Anatomy - Theory Flashcards
The outer material of bones is different to the inner material, what are each called and how are they different?
- Outer cortex - dense, strong, heavy, compacted
- Inner medulla - porous, lightweight, weaker
What is the name of the bone within the medulla?
Trabecular/cancellous bone
How does cancellous bone compensate for weaker areas?
The structure is organised with more “struts” in areas where more pressure is applied
Where are the areas where bone marrow is likely to be found?
- Hip bone 2. Sternum 3. Ribs 4. Vertebrae 5. Cancellous regions of the femurand humerus
What is the function of bone marrow?
To produce red and white blood cells
What is the periosteum?
A dense envelope of connective tissue which surrounds bones, yet avoids joints and tendon articulations
During a fracture, why is the periosteum responsible for much of the pain?
It is well vascularised and innervated (also contains lymph vessels - but these don’t contribute to pain)
Where do nutrient vessels enter the periosteum?
Near the middle of the bone These vessels them ramify and continue through the inner medulla
Describe the process of endochondral ossification
Process by which a small hyaline cartilage piece grows and ossifies into bone. A capillary bud initiates the ossification by creating the primary ossification centre and entering the bone
How many primary ossification centres do long bones have?
1
What are the 4 different parts of a long bone?
Epiphysis - rounded end
Epiphyseal growth plate - hyaline cartilage plate between metaphysis and epiphysis
Metaphysis - part of growth plate leding to epiphysis
Diaphysis - middle section of bone
What are the 5 different classifications of bone?
- Long bones - long and hollow
- Flat bones - protective
- Irregular bones - strangely shaped
- Sesamoid bones - present within tendons
- Shorts bones - cuboid shapes
How do fractures heal?
Weak collagen, cartilage and bony material - collectively called callus - surrounds the fracture The callus proceeds to remodel the bone to a normal shape
In what ways can a bone’s shape be influenced?
- Functional - due to genetics
- Adjacent structures apply a force
- Bone must grow around another structure
What is a tubercle?
A bump/small rounded area
What is a condyle?
A large rounded surface at the end of some bones
What is a fossa?
A small depression or hole
Which three fossae are present in the neurocranium?
- Anterior cranial 2. Middle cranial 3. Posterior cranial
What are foramina?
Holes for cranial nerves and blood vessels to pass through
What is the axial part of the skeleton?
The central skeleton
What is the appendicular skeleton?
Comprised of offshoots from the axial skeleton such as arms/legs/pelvic/pectoral girdles
What are Le Fort fractures?
There are three types and all involve different sections of the facial skeleton coming separated from the main skull
How many bones make up the vertebral column?
33
What are the five different categories of bones in the vertebral column and how many bones are in each category?
Cervical - 7 (C1-C7) Thoracic - 12 (T1-T12) Lumbar - 5 (L1-L5) Sacral - 5 (fused together) Coccygeal - 4 (fused together, forming coccyx)
What is the distinction between primary and secondary curves of the spine?
There are 4 curve - 2 point outwards, 2 point inwards Primary point out Secondary point in
Within a vertebral body, what is the function of the vertebral arch?
To protect spinal cord Formed of 2 x lamina and 2 x pedicle
What can emerge from an intervertebral formamen?
Spinal nerves
Where do facet joints form?
Between two articular processes of two adjacent vertebral bodies
All cervical vertebrae have ___ transverse foraminae for allowing passage of _________ ________
Two
Vertebral arteries
Why is C1 (atlas) unique?
It has no body or spinous process Instead it has posterior and anterior arches
Why is C2 (axis) unique?
It has an odontoid process (dens) which articulates with C1 and allows for head rotation
Why is C7 (vertebrae prominens) special?
It is (usually) the first spinous process that can be palpated
How many pairs of ribs exist?
12
What are the three categories of ribs?
- True ribs - articulate directly to sternum
- False ribs - articulate to sternum via coastal cartilage
- Floating ribs - do not articulate to sternum
Which ribs are the true ribs?
Pairs 1-7
Which ribs are the false ribs?
Pairs 8-10
Which ribs are the floating ribs?
Pairs 11-12
Why is rib 1 less likely to fracture?
It is protected by the sternum
What composes the pectoral girdle?
2 scapulae, 2 clavicles
What composes the pelvic girdle
2 hip bones
the sacrum
coccyx
What is the most proximal bone in the arm?
Humerus
What are the names of the two more distal bones in the arm?
Radius (more lateral) and ulna (more medial)
What three types of bones make up the hand?
Carpals, metacarpals, phalanges
What is the largest bone in the leg?
Femur
What are the two long bones in the lower leg?
Tibia (more medial) and fibula (more lateral)
What three types of bones make up the foot?
Tarsals, metatarsals and phalanges
What are four functions of bone?
- Support and protection
- Calcium metabolism
- Red blood cell formation
- Provides and area for skeletal muscle attachment
What are three functions for cartilage?
- Flexibility
- Shock absorber
- Provide motility in joints where it is required
What is the name of the joint between the clavicle and the acromium process of the scapula?
Acromioclavicular joint
What are the three classes of joints?
- Fibrous
- Cartilaginous
- Synovial
Fibrous joints have the primary function of _________
Stability
There are two types of fibrous joint, what are they?
- Syndesmoses
- Sutures
What are syndesmoses?
Fibrous joints
Unites bones with a fibrous sheet such as the interosseous membrane between the fubula and tibia
What are sutures?
Fibrous joints
Found between bones in the skull
During infancy, what are in place of sutures in the skull?
Fontanelles
Soft and membranous wide sutures
There are anterior, posterior and lateral fontanelles and allow the bones to slide over eachother during birth
What are cartilaginous joints?
These are joints with a balance between stability and mobility
They are composed of cartilage
What are cells of cartilage called?
Chondrocytes
What are the two types of cartilaginous joint called?
- Primary - synchondroses - growth plates
- Secondary - symphyses
What are synchondroses?
Primary cartilaginous joints
Consist of a plate of hyaline cartilage allowing for bone growth by ossification
What are symphyses?
Secondary cartilaginous joints
Very strong and act as cushioning
They are fibrocartilage - a hybrid of firbrous and cartilaginous tissue
What is the inside of a intervertebral disc called?
Nucleus pulposus
What is the outside of the intervertebral disc called?
Annulus fibrosus
Why can a slipped disc cause pain in the legs?
Herniation of the disc may occur, which involves fluid contacting the spinal nerves causing leg pain
Where are synovial joints present?
Where two or more bones come together
How is a synovial joint structures around bone?
The joint will encapsulate bone from each side which forms a central joint cavity that contains synovial fluid for cushioning
What are bursae?
Fluid filled sacs around synovial joints that reduce friction
What are the five types of synovial joints?
- Pivot
- Balla and socket
- Plane (uniaxial)
- Hinge
- Biaxial
Whata re the two types of biaxial synovial joint?
- Saddle - i.e. between trpezium and metacarpal I
- Condylar - i.e. between metacarpal and phalangeal joints
Condylar - oval surface articulating within a concave surface prevents full ball and socket type movement
Of the three main joint types which is the most stable and which has highest motility?
Most stable - Fibrous
Most mobile - Synovial
What is a slipped disc?
Articular surfaces are still in their normal anatomical relationship
What is subluxation?
There is recuced contact area between articular surfaces and they are slightly out of position
What is a dislocation?
There is complete loss of contact between articular surfaces - the bones are completely out of position
What type of joint is the temporomandibular joint?
Synovial
The temporomandibular joint is an articulation between the _________ ______ and the _________ ________ (of the temporal bone) with the head of the _________ ________ of the mandible
Mandibular fossa
Articular tubercle
Condylar process
What are the three different types of muscle?
- Cardiac
- Smooth
- Skeletal
Skeletal muscle is made up of many __________ which are made up of many muscle fibres which are made up of ____________ which are composed of _______ and _________ fibres within functionla units called ___________
Fascicles
Myofibrils
Actin and myosin
Sarcomeres
What is the difference between a sprain and a strain?
Muscles strain - think straining to lift a weight
Ligaments sprain - think sprained ankle - ankle has lots of ligaments and little muscle
In order to make a joint move, a muscle must do what?
Attach before and after the joint
What attaches muscle to bone?
Tendons
In releation to a muscle what are its “origin” and “insertion”?
Origin - this is where the beginning of the muscle attaches on one side of the joint
Insertion - this is where the end of the muscle will attach on the other side of the joint
What is an aponeurosis?
A flat tendon
(generally articulates with flat muscles and attaches to soft tissue rather than bone)
What movements does the deltoid muscle allow for?
- Extension of shoulder - posterior fibres
- Abduction of shoulder - middle fibres
- Flexion of shoulder - anterior fibres
The shallow socket of the glenoid fossa allows for what of the shoulder?
Circumduction
What are reflexes?
Involuntary protective actions mediated by the nervous system
What are the two main reflexes in relation to skeletal muscles
- Stretch reflex
- Flexion withdrawal
Describe the reflex responsible for protecting against overstretching
Stretch reflex
Stretch to muscle by action on tendon causing contraction
The reflex arc will bypass the brain
What is paralysis?
A muscle without a functioning motor nerve - muscle has reduced tone
What is spasticity?
Motor nerve is intact, descending controls from brain do not function so inhibitory factors are gone meaning the muscle has increased reflex action that is not filtered or controlled
What is atrophy?
Muscle wastage
Myocytes become smaller reducing muscle bulk and strength
Why is hypertrophy?
Muscle enlargement
Myocytes increase in size
What is hyperplasia?
Increase in the number of cells
What is hypoplasia?
Decrease in the number of cells
In what layer of tissue are skeletal muscles found?
Deep fascia
What is a septum?
A partion separating two compartments
How many compartments are in:
- The thigh
- The leg (calf)
- Arm
- Forearm
- The thigh - 3
- The leg (calf) - 3
- Arm - 2
- Forearm - 2
What is compartment syndrome?
Pressure can build within fascia formed compartments due to haemorrhage or fluid build up
This can affect the functioning of the muscles/nerves sue to pressure
The condition can be acute or chronic
What is the treatment for compartment syndrome?
Fasciotomy
Fascia is cut to relieve tension
What two components make up mucosa?
Epithelium and lamina propria
The upper and lower GI tract is separated by what?
Ileocecal junction
Which joint is most involved in chewing?
Temporomandibular joint
What is the collective name for the muscles involved in chewing?
Muscles of mastication
Which muscles are in control of closing the mouth?
Temporalis, masseter and medial pterygoid
Opening the mouth is controlled by which muscle?
Lateral pterygoid
What is the name of the circular muscle surrounding the mouth?
Orbicularis oris
What are gingivae?
The area of the gums
What are papilla?
Finger-like projections on the surface of the tongue
What are the four types of papillae?
- Foliate - edges of tongue (taste)
- Vallate - large lumps to the back (taste)
- Fungiform - visible all over (taste)
- Filiform - very small (touch and temperature)
Which two classes of muscle is the tongue made up of?
- Extrinsic - attaches tongue to skeleton to move it around during speech, swallowing and mastication (four pairs)
- Intrinsic - allows the shape of the tongue to be changed (four pairs)
What is the main muscle associated with the cheek?
Buccinator
What are the 4 types of teeth present at adulthood?
- Incisors
- Canines
- Premolars
- Molars (includes wisdom teeth)
How many teeth are present at adulthood?
32
What are the three main types of salivary glands?
- Parotid
- Submandibular
- Sublingual
Where does the parotid gland secrete saliva into the mouth?
By the upper second molar
Where does the sublingual gland secrete saliva?
In the floor of the mouth
(saliva is secreted superiorly)
Where does the submandibular glands secrete saliva?
Base of the tongue at the point where the tongue joins the mouth floor
What three parts of the pharynx split?
- Nasopharynx - posterior to nasal cavity
- Oropharynx - posterior to oral cavity
- Laryngopharynx - posterior to larynx
Tonsils produce _______ ______ ______
White blood cells
The pharynx is composed of which three constrictor muscles?
- Superior pharyngeal
- Middle pharngeal
- Inferior pharyngeal
(their purpose is to push food inferiorly towards the oesophagus)
Why is the larynx raised during aspiration?
To prevent the aspiration of food or unwanted material.
It move the laryngeal outlet away from the passage of food and the epiglottis will close the inlet
Where is the oesophagus located in relation to the trachea?
Posterior
The oesophagus pierces the diaphragm at which verebral level?
T10
What is the peritoneum?
A serous membrane which can secrete lubricating peritoneal fluid that forms the lining of the abdominal cavity
What are thw two types of peritoneum?
- Visceral
- Parietal
What is peritonitis?
Inflammation of the peritoneum
What is abdominal guarding?
A defence mechanism by which the muscles of the abdomen involuntarily contracts to provide organ protection
The stomach will pass its contents through the _________ into the small intestine
Duodenum
How is the small intestine joined to the body wall?
Via the mesentary
What are the three parts of the small intestine?
- Duodenum
- Jejunum
- Ileum
What is the mesentary?
A double fold in the peritoneum involved in connecting intraperitoneal organs to the body wall
The space it creates between the folds allows for passage of neurovasculature
What are the three main functions of the large intestine?
- Transit
- Reabsorption of water and electrolytes
- Stool formation
What are the 5 different areas to the large intestine?
- Caecum
- Ascending colon (retroperitoneal)
- Transverse colon (intraperitoneal)
- Descending colon (retroperitoneal)
- Sigmoid colon (intraperitoneal)
The functions of the rectum and anus?
Stool formation
Waste excretion
Control of defecation is conferred by what?
Anal sphincter
(voluntary control)
What is the name given to the process that moves contents distally in the GI tract?
Peristalsis
There are two types of muscle in the walls of the GI tract - these are?
- Longitudinal (outer layer) - shortens the tube
- Circular (inner layer) - constricts the diameter
In the stomach which type of mucosa exists?
Secretory mucosa
Sphincter muscles have what function?
Control flow of substances
(through the GI tract)
Where is the cricopharyngeal sphincter muscle located?
Between the laryngopharynx and oesophagus - it prevents regurgitation
What is the name of the sphincter muscle between the stomach and duodenum called?
Pyloric sphincter
What are the names of the two sphincter muscles near the anus?
- Internal sphincter
- External (anal) sphincter
The abdominal organs are split into three parts, what are these three parts?
- Foregut - oesophagus to mid-duodenum
- Midgut - mid-duodenum to proximal 2/3rd of transverse colon - contains half of pancreas
- Hindgut - distal 1/3rd of transverse colon to proximal 1/2 of anal canal - includes other half of the pancreas
The foregut, midgut and hindgut regions are each supplied by which branches of the ascnding aorta?
- Foregut - splenic vein
- Midgut - superior mesenteric vein
- Hindgut - inferor mesenteric vein via splenic vein
The foregut, midgut and hind gut are each drain by different veins, what are these?
- Foregut - splenic vein
- Midgut - superior mesenteric vein
- Hindgut - inferior mesenteric vein via splenic vein
The splenic and superior/inferior mesenteric arteries drain into which vein?
Hepatic portal vein
Hepatic veins in the liver drain into which vein?
Inferior vena cava
What are the two venous systems in the body?
Portal system - drains absorptive organs (associated with the liver via the HPV)
Systemic system - drains all body organs (includes blood from liver)
Where do foregut structures drain lymph?
Via nodes along the splenic artery towards coeliac nodes around the origin of the coeliac trunk
Where do midgut structures drain lymph?
Via nodes located along the superior mesenteric artery towards superior mesenteric nodes located around the origin of the superior mesenteric artery
Where do hindgut structures drain lymph?
Via nodes located along the inferior mesenteric artery towards the inferior mesenteric nodes which are located around the origin of the inferior mesenteric artery
Obstruction of the GI tract can be caused by which two factors?
External - compress the wall of the tract
Internal - obstruct the lumen e.g. tumour, foreign body etc
How does the GI tract respond to a blockage?
The action of peristalsis is increased
What are collections of nerve cell bodies called in the CNS and PNS respectively?
Nucleus
Ganglion
What are bundles of axons termed in the CNS and PNS respectively?
Tracts
Nerves
What are afferent neurones?
Sensory neurones that bring signal towards the CNS
What is the somatic nervous system?
The nervous system of the external environment (out with organs) and the body wall
What is the automonic nervous system?
The nervous system associated with the interal environment of organs
It is composed of sympathetic and parasympathetic divisions
What are the four lobes of the brain?
- Frontal
- Parietal
- Occipital
- Temporal
What are gyri and sulci?
The outmost layer of brain tissue - the cerebral neocortex - is covered in lumps (gyri) and crevices (sulci)