Lectures 1-8 Flashcards
What is feedforward in homeostasis?
Anticipation of an event that will alter a controlled variable, leading to actions that minimize the effect.
Describe irregular bones.
Various shapes and functions; they often have foramina (holes).
What are the functions of the skeletal system?
Support, movement, protection, storage of minerals, and red blood cell formation.
What are movements in the sagittal plane?
Flexion and extension.
What are the two determinants of skeletal muscle force generation?
The number of muscle fibres recruited and the rate of muscle stimulation.
How is bone homeostasis maintained?
Balance between Osteoblast and Osteoclast activity, allowing constant bone formation and destruction.
Describe the pelvic girdle.
Made up of the two hip bones and the sacrum; supports weight-bearing.
What are sarcomeres and what do they contain?
Repeating units in myofibrils made of contractile proteins: actin (thin filaments) and myosin (thick filaments).
Identify the major bones of the skeleton, and understand why/how some are sexually dimorphic.
Major bones include the skull, vertebral column, rib cage, and limb bones. Sexual dimorphism is seen in the pelvis to accommodate childbirth in females.
What are the components of an osteon?
Central canal (with blood vessels and nerves), lamellae (cylinders of ECM), lacunae (for osteocytes), and canaliculi (channels for osteocytes).
What does the appendicular skeleton consist of and what is its function?
Consists of the limb bones; it is important for movement.
Which tissue can be divided into skeletal, cardiac, and smooth?
Muscle tissue.
What does the axial skeleton consist of and what is its function?
Consists of the skull, vertebral column, and rib cage; it protects vital organs.
Describe the microscopic structure of bones.
Compact bone has osteons with central canals, lamellae, lacunae, and canaliculi; cancellous bone has trabeculae with marrow and osteocytes.
Describe the structure and function of the skull.
Made up of the cranium and facial bones; protects the brain and supports sensory organs.
What is inversion?
Turning the sole of the foot towards the midline.
What are movements in the coronal plane?
Abduction and adduction.
What responses are coordinated by the Heat-Gain centre when body temperature lowers?
Behavioral changes, vasoconstriction, reduced sweat production, shivering, and goosebumps.
What happens if there is an imbalance of water and solute concentrations across the cell membrane?
Water will move to balance the concentrations, affecting cell size and integrity.
What is osmosis?
Movement of water across a membrane to equalize solute concentration.
Define terms used to describe spatial and positional relationships of structures.
Anterior/posterior, superior/inferior, medial/lateral, proximal/distal, superficial/deep.
Describe the gross structure of bones and explain how they reflect their functions.
Compact bone is strong for force transmission; cancellous bone is light and spongy for shock absorption.
How does the length-tension relationship affect muscle strength?
Each muscle has an optimal length where it is strongest, with changing overlap between actin and myosin filaments affecting strength.
What is DFCT, and what are its characteristics?
Dense Fibrous Connective Tissue; contains fibroblasts, collagen, and some elastin, resists tension, and has little vascularity.
Where are the secondary ossification centers located, and what is their function?
In the epiphyses; they enable bone growth in length through the epiphyseal/growth plate.
What does the term “lateral” mean in anatomical terminology?
Farther from the midline of the body.
What is the difference between passive ion channels and active pumps?
Passive channels allow ions to move down their gradient, active pumps use energy to move ions against their gradient.
What percentage of tissue in the human body is muscle tissue?
50%
Describe a bone pathology related to lack of homeostasis.
Osteoporosis, caused by more Osteoclast activity than Osteoblast activity, leading to thinning trabeculae and increased fracture risk.
Describe the pectoral girdle.
Made up of the clavicle and scapula; provides stability and muscle attachments.
What does hypotonic mean?
Higher solute concentration inside the cell, causing water to enter the cell.
What structures are included in epithelial tissue?
Epithelia and glands (exocrine and endocrine).
Where is compact bone found and what is its function?
Found in the diaphysis; it is strong and good at transmitting force in one direction.
What is supination?
Turning the palms to face anteriorly.
Which tissue forms glands?
Epithelial tissue.
Describe the general principles of bone growth.
Bone grows in length at epiphyseal plates and in width through appositional growth involving osteoblasts and osteoclasts.
What is plantarflexion?
Pointing the toes towards the ground.
Why is knowing terminology important in anatomy?
It allows effective communication and avoids vague descriptions or directions.
What is the function of fibrocartilage?
To resist tension and compression, act as a shock absorber, and deepen articular surfaces.
What are the characteristics of fast muscle fibres?
They produce a lot of force quickly but fatigue quickly.
What is rotation in anatomical movement?
Movement around the long axis of a joint.
What percentage of tissue in the human body is nervous tissue?
2%
What percentage of tissue in the human body is connective tissue?
45%
What is adduction?
Moving a limb towards the midline of the body.
What is the difference in structure between compact and cancellous bone?
Compact bone has an osteon structure; cancellous bone has a trabecular structure.
Describe the structure of limb bones.
Each limb has a single proximal long bone (humerus/femur), two distal long bones (ulna and radius/tibia and fibula), and bones of the hands and feet.
What is the primary site of ion loss?
The kidney.
What are the functions of nervous tissue?
Conducts electrical impulses and carries information.
Describe short bones.
Nearly equal in width and length, mostly cancellous bone; they are weight-bearing (e.g., carpals and tarsals).
Describe flat bones.
Thin plates of compact bone (with some cancellous); they function for muscle attachment and protection (e.g., scapula, skull, sternum).
What is the coronal plane?
The plane that divides the body into front and back sections.
Where is cancellous bone found and what is its function?
Found in the epiphyses; it is light, spongy, and good for shock absorption.
What is bony congruence?
The sum of bone surfaces that form an articulation, requiring more soft tissue where there is less congruence.
What is the function of hyaline cartilage?
To resist compression, mold bone surfaces at joints, and enable frictionless movement.
What does the term “anterior” mean in anatomical terminology?
Towards the front of the body.
What is the function of cartilaginous joints?
To allow some movement, found in intervertebral discs and pubic symphysis.
What is an osteon, and what is its function?
A lengthwise unit in compact bone; provides a pathway for nutrients to cells in the ECM.
Where is the primary ossification center located, and what does it do?
In the diaphysis (shaft); it develops bone at different times.
How does bone grow in width?
Through appositional growth; osteoblasts add bone matrix to the surface, and osteoclasts remove bone matrix from the inside.
What is the function of trabeculae in cancellous bone?
Resist force from multiple directions and spread force distally.
What does the term “superficial” mean in anatomical terminology?
Closer to the surface of the skin.
What causes Osteoporosis?
More Osteoclast activity than Osteoblast activity, leading to a loss of cortical bone and thinning of trabeculae.
What does isotonic mean?
The solute concentration is balanced between the inside and outside of the cell.
What is the sagittal plane?
The plane that divides the body into left and right sections.
What does the term “distal” mean in anatomical terminology?
Farther from the point of attachment or origin.
What is the main difference between the radius and ulna vs. the tibia and fibula?
The radius and ulna can supinate and pronate, allowing for wrist mobility, while the tibia and fibula provide stability with no pronation or supination.
Where are ion reserves primarily located?
In the bones of the skeleton.
