Physiology Exam Prep

Where does chemical digestion of proteins begin?

Chemical digestion of proteins begins in the stomach

Name the chemical substance(s) or enzyme(s) is/that are involved in the digestion of proteins along this pathway. Briefly describe the role each play.

Hydrochloric acid (HCL) denatures the proteins (unravels the protein structure) and converts pepsinogen into active pepsin. Pepsin then begins the chemical digestive process of proteins. Proteases and peptidases in the small intestine (from the pancreas and brush border) finalise the chemical digestive process. Final components = individual amino acids, dipeptides and tripeptides

Instead of the villi and circular folds seen in the small intestine has …, which forms expansible pouches

Haustra

What is the hormone released in response to the arrival of food from the stomach into the duodenum.

Cholecystokinin (CCK)

What is released in response to the release of cholecystokinin?

Bile salts

What is the process that the muscularis externa contracts to mix and churn the digestive materials as they move through the digestive tract?

Segmentation

What is segmentation?

The process that involves the muscularis externa contracting to mix and churn the digestive materials as they move through the digestive tract

What do the salivary glands produce?

Salivary amylase

What does salivary amylase do?

Begins the process of chemical digestion of carbohydrates

Which of the following products is in a form that can be absorbed across the small intestinal epithelium into the capillaries?

Tripeptides

What is the intestinal phase?

The stomach secretes juice and mixes food into chyme

What is the gastric phase?

The stomach empties and decreases secretions

What is the cephalic phase?

Prepares stomach for arrival of food

Swallowing

Deglutition

What occurs to the bolus during deglutition?

The bolus is pushed towards the oropharynx.

What occurs to the larynx and epiglottis during deglutition?

The larynx elevates and the epiglottis closes.

What occurs to the oesophageal sphincter during deglutition?

The lower oesophageal sphincter opens.

What occurs to the smooth muscle during deglutition?

The smooth muscle contracts.

What occurs during degluttion?

The bolus is pushed towards the oropharynx. The larynx elevates and the epiglottis closes. The lower oesophageal sphincter opens. The smooth muscle contracts.

The lamina propria and digestive epithelium are components of the …?

Mucosa

Identify the components of the respiratory membrane and explain how its structure is adapted to maximise gas exchange efficency?

Alveolar type l epithelial cells. Fused basement membranes (fused between capillary and alveoli). Endothelial cells lining an adjacent capillary. Thin membrane with short diffusion distance.

Explain how oxygen and carbon dioxide move between the air, lungs, blood and tissues

Oxygen gets into the lungs through inhalation and carbon dioxide out of the lungs through exhalation. Gas diffusion at the lungs is oxygen from alveoli to blood and carbon dioxide from blood to alveoli. Gas diffusion at the tissues is oxygen from blood to interstitial fluid in tissues and carbon dioxide from intertestinal fluid in tissues to blood

When arterial PCO₂ increases, the ______ and ______ __________ stimulate an ______ in respiratory rate (write full sentence)

When arterial PCO2 increases, the central and peripheral chemoreceptors stimulate an increase in respiratory rate

What does the dorsal respiratory group neurons in the medulla regulate during both quiet and forced breathing?

Inspiration

The ventral respiratory group neurons function only in ______ ______

Forced breathing

1.5% of oxygen in the blood is ______ _______

Physically dissolved

98.5% of oxygen in blood is ______ __ _______

Carried on haemoglobin

The trachea and primary bronchi are …

Fairly rigid, non-muscular tubes

Bronchioles are dynamic because …

They lack cartilage and have smooth muscle innervated by the autonomic nervous system.

Alveolar ventilation is defined as or calculated by?

The respiratory rate x (tidal volume - anatomic dead space)

Lung compliance

Is decreased by high alveolar surface tension

Frick’s law of diffusion states that …

The rate of diffusion of a gas is directly proportional to its partial pressure gradient

Factors affecting end diastolic volume (EDV) 2

EDV is affected by filing time (increased filling time increased EDV) which is determined by the duration of ventricular diastole (or determined by heart rate). EDV is also affected by venous return (amount of blood returning to the heart from the veins during ventricular diastole) with increased venous return increasing EDV

What negative feedback mechanism results in an increased blood pressure back to normal through increasing cardiac output?

Baroreceptor reflex

When the baroreceptor reflex occurs in response to a decrease in blood pressure, what happens to increase blood pressure and what controls it? sentence

The baroreceptor reflux stimulates an increase in cardiac output via the sympathetic nervous system.

Mean arterial pressure is determined by the produce of _ _ _ _ _ _ _ _ _ _ _ _ _ and _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Cardiac output total peripheral resistance

What is the difference between systolic and diastolic pressure?

Pulse pressure

The ____ cells of the ____ node are known as the pacemakers of the heart.

Autorhythmic sino-atrial

Heart rate increases by … (4)

Faster depolarizatioemaker potential, decreased parasympathetic stimulation of nodal fibres, increased plasma levels of epinephrine, and increased sympathetic stimulation of SA node

What would an increase in capillary hydrostatic pressure would most likely do?

Increase filtration out of the capillary

The right pulmonary veins carry _____ blood to the _____ ______ repeat sentence

The right pulmonary veins carry oxygenated blood to the left atrium

Blood moves forward through veins due to? (4)

Valves in the veins preventing the backflow of blood, the pressure in the veins is lower than in the arteries, the respiratory pump, and by muscular compression

What muscle component would increase in response to increased endurance of skeletal muscles?

Increased number and size of mitochondria (more ATP) and increased number of blood capillaries resulting in increased oxygen, nutrients, myoglobin, motor neuron recruitment, and increased neural excitation of muscle fibres

What type of contraction is occurring in the bicep muscle during the bicep curl?

Concentric

What type of skeletal muscle fibre would be expected to be increased in a sprinter and why?

More fast-twitch or Type ll fibres due to lots of myofibrils and fewer mitochondria.

Fast-twitch fibres?

Short and intense bursts of activity or generate more force and power

Where is ADP and inorganic phosphate released when it causes the stroke to occur in the contraction-relaxation cycle.

Myosin head

What muscle is located in the walls of hollow organs?

Smooth muscle

At rest, active sites on the actin filament are covered by _ _ _ _ _ _ _ _ _ _ _

Tropomyosin

When a muscle contracts repeatedly, fatigue can occur due to a decline in which molecule?

ATP

Where are calcium ions in muscle contraction released from? sentence

Calcium ions are released from the sarcoplasmic reticulum

Contraction of skeletal muscle fibre begins when _____ binds to troponin

Calcium

A decrease in blood calcium concentration triggers a physiological response to restore homeostasis. What is the hormone involved?

The hormone released is Parathyroid Hormone or PTH

A decrease in blood calcium concentration triggers a physiological response to restore homeostasis. What is the bone cell type stimulated?

The bone cell activated is an osteoclast

A decrease in blood calcium concentration triggers a physiological response to restore homeostasis. What is the resulting effect on bone tissue?

The actions of the bone will be to breakdown or resorb bone matrix, to release calcium from the bone and into the blood to restore homeostasis

_____ ____ _____ cover the surface of active bone

Bone lining cells

Bone lining cells

Bone lining cells end up on the surface of bone and are thought to have been derived from osteoblasts that have become osteocytes and did not undergo apoptosis

The bone cell known as _______ is responsible for being new bone when calcium levels are ____

Osteoblasts high

What substance is primarily found within the medullary cavity of a long bone?

Bone marrow

Hyaline cartilage

Articular cartilage

Articular cartilage

Hyaline cartilage

What is the structure of the epiphysis is primarily made of?

Cancellous bone

What is the ongoing process of braking down and rebuilding the bone matrix?

Remodelling

During an action potential what is the name given to the period in which an excitable membrane will not respond to a stimulus even if it is greater than the threshold stimulus?

Absolute refractory period

If a neurotransmitter creates an ‘inhibitory post synaptic potential’, how will this affect the membrane potential of the post synaptic neuron and neurotransmission?

The membrane potential will get more negative and further away from threshold, which will cause neurotransmission to reduce and/or stop

In presynaptic inhibition there is a/an ____ in the amount of neurotransmitter released from the pre-synaptic neuron

Decrease

The myelin sheath that covers an axon of a neuron in the peripheral nervous system is formed by _______ ______ and _______ the spread of an action potential along an axon. sentence

The myelin sheath that covers an axon of a neuron in the peripheral nervous system is formed by schwann cells and increases the spread of an action potential along an axon

Action potential

During the depolarisation phase the membrane potential becomes positive. Repolarisation occurs as potassium ions leave the axon. During this phase the sodium channels and potassium channels open. During the hyperpolarisation phase, the ion pumps re-establish the sodium and potassium concentrations across the cell membrane.

The flow of ____ into the axon terminal triggers the release of neurotransmitters from synaptic vesicles into the synaptic cleft

Calcium

The largest and most numerous of the glial cells in the central nervous system (CNS) are the

Astrocytes

Formed elements of fluid connective tissue blood

Red blood cells, white blood cells, and platelets

What is the name if the other fluid connective tissue that is monitored by the immune system?

Fluid elements are plasma, inter