatic acini
Centroacinar cells
Endocrine pancreas
Regulates blood glucose levels
Islets of langerhans
Alpha cells = glucagon
Beta cells = insulin
Delta cells = somatostatin (inhibits alpha and beta cells)
What regulates pancreatic enzyme secretion ?
Secretin in the duodenum (increase bicarbonate secretion)
CCK (increase proenzyme secretion)
Urinary system components
Kidneys
Ureters
Urinary bladder
Urethra
Kidney functions
Remove metabolic waste Conserve body fluids Synthesize erythropoietin Synthesize renin Hydroxylatea vitamin D
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 rectaPyramids of kidney
Conical structures in medulla composed of medullary straight tubules, collecting ducts, and vasa recta
Medullary rays of kidney
Striations in the cortex radiating from medulla composed of cortical straight tubules and collecting ducts
Juxtaglomerular apparatus
Macula densa: part of distal convoluted tubule
Juxtaglomerular cells: modified smooth muscle cells that secrete renin
Extraglomerular mesangial cells: phagocytosis cells
What does renin do?
Regulates blood pressure
Produced in juxtaglomerular cells
Nephron functions
Filtration
Absorption
Secretion
Excretion
Nephron components
Glomerulus Bowman' capsule Proximal convoluted tubule Loop of Henle Distal convoluted tubule
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
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
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
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
Layers of the heart
Endocardium (simple squamous)
Myocardium (cardiac muscle)
Pericardium (connective tissue and adipose)
Sinusoid
fenestrated or disconinuous capillaries in liver, spleenand endocrine glands
larger and irregular compared to capillaries in order to accommodate phagocytic cells
Where does the greatest drop in blood pressure in circulation occur?
From arteries to arterioles
Capillaries
Only endothelial layer
one erythrocyte wide
slowest velocity of blood flow
gas and metabolite exchange via diffusion
Venules vs Veins
Venules have thick tunica adventitia
Veins have thickest tunica adventitia, some valves, some vasa vasora
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
Tachycardia and Bradycardia
Tachycardia > 100bpm
Bradycardia
Lymph
Yellowish, plasma like liquid containing mostly lymphocytes
Lymph is not pumped; it relies on valves, gravity, and skeletl muscle contractions
Where is most of the lymph reurned to?
The junction of the left internal jugular and subclavian veins
Functions of lymphatic system
Transport tissue fluid to circulation
Tranport fat metabolites to circulation
Filtration of foreign agents in lymph nodes
Immunological surveillance
Lymph Drainage
Thoracic duct: majority of the body (left sublcavian vein)
Right lymphatic duct: upper right body (right subclavian vein)
Components of Lymphatic System
Bone marrow Thymus Spleen Lymph Lymphatic vessels Lymph nodes Lymphatic nodules (tonsils, appendix, Peyer's patches)
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
Bone Marrow
Site of B cell maturation
Contains pluripotent stem cells capable of differentiating into lymphocytes or phagocytes
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)
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
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
What is the most abundant of the pituitary hormones?
GH
ADH and oxytocin are synthesized in hypothalamus and stored in posterior pituitary
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
What is the normal T4 to T3 ratio?
20:1
Thyroid gland issues
Hypothyroidism: Cretinism (children), Myxedema (adults), Hashimoto’s thyroiditis (autoimmune)
Hyperthyroidism: Grave’s disease (toxic goiter)
Cell components of thyroid follicles
Follicular cells: T4 and T3 secretion
Parafollicular cells: secrete calcitonin
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
Effects of PTH
Increased blood calcium levels Stimulation of bone resorption Increased renal calcium resorption Decreased renal phosphate resorption Increased intestinal calcium absorption
Pineal Gland
Small, cone-shaped gland located at back of 3rd ventricle of brain
Regulates sleep-wake cycle Contains numerous neurotransmitters including melatonin
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
Hormones produced in posterior pituitary (neurohypophysis)
Antidiuretic hormone (ADH) Oxytocin
Note: embryological origin is Infundibulum
Major Parathyroid Cells
Chief cells: secrete PTH
Oxyphil cells: unknown function
Adrenal Glands
Located superior to kidneys
Provides regulatory feedback to pituitary and hypothalamus
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
Inner medulla of adrenal glands
Developed from neural crest ectoderm Produces catecholamines (epinephrine, norepinephrine)
Respiratory System Functions
Air filtration
Air conduction
Gas exchange
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
Alveoli
site of gas exchange
aleolar septum separates adjacent alveolar air spaces
Types of alveolar epithelial cells
Type 1: 95%; gas exchange, joined by tight junctions
Type 2: 5%: secretion of surfactant
What are dust cells?
Alveolar macrophages
Functions of the upper digestive system
Barrier
Absorption
Secretion
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
Peristalsis
the waves of smooth muscle contraction of the muscularis externa that propels GI contents along
Esophagus
Transports food from oropharynx to the stomach
nonkeratinized stratified squamous epithelium
Glands: mucous
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
Small Intestine
Digestion of chyme and absorption
Simple columnar epithelium renewing 5-6 days
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
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)
Muscularis externa
Myenteric (Auerbach’s) plexus is located between two layers of smooth muscle
Small Intestine Glands
Intestinal glands (Crypts of Lieberkuhn): small intestine at base of villi Submucosal glands of Brunner: only in duodenum
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
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
Large intestine organization
Cecum: appendix Ascending colon Transverse colon Descending colon Sigmoid colon Rectum (no teniae coli) Anal canal
Gut-Associated Lymphatic Tissue (GALT)
Lamina propria (GI tract) Peyer's patches (ileum) Lymphoid aggregates (large intestine and appendix)
Liver
Exocrine: bile
Endocrine: albumin, lipoproteins, alpha/beta globulins, prothrombin, fibronectin
Portal Triad
Hepatic artery
Portal vein
Bile duct
Liver lobules
Hexagonal stacks of hepatocyte cords separated by anastamosing sinusoid
Surround a central vein (where sinusoids drain)
Portal triads located at each corner
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
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
Biliary flow
Hepatocytes -> Canaliculi -> Canals of Hering -> Inerlobular bile ducts -> Lobar ducts -> Common hepatic duct -> Common bile duct -> Duodenum
What increases biliary flow?
Primarily CCK (produced by enteroendocrine cells)
secretin and gastrin also increase biliary flow
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
True or false: biliary flow is opposite to that of blood flow?
True
Central vein -> portal canal
What condition does elevated serum bilirubin result in?
Jaundice
Bile composition
Water
Electrolytes
Cholesterol
Lecithin
Bile salts (glycocholic acid, taurocholic acid)
Bile pigments (bilirubin, biliverdin, glucoronide)
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
Duct system of testes
Seminiferous tubules -> Rete testis-> Efferent ductules -> Ductus epididymis-> Ductus (vas) deferens-> Ejaculatory duct
Prostate gland
Surrounds proximal urethra
Secretes acid phosphatase, fibrinolysin, citric acid
Penis
3 major masses of tissue surrounded by dense fibroelastic capsule (tunica albuginea)
Corpora cavernosa (2): dorsal erectile tissue
Corpus spongiosum: ventral, urethra
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)
Ovarian follicle development
- Primordial oocytes
- Multilayered theca interna (secretes estrogen)
- Surrounding stromal cells
- Split in theca interna forms Graafian follicle
Oviducts
4 sections from ovary to uterus
- Infundibulum: contains fimbriae
- Ampulla: longest, fertilization
- Isthmus
- Uterine
Uterus
3 layers
- Endometrium
- Myometrium
- Perimetrium
Cervix = lowest section of uterus connecting to vagina
Vagina
Lined by nonkeratinized stratified squamous
Does not contain glands
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
Functions of skin
Protection Sensory Homeostasis Synthesis (vit D) Excretion (sweat)
Layers of skin
Epidermis
Basement membrane
Dermis
Hypodermis
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
Layers of basement membrane
Lamina lucida
Lamina densa (basal lamina)
Type 4 collagen, proteoglycans, laminin, fibronectin, anchoring fibrils
Reticular lamina: type 3 collagen
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
Specialized epidermal cells
Melanocytes: produce melanin
Keratinocytes: produce keratin
Langerhans cells: APCs
Merkel cells: touch sensation
Concentrated in basal layer
Skin nerve endings
Free nerve endings: most abundant; touch, temperature, pain
Pacinian corpuscles: pressure and vibration
Meissner’s corpuscles: touch
Ruffini endings: mechanoreceptors
Hair
Regulates body temp
Composed of keratinized cells
Produced by hair follicles
Components of hair follicle
Bulb
Internal root sheath
External root sheath
Arrector pili muscle
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
Sebaceous glands
Sebocytes: secrete sebum (oily substance on skin and hair)
Outgrowths of external root sheaths of hair follicles
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 conesWhat is aqueous humor?
The watery fluid within the anterior and posterior chambers of the eye
What is vitreous humor?
The transparent watery gel within the vitreous chamber
Chambers of the eye
Anterior: cornea to iris
Posterior: iris to lens
Vitreous: lens to neural retina
10 layers of retina
Outermost to innermost
- Pigment epithelium
- Photoreceptors cells (rods - light, cones - color)
- External limiting membrane
- Outer nuclear layer
- Outer plexiform layer
- Inner nuclear layer
- Inner plexiform layer
- Ganglion cell layer
- Optic nerve fibers
- Internal limiting membrane
What vitamin is a source of retinal, an essential component of rods?
Vitamin A
Deficiency results in night blindness
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
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
