WEEK 4-8 Flashcards
Which side of the heart receives poorly oxygenated blood?
Right side of heart through SVC and IVC
Apex of the heart
Formed by inferolateral part of LEFT ventricle
- Lies posterior to the left 5th intercostal space in adults (9cm from median plane)
- Motionless throughout cardiac cycle
Anterior (sternocostal) surface
Formed mainly by RIGHT ventricle
Diaphragmatic (inferior) surface
Formed mainly by left ventricle and partly by right ventricle
Also related to central tendon of diaphragm
Right pulmonary surface
Formed mainly by the right atrium
Left pulmonary surface
Formed mainly by the left ventricle (forms cardiac impression of the left lung)
Peritoneum
Continuous, glistening and slippery transparent serous membrane
- lines the abdominopelvic cavity and invests the viscera
Mesentery
Double layer of peritoneum that occurs as a result of invagination of the peritoneum by an organ
- provides means for neurovascular communications
- Constitutes continuity of visceral and perietal peritoneum
What connects the liver to the anterior abdominal wall?
falciform ligament
What connects the liver to the stomach?
Hepatogastric ligament (membranous portion of lesser omentum)
What connects the liver to the duodenum?
Hepatoduodenal ligament (thickened edge of lesser omentum)
What connects the stomach to the inferior surface of diaphragm?
Gastrophrenic ligament
- phrenic means diaphragm
What connects the stomach to the spleen?
Gastrosplenic ligament
- Splenic meaning spleen
What connects the stomach to the transverse colon?
Gastrocolic ligament
- colic meaning colon
What are ‘bare areas’ in relation to peritoneum?
Every organ has to have an area that is nont covered with visceral peritoneum to allow entrance and exit of neurovascular structures
What is a peritoneal fold?
Reflection of peritoneum that is raised from the body wall by underlying blood vessels, ducts and ligaments formed by obliterated fetal vessels e.g. umbilical folds on internal surface of anterolateral abdominal wall
What is a peritoneal recess (or fossa)?
Pouch of peritoneum that is formed by a peritoneal fold
What is the function of the greater omentum?
To prevent the visceral peritoneum from adhering to the parietal peritoneum. Also to prevent infection
What does the foregut develop into?
Distal oesophagus, stomach, and proximal duodenum
In development, what structures are outgrowths of the foregut?
The liver, gallbladder and pancreas
What are the three layers of smooth muscle in the stomach?
Outer longitudinal, Inner circular, Innermost oblique
Where does the foregut end?
In the second (descending) part of the duodenum with the major duodenal papilla
Which type of muscle is in the superior to inferior thirds of the oesophagus respectively?
Superior third: Skeletal striated muscle
Middle third: Mixture of skeletal striated and smooth
Inferior third: smooth muscle
Where does the stomach lie in the supine position?
In the right and left upper quadrants (epigastric, umbilical (right) and hypochondrium and flank (left) regions
Cardial notch location
Between the oesophagus and the fundus
What structure is the stomach covered by?
Visceral peritoneum except for where the blood vessels run along its curvatures
What is the blood flow of the heart?
SVC/IVC (upper and lower trunk regions respectively)—> Right atrium—>Right ventricle—-> Pulmonary artery—>lungs—>Pulmonary veins—>Left atrium—> Left ventricle—> aorta (ascending for head and upper limbs and descending for lower trunk and limbs)
What systemic circulation?
The blood vessels that carry blood from the left side of the heart to the tissues and back to the right side of the heart
What is the diastole?
Ventricular elongation and filling
What is the systole?
Period of ventricular shortening and emptying
What is the Epicardium?
a thin external layer (mesothelium) formed by the visceral layer of serous pericardium
What is the Myocardium?
The THICK, MIDDLE helical layer composed of cardiac muscle
What is the Endocardium?
The THIN, INTERNAL layer (endothelium and subendothelial connective tissue) or lining membrane of the heart that also covers its valves
What do the walls of the heart mainly consist of?
Myocardium especially in the ventricles
What motion do the ventricles produce when contracting and why?
They produce a wringing motion due to the double helical orientation of the muscle fibres
Which part of the spiral of the ventricle causes the blood to be ejected?
the outer (basal) spiral contracts, first narrowing then shortening the heart, reducing the volume of the ventricular chambers thus ejecting blood
Which part of the spiral of ventricle causes the blood to come in (draw blood in)?
the inner (apical) spiral ELONGATES the heart, followed by widening as myocardium briefly relaxes, increasing the volume of chambers thus drawing blood from the atria
Which part of heart does the outer basal spiral constitute?
The outer wall of the RIGHT ventricle (fibres are nearly horizontal) AND the external layer of the outer wall of the LEFT ventricle (Is)
Which part of the heart does the deeper apical spiral constitute?
The INTERNAL layer of the outer wall of the left ventricle. It is a lighter appearance than the basal muscle and fibres are ‘criss-cross’ which makes up he interventricular septum
What in the heart is double layered?
The septum and outer wall of the left ventricle
What is the skeleton of the heart?
Complex framework of dense collagen forming four FIBROUS RINGS that surround the orifices of the valves, a right and left FIBROUS TRIGONE (formed by connections between rings), and the membraneous parts of the interatrial and interventricular septa
Atrioventricular groove also known as…
Coronary sulcus
which animals have a bileterally symmetrical body plan?
Arthropods and mammals
What are the four characteristics of all chordates?
Notochord,(skeletal), Dorsal hollow nerve cord, Pharyngeal slits(modified for breathing in some animals) or clefts and a muscular post anal tail (locomotion)
What are some common tetrapod characters?
Neck, Ribs, Fin skeleton, flat skull, eyes on top of skull
What are the four features of the amniotic egg?
Allatois, Amnion, Chorion, Yolk Sac
How are body plans classified?
Based on the tissue structures of organisms
How are animals classified?
By a heirachial classification of evermore comprehensive more inclusive categories (taxa are grouped into increasingly more inclusive groups)
What is a phylogeny?
Animal phylogeny describes the evolutionary history of a species or group of related species as a representation of their evolutionary relationships (common ancestors) . They can share common genes, metabolic pathways and structural proteins.
phylogenetic trees show…
patterns of descent
Which vertebrates don’t have jaws?
Hagfishes and lampreys
- They have no paired apendages (no fins)
What are vertebrates containing jaws called?
Gnathostomes . Jaws derived from pharangeal slits
What are the steps in the evolution of limbs with digits for tetrapods?
Developed a neck, stronger vertebral column, Ribs (reduced so body can move side to side), Supporting girdles (to support limbs)
Amphibia are modern tetrapods..what do they have?
Legs, lungs, often terrestrial
What are the features of the amniotes (reptiles and birds)?
The amniotic egg (waterproofing and gas exchange), Keratin (feathers, scales, beaks etc.)
Are mammals amniotes?
Yes. They produce milk and hair
Amniotes are…
Tetrapod vertebrates including birds, mammals and reptiles
What anatomical traits define order of primates?
`Specialised limbs for locomotion (quadrapaedal), lack of dietary specialisation which is relflected in dentition, visual aucity and reduced sense of smell (rely on vision rather than smell) , neocrtex expansion (related to vision)
Primate limbs
Primates orginiate in an aborial environment
Primates are characterised by FLAT nails
What are the four forms of locomotion in primates?
Terrestrial quadrapedalism, vertical clinginng and leapinging, brachiation (hanging from hind limb), and bipedalism
Primate vision
Allows us to see 3D objects (unlike dogs)
Have large field of vision (overlapping binoccular and peripheral)
Neocortex expansion
Related to vision and this part expanded
What is a hominin?
Members of the tribe ‘hominini’
Dental features, bipedal locomotion, large brain size and tool making behaviour (mosaic evolution-developed at different times and rates)
Modern Homo Sapiens (humans) characteristics for locomotion:
Bipedal: shortened pelvis;larger body and legs; fingers and toes not as long
Early hominin characteristics for locomotion:
Bipedal: shortened pelvis;differences from later hominins, smaller body and long arms relative to legs; long fingers and toes; capable of CLIMBING
Generalised Apes (hominoids) for locomotion:
Quadrapedal: Long pelvis, capable of considerable arm swinging, suspensory locomotion
Modern Homo Sapiens (humans) characteristics (for brain):
Greatrly increases brain size -highly encephalised
Early hominin characteristics for brain:
Larger than miocene (ape like) forms, moderatley encephelised -prior to 6 mya no more encephalized than chimpanzees
Miocene, gneeralised ape (hominoid) characteristics for brain:
SMALL compared to hominins, large compared to other primates; a fair degree of encephalization
Modern homo sapiens features for dentition:
Small incisors; canines further reduced; molar tooth enamel caps thick
Early hominin dentition features:
Moderatley large incisors; canines somewhat reduced; molar tooth enamel caps very thick (hard and abrasive type of diet)
Miocene generalized ape (hominoid) dentition features:
Large front teeth; molar teeth variable, depending on species; some have thin enamel caps, others thick enamel caps (gorilla thin enamel layer because they eat soft food-leaves)
What are the 4 main hominin groups?
Ardipithecus group, Australopithecus group, Paranthropus group, Homo group
When in time did the Ardipithecus group originate?
Around 6mya but debate as to whether they are hominins or not
When in time did the Australopithecus originate?
Emerged around 4 mya (dissappeared around 2mya)
When in time did the Paranthropus group originate?
Around 3 mya (more or less same time as australopithecus) More robust survived until 1 mya
When in time did the homo group emerge (us)
2.5 mya
Homo Habillus
First stone tools around 2.5 mya
Ardipithecus anatomy:
curved fingers, short and broad ilium, hightly diverged big toe, ape like dentition, similar to chimpanzee (long forearm), relatively SMALL cranial capacity
Australopithecus anatomy:
‘Lucy’, very short (1.1m) short lower limbs but long upper limbs, bipedal AND aborial, big toe is aligned with other toes of foot (more human like)
Paranthopus anatomy:
More robust features; face flatter, sagittal crest for attachment of mastication muscles, small cranial capacity (but bigger than chimpanzee), prominent brow ridge, large zygomatic arch
Homo group phase 1: 2.4 mya (early homo)
900 cm3 (large expansion), less projected face (prognathous), relativley flat forehead and prominent brow region
Hominin original definition:
Bipedal
Second phase of evolution (asian homo) (1.8mya)
Found homo outside Africa; in Asia (Indonesia) larger body. Also first one to be given name homo erectus
Homo Errectus: Indonesia
940cm3 capacity (larger than Australopithecus), femur looked almost identical to modern humans, still prominent brow ridge (1mya)
Phase 3: Archaic Homo (600 thousand y.a - 130 thousand y.a)
Different species found in Europe, Africa and Asia
Cranial capacity 12800 cm3 (larger and getting closer to size of modern humans), also still prominent brow ridge
- Neanderthals also found `
Neanderthals
225-28kya
- Projecting midface,
- Very large cranial capacity (1500cm3)
- No retromolar space
- Doesn’t have a chin
Multiregional hypothesis
Was one homo from Africa that moved out (1-2mya) and started to conquer all the other continents then evolved to modern species (e.g. asian homoerectus gave rise to asian people and african homoerectus gave rise to african people)
- Suggests interbreeding to maintain the same species
- This model was ABANDONED
Out of Africa Hypothesis:
2mya a homoerrectus that moved out of Africa and started to conquer europe and Asia. Then there was another migration out of Africa 100000 years ago that REPLACED the other hominins living in Asia and Europe and Austrlalasia
Modern Humans phase:
All came from Africa
- Extremely large cranial capacity (1450cm3)
- Still prominent brow ridge
- Still modern but prreserving archaic features
- large posterior teeth and robust face
- Has a chin
Modern Face
25-30 kya
Which nerve branches from the femoral nerve?
The saphenous nerve
Which two nerves branch from the sciatic nerve?
The common fibula nerve and tibial nerve
Compartments of uper limb
Anterior and posterior compartments
What movement is the anterior compartment related to in upper limbs?
Flexion
What movement is the posterior compartment related to in upper limbs?
Extension
Pectoralis Major Action
The most powerful adductor of the arm (brings the arm closer into body)