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At what level does the abdominal aorta bifurcate into the common iliac arteries and also gives rise to the middle sacral artery?
- L4, The aorta (contains a lot of elastic fibers in the tunica media) is the main trunk of a series of vessels that convey oxygenated blood, commences at the upper part of the left ventricle and arches backward to the left side and descends within the thorax on the left side of the column and passes through an opening of the diaphragm in front of the T12. At the level of L4 it divides into the 2 common iliac arteries and gives rise to median sacral artery.
- Ascending aorta - short vessel at the aortic opening of the left ventricle (only branches are right and left coronary arteries that supply blood to heart)
- Aortic Arch - gives rise to 3 arterial branches - brachiocephalic, left column carotid and left subclavian (blood to head, neck and upper limbs)
- Descending aorta - Thoracic portion (from T4 to T12), its arterial branches (posterior intercostal, subcostal arteries) supply thorax and diaphragm. Abdominal portion begins at the aortic hiatus in the diaphragm and extends from T12 to L4, supplies abdomen, pelvic and lower limb regions.
As a result of curiosity a 2 year -old boy decides to stick a sharp object up his nose and causes a nosebleed (epistaxis) of the anteroinferior portion of the nasal septum. This bleeding involves the septal branches of the:
a) Ophthalmic and occipital arteries
b) Sphenopalatine and facial arteries
c) Frontal and parietal arteries
d) Pharyngeal and meningeal arteries
- Arterial blood supply to the nose derives mainly from branches of the maxillary artery, the most important branch of which is sphenopalatine artery (enters nasal cavity through the sphenopalatine foramen). Kiesselbach's area is the area of anastamosis between the sphenopalatine, ethmoid and superior labial (branch of facial artery), responsible for more common epistaxis.
- Other small arteries that supply blood to the nasal cavity - descending palatine (branch of maxillary artery), superior labial branch (facial artery), posterior and anterior ethmoidial branches of ophthalmic artery.
- Ophthalmic artery is branch of internal carotid
- Maxillary artery and superficial temporal artery are terminal branches of external carotid
- Pterygopalatine fossa cone shaped paired depression deep to the infratemporal fossa. Is between maxillary tuberosities and pterygoid process contains maxillary artery and nerve.
The portion of the duodenum proximal to the entry of the bile duct is supplied by the ______.
The portion of the duodenum distal to the entry of the bile duct is supplied by the ______.
a) superior pancreaticduodenal artery; inferior pancreaticduodenal artery
b) inferior pancreaticduodenal artery; superior pancreaticduodenal artery
c) Superior renal artery; inferior renal artery
d) inferior renal artery; superior renal artery
- The duodenum proximal to the entry of the bile duct receives its arterial supply from the superior pancreaticduodenal artery (a branch of the gastroduodenal artery that comes from the celiac trunk). The distal portion of the duodenum receives its arterial supply from the inferior pancreaticduodenal artery which branches from the superior mesenteric artery.
- Large intestine extends form the ileum to the anus, it is divided into the cecum, the appendix, the ascending colon, the transverse colon, the descending colon and the sigmoid colon.
Which of the following arteries branches directly from the aortic arch?
a) left external carotid artery
b) right common carotid artery
c) right subclavian artery
d) brachocephalic trunk
- The brachocephalic trunk branches directly form the aorta arch. The AA lies behind the manubruim sterni and arches upward, backward and to the left, then passes down at the level of the sternal angle T4 becoming the descending thoracic aorta.
- Branches of the AA are:
- Brachocephalic artery- extremely short and is the first branch, passes upward to the right of the trachea and divides into the right common carotid and the right subclavian arteries (behind the right sternoclavicularjoint) There are 2 brachocephalic veins (L and R) but one artery)
- Left common carotid artery - arises from the convex surface of the AA on the left side of the brachocephalic artery, goes up to the left of the trachea and enters the neck at the sternoclavicularjoint)
- Left subclavian artery - arises from the AA behind the left common carotid artery. arches over the apex of the left lung.
- *upper limbs are supplies by subclavian arteries.
All of the following statements concerning the common carotid arteries are true EXCEPT one, WHICH ONE?
a) The common carotid arteries are the same in length
b) The common carotid arteries differ in their mode of origin
c) the right common carotid artery is a branch of the brachiocephalic trunk
d) The left common carotid artery is a branch of the aortic arch
- The common carotid arteries are the same in length . THE CCA travels in a deep sheath containing internal jugular vein and vagus nerve.
- Internal carotid has no branches in the neck it supplies the inside of the cranial cavity. Gives rise to the ophthalmic artery, major blood supply to the orbit and eye, enters orbit through the optic foramen with the optic nerve. It ends by dividing into anterior and middle cerebral arteries.
- External carotid supplies OUTSIDE the cranial mostly
- ANTERIOR BRANCH: superior thyroid artery. lingual artery, facial artery, maxillary artery
- POSTERIOR BRANCH: Ascending pharyngeal artery, occipital artery, posterior auricular artery, superficial temporal artery.
What is the major arterial origin supplying the mandibular anterior teeth?
a) mandibular artery
b) facial artery
c) vertebral artery
d) maxillary artery
- Maxillary artery arises from the External carotid and gives rise to 3 branches to form a plexus to supply the maxillary arches.
- Maxillary: Anterior superior alveolar, middle superior alveolar (both through infraorbital), posterior superior alveolar (comes from the 3rd part of the max. art. before it enters pterygopalatine fossa)
- Mandibular: Inferior alveolar (from the first part of the max. art.)
A collision during a basketball game left the point gaurd seeing double. The on-court physician determined that the paper-thin wall that holds up the eye had collapsed and the right eye sat lower than it should have, this causing the diplopia. Name the projection of the ethmoid bone that collapsed:
a) Cribiform plate
b) Crista galli
c) Ethmoid sinus
d) Lamina papyracea
- Lamina papyracea of the ethmoid bone, which is a light and spongy cubical bone at the anterior part of the base of the cranium. 4 parts horizontal: cribiform plate (olphactory foramina nerves), perpendicular plate (nasal septum, crista galli, attatches falx cerebri) and 2 lateral masses.
- Lateral masses (L and R) project downward from the cribiform plate, they contain the ethmoid sinuses and the orbital plate of the ethmoid bone (lamina papyracea) a paper thin medial wall of the orbit.
Which of the following is not an aperture of the sphenoid bone?
a) foramen ovale
b) foramen spinosum
c) optic canal
d) carotid canal
e) superior orbital fissure
- Carotid canal is not an aperture of the sphenoid bone, which is a bone situated at the base of the skull in front of the temporal and basilar part of occipital bone.
- Hollow body: sella turcica (pituitary gland)
- Greater wings: foramen rotundum (V.2), foramen ovale (V.3), foramen spinosum (middle meningeal vessels and nerves to the brain)
- Lesser wings: Help form the roof of orbit and superior orbital fissure; contain 'optic canal' (foramen, that transmits optic nerve CNII and ophthalmic artery)
- Pterygoid processes: descends from where the greater wings and body unite
Bones of the skull, part of the mandibule and the clavicle are formed by:
a) endochondral ossification (going through a cartiliginous stage)
b) subchondral ossification
c) Intramembranous ossification (forms directly as bone)
d) primary ossification
- They are formed by Intramembranous ossification, MOST bones are endochonral and began as hyaline cartilage (osteocytes replace chondrocytes at the ossification center, then mesenchymal cells differentiate into osteoblasts)
- Intermembranous bone grows by appositional growth ONLY (new layers), Endochondral both appositional and interstitial growth
During distalization of molars in a bodily orthodontic movement, the alveolar bone distal to the tooth must resorb, and the alveolar bone mesial to the tooth must appositionally grow. In orthodontic movement, the alveolar bone is being remodeled. This remodeling is a function of:
a) osteoclasts and osteoblasts
b) chondroblasts and osteoblasts
c) osteoblasts and osteocytes
d) chondrocytes and osteocytes
- Osteoclasts and osteoblasts.
- Osteoblasts derives from mesenchyme (fibroblasts) and are bone building cells. synthesize collagenous fibers and bone matrix. Once trapped in their own matrix they turn into osteocytes.
- Osteoclasts derive from stem cells in bone marrow (like monocytes and macrophages), large multinucleated contain phagocytic vacuoles (Howship's lacuna is a hollow created in bone due to osteoclast activity)
- Osteoid is newly formed organic bone matrix with NO CALCIFICATION, surrounded by glycosaminoglycan gel with affinity for calcium mineral.
All are functions of the skeletal system EXCEPT ONE:
a) Lymph filtration
b) Mineral storage
e) body movement
- Lymph filtration is NOT a function of the skeleton. Bone exists in 2 forms COMPACT and SPONGY (or cancellous, which consists of a branching network of trabeculae)
- Bone mineralization starts with 1. holes or pores in collagen fibers 2. release of matrix vesicles by osteoblasts 3. alkaline phosphatase activity in osteoblasts and matrix vesicles 4. degradation of matrix pyrophosphate to release inorganic phosphate group.
- Fracture repair, 1. clot formation 2. bridging callus formation 3. periosteal callus formation and 4. New endochondral bone formation.
At the TMJ, hinge movements occur between the:
a) condyle and articular eminence
b) articular disc and articular eminence
c) condyle and articular disc
d) Articular disc and articular cavity
e) condyle and articular cavity
- Condyle and articular disc, the TMJ is a synovial joint with 2 articular cavities (each responsible for a different movement at the joint (one between the disc and condyle process of mandible THIS IS THE HINGE and one between the disc and articular eminence of temporal THIS IS THE GLIDING COMPONENT). The gliding occurs after the hinge movement.
- The mandibular notch/coronoid notch (concave area between condyle and coronoid process) transmits arteries and nerves to masseter, posterior slope of which is lined by fibrous connective tissue.
A patient comes into the orthodontist's office as reffered to by his general dentist. The orthodontist notes the patients tongue thrusts and notes that early treatment could prevent skeletal problems. Soft tissue development is though to encourage mandibular growth:
a) upward and forward
b) upward and backward
c) downward and forward
d) downward and backward
- Downward and forward is the wat the mandible grows. Soft tissue development carries mandible this way, while the condylar growth fills the resultant space to maintain contact with skull.
- Alveolar bone only grows to support teeth, no tooth grows no bone grows.
Which of the following structures does not form a portion of the lateral wall of the nasal cavity?
b) Palatine bone
e) Ethmoid bone
- Vomer does not form portion of the lateral wall of the nasal cavity. walls are formed by maxilla, palatine bone, ethmoid and cohchaes. Medial wall formed by Vomer, ethmoid and septal cartilage.
- Nasal cavity is innerved by the olphactory CNI and branches of the trigeminal CNV. Blood supply comes from sphenopalatine branch of maxillary artery, ethmoidal branch of ophthalmic artery and septal branch of labial artery (facial) and descending palatine branch of maxillary.
- Nasopalatine nerve comes from pterygopalatine ganglion, passes through sphenopalatine foramen into the incisive canal.
- Communication between pterygopalatine fossa and nasal cavity is sphenopalatine foramen.
A tubercle is:
a)a small, rounded process
b) a prominent elevated ridge or border of a bone
c) a large, rounded, roughened process
d) a sharp, slender, projecting process
A tubercle is a Small rounded process
The shaft of a long bone is capped on the end by a spongy bone that is surrounded by compact bone, This is called the:
Epiphysis. Long bones have a tubular shaft (diaphysis) and are usually called by an Epiphysis at each end. They are separated at the growing phase by an epiphyseal cartilage.
Which craneal fossa houses the cerebellum, medulla, and pons?
a) anterior craneal fossa
b) middle craneal fossa
c) posterior cranial fossa
- Posterior cranial fossa. The internal surface of the base of the skull consists of 3 cranial fossae They increase in size and depth from anterior to posterior.
- Anterior - frontal lobes of the brain, formed by frontal, ethmoid and sphenoid. Crista galli (attatches the falx cerebri and cribiform plates olphactory nerves.
- Middle - composed by the body and great wings of the sphenoid. It is the busiest, with the temporal lobes of the brain. Optic canal, optic chiasma, sella turcica, hypophyseal fossa for pituitiary gland.
- Posterior - deepest of all, houses cerebellum, medulla and pons, comes from petrous part of sphenoid and enclosed by occipital bone. Contains 4 important foramina; internal acoustic meatus, jugular foramen, hypoglossal canal and foramen magna.
Treacher Collins syndrome is a rare genetic disorder that presents with many craniofacial deformities. One of the characteristic traits is downward slanting eyes, which is caused by underdevelopment of the bone that forms the substance of the cheek. Which bone is this that anchors many of the muscles of mastication and facial expression.
a) ethmoid bone
b) zygomatic bone
c) occipital bone
d) sphenoid bone
- Zygomatic bone, forms the prominence of the cheek, part of the lateral wall and floor of the orbit and parts of the temporal and infratemporal fossae.
- Articulates with 4 bones - frontal, sphenoidal, temporal (to form the zygomatic arch) and maxilla. Above the zygomatic arch is the TEMPORAL FOSSA, which is filled with the temporalis muscle (passes medial to the zygomatic arch before it inserts in the coronoid process)
- The pterygopalatine fossa communicates laterally with the infratemporal fossa through the pterygomaxillary fissure, medially with the nasal cavity though the sphenopalatine foramen. superiorly with the skull through the foramen rotundum and anteriorly with inferior orbital fissure.
Which can be defined as a tube-like passage running through a bone?
Which fossa has no bony inferior or posterior boundary?
a) Ptrygopalatine fossa
b) infratemporal fossa
c) temporal fossa
All of the following are openings from the pterygopalatine fossa EXCEPT one. Which is the exception?
a) sphenopalatine foramen
b) foramen rotundum
c) foramen lacerum
e) pterygomaxillary fissure
f) inferior orbital fissure
- Foramen lacerum is on the BASE OF THE SKULL.
- The pterygopalatine fossa (sphenopalatine fossa0 is a small triangular space behind and below the orbital cavity that communicates laterally with infratemporal fossa through pterygomaxillary fissure, medially with the nasal cavity through the sphenopalatine foramen, superiorly with the skull thru foramen rotundum and anteriorly with the orbit through the inferior orbital fissure.
- Pterygopalatine ganglion is in the pterygopalatine follow below the maxillary nerve V2. receives pregangliotic fibers from the facial nerve by the greater petrosal nerve.
Which of the following receives the opening of the nasolacrimal duct?
a) superior meatus
b) middle meatus
c) inferior meatus
- Inferior meatus
- The nasal conchae are 3 pairs of scroll-like, delicate shelves or projections that hang into the nasal cavity from the lateral walls. These increase surface area for filtering, heating and moistening air. The superior and middle are part of the ethmoid bone, inferior conchae are separate bones. The space below each concha is referred to as a MEATUS.
- Superior - below sup. concha, openings of the posterior ethmoidal sinuses
- Middle. Openings of the frontal, maxillary, anterior, and middle ethmoidial sinuses. The middle ethmoidial sinuses
- Inferior- lies below lateral to inf. conchae, opening of nasolacrimal duct. drains fluid from eye into meatus for evaporation thru respiration
A prosthodontist designs his maxillary removable complete and partial dentures to engage the hamular notch behind the maxillary tuberosities. The hamulus is a small slender hook, which accomodates the action of the tensor veli palatini. The hamulus is a component of which bone.
c) horizontal plate of palatine bone
d) perpendicular plate of palatine bone.
Sphenoid bone, the left and right pterygoid processes project downward from near the junction of each of the greater wings within the body of the sphenoid bone. Each process has a medial and lateral pterygoid plate. The medial plate ends inferiorly as a hamulus, a small, slender hook that acts as a pulley for the tensor veli palatini (innvervation V3)
A young patient arrives in the physicians office with unexplained, persistent symptoms. The patient has a bloody nasal discharge and painful oral lesions. A chest x-ray reveals "coin lesions", and labs reveal kidney failure. Ultimately, the isolation of the ANCAs - IgG antibodies - yield diagnosis of Wegener's granulomatosis. The dentist who referred this patient to the physician made a note of necrotizing oral lesion that had perforated the hard palate into the nasal cavity. The roof of the oral cavity is formed by the:
a) Ethmoid and palatine bones
b) maxilla and nasal bones
c) maxilla and palatine bones
d) nasal and vomer bones
- Maxilla and palatine bones form the roof of the oral cavity (more specifically the palatine processes of the maxilla and the horizontal plates of the palatine bones). It forms the roof of the osal cavity and the floor of the nasal cavity. The greater anterior palatine vein artery and nerve travel along the maxillary alveolar process where they join nasopalatine and sphenopalatine artery and vein exiting in the incisive Foramen.
- The anterior 2/3 of the hard palate is the palatine process of the maxilla and the posterior 1/3 os the horizontal plates of the palatine bones.
- Most palatal muscles receive motor innervation from pharyngeal plexus of nerves, tensor muscles of the palate receives motor branch from v3 and sensory by V2
Most precisely, osteocytes are located in these spaces:
Between the rings of bone matrix, the bone cells are located in spaces called lacunae. Compact bone has closely packed osteon or haversian systems, they have central canals called haversian canal surrounded by centric rings (lamallae) of matrix. Canaliculi are small channels that radiate from the lacunae to haversian canal (containts blood vessels) to provide a passageway through the hard matrix.
A 62 year old patient with osteoarthritis is having her right hip replaced. A titanium-ceramic prothesis will act as the head of her femur and a poly-ethylene cup will act as the socket in the hip bone. In a normal hip, this cup shaped cavity that receives the head of the femur is called:
a) Pubic tubercule
b) Obturador foramen
d) pelvic girdle
- The Os Coxa or HIPBONE is formed by the fusion of the ilium, ischium and pubis on each side of the pelvis. The Os Coxa articulates with the sacrum at the sacroiliac joint PELVIC GIRDLE. Two hipbones articulate at SMPHYSIS PUBIS
- The ilium, posseses iliac crest, posseses greater sciatic notch.
- The ischium - L shaped, bears weight when person is upright, seated. Has ischial spine and ischial tuberosity. The obturator foramen is formed by ramus of ischium together with pubis.
- Pubis - is divided into a BODY, superior ramus and inferior ramus. The body of the 2 pubic bones articulate to form symphysis pubis
A young couple is undergoing in vitro fertilization because of incompetent and relatively non-fertile sperm. Which organelle is responsible for sperm motility?
Flagellum is only present in spermatozoa, they are similar to cilia (short hair like projections that produce movement in coordinated waves) but much longer and they produce movement. They both resemble centrioles in having nine sets of microtubules arranged in a cylinder, but unlike centrioles each set is a doublet rather than triplet.
The inactive X chromosome in a female cell is called the:
a) Pineal body
b) Lateral body
c) Golgi body
d) Barr body
- The Barr body is also known as the sex cromatin body. In the first few weeks after conception, both X chromosomes are active, later one is deactivated and appears a dense chromatin mass called the Barr Body. This is NOT present in males.
- Sex of the embryo is determined in the 8th week.
- Females have 45 active chromosomes in the Barr body.
In which cellular component are glycoproteins assembled for extracellular use?
a) The golgi apparatus
b) the endoplasmic reticulum
c) The nucleus
d) The nucleolus
- The golgi apparatus (has cisternae, convex cis, concave trans) modifies lipids and proteins, then stores and packages the materials that will be exported.
- Lysosomes cytoplasmic membrane bound vesicles that contain glycoprotein hydrolytic enzymes that digest and destroy exogenous material (bacteria)
Which of the following is the distinctive array of microtubules in the core of the cilia and the flagella composed of a central pair surrounded by a sheath of nine doublet microtubules (Characteristic "9+2) pattern?
An Axoneme is the core scaffold of the eukaryotic cilia and flagella, which are projections from the cell made up of microtubules. The axoneme serves as a skeleton in both. The characteristic feature of "9+2" arrangement of microtubules (nine pairs of doublet microtubules)
Which organelle is the major site of oxidative phosphorylation and contains proprietary, maternally transmitted DNA?
Mitochondria are the thread-like structures within the cytoplasm that provide most of the body's ATP, which fuels many other cellular activities. Double membranous structure, catabolism, ATP synthesis
Kupffner cells in the liver are a specialized type of:
b) plasma cell
c) mast cell
A Macrophage is any phagocytic cell derived from a monocyte, including the Macrophages of the liver (Kupffner cell), spleen and loose connective tissue (histiocyte).
Which cell lines the lumen of the seminiferous tubules and secretes hormones and proteins that facilitate spermatogenesis?
a) Interstitial cells of leydig
b) principal cells
c) Sertoli cells
d) Clara cells
Sertoli cells, together with a stratified later of developing gametes comprise the cellular majority of the seminiferous tubules. Sertoli cells bind testosterone and hydroxytestosterone produced outside of the cell through an androgen binding protein ABP. These hormones are essential to produce sperm. Follicle stimulating hormone FSH is produced by pituitary gland. Insterstitial cells of Leydig are on the loose vascular connective tissue surrounding the seminiferous tubules.
In which phase of the interfase does the DNA replicate in preparation for mitosis.
a) G1 phase
b) S phase
c) G2 phase
d) M Phase
- S phase. The cell cycle consists of "INTERPHASE (including growth and synthesis) and MITOSIS."
- GROWTH (increase size through metabolism)
- SYNTHESIS (double DNA
- MITOSIS (splitting of nucleus, diploid cells formed)
- Interphase can be subdivided into G1 phase (first growth, S phase (DNA synthesis) and G2 phase (second growth phase.
- THEN COMES M phase or MITOSIS
The plasma membrane (cell membrane):
a) Surrounds the cell wall and serves to protect the cell from changes in osmotic pressure
b) is a polysaccharide-containing structure that functions in attachment to solid surfaces, preventing desiccation and protection
c) Is a non-permeable membrane enclosing the cell wall
d) Is a dynamic, selectively permeable membrane enclosing the cytoplasm.
The plasma membrane Is a dynamic, selectively permeable membrane enclosing the cytoplasm. 7.5-10nm thick. Located between the cell wall and the cytoplasm. Essential for passive nutrient diffusion and active transport across the membrane (requires energy). Consists of a PHOSPHOLIPID BIOLAYER called fluid MOSIAC found in both prokaryotic and eukaryotic. Cell wall surrounds membrane to protect from changes in osmotic pressure, anchor flagella, transport molecules etc... Mitochondrion contains inner membrane and outer membrane (as does the nucleus)
What type of cell in the dental papilla adjacent to the inner enamel epithelium differentiates into odontoblasts:
a) stellate reticular cell
b) mesenchymal cell
d) follicular cell
- Mesenchymal cells (also called mesoblastic cells), differentiate into diverse type of cells, these adjacent to the inner enamel epithelium differentiate into odontoblasts which become predentin that calcifies into dentin.
- Mesectoderm (ectomesenchyme) is derived from the ectoderm, NEURAL CREST in the young emrybo. These neural crest cells give rise to the spinal ganglia and the ganglia of the autonomic nervous system. These also give rise to the neurolemma cells (schwann cells), cells of the meninges, melanocytes , skeletal and muscular components of the head, and chromaffin cells of the adrenal medulla etc..
On the playground at recess, a young girl is stung by a bee and immediately breaks out in hives and starts gasping for air. The teacher grabs an epinephrine autoinjector form the first aid kit and is able to save the girl, What cells, when bound by IgE, are responsible for this anaphylactic reaction?
d) kupffner cells
- Mast cells are large cells with coarse metachromatic granules, containing heparin (anticoagulant) and histamine (vasodilator) and other substances, normally NOT found in circulation are the mediators of inflammation on contact with antigen.
- The IgE antibody causes allergic reactions has a propensity to attach to Mast cells and basophils, this reaction causes the cell to rupture and release large quantities of histamine, heparin, seratonin, bradykinin SlowReactingSubstance-Anaphylaxis, this causes the allergic reaction.
A chromosome is a maximally condensed chromatin wrapped around a protein base of primarily:
- Chromatin consists of stands of DNA would around a protein base of HISTONES.
- Chromatin appears in 2 forms - Euchromatin (extended) and Heretochromatin (condensed).
Plasma cells are immediate derivations of which cell type:
a) CD8+ Tcell
b) CD4+ Tcell
c) B lymphocyte (b-cell)
- B lymphocyes, plasma cells are further differentiated B cells that are very important in the production of antibody (rarely found in peripheral blood and life of 5-10 days).
- B-cells - 20-30% of circulating lymphocytes and are associated with lymphoid organs. When they become sensitized to an antigen they develop into plasma cells or memory B cells.
- T-cells - 70-80% of lymphocytes, asspciated w spleen, lymphnodes and other lymphoid tissues once sensitized they differentiate into other t cells like Memory T cells, Killer T-cells, Helper T cells(help activate other t-cells)
A chronic alcoholic is starting to show signs of cirrhosis and liver failure. Which of the following cell types will start to become ineffective in manufacturing albumin, fibrinogen and the prothrombin group of clotting factors:
c) Kupffer cell
- Hepatocytes (hepatic cells), make up the livers functional unit "the LOBULE", they separated by the sinusoids (livers capillary system).
- They make up 60-80% of the livers cytoplasmic mass. They synthesize protein, store protein, transform carbs, synthesize cholesterol, , bile salts and phospholipids, detox. The hepatocyte also initiates the formation and secretion of Bile.
- Kupffer cells are reticuloendothelial macrophages which line in the sinusoids. They remove bacteria and toxins that entered the blood through intestinal capillaries.
The following is the site of synthesis of rRNA:
a) Endoplasmic reticulum
c) Golgi apparatus
e) Plasma membrane
- Nucleolus is an oval body found inside the nucleus. Consists of RNA and protein not bounded by limiting membrane. It is the sure of rRna synthesis.
- Ribosomes are small particles consisting or rRna and protein, protein factories, and translation of DNA encoding it to RNA.
- Smooth endoplasmicreticulum (NO RIBOSOMES)
- ROUGH ER- RIBOSOMES
In which phase of mitosis does the chromatin condense into chromosomes and the nuclear envelope break down?
- Mitosis is a cycle with these two stages
- Interphase: Where the G1, S and G2 phase happen
- Prophase: chromatin diffuse and condense into chromosomes, at the end of prophase nuclear envelope breaks down into vesicles.
- Metaphase: Chromosomes align at the equatorial plate and attached to mitotic spindle and centromere
- Anaphase: centromeres divide, sister chromatids move towards corresponding poles.
- Telophase: daughter chromosomes arrive at poles, cytoplasm divides cytokinesis, produces the two identical daughter cells.
Meiosis occurs in which of the following cell types?
- Somatic cells only
- Germ cells only
- Both somatic and germ cells
- Neither somatic nor germ cells
- Germ cells only
- Meiosis is really 2 phases of Mitosis in which the first division the number of cells is doubled but the number of chromosomes isn't. In the second division the number of chromosomes does NOT get reduced.
The preferred site for Vitamin B12 absorption is the:
- The small intestine is the main site of absorption of digested food and consists of 3 segments; Duodenum, jejunum and ileum.
- Duodenum: Glands (Brunner's glands) produce alkaline secretions for acid.
- Jejunum: prominent valves of Kerckring
- Ileum: lymph tissue, Payer's patches, preferred site for vitamin B12 (cobalamin) absorption
- Small intestine has these important features: Intestinal villi (finger-like projections into the lumen), Epithelium lining with cells having a "brush border" of microvilli for absorption. Lamina propia (absorption of lipids). Intestinal glands (crypts of Lieberkuhn)
A patient comes to the emergency room presenting with jaundice and intense pain in the upper abdominal and between the shoulder blades. The physician suspects Choledocholithiasis that is caused by cholesterol stones formed in which organ that stores and concentrates the bile.
- Gallbladder, sac shaped organ about 3-4 inches loner and attached to the lower surface of the liver, lies on the right side of the abdomen below the ribs.
- It is joined to the liver by the cystic duct and bilary ducts and is joined to the duodenum by the common bile duct which drains at the duodenal ampulla.
- Hormone cholecystokinin (CKK) stimulates the contraction and relaxation of Oddi's sphincter and bile mixes with the chyme.
- Gallbladder receives blood from the cystic artery (branch of the right hepatic) and innervated by vagal fibers from celiac plexus.
The smooth muscle coat of the large intestine consists of three bands called taeniae coli
The walls of the large intestine have more villi than the small intestine.
- Which is true and or false?
- First statement is true, second is false
- The large intestine is composed of...
- The Cecum: beginning of the large intestine, bag- like that receives the ileum from the small intestine. The vermiform appendix extends downward from the cecum containing large amount of lymphoid tissue.
- Colon: Ascending colon (short part and extends upward on the side side of abdomen), Transverse colon, extends across the abdomen and bends downward towards descending colon. Lower in the abdomen the colon bends downward in an s-shape and into the pelvis making the sigmoid colon.
- Rectum: From the sigmoid colon to the anus. Does not contain the taeniae coli which are present in the rest of the large intestine.
- Taeniae coli: 3 thick bands of longitudinal muscle which contractions gather the colon giving it a puckered appearance.
- Large intestine is the site of water absorption and formation of feces with secretion of Goblet cells for lubrication.
Name the glands found in the submucosa of the duodenum that secrete an alkaline mucus to protect the walls of the mucosa
- Peyer's patches
- Glands of Kerckring
- Hertwig's glands
- Brunner's glands
- Crypts of Lieberkhun
- Brunner's glands (duodenal glands or submucosal glands) secrete alkaline mucus to protect the walls from enzymes in the intestinal juice (these glands histologically distinguish the stomach from the duodenum)
- Duodenum: 12 inches, C-shape, folded surface to increase absorption of sugars, fats and amino acids. It receives the common bile duct, pancreatic duct and duodenal papilla.
- Blood from the superior pancreaticoduodenal artery and inferior pancreaticoduodenal artery.
- Sympathetic and parasympathetic control contraction of smooth muscles in the intestinal wall.
Heartburn or GERD is a reflux disease associated with substernal burning pain and even metaplasia where the acidic juices of the stomach enter the esophagus and possibly the pharynx and oral cavity. In order for the gastric contents to re-enter the esophagus, they must first pass through what structure?
- Sphincter of Oddi
- Pyloric sphincter
- Hepatopancreatic sphincter
- Cardiac sphincter
- Cardiac sphincter (aka inferior esophageal sphincter)
- Esophagus: 10 inch collapsible muscular tube dorsal to the trachea and ventral to the vertebral column. The esophagogastic junction enters the cardiac portion of the stomach at the cardiac orifice. (change in surface epithelium from strat. squa. to simple columnar)
- Esophageal wall contains four layers (from lumen outward); Mucosa (epithelium lamina propia and glands), Submucosa (connective tissue, blood vessels and glands), Muscularis (middle layer, striated to smooth muscle) and Adventitia (merges with connective tissue of surrounding structures)
A newborn boy of Jewish ancestry has been vomiting frequently. His parents bring him to the physician, who notes a narrowing (stenosis) of the opening from the stomach to the duodenum due to functional hypertrophy of the surrounding muscle. What is the name of the opening from the stomach into the small intestines?
- Cardiac orifice
- Pyloric sphincter
- Lesser omentum
- Greater omentum
- Pyloric sphincter
- Stomach has 4 main regions: Cardia (junction of the esophagus and the stomach), Fundus, Body (middle portion of the stomach) and Pylorus (lower portion between the body and the gastroduodenal junction),
- Max capacity of the stomach is about 3-4 liters. Receives blood from all 3 branches of the celiac artery; Left gastric artery, right gastric artery and left and right gastro-omental arteries.
- Mucosa of the stomach contains gastric glands in the lamina propia: Parietal (found in fundus and body secrete HCl and intrinsic factor for Vit b12 absorption), Zymogenic (found in fundus and body secrete pepsinogen) and Enteroendocrine (found throughout the stomach secretes gastrin)
Which of the following vessels does not supply blood to the liver?
- Hepatic veins
- Hepatic portal vein
- Common hepatic artery
- Celiac trunk
- Hepatic veins
- The liver receives from two sources; the hepatic artery proper a branch of the common hepatic artery (branches from the celiac trunk) and the hepatic portal vein. The blood from the liver drains through the hepatic veins, inferior to the vena cava which transport blood back to the heart.
- The liver has digestive (producing bile to emulsify fats), metabolic and regulatory functions.
- Bile is produced by hepatocytes (the most versatile cells in the body. Kupffer cells line the sinusoids of the liver and function to filter bacteria and foreign particles out of blood.
- The liver is attached to the diaphragm by the falciform, triangular and coronary ligaments and attached to the stomach by the gastrohepatic and hepatoduodenal ligaments respectively.
One significant difference between the jejunum and the ileum is that the ileum characteristically contains more of which feature below?
- Plicae circulares
- Brunner's glands
- Taeniae coli
- Peyer's patches
- Peyer's patches
- The ileum is characteristic for his extensive lymphoid tissue in the form of Peyer's patches.
- Jejunum: middle portion of the small intestine, extends from the duodenum to the ileum, thicker mucosal wall for more active peristalsis. Greater diameter of mucosal inner lining for absorption. Larger valves of Kerckring and more villi for more absorption.
- Ileum: distal portion of the small intestine, extends from the jejunum to the cecum. More lymphoid tissue (peyer's patches), blood supply is more complex and more Goblet cells (secrete mucus).
Peristalsis for what organ is controlled by the taeniae coli?
- Large intestine
- Small intestine
- Large intestine, unlike the rest of the GI tract, the large intestine's longitudinal muscles do NOT form a continuous layer, instead 3 bands of longitudinal muscle called Taeniae coli.
- Large intestines main function is the absorption of water from chyme, it does NOT secrete enzymes like the small intestine.
- Vagus nerve provides parasympathetic fibers to ascending and transverse colons while descending and sigmoid colong along with rectum and anus are supplied by the pelvic splanchnic nerves.
Which cells, located in the crypts of Lieberkuhn, secrete an antibacterial enzyme that maintains the gastrointestinal barrier?
- Paneth cells
- Enteroendocrine cells
- Sertoli cells
- Absorptive cells
- Paneth cells
- Intestinal glands are sometimes called crypts of Lieberkuhn. Paneth cells are specialized secretory epithelial cells locatd at the bases of intestinal crypts. They are most common in the ileum. The secrete an antibacterial lysozyme to maintain the gastrointestinal border.
Which of the following is not produced by the pancreas?
- Cholecystokinin, is produced by the duodenum and regulates pancreatic juice secretion.
- Pancreas: Elongated gland lying behind the stomach and in front of the aorta and inferior vena cava. C-shaped and the tail meets the spleen on the left of the abdomen.
- The endocrine portion of the pancreas takes form in many small clusters of cells called islets of Langerhans. Their Alpha cells secrete Glucagon and their Beta cells secrete Insulin.
- The exocrine portion of the pancreas secretes through duct into the duodenum, trypsinogen, lipase, amylase, elastase, etc...