Anatomy and Physiology Systems 1

How is the body organised?

Micro to macro level, starting at atoms, going to molecules, organelles, cellular level, tissue level, organ level, organ system level and organism level

What are atoms?

Building blocks of matter, which form molecules like water and proteins

What are organelles?

basic components of microscopic cells formed by molecules (mitochondria)

What are tissues

Groups of similar cells with similar functions

What are organs?

at least 2 different tissue types performing different functions

What is an organ system

Many organs with common purposes working together to achieve a common purpose (cardiovascular system)

What are the 4 types of tissue?

Connective tissue, muscle tissue, epithelial tissue, nervous tissue

What is connective tissue

provide support and protect organs

What is muscle tissue

enable movement in body

What is epithelial tissue

Covers or lines surfaces of body to act as a barrier

What is nervous tissue

sends rapid electrical impulses for rapid communication

What is anatomical position?

Standing facing forwards with feet slightly apart and palms facing forwards

What is a body plane?

Flat surface along the body to provide different views of structures on the body

What types of body planes are there?

Frontal (front/back), sagittal (left/right), transverse (top/bottom section)

Types of directional terms

Superior/inferior (above or below a section), anteror/posterior (in front of or behind the section), medial/lateral (toward or further from the section)

What is a body cavity?

Space within body that protects internal organs

Ventral body cavity

On the front (anterior) of body. Thoracic cavity (ribs/lungs), abdominal cavity (stomach/intestines), pelvic cavity (urinary bladder, reproductive organs)

Dorsal body cavity

On the back (posterior) of body. Cranial cavity (skull/brain), vertebral cavity (spine)

Skeleton function

protection, support, blood cell formation, fat storage

How many bones are in the human skeleton?

206 bones split into axial (skull/rib cage) and appendicular groups (upper/lower limbs and shoulder/hip).

Cells of bone tissue

Osteoprogenitor cell (stem cell - special types of cells that have 2 important properties and can duplicate themselves), osteoblasts (bone forming), osteocyte (sensors of stress/strain arranging bone formation), osteoclast (reabsorb bone/break down)

Composition of bones

organic components like cells and osteoid (composed of ground substance and collagen)

inorganic components (mineral salts)

Anatomy of bone

Structural unit called Osteon or Haversian system of long cylinders

Haversian canal (hollow central canal filled with blood vessels/nerves)

Lamelia (layers of bony matrix surrounding each canal)

Volkmann's canal (join Haversian canals)

Osteocytes (hidden in lacunae (cavity in bones) and monitor bone matrix)

Canaliculi (connect osteocytes for nutrient exchange)

Ossification meaning

bone tissue formation in skeleton

Endochondral ossification

Bone develops by replacing cartilage

Bone collar forms, calcification (hardening of tissue by converting into calcium) of hyaline cartilage, periostel bud invade internal cavities, diaphysis elongates forming medullary cavity, second ossification centres in epiphyses around birth, epiphyses ossify in adolescence

Intramembranous ossification

development inside the membrane

mesenchymal cells become osteoblasts, osteoid is secreted and woven bone forms, blood vessels grow, woven bone replaeced by lameller bone and result in flat bones

Importance of bone growth

Bone growth is a continuous cycle, and the constant reshaping and remodelling of bones increase bone strength and thickness, and also reduce weight of bone

Osteoblasts vs Osteoclasts

Osteoblast build bone, osteoclast crush bone (via secretion of acid and enzymes) - osteoblasts are more active between 0-20 years, becomes equal between 20-50 then osteoclasts are more active from 50 years old+

Wolff's law

Bone grows and remodels in response to the pressure placed on it (tension and compression forces upon bone)

Osteoporosis meaning

bones are weaker and resorption is greater than deposition leaving more fragile bones behind

Osteomalacia and Rickets meaning

cause soft bones due to vitamin d and calcium deficiencies.

Rickets affects children which can cause bowed legs due to bones still growing and plates cannot calcify due to limited calcium

Disorders of bone growth

Marfan's syndrome (results in tall, thin builds with longer limbs), pituitary dwarfism (insufficient growth hormone production in pituitary gland causing short body parts), achondroplasia (cartilage to bone conversion is inhibited which affects body part proportions)

How are bones connected?

At joints by ligaments, and muscles are attached to bones through tendones. Tendons can also be found at certain joints

Components and roles of Axial skeleton

Skull, vertebral column, thoracic cage (rib cage+sternum)

Support of head, neck and trunk, protection of vital organs (brain, heart), attachment site for muscles

What are the 22 bones in human skull

8 cranial bones to protect the brain (1 frontal, 2 parietal, 2 temporal, 1 occipital, 1 sphenoid, 1 ethmoid). Have special features of sutures (fibrous joints between bones), foramina (openings for nerves and vessels), sinuses (air-filled spaces)

14 facial bones to form face structure (1 mandible, 2 maxillae, 2 zygomatic, 2 nasal, 2 lacrimal, 2 palatine, 2 inferior nasal conchae, 1 vomer). Have special features of mandible (skull bones are moveable), maxillae (hold upper teeth)

What can be viewed on skull?

Anterior: Orbits, nasal cavity, maxilla, mandible, zygomatic bones

Posterior: occipital, lambdoid

Superior: sagittal, coronal, parietal

Inferior: Hard palate, mastoid process

Cranial floor (base of skull) structure

3 cranial fossae:

Anterior cranial fossa - support frontal lobe

Middle cranial fossa - support temporal lobe

Posterior cranial fossa - support cerebellum

Components of vertebra

Vertebral body, vertebral arch (pedicles and laminae), vertebral foramen, spinous process, 2 transverse processes, superior/inferior articular processes

What are spinal curvatures and what are normal and pathological

Sideways curves on the backbone

Normal: cervical lordosis, lumbar lordosis, thoracic kyphosis, sacral kyphosis and they improve balance, weight distribution and shock absorption

Pathological: Scoliosis (lateral curvature), hyperlordosis (excessive lumbar (lower back) curve) and hyperkyphosis (excessive thoracic (upper back) curve)

What are the structural and functional differences of vertebrae

Cervial (C1-C7) are bifid (split into 2) spinous processes, and are small bodies that function for head movement.

Thoracic (T1-T12) are bones connected to ribs and are long spinous processes which function for rib attachment.

Lumbar (L1-L5) are large bodies with thick spinous processes functioning for weight bearing (weight placed on limbs)

What are specialised vertebrae?

Specific bones that have adapted unique shapes.

Atlas (C1) supports skull with no body, allowing the nodding movement.

Axis (C2) acts as a pivot due to its shape to allow the shaking of head.

Sacrum forms a joint with sacroillia joint and is formed by 5 fused vertebra (superior connection to L5 and inferior connection to coccyx)

Rib cage (Thoracic cage) components

Sternum (manubrium, body, xiphoid process)

12 pairs of ribs with 1-7 true ribs attached to sternum via individual costal cartilages, 8-10 attach indirectly to sternum via common costal cartilage, 11-12 are floating and have no attachment

Functions: protect heart and lungs, assist respiration

How do rib ends connect to rib cage?

sternal end (smooth end) attach to costal cartilage anteriorly

vertebral end (rougher surface) have attachment points on verterbral body posteriorly

What separates axial and appendicular skeleton?

Axial is the central supporting axis like the spine and skull, whereas appendicular are the limbs attached to the axial

What is a process?

Process is a projection or bump in a bone allowing it to connect to other bones

What is a fossa

a groove or dent in a bone to allow other bones to connect to it

Describe the pectoral girdle (shoulder)

connects the limbs (arm) to the axial skeleton consisting of a clavicle (anterior) and scapula (posterior), and they are connected to the axial through the sternoclavicular joint, enabling movement like throwing a ball, therefore enhancing mobility as the cost of stability

Describe clavicle (collarbone)

s-shaped and acts as an anchor to hold scapula and arms out and backwards. Has a sternal end which is cone-shaped and acromial end which is flat

Describe scapula (shoulder blade)

triangular with 3 borders: superior, lateral and medial. Anterior view shows coracoid process, glenoid cavity, subscapular fossa. Posterior shows spine of scapula, acromion process, supraspinous fossa (above), infraspinous fossa (below)

Describe humerus

attaches to scapula. Anterior view shows head of humerus, anatomical neck, greater tubercle, lesser tubercle, intertubercular sulcus (between), deltoid tuberosity, capitulum (ball-like), trochlea, medial epicondyle, lateral epicondyle. Posterior view shows head of humerus, anatomical neck, surgical neck, deltoid tuberosity, olecranon fossa (funny bone), medial epicondyle, lateral epicondyle, trochlea

Describe forearm

Forearm is made of Radius and Ulna and they are connected by the interosseous membrane.

Radius includes the head (bicep attaches here), radial tuberosity, radial styloid process.

Ulna (elbow) includes olecranon, ulnar styloid process.

Describe hand

Hand is made of carpus (wrist), 5 metacarpals (palm), 14 phalanges (fingers) with 3 in fingers 2-5 and 2 in thumb

What does appendicular skeleton consist of?

pectoral girdle, pelvic girdle, upper limbs, lower limbs

Describe pelvic girdle (hip)

consists of 2 hip bones and sacrum and are connected to axial skeleton through sacroiliac joint

What do the hip bones consist of?

3 fused bones called ilium (helps spine stability), pubis (structural stability) and ischium (provides balance while seated), and are connected through a pubic symphysis called a pubic arch anteriorly, and the sacrum posteriorly. The shape is important for balance and emphasises stability over mobility

Differences between male and female pelvis

Angle of pubic arch (female is more semi-circular and male is triangular), female pelvis is wider, thinner and lighter which is adapted for child bearing, ischial spines are wider for female and more circular, with male more heart-shaped

Describe femur (thigh)

largest, strongest bone in the body. Has a head, neck (often fractured), greater and lesser trochanter, gluteal tuberosity, linea aspera, epicondyles (lateral and medial), condyles (lateral and medial)

Describe patella (kneecap)

projects the knee joint (formed by the condyles and tibia) and has an apex in the anterior

Describe lower leg

2 parallel bones (tibia and fibula) form lower leg, and have an interosseous membrane between them. They connect to knee and ankle.

Fibula is the thinner bone, and has a head and lateral malleolus.

Tibia has tibial plateau, tibial tuberosity, condyles (medial and lateral) and malleolus (medial and lateral)

Describe the foot

7 tarsal bones form the ankle, with the largest being talus and calcaneus.

Tibia connects to the talus (sits on top), with talus also connected to calcaneus (heel bone), tarsals connects to metatarsals (5 long bones in mid-foot region), and metatarsals are connected to phalanges (28 total bones making toes)

What is a joint?

articulation where 2 bones meet, allowing movement in the body. They are also the weakest part of skeleton. They are classified by structure and function.

What are ligaments?

Ligaments are strong connective tissues connecting bones to each other.

What are common knee injuries?

MCL, ACL and medial meniscus tears

What is joint swelling and what are common diseases

Arthritis is caused by joint stiffness and swelling. Joint swelling is the build up of excess fluid at joints which can cause joints to appear larger

Shapes of synovial joints

Nonaxial - plane joints (movement between flat surface)

Uniaxial - hinge (flexion and extension) and pivot (rotation)

Biaxial - condylar (movement between 2 connected cylindar shapes) and saddle (movement in concave and complementary convex)

Multiaxial - ball and joint (all movements)

What is joint classfication?

Organisation of joints depending on where joints meet based on structure or function

Structural joint classification

structural (material binding joints) are fibrous (where 2 bones won't have joint cavity and are joined by fibrous tissue), cartilaginous (have not joint cavity and are joined by cartilage), synovial (have joint cavity and are most common, filled with synovial fluid)

Functional joint classification

Functional (range of movement at joint) are synarthrotic (immovable), amphiarthrotic (slight movement), diarthrotic (free moving joints like knees, hips, shoulders)

Describe fibrous joints

most immovable joints, with 3 types: sutures (only in skull), syndesmoses (connected by ligaments), gomphoses (peg-in-socket (nails itself into bone socket))

What reinforces knee joints?

Tendons (semimembranosus and gastrocnemius), muscles (popliteus) and ligaments (oblique popliteal ligament, arcuate popliteal ligament, tibial collateral ligament, fibula collateral ligament).

What stabilises the knees?

Extracapsular and intracapsular ligaments. Extracapsular are on outsides of joint capsule with tibial (medial) collateral ligament (MCL) and fibula (lateral) collateral ligament. Intracapsular cross over each other forming X shape, with anterior cruciate ligament (ACL) to prevent tibia sliding forward on femur and posterior cruciate ligament (PCL) to prevent femur sliding forward

Describe cartilaginous joints

not highly movable, with 2 types: synchondroses (plate of hyaline cartilage), symphyses (act as shock absorbers by compressing)

Describe synovial joints

freely movable with 6 features: articular cartilage (act as a cushion when bone ends compress), joint cavity (space with fluid which can expand when fluid accumulates), articular capsule (joint cavity enclosed by 2 layers of articular capsule), synovial fluid (reduce friction filling free space in capsule), ligaments (reinforce and strengthen joint), nerves and blood vessels

What are the 4 ranges of motion of synovial joints and special movements

nonaxial (gliding - movement of bones over each other), uniaxial (movement in 1 plane), biaxial (movement in 2 planes), multiaxial (movement in 3 planes). There are also special movements which don't fit into categories: pronation/supination (inward rotations), opposition (allow thumb to touch other fingers to allow grabbing)

Describe knee joints

Knee joints are the largest and most complex joints, and have a single joint cavity consisting of 3 joints.

Tibiofemoral joint (lateral and medial) is a hinge joint but with some rotation and patellofemoral (plane joint between patella and femur).

Knee also has bursa (fluid filled sacs that reduce friction) and menisci (shock absorbers and reduce side to side rocking and can be torn free during injury). Knee also has synovial joints.

Function of synovial joints

supported by ligaments used to strengthen and reinforce joint, with 3 types of ligaments which join with joint capsule to make capsular ligaments: patellar ligaments, medial patellar retinaculum and lateral patella retinaculum

Structure of short, flat and irregular bones

Has a spongy bone and 2 layers of compact bone, and in spongy bone, a deceased person would have holes, but a living person would have marrow in the spongy bone

Structure of long bones

shaft, proximal and distal epiphysis (rounded head at end of bone). Start from hyaline cartilage and grow into long bone

What are the 6 cranial bones?

Parietal, Ethnoid, Sphenoid, Temporal, Occipital, Frontal

What are the 8 facial bones?

Vomer, Inferior nasal concha, Nasal, Maxilla, Mandible, Palatine, Zygomatic, Lacrimal

Locate frontal bone and its features

1 bone at front of cranium, and has supraorbital foramen which are 2 small holes above the eyes

Locate parietal bone and its features

2 bones at back of cranium with 2 sutures that articulate with the frontal

Locate temporal bone and its features

2 bones around the ears connecting to zygomatic and mandible bones. it sticks out and points forward to create a connection to cheekbone

Locate occipital bone and its features

1 bone at posterior base of skull, with a line at the back in the shape of a lamda sign. Helps nodding movement through occipital condyles, and has a hole at the foramen magnum for spinal cord to go through

Locate sphenoid bone and its features

Shaped like a bat with its wings, with 2 small flatter wings and 2 bigger wings. Pituitary gland sits on the sella turcica part behind eyes

Locate ethmoid bone and features

Has crista galli which pops through frontal bone, perpendicular plate goes through crista galli, olfactory foramina sends messages of smell. Separates nasal cavity from brain

Locate mandible and its features

Bottom half of jaw and joins with temporal bone. Teeth come out of inferior alveolar margin in bottom row, madibular condyles come out of mandibular ramus (verticle section) to articulate with temporal. There is also a hole in the mandible

Maxilla

2 bones. Alveolar margin is where top teeth come from, and maxilla articulates to almost every bone

Lacrimal

2 small bones that articulate with maxilla and ethmomid behind nasal

Palatine

2 bones. Stands up to support nasal cavity at the back of the nasal cavity

Zygomatic

2 bones. Cheek bones, curving at the top to form eye bone

Nasal bone

2 bones which sit on the nose and connect with frontal and maxilla bones

Vomer

Below ethmoid, joins with maxilla

Inferior nasal concha

2 bones just above top teeth behind nose

How is vertebral column separated?

Cervical (7 bones) - has 2 transverse foramen and spinous process which splits in 2 at the top

Thoracic (12 bones) - more round foramen, long spiky spine, has costal facets to connect to ribs

Lumbar (5 bones) - spine isn’t point but rounded like a shovel

What are the sacral canal and sacral hiatus?

Holes at the top and bottom of the sacrum

Scapula

caracoid process faces lateral side and is shaped like a bird beak to allow attachment to many muscles

Clavicle

Has an acromial and sternal end, with acromial end being a flatter side and connects to axial skeleton

Humerus

Head of humerus always points towards body

Ulna

Olecranon process connects to olecranon fossa, and looks like an ice-cream scooper at the top. The head of the ulna is at the bottom