Title: Anatomy / part1

Q: types of tissues
A: We differentiate 4 different types of tissues:
 epithelial tissue
connective and supporting tissue (cartilage, fat and bone)
muscle tissue (contracting and relaxing)
nerve tissue (ex. Rückenmark)

Q: tissue - organs - organ systems
A: Tissues are cluster of similarly differentiated cells.
Organs are cluster of several different tissues.
Organ systems are organs with same or similar function.

Q: Epithelial tissue - characterization - defined
A: Characterized by a basal membrane (dark brown layer). On top of the membranes are the cells which can come in different formations.
The hairs (green) are typical for hair cells.
 All the cells of the glands (for ex. the ones that produce sweat or saliva) are all defined as epithelial tissue, even if they are not on the surface.

Q: exocrine, endocrine tissue
A: Exocrine means the tissue has their own duct allowing the outflow of the own products, while endocrine means they have a large vascularization, allowing to transport the product via the blood system

Q: types of epithelial tissue
A: For ex. on the inside of the eyes are epithelial tissue (sensory organs).
This means we differentiate between 3 types of epithelial tissue:
epithelial surfaces
glandular epithelium
epithelium of sensory organs

Q: Connecting tissue
A: It could also be called “gap fillerˮ. Everywhere there is space in the body, there is connective tissue.
It connects different tissues and is also used as as storage for calories in the form of fat, as the storage of water, collagen fibers and defence cells.
We differentiate between structural fat and storage fat. If we are in need of energy, there is a hierarchy which fat is used first. First is always the storage fat, only afterwards the structural fat is used, because this has other important functions. (Ex. structural fat in the eyeballs holding them in the correct position. )
In infants we can also find brown fat. It is needed for temperature regulation (it produces heat), since they lack the muscles to produce their own heat. They are also not able to cool themselves correctly in the summer. In adults this fat is going to diminish.

Q: what is supporting tissue?
A: Everything that is hard. It ranges from cartilage, bones to chorda tissue to dental tissue.

Q: cartilage - 3 types + description
A: There are 3 types of cartilage:
 Hyaline cartilage: articular cartilage, nasal cartilage, windpipe. It does not have any connective cells in between. It can move a little bit. In the windpipes it is especially important, because without it, it would always collapse with each inhalation. It has no blood supply at all, regeneration is problematic. It also has the possibility of ossification, the probability of that happening grows with age.
Elastic cartilage: auricular cartilage (Ear), epiglottis (Kehldeckel) . There are more elastic fibres in it. It can move, and get back into position. It also needs to be very robust in its movement.
Fibrous cartilage: articular disk, meniscus, intervertebral disk. The amount of collagen is very high. There is also a very ordered structure in them.

Q: bone - differences in maturation
A: We differentiate 2 types of bone (in maturation):
Woven bone: very immature bone with a lot of turnover. After development
or fracture.
Lamellar bone: major bone, the orientation of the osseous structure is very
stress orientated.
The differentiation does not have to do anything with it`s structure, only its maturation.

Q: longbone - layers
A: The outermost layer is the periosteum, which contains the largest part of the blood vessels. Under that we find the cortical bone, which is the osseous layer of the bone. At the ends of the long bones we find cancellous bone. In the middle we find the medullar cavity. This is not found in all bones.

Q: bone - growth
A: When talking about the growth, we need to consider length and thickness. We need both and it has to work in parallel.
The growth in length occurs in the epiphyseal plate. An ossification based on cartilage is called chondral ossification.
Desmal ossification is typical on top of the skull. Each long bone has 2 Epiphysis, 2 Metaphysis (the location where the former growth plane was) and 1 Diaphysis

Q: types of bones
A: long bones,
flat bones,
ventilated bones (sinus, nasal region, front of skull),
short bones,
irregular bones,
Sesambeine (inserted in muscle tendons, ex, knee or base of feet )

Q: types of bone marrow
A: Red vs. yellow bone marrow (inside the medullar cavity). In infants we find red bone marrow in the medullar cavity, since it aids in cell formation. In adults it gradually changes to fat, which we call yellow bone marrow.

Q: muscle tissue
A: The muscle cells which perform the actual work of contraction and deflection are called myofibrils.
We differentiate skeletal muscles (trainable, can get tired), smooth muscles (intestinal, involuntary movements, not trainable) and special heart muscles
(involuntary, trainable, does not tire). Heart muscle cells can generate their own impulse for contraction.
The length of a muscle cell is as long as the muscle. The skeletal muscle cells do not multiply, the only thing that changes is the
volume. Since they don`t have an own nucleus, they also don`t know when to die and need an own mechanism to be able to.
The contraction impulse is transmitted trough a neuromuscular junction. Each muscle cell has their own junction.
If a muscle is not used, the body transforms it into fat.

Q: muscle - structure (big to small)
A: muscle → muscle fibres → muscle cell → myofibrils → sarcomere → actin & myosin, subdivided by Z-line/disk

Q: neurol tissue
A: All cells that are used for information transmission (neural activity). Are made out of dendrites, axons, synapses and myelin.
Schwann cells allow for faster transmission and astrocytes (and glia cells) ensure the blood-brain-barrier. When a nerve is cut it can regrow again. A nerve ending can grow by 1 mm per day.

Q: Serous cavities
A: 3 cavities around the body: abdominal cavity, pleural cavity (lungs) and pericardial cavity (heart). These cavities always have a visceral and a parietal layer, which is separated by fluid to allow movement.

Q: connective tissue spaces
A: We also have 3 connective tissue spaces: mediastinum, retroperitoneum and subperitoneum. They lay between the cavities.
(peri = um)

Q: locomotor system - active/passive
A: Differentiate between active (muscles, tendons, auxillary structures…(all you can move voluntary)) and passive (skeleton and joints) system.
If the spine has a strong curvature (on the frontal plane), we call this scoliosis.

Q: joints - synovial/continous
A: We differentiate between synovial (diarthroses) and continuous (synarthroses) joints. Only synovial joints are
considered “Gelenkeˮ, continuous joints in German are called “Knochenverbindungenˮ (in English there is no term for it, that`s why we also call it joints).

Q: synarthroses - types
A: With synarthroses we differentiate 3 subcategories:
syndesmosis (osseous connections by ligaments, between ulnar and radius, fontanel)
synchondrosis (connection based on cartilage, not as flexible as syndesmosis, rips, ossification centers of developing bones)
synostosis (fusion by bones, skull, sacrum, hips)

Q: diathroses - components
A: Synovial Cavity - A fluid-filled space between articulating bones that allows movement.
Articular Cartilage - Covers the ends of bones, reducing friction and absorbing shock.
Synovial Fluid - Lubricates the joint, nourishes cartilage (nutrients), and reduces wear.
Joint Capsule -  A fibrous structure that encloses the joint and maintains stability.
Ligaments - Connect bones and provide additional support. They also limit wrong movements.
Tendons - Assist in movement and reduce friction.
The joints can be classified by axis and shape ( uniaxial, biaxial, multiaxial) or by complexity (simple, compound, complex).

Q: muscles - locomotive system
A: Muscles are responsible for the active locomotive system.
The muscle has 2 defined points: the origin (fixed from it`s position/does not move) and insertion (the point where a muscle is attached which moves towards the origin/mobile).
Most muscles (not all) have synergists, all have antagonists. Only in combination with an antagonist, the stability of the osseous structure is given.
Another important feature are bursae (Schleimbeutel). These are sacks filled with fluid, that allow gliding on the osseous structures underneath the skin. They can also be found in between the muscles.

Q: cardiovascular system
A: Consists of the heart, vessels, blood and blood pressure.
The blood vessels can be divided into veins and arteries. There are also other vessels in the body such as the lymphatic vessels, when talking about the cardiovascular system we only mean blood vessels.

Q: ateries vs. veins
A: Veins don`t have an external elastic membrane and also the muscle layer is thinner.
Blood pressure is higher in the arteries than in the veins.
The task of the muscle layer is it to transport the blood where it belongs. The artery can not in itself transfer oxygen from the blood to wherever it is needed, therefore it needs a capillary to be able to transfer the oxygen out of the artery.
Going back we start at a Venole and go larger and larger to the veins. (clockwise in the image)
Veins don`t have as much muscle fibres to transport the blood back, that`s why we need to rely on other mechanisms such as the muscle pump. The nearer we get to the heart, the larger it`s own suction power gets.
Krampfadern: when not able anymore to fight gravity in veins.
Blood flow from heart to lungs is defined as arterial, BUT the blood has a low oxygen concentration. The blood coming from the lung circulation has a higher oxygen concentration, but goes TOWARDS the heart = vein!

Q: heart - regions
A: The heart is a muscular hollow organ shaped like a pyramid.
All large blood vessel are located at the back of the heart (base of pyramid).
The heart can be divided into two regions, the pericardium and epicardium, which are separated by the endocardium and myocardium.
The heart has to work harder the older you get to work against the loss of flexibility of the body over a lifetime. In fetal development, the heart 90° rotated.

Q: heart - structure
A: Aufbau: the heart has 2 halves with each:
one atrium (with auricle)
one ventricle
2 valves
between the chambers is a septum
The heart is build around a cardiac skeleton and has valves called cardiac valves (semilunar valves, atrioventricular valves =Segelklappen). The cardiac skeleton is an inhibiting place of electrical conduction, but the bundle of His goes through it.
The left coronary artery splits into circumflex branch and anterior interventricular branch
while the right coronary artery goes towards back and into posterior interventricular branch.
The heart has two heart beats/sounds: made by heart valves during their closing (not opening).

Q: heart - electrical conduction
A: The electrical conduction system of heart consists of the sinoatrial node (main pacemaker of heart, 60-80bpm) which goes over more than one way to atrioventricular node (located: bottom of right atrium) to the bundle of His which separates into the two tawara branches (left and right) and the small purkinje fibers.
From the sinus node to the atrioventricular node (acts as filter) exist different paths, but only on impulse must go towards ventricle because they need to contract in sync.
The contraction of the atrium is not as important as contraction of the ventricles.
Kochʼs triangle = location of atrioventricular node
- Tendon of Todaro
- Ostium of the coronary sinus
- septal leaflet of tricuspid valve

Q: heart - blood flow
A: The blood collected by superior vena cava and inferior vena cava → right atrium → right ventricle → exits heart through pulmonary trunk towards the lung → blood comes back into heart through pulmonary trunk → left atrium → left ventricle → aorta into Arcus aortae (connected to: brachiocephalic trunk, let common carotid artery, left subclavian artery)

Q: circulatory system - fetus/infant
A: During pregnancy, parts of the circulatory system of the fetus is bridged with venous duct for liver and in heart two shortcuts (oval foramen and arterial duct) so that no blood goes towards lungs), because it is not needed in the womb. Especially the 2 lung sides and the liver are not used until birth.
During birth, all 3 shortcuts have to close. As adults, the
arterial duct becomes the arterial ligament,
oval foramen → oval fossa,
venous duct → venous ligament.

Q: circulatory system - right to right atrium
A: right atrium -> tricuspid valve -> right ventricle -> pulmonary valve -> pulmonary trunk -> left and right pulmonary arteries -> capillaries -> pulmonary veins -> left atrium
• left atrium -> mitral valve -> left ventricle -> aortic valve -> aorta -> arteries -> arterioles -> capillaries -> venoles -> veins -> inverior and superior caval veins -> right atrium

Q: circulatory system - abdominal organs
A: portal circulation
arteries of abdominal organs -> nutrien absorbtion -> portal vein -> liver -> hepatical veins -> inferior caval vein

Q: circulatory system - extracellular space
A: fluid in extracellular space -> lymph capillaries -> lymph vessels with intersecting lymph
nodes -> thoracic duct resp. right lymphatic duct -> superior caval vein