Anatomy Flashcards
What nerves make up the lumbar plexus?
L1 - L4
What nerves make up the sacral plexus?
L4 - S4
What is connective tissue proper?
Adipose tissue, loose connective tissue (fascia) and dense regular tissue (tendons and ligaments)
What is specialised connective tissue?
Cartilage and bone
What are three components of connective tissue?
Cells (i.e. fibroblasts, chondrocytes, etc), Fibres (collagen and elastin), ground substance (can be firm, hard or fluid)
What are the tissue layers (superficial to deep)?
Skin -> superficial fascia (hypodermis) -> deep fascia -> muscle -> bone
Describe the epidermis
Epithelial tissue, keratinised, self-regenerating, avascular, waterproof
Describe the dermis
Fibro-elastic connective tissue, contains most of the sensory nerve endings/ blood vessels, nourishing layer
Which nervous system are the arrector pili muscles supplied by?
SNS
Function of hair
Sensory and thermoregulation
Function of sebaceous glands
Produce sebum, epidermal barrier
Function of sweat glands
Thermoregulation
Function of nails
Protects the tips of the fingers and toes and supports the grasping function of the fingers
Describe the superficial fascia
Attaches dermis to underlying tissue/deep fascia, mainly adipose tissue, contains sensory receptors and large vessels for dermal vasculature
What do meissner corpuscles detect?
Small and light touch
What do Pacinian corpuscles detect?
Large and pressure/vibration
Why is fascia important in terms of infection?
The fascia splits muscles into compartments to facilitate muscle movement and it is hard for the infection to get past the fascia
What are the layers of muscles?
Epimysium -> muscle -> perimysium -> muscle fasicle/bundle -> endomysium -> muscle fibres/cells -> myofibril -> sarcomeres -> actin and myosin
Describe type I muscles
- Oxidate, slow twitch, red
- Obtain energy from aerobic oxidation
- Large number of mitochondria/myoglobin
- Fatigue resistant i.e. longer periods of time/endurance muscles
Describe type II muscles
- Energy obtained by anaerobic glycolysis
- Fewer mitochondria/myoglobin
- Non-fatigue resistant i.e. only for short bursts of energy/sprinters
What is hypertrophy?
Increased muscle size due to longitudinal division of myofibrils. This happens in response to physical stress
What is atrophy?
Decreased muscle size
What happens to muscle as you age?
- Myofibrils replaced by fibrous CT
- Decrease in size and elasticity of muscle
Layers of bone
Periosteum -> endosteum (cellular layer) -> medullary cavity
Describe compact/cortical bone
Strength/rigidity, resists tensile forces, limited to outer parts of the bone
Describe trabecular bone
Provide support to the bone while minimising weight, resists compressive forces, seen in epiphysis and vertebral bodies
Describe the microstructure of bone (1. and 2.)
- Inorganic (70%) = mineral salts and is hard - resists compression/deformation
- Organic (30%) = collagen fibres which resists tension and bending forces
- Osteoblasts: bone-forming cell
- Osteocytes: mature bone cell
- Osteoclasts: bone-removing cell
Describe lamella
Layers of ossified ECM
- Interstitial = between Haversian systems
- Circumferential = periphery of bone is surrounded by circumferential
Describe Haversian systems/osteons and Haversian canal
Haversian System = bony tubes that lie parallel to each other in bones
Haversian Canal = tube in the haversian system and has some fenestrated capillaries/unmyelinated axons
Describe Volkmann’s canals
Communicate haversian canals with each other (pretty much lie horizontal)
What is intramembranous ossification?
Formation of bones such as the skull bones and clavicle
What is endochondral ossification (including primary and secondary)?
Hyaline cartilage at the end of long bones are turned into bone
There is primary (diaphysis) and several secondary (epiphysis)
